BACKGROUND

[0001] The present disclosure is directed to a die assembly for producing a film.

[0002] Stand up pouches (SUPs) formed from film have been gaining market acceptance over rigid packaging in many applications, including food, home and personal care applications. Stand up pouches offer the advantage of lower weight, better use of materials, good visual appeal (direct printing instead of using labels), and better overall sustainability. Nevertheless, SUPs' commercial utilization is limited due to lack of specific functionalities, including product flow control, such as when the user requires a "spray" or "aspersion" dispensing from the packaging. This is a common feature required in household and automotive cleaners, disinfectants, glass cleaners, liquid waxes; personal care items such as lotions and sun blocks; and food products such as salad dressings and sauces. In most cases, when a fine spray dispensing is required, a rigid packaging with a specialized nozzle, or a complex trigger pump spray system which is very high cost and limits the application of such packaging, is typically required.

[0003] Microcapillary films are low cost alternatives to allow the user to obtain the spray or aspersion dispensing with a minimal increment in cost. To integrate a microcapillary film into a SUP, lamination is typically performed, which requires uniform film thickness. However, the conventional die assemblies with which microcapillary films are formed are known to produce microcapillary films with high variation in film thickness [i.e., films with non-uniform thickness).

[0004] A need exists for a die assembly capable of forming a microcapillary film with low variation in film thickness.

SUMMARY

[0005] The present disclosure provides a die assembly. In an embodiment, the die assembly includes a first die plate and a second die plate. Each die plate has a respective bottom surface. Located between the pair of die plates is a manifold that defines a plurality of film channels therebetween. The plurality of film channels converge into an outlet assembly. A thermoplastic material is extrudable through the plurality of film channels and through the outlet assembly to form a microcapillary film. A plurality of nozzles is located between the plurality of film channels. The nozzles are operatively connected to a source of channel fluid for emitting the channel fluid between layers of the microcapillary film, whereby a plurality of microcapillary channels are formed in the microcapillary film. The outlet assembly includes a first outlet plate and a second outlet plate, with each outlet plate located along the bottom surface of the respective first die plate and second die plate. The first outlet plate and the second outlet plate each has a respective inner face. The first inner face of the first outlet plate is in mirror-image relation to the second inner face of the second outlet plate along an axis of symmetry. The first inner face and the second inner face together form an elongate outlet through which the microcapillary film exits the die assembly. Each inner face has two tapered surfaces extending in opposite directions away from a midpoint. For each respective inner face, a mid-segment (Ms) extends between the midpoint and the axis of symmetry, and a peak segment (Ps) extends between a peak point and the axis of symmetry. The mid-segment (Ms) and the peak segment (Ps) each have a length. The length of the mid-segment (Ms) is less than the length of the peak segment (Ps).

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a perspective view of a die assembly in accordance with an embodiment of the present disclosure.

[0007] Figure 2 is a cross-sectional view of the die assembly taken along line P-P of Figure 1 in accordance with an embodiment of the present disclosure.

[0008] Figure S is an enlarged view of Area S of Figure 2.

[0009] Figure 4 is a cross-sectional view of the die assembly taken along line Q-Q of

Figure 1 in accordance with an embodiment of the present disclosure.

[0010] Figure 5 is a top plan view of the die assembly in accordance with an embodiment of the present disclosure.

[0011] Figure 6 is a front elevation view of the die assembly in accordance with an embodiment of the present disclosure. [0012] Figure 7A is a bottom plan view of the die assembly in accordance with an embodiment of the present disclosure.

[0013] Figure 7B is a bottom plan view of the outlet assembly in accordance with an embodiment of the present disclosure.

[0014] Figure 7C is a perspective view of the outlet assembly in accordance with an embodiment of the present disclosure.

[0015] Figure 7D is a perspective view of the outlet assembly in accordance with an embodiment of the present disclosure.

[0016] Figure 7E is an enlarged perspective view of Area E of Figure D.

[0017] Figure 8 is an exploded view of the die assembly in accordance with an embodiment of the present disclosure.

[0018] Figure 8A is a perspective view of a multi-jackbolt tensioner in accordance with an embodiment of the present disclosure.

[0019] Figure 9 is a perspective cross-sectional view of a manifold in accordance with an embodiment of the present disclosure.

[0020] Figure 10 is an enlarged view of a plurality of nozzles in accordance with an embodiment of the present disclosure.

[0021] Figure 11 is a bottom cross-sectional view taken along line Q-Q of Figure 1, with no cartridge heaters, in accordance with an embodiment of the present disclosure.

[0022] Figure 12 is a perspective view of a die assembly and microcapillary film in accordance with an embodiment of the present disclosure.

[0023] Figure 13 is a front plan view of a microcapillary film in accordance with an embodiment of the present disclosure.

DEFINITIONS AND TEST METHODS

[0024] Any reference to the Periodic Table of Elements is that as published by CRC Press, Inc., 1990-1991. Reference to a group of elements in this table is by the new notation for numbering groups.

[0025] For purposes of United States patent practice, the contents of any referenced patent, patent application or publication are incorporated by reference in their entirety (or its equivalent US version is so incorporated by reference) especially with respect to the disclosure of definitions (to the extent not inconsistent with any definitions specifically provided in this disclosure) and general knowledge in the art.

[0026] The numerical ranges disclosed herein include all values from, and including, the lower and upper value. For ranges containing explicit values (e.g., 1 or 2; or S to 5; or 6; or 7), any subrange between any two explicit values is included (e.g., 1 to 2; 2 to 6; 5 to 7; S to 7; 5 to 6; etc.).

[0027] Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percents are based on weight and all test methods are current as of the filing date of this disclosure.

[0028] A "channel fluid" is a flowable substance. Nonlimiting examples of suitable channel fluid include air, gas, and melted polymeric material. A nonlimiting example of a suitable polymeric material is a melted thermoplastic material. In an embodiment, the channel fluid is air or a gas. In an embodiment, the channel fluid excludes polymeric material.

[0029] The term "composition" refers to a mixture of materials which comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0030] The terms "comprising," "including," "having" and their derivatives, are not intended to exclude the presence of any additional component, step or procedure, whether or not the same is specifically disclosed. In order to avoid any doubt, all compositions claimed through use of the term "comprising" may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term "consisting essentially of" excludes from the scope of any succeeding recitation any other component, step, or procedure, excepting those that are not essential to operability. The term "consisting of" excludes any component, step, or procedure not specifically delineated or listed. The term "or," unless stated otherwise, refers to the listed members individually as well as in any combination. Use of the singular includes use of the plural and vice versa. [0031] Density is measured in accordance with ASTM D792, Method B. The result is recorded in grams per cubic centimeter (g/cc).

[0032] The term "horizontal deflection" refers to distortion of the first die plate away from the second die plate along the X axis, as shown in Figure 11, during extrusion due to the pressure exerted on the inner surface of each die plate from the thermoplastic material.

[0033] "Low density polyethylene" (or "LDPE") consists of ethylene homopolymer, or ethylene/a-olefin copolymer comprising at least one C ₃ -Ci ₀ a-olefin, or C ₃ -C ₄ a-olefin that has a density from 0.915 g/cc to 0.940 g/cc and contains long chain branching with broad MWD. LDPE is typically produced by way of high pressure free radical polymerization (tubular reactor or autoclave with free radical initiator). Nonlimiting examples of LDPE include MarFlex™ (Chevron Phillips), LUPOLEN™ (LyondellBasell), as well as LDPE products from Borealis, Ineos, ExxonMobil, The Dow Chemical Company (e.g., Dow™ LDPE 5011), and others.

[0034] Melt index (Ml) (12) in g/10 min is measured using ASTM D-1238-04 (190°C/2.16kg).

[0035] The term "parallel," as used herein, refers to components, surfaces, or openings that extend in the same direction and never intersect.

[0036] A "polymer" is a compound prepared by polymerizing monomers, whether of the same or a different type, that in polymerized form provide the multiple and/or repeating "units" or "mer units" that make up a polymer. The generic term polymer thus embraces the term homopolymer, usually employed to refer to polymers prepared from only one type of monomer, and the term copolymer, usually employed to refer to polymers prepared from at least two types of monomers. It also embraces all forms of copolymer, e.g., random, block, etc. The terms "ethylene/a-olefin polymer" and "propylene/a-olefin polymer" are indicative of copolymer as described above prepared from polymerizing ethylene or propylene respectively and one or more additional, polymerizable a-olefin monomer. It is noted that although a polymer is often referred to as being "made of" one or more specified monomers, "based on" a specified monomer or monomer type, "containing" a specified monomer content, or the like, in this context the term "monomer" is understood to be referring to the polymerized remnant of the specified monomer and not to the unpolymerized species. In general, polymers herein are referred to has being based on "units" that are the polymerized form of a corresponding monomer.

[0037] A "thermoplastic material" is a linear or branched polymer which can be repeatedly softened and made flowable when heated and returned to a hard state when cooled to room temperature. It generally has an elastic modulus greater than 10,000 psi (68.95 MPa), as measured in accordance with ASTM D638 - 72. In addition, thermoplastic materials can be molded or extruded into articles of any predetermined shape when heated to the softened state. Nonlimiting examples of suitable thermoplastic materials include homopolymers and copolymers (including elastomers) of one or more a-olefins such as ethylene, propylene, 1-butene, 3-methyl-l-butene, 4-methyl-l-pentene, 3 -methyl- 1- pentene, 1-heptene, 1-hexene, 1-octene, 1-decene, and 1-dodecene, as typically represented by polyethylene, polypropylene, poly-l-butene, poly-3-methyl-l-butene, poly- 3-methyl-l-pentene, poly-4-methyl-l-pentene, ethylene-propylene copolymer, ethylene-l- butene copolymer, and propylene-l-butene copolymer; copolymers (including elastomers) of an a-olefin with a conjugated or non-conjugated diene, as typically represented by ethylene-butadiene copolymer and ethylene-ethylidene norbornene copolymer; and polyolefins (including elastomers) such as copolymers of two or more a-olefins with a conjugated or non-conjugated diene, as typically represented by ethylene-propylene- butadiene copolymer, ethylene-propylene-dicyclopentadiene copolymer, ethylene- propylene-1, 5-hexadiene copolymer, and ethylene-propylene-ethylidene norbornene copolymer; ethylene-vinyl compound copolymers such as ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-vinyl chloride copolymer, ethylene acrylic acid or ethylene-(meth)acrylic acid copolymers, and ethylene-(meth)acrylate copolymer; styrenic copolymers (including elastomers) such as polystyrene, ABS, acrylonitrile-styrene copolymer, a methylstyrene-styrene copolymer, styrene vinyl alcohol, styrene acrylates such as styrene methylacrylate, styrene butyl acrylate, styrene butyl methacrylate, and styrene butadienes and crosslinked styrene polymers; and styrene block copolymers (including elastomers) such as styrene-butadiene copolymer and hydrate thereof, and styrene-isoprene-styrene triblock copolymer; polyvinyl compounds such as polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinylidene chloride copolymer, polyvinylidene fluoride, polymethyl acrylate, and polymethyl methacrylate; polyamides such as nylon 6, nylon 6,6, and nylon 12; thermoplastic polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyurethane, polycarbonate, polyphenylene oxide, and the like; and glassy hydrocarbon-based resins, including poly- dicyclopentadiene polymers and related polymers (copolymers, terpolymers); saturated mono-olefins such as vinyl acetate, vinyl propionate, vinyl versatate, and vinyl butyrate and the like; vinyl esters such as esters of monocarboxylic acids, including methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, n-octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate and the like; acrylonitrile, methacrylonitrile, acrylamide, mixtures thereof; resins produced by ring opening metathesis and cross metathesis polymerization and the like; and combinations thereof. A nonlimiting example of a suitable ethylene/a-olefin copolymer is a low density polyethylene (LDPE).

[0038] The term "vertical deflection" refers to separation of the first die plate from the second die plate along the Y axis, as shown in Figure 11, during extrusion due to the pressure exerted on the inner surface of each die plate from the thermoplastic material.

DETAILED DESCRIPTION

[0039] The present disclosure provides a die assembly. In an embodiment, the die assembly includes a first die plate and a second die plate. Each die plate has a respective bottom surface. Located between the pair of die plates is a manifold that defines a plurality of film channels therebetween. The plurality of film channels converge into an outlet assembly. A thermoplastic material is extrudable through the plurality of film channels and through the outlet assembly to form a microcapillary film. A plurality of nozzles is located between the plurality of film channels. The nozzles are operatively connected to a source of channel fluid for emitting the channel fluid between layers of the microcapillary film, whereby a plurality of microcapillary channels are formed in the microcapillary film. The outlet assembly includes a first outlet plate and a second outlet plate, with each outlet plate located along the bottom surface of the respective first die plate and second die plate. The first outlet plate and the second outlet plate each has a respective inner face. The first inner face of the first outlet plate is in mirror-image relation to the second inner face of the second outlet plate along an axis of symmetry. The first inner face and the second inner face together form an elongate outlet through which the microcapillary film exits the die assembly. Each inner face has two tapered surfaces extending in opposite directions away from a midpoint. For each respective inner face, a mid-segment (Ms) extends between the midpoint and the axis of symmetry, and a peak segment (Ps) extends between a peak point and the axis of symmetry. The mid-segment (Ms) and the peak segment (Ps) each have a length. The length of the mid-segment (Ms) is less than the length of the peak segment (Ps).

[0040] A "die assembly," as used herein, is a multi-component apparatus through which a thermoplastic material flows and is shaped. The die assembly is for producing a film, and further a microcapillary film.

[0041] In Figure 1, a die assembly 10 is operatively connected to an extruder 2 having a thermoplastic material passing therethrough. Figure 1 depicts a portion of an extruder 2 that is operatively connected to the die assembly 10. In an embodiment, the extruder 2 includes a material housing, a material hopper, a screw, and electronics (e.g., controllers, processors, and motors). Nonlimiting examples of suitable extruders 2 include single-screw extruders and twin-screw extruders. A nonlimiting example of a suitable extruder 2 is the extruder described in U.S. Publication No. 2015/0321409, published 12 November 2015, the entire contents of which are herein incorporated by reference.

[0042] In an embodiment, the thermoplastic material is placed into the material hopper and passed into the material housing for blending. The thermoplastic material is heated and blended by rotation of the screw rotationally positioned in the housing of the extruder 2. A motor may be provided to drive the screw or other driver to advance the melted thermoplastic material. Heat and pressure are applied from a heat source and a pressure source (e.g., the screw), respectively, to the blended melted thermoplastic material to force the material through the die assembly 10, as indicated by the Arrow A of Figure 1. The melted thermoplastic material passes through the die assembly 10, and is formed into the desired shape and cross-section.

A. First Die Plate and Second Die Plate

[0043] The present die assembly includes a first die plate and a second die plate. A "die plate," as used herein, is a rigid structure that defines the body of the die assembly. The pair of die plates includes the first die plate 12 and the second die plate 28, as shown in Figures 1, 2 and 4. The first die plate 12 and the second die plate 28 may or may not be mirror images of one another. In an embodiment, the first die plate 12 and the second die plate 28 are mirror images of one another, as shown in Figure 2. The first die plate 12 and the second die plate 28 may be connected via a plurality of multi-jackbolt tensioners.

[0044] Each die plate (12, 28) has a top surface 14, a bottom surface 16, an outer surface 18, and an inner surface 20, as shown in Figures 2 and 3.

[0045] The first die plate 12 and the second die plate 28 are aligned with one another such that the inner surface 20 of the first die plate 12 is adjacent to the inner surface 20 of the second die plate 28. The first die plate 12 and the second die plate 28 are spaced apart such that the melted thermoplastic material 4 may flow between the first die plate 12 and the second die plate 28.

[0046] Each die plate (12, 28) has a width, W, as shown in Figure 1. In an embodiment, the width, W, of each die plate (12, 28) is from 50 cm, or 55 cm, or 60 cm, or 70 cm, or 75 cm, or 80 cm, or 85 cm to 87 cm, or 90 cm, or 100 cm, or 110 cm, or 120 cm, or 150 cm, or 200 cm, or 250 cm. In an embodiment, the width, W, of each die plate (12, 28) is 86.36 cm (34 inches). The width, W, of the first die plate 12 is equal to the width, W, of the second die plate 28.

[0047] Each die plate (12, 28) has a thickness, T, as shown in Figure 2. The thickness of die plate 12 can be the same as, or different than, the thickness of die plate 28. In an embodiment, the thickness, T, of each die plate (12, 28) is from 7 cm, or 8 cm, or 9 cm, or 10 cm, or 11 cm to 12 cm, or 13 cm, or 14 cm, or 15 cm. In an embodiment, the thickness, T, of each die plate (12, 28) is 11.43 cm (4.5 inches). In an embodiment, the thickness, T, of the first die plate 12 is the same as thickness, T, of the second die plate 28. [0048] Each die plate (12, 28) has a height, H, as shown in Figure 4. In an embodiment, the height, H, of each die plate (12, 28) is from 20 cm, or 21 cm, or 22 cm, or 23 cm, or 24 cm, or 25 cm to 27 cm, or 30 cm, or 35 cm, or 40 cm, or 50 cm, or 60 cm. In an embodiment, the height, H, of each die plate (12, 28) is 25.4 cm (10 inches). The height, H, of the first die plate 12 is equal to the height, H, of the second die plate 28.

[0049] In an embodiment, each die plate (12, 28) includes:

(a) a plurality of multi-jackbolt openings 22 (Figure 2);

(b) optionally, a plurality of adjustment openings 24 (Figure 2); and

(c) optionally, a plurality of cartridge heater openings 26 (Figure 4).

[0050] A plurality of multi-jackbolt openings 22 extend through each die plate (12, 28), as shown in Figure 2. A "multi-jackbolt opening" is a void in a die plate sized and shaped to receive a multi-jackbolt tensioner. Each multi-jackbolt opening 22 extends from the outer surface 18 of a die plate (12, 28) to the inner surface 20 of a respective die plate (12, 28). The multi-jackbolt openings 22 are spaced apart along the width, W, of the die plate (12, 28).

[0051] In an embodiment, each multi-jackbolt opening 22 is parallel to one another. Figures 1 and 2 depict parallel multi-jackbolt openings 22. In an embodiment, each multi- jackbolt opening 22 extends in the same direction along the thickness, T, of the die plate (12, 28), as shown in Figures 1 and 2.

[0052] In an embodiment, each multi-jackbolt opening 22 extends parallel to the top surface 14 of the die plate (12, 28), as shown in Figures 1 and 2.

[0053] In an embodiment, the multi-jackbolt openings 22 are aligned in a linear configuration along the width, W, of the die plate (12, 28), as shown in Figure 1.

[0054] Each multi-jackbolt opening 22 in the first die plate 12 is positioned to align with a multi-jackbolt opening 22 in the second die plate 28, such that a multi-jackbolt tensioner may extend through the first die plate 12 and the second die plate 28, as shown in Figure 2, thereby connecting the first die plate 12 to the second die plate 28. [0055] In an embodiment, each die plate (12, 28) includes from 2, or 4, or 6, or 8, or 10 to 12, or 14, or 16, or 18, or 20 multi-jackbolt openings 22. In an embodiment, each die plate (12, 28) includes twelve multi-jackbolt openings 22.

[0056] In an embodiment, a plurality of adjustment openings 24 extend through each die plate (12, 28), as shown in Figures 2 and 3. An "adjustment opening" is a void in a die plate sized and shaped to receive an adjustment assembly. Each adjustment opening 24 extends from the outer surface 18 of a die plate (12, 28) towards the inner surface 20 of the respective die plate (12, 28), but does not extend through the inner surface 20 of respective die plate (12, 18), as shown in Figures 2 and 3. In other words, the adjustment openings 24 in the first die plate 12 extend from the outer surface 18 of the first die plate 12 towards the inner surface 20 of the first die plate, but do not extend through the inner surface 20 of the first die plate 12.

[0057] In an embodiment, each adjustment opening 24 is parallel to one another. Figures 1 and 2 depict parallel adjustment openings 24. In an embodiment, each adjustment opening 24 extends in the same direction along the thickness, T, of the die plate (12, 28), as shown in Figures 1 and 2.

[0058] In an embodiment, each adjustment opening 24 extends at an angle, G, from the inner surface 20 of the die plate (12, 28), as shown in Figure 3. In an embodiment, the angle, G, between the inner surface 20 of the die plate (12, 28) and the adjustment opening 24 is from 20°, or 25° to 30°, or 35°, or 40°, or 45°, or 50°, or 60°, or 70°, or 80°, or 90°. In a further embodiment, the angle, G, between the inner surface 20 of the die plate (12, 28) and the adjustment opening 24 is 30°.

[0059] The multi-jackbolt openings 22 are positioned above the adjustment openings 24 such that the multi-jackbolt openings 22 and the adjustment openings 24 do not intersect, as shown in Figure 2.

[0060] In an embodiment, each die plate (12, 28) includes from 2, or 4, or 6, or 8, or 10 to 12, or 14, or 16, or 18, or 20 adjustment openings 24. In a further embodiment, each die plate (12, 28) includes ten adjustment openings 24. [0061] In an embodiment, a plurality of cartridge heater openings 26 extend through each die plate (12, 28), as shown in Figure 4. A "cartridge heater opening" is a void in a die plate sized and shaped to receive a cartridge heater. Each cartridge heater opening 26 extends from the top surface 14 of a die plate (12, 28) to the bottom surface 16 of the respective die plate (12, 28).

[0062] In an embodiment, each cartridge heater opening 26 is parallel to one another. Figures 4 and 7 depict parallel cartridge heater openings 26. Each cartridge heater opening 26 extends in the same direction along the height, H, of the die plate (12, 28), as shown in Figures 4 and 7.

[0063] The cartridge heater openings 26 are positioned between the multi-jackbolt openings 22 such that the cartridge heater openings 26 and the multi-jackbolt openings 22 do not intersect, as shown in Figure 4. Further, the cartridge heater openings 26 are positioned between the adjustment openings 24 such that the cartridge heater openings 26 and the adjustment openings 24 do not intersect, as shown in Figure 4.

[0064] In an embodiment, each die plate (12, 28) includes from 2, or 4, or 6, or 8, or 10 to 11, or 12, or 14, or 16, or 18, or 20 cartridge heater openings 26. In a further embodiment, each die plate (12, 28) includes twelve cartridge heater openings 26.

[0065] The first die plate 12 may comprise two or more embodiments disclosed herein.

[0066] The second die plate 28 may comprise two or more embodiments disclosed herein.

B. Multi-Jackbolt Tensioners

[0067] In an embodiment, the present die assembly may also include a plurality of multi-jackbolt tensioners.

[0068] A "multi-jackbolt tensioner" is a bolt structure including a main bolt, a plurality of jackbolts, a washer, and a bolt body. The "bolt body" is a rigid structure with threads engaged with the plurality of jackbolts. The bolt body and the main bolt may or may not be integral. In an embodiment, the bolt body and the main bolt are integral such that the main bolt is an extension of the bolt body. In another embodiment, the bolt body and the main bolt are separate components and the bolt body is connected to the main bolt, such as by engaging with threads of the main bolt. In an embodiment, the main bolt extends through, or partially through, the center of the bolt body and is connected to the bolt body. The washer surrounds, or encircles, the bolt body.

[0069] A "jackbolt" is a rotatable structure with threads engaged with the bolt body, the jackbolt capable of exerting a force on the washer. The jackbolts are axially arranged around the circumference of the bolt body. Each jackbolt extends through the bolt body and has two opposing ends, including a first end that is sized and shaped such that a user may rotate the jackbolt (such as with a wrench), and a second end that is in contact with the washer. As a jackbolt is rotated in a tightening fashion (in contrast to a loosening fashion), the second end of the jackbolt exerts a force on the washer, thereby separating the bolt body from the washer to form a gap between the bolt body and the washer. When the multi-jackbolt tensioner is positioned within a die plate (12, 28), the washer is in contact with the outer surface 18 of the die plate (12, 28). As a jackbolt is rotated in a tightening fashion, the second end of the jackbolt exerts a force on the washer, which in turn exerts a force on the outer surface 18 of the die plate (12, 28). A gap is formed between the washer and the bolt body. Because the main bolt is connected to the bolt body, the bolt body pulls the main bolt as the bolt body separates from the washer (as the jackbolt is tightened).

[0070] A nonlimiting example of a suitable multi-jackbolt tensioner 30 is provided in Figure 8A. The multi-jackbolt tensioner 30 of Figure 8A includes a main bolt 32, a plurality of jackbolts 34, a washer 33, and a bolt body 31. The bolt body 31 has threads engaged with the main bolt 32 and threads engaged with the plurality of jackbolts 34. The washer 33 surrounds the bolt body 31. The main bolt 32 extends through, or partially through, the center of the bolt body 31 and is connected to the bolt body 31. Each jackbolt 34 has threads engaged with the bolt body 31 and is capable of exerting a force on the washer 33. The jackbolts 34 are axially arranged around the circumference of the bolt body 31. Each jackbolt 34 extends through the bolt body 31 and has two opposing ends, including a first end that is sized and shaped such that a user may rotate the jackbolt 34 (such as with a wrench), and a second end that is in contact with the washer 33. As a jackbolt 34 is rotated in a tightening fashion, the second end of the jackbolt 34 exerts a force on the washer 33,

IB thereby separating the bolt body 31 from the washer 33 to form a gap 35 between the bolt body 31 and the washer 33.

[0071] Figure 2 shows a multi-jackbolt tensioner 30 positioned to extend from the outer surface 18 of the first die plate 12 through the first die plate 12 and the second die plate 28, such that threads of the main bolt 32 are engaged with the second die plate 28 and the washer 33 is in contact with the outer surface 18 of the die plate. As one or more jackbolts 34 are rotated in a tightening fashion, the second end of the tightened jackbolt 34 exerts a force on the washer 33, which in turn exerts a force on the outer surface 18 of the first die plate 12. A gap 35 is formed between the washer 33 and the bolt body 31. Because the main bolt 32 is connected to the bolt body 31, the bolt body 31 pulls the main bolt 32 as the bolt body 31 separates from the washer 33 (as the jackbolt 34 is tightened). Because the threads of the main bolt 32 are engaged with the second die plate 28, the second die plate 28 is pulled in the same direction as the main bolt 32. Consequently, as the washer 33 exerts a force on the outer surface of the first die plate 12, the main bolt 32 and the second die plate 28 each is pulled towards the outer surface of the first die plate 12. Thus, the plurality of multi-jackbolt tensioners 30 connect the first die plate 12 to the second die plate 28.

[0072] In an embodiment, the multi-jackbolt tensioner 30 includes a main bolt 32 and eight jackbolts 34, as shown in Figure 8A.

[0073] In an embodiment, the multi-jackbolt tensioner 30 is a SUPERBOLT™ bolt-style tensioner, available from Nord-Lock, Inc.

[0074] The plurality of multi-jackbolt tensioners 30 connect the first die plate 12 to the second die plate 28. Each multi-jackbolt tensioner 30 extends through a multi-jackbolt opening 22 in the first die plate 12 and a corresponding multi-jackbolt opening 22 in the second die plate 28, as shown in Figure 2.

[0075] The number of multi-jackbolt openings 22 in each die plate (12, 28) is equal to the number of multi-jackbolt tensioners 30 included in the die assembly 10. In an embodiment, the die assembly includes twelve multi-jackbolt tensioners 30. [0076] Applicant surprisingly found that connecting the first die plate to the second die plate with a plurality of multi-jackbolt tensioners 30 reduces the vertical deflection and/or horizontal deflection of the die assembly 10. Vertical deflection and horizontal deflection are problematic in conventional die assemblies because they result in variation in film thickness. The torque required to tighten a conventional bolt exponentially increases as the diameter of the conventional bolt increases. Multi-jackbolt tensioners 30 enable easy application of high tensional forces on large main bolts 32 compared to conventional bolts having the same diameter as the main bolt 32 because the diameter of the single jackbolt 34 is less than the diameter of said conventional bolt. In other words, less torque is required to tighten a single jackbolt 34 of a multi-jackbolt tensioner 30 than a conventional bolt having the same diameter as the main bolt 32 of the multi-jackbolt tensioner 30. The multi-jackbolt tensioners 30 further enable precise and uniform application of preloading on the die plates (12, 28). The preloading counters the deflection force exerted by the melt flow of the thermoplastic material 4 between the two die plates (12, 28). This results in decreased vertical deflection and/or decreased horizontal deflection of the die plates (12, 28) during extrusion of the microcapillary film 54.

[0077] The multi-jackbolt tensioners 30 may comprise two or more embodiments disclosed herein.

C. Manifold

[0078] The present die assembly includes a manifold.

[0079] The manifold 36 is located between the pair of die plates (12, 28) and defines a plurality of film channels 38 therebetween, as shown in Figures 2, 3, and 4.

[0080] The manifold 36 includes a manifold intake 40 and a manifold outtake 42, as shown in Figure 8. Thermoplastic material 4 extrudes and flows through the manifold intake 40, out the manifold outtake 42, and into the plurality of film channels 38, as shown in Figure 9. As the thermoplastic material 4 flows between the manifold 36 and the die plates (12, 28) within the film channels 38, the thermoplastic material 4 exerts a pressure on the inner surface 20 of each die plate (12, 28). [0081] In an embodiment, the die assembly 10 includes a manifold spacer 44, as shown in Figures 2 and 8. The manifold spacer 44 is located between the pair of die plates (12, 28) and above the manifold 36.

[0082] The manifold spacer 44 includes a manifold spacer intake 46 and a manifold spacer outtake 45, as shown in Figure 4. Figure 8 depicts a manifold spacer 44 with a manifold spacer intake 46. The manifold spacer intake 46 is positioned to align with the manifold intake 40.

[0083] In Figure 3, thermoplastic material 4 flows into the manifold spacer intake 46, through the manifold spacer 44, and out the manifold spacer outtake 45 into the manifold intake 40. In an embodiment, thermoplastic material 4 (Figure 3) flows from the extruder 2 (Figure 1) into the manifold spacer intake 46 (Figure 4), through the manifold spacer 44 (Figure 4), out the manifold spacer outtake 45 (Figure 4), into the manifold intake 40 (Figure 8), out the manifold outtake 42 (Figure 9) into the film channels 38 (Figure 2), which converge into an outlet assembly 52 (Figures 7A-7C) through which the thermoplastic material 4 extrudes to form a microcapillary film 54 (Figure 12).

[0084] In an embodiment, a plurality of manifold spacer multi-jackbolt openings 48 extend through the manifold spacer 44, as shown in Figure 8.

[0085] In an embodiment, each manifold spacer multi-jackbolt opening 48 is parallel to one another. Figures 2 and 8 depict parallel manifold spacer multi-jackbolt openings 48.

[0086] Each manifold spacer multi-jackbolt opening 48 is positioned to align with a multi-jackbolt opening 22 in the first die plate 12 and a multi-jackbolt opening 22 in the second die plate 28, such that a multi-jackbolt tensioner extends through the first die plate 12, the manifold spacer 44, and the second die plate 28, as shown in Figure 2, thereby connecting the first die plate 12 to the manifold spacer 44 and the second die plate 28.

[0087] The manifold spacer 44 and each die plate (12, 28) includes the same number of multi-jackbolt openings (22, 48). In an embodiment, the manifold spacer 44 includes twelve manifold spacer multi-jackbolt openings 48.

[0088] In an embodiment, the manifold spacer 44 is connected to the manifold 36 via a plurality of fasteners 50, as shown in Figure 8. [0089] The manifold 36 and the manifold spacer 44 may comprise two or more embodiments disclosed herein.

D. Elongate Outlet

[0090] Figures 7A-7C show the outlet assembly 52 includes a first outlet plate 56a and a second outlet plate 56b. The first outlet plate 56a is attached to the bottom surface 16 of the first die plate 12 (as shown in Figure 2). Similarly, the second outlet plate 56b is attached to the bottom surface 16 of the second die plate 28 (as shown in Figure 2). The first outlet plate 56a and the second outlet plate 56b each has a respective inner face (106, 108), as shown in Figures 7B and 7C. The open area, or otherwise the void space, between the first outlet plate 56a and the second outlet plate 56b is the elongate outlet 57.

[0091] The first outlet plate 56a may or may not be symmetrical (i.e., "symmetrical" being the same size and the same shape) to the second outlet plate 56b. In an embodiment, the first outlet plate 56a is symmetrical to the second outlet plate 56b and the first inner face 106, of the first outlet plate 56a, is in mirror-image relation to the second inner face 108, of the second outlet plate 56b, along an axis of symmetry 56c. The "axis of symmetry," 56c, as best seen in Figure 7B, is an axis extending along the elongate outlet 57 and equidistant between the first outlet plate 56a and the second outlet plate 56b, the axis of symmetry bisecting the elongate outlet 57. The first inner face 106 is in "mirror-image relation" to the second inner face 108, such that if the second inner face 108 is folded along the axis of symmetry 56c and superimposed over the first inner face 106, the second inner face 108 aligns exactly with the first inner face 106. The first inner face 106 and the second inner face 108 together form the elongate outlet 57 through which the microcapillary film 54 exits the die assembly 10. The elongate outlet 57 is best seen in Figure 7A.

[0092] As shown in Figures 7B and 7C, the first inner face 106 of the first outlet plate 56a has two tapered surfaces (110a, 110b). A first tapered surface 110a extends between a first midpoint 112a and a first peak point 114a on one side of the first midpoint 112a. A second tapered surface 110b extends between the first midpoint 112a and a second peak point 114b, on the other side of the first midpoint 112a. Stated differently, the first tapered surface 110a intersects the second tapered surface 110b at the first midpoint 112a of the first inner face 106. The first tapered surface 110a and the second tapered surface 110b each is not parallel to the axis of symmetry 56c.

[0093] As shown in Figure 7B, the second inner face 108 has two tapered surfaces (110c, llOd). On the second inner face 108, a third tapered surface 110c extends between a second midpoint 112b and a third peak point 114c on one side of the second midpoint 112b. A fourth tapered surface llOd extends between the second midpoint 112b and a fourth peak point 114d, on the other side of the second midpoint 112b. Stated differently, the third tapered surface 110c intersects the fourth tapered surface llOd at the second midpoint 112b of the second inner face 108. The third tapered surface 110c and the fourth tapered surface llOd each is not parallel to the axis of symmetry 56c.

[0094] In an embodiment, the tapered surfaces llOa-d are all of equal length.

[0095] Figure 7B shows first midpoint 112a (on first inner face 106) in mirror image relation to second midpoint 112b (on second inner face 108). A first mid-segment (Msi) extends between the first midpoint 112a and the axis of symmetry 56c. The mid-segment, Msi is a tangent segment whereby the mid-segment, Msi is perpendicular to the axis of symmetry, 56c. Similarly, a second mid-segment, Ms ₂ extends between the second midpoint 112b (on the second inner face 108) and the axis of symmetry 56c. Ms ₂ is a tangent segment, perpendicular to the axis of symmetry 56c.

[0096] Figure 7B shows first peak point 114a (on first inner face 106) in mirror image relation to third peak point 114c (on second inner face 108). On first inner face 106, a first peak segment, Psi, extends between the first peak point 114a and the axis of symmetry 56c. Psi is a tangent segment, perpendicular to the axis of symmetry 56c. On first inner face 106, peak segment, Ps ₂ extends between second peak point 114b and the axis of symmetry 56c. On second inner face 108, peak segment, Ps ₃ extends between the third peak point 114c and the axis of symmetry 56c. On second inner face 108, peak segment, Ps ₄ extends between the fourth peak point 114d and the axis of symmetry 56c. Each peak segment, Psi, Ps ₂ , Ps ₃ and Ps ₄ is a tangent segment perpendicular to the axis of symmetry 56c. [0097] Figure 7B shows on inner face 106, Msi has a length that is less than the length of Psi. Msi also has a length that is less than the length of Ps ₂ . In an embodiment, Psi and Ps ₂ have the same length, and the length of Msi is less the length of Psi and Ps ₂ . The length of Msi is from 0.50x to 0.9x the length of Psi and Ps ₂ . In an embodiment, the length of Msi is from 0.5x, or 0.6 x or 0.7x to 0.8, or 0.85x, or 0.90x the length of Psi and Ps ₂ . Figure 7B shows on inner face 108, Ms ₂ has a length that is less than the length of Ps ₃ . Ms ₂ also has a length that is less than the length of Ps ₄ .

[0098] In an embodiment, Ps ₃ and Ps ₄ have the same length, and the length of Ms ₂ is less than the length of Ps ₃ and Ps ₄ . The length of Ms ₂ is from 0.50x to 0.9x the length of Ps ₃ and Ps ₄ . In an embodiment, the length of Ms ₂ is from 0.5x, or 0.6 x or 0.7x to 0.8, or 0.85x, or 0.90x the length of Ps ₃ and Ps ₄ . In an embodiment, Psi, Ps ₂ , Ps ₃ and Ps ₄ each has the same length.

[0099] Figures 7B and 7C show an embodiment wherein the first inner face 106 has a first flare surface 120a extending between the first peak point 114a and a first flare point 122a. The first flare surface 120a extends from the first peak point 114a towards the axis of symmetry 56c, and the first flare surface 120a is not parallel to the axis of symmetry 56c. The first inner face 106 has a second flare surface 120b extending between the second peak point 114b and a second flare point 122b. The second flare surface 120b extends from the second peak point 114b and toward the axis of symmetry 56c. The second flare surface 120b is not parallel to the axis of symmetry 56c.

[00100] The second inner face 108 has a third flare surface 120c extending between the third peak point 114c and a third flare point 122c. The third flare surface 120c extends from the third peak point 114c and toward the axis of symmetry 56c. The third flare surface 120c is not parallel to the axis of symmetry 56c.

[00101] The second inner face 108 has a fourth flare surface 120d extending between the fourth peak point 114d and a fourth flare point 122d. The fourth flare surface 120d extends from the fourth peak point 114d toward the axis of symmetry 56c. The fourth flare surface 120d is not parallel to the axis of symmetry 56c. [00102] Figure 7B shows first flare point 122a (on inner surface 106) in mirror image relation to third flare point 122c (on inner surface 108). On first inner surface 106, first flare segment, Fsi, extends between the first flare point 122a and the axis of symmetry 56c. Fsi is a tangent segment to the axis of symmetry, Fsi being perpendicular to the axis of symmetry, 56c. On first inner surface 106, flare segment, Fs ₂ , extends between the second flare point 122b and the axis of symmetry, 56c. On second inner surface 108, flare segment FS ₃ extends between the third flare point 122c and the axis of symmetry 56c. On second inner surface 108, flare segment Fs ₄ extends between the fourth flare point 122d and the axis of symmetry 56c. Each flare segment Fsi, Fs ₂ , Fs ₃ and Fs ₄ is a tangent segment because each flare segment is perpendicular to the axis of symmetry, 56c.

[00103] Figure 7B shows inner surface 106 and flare segment Fsi has a length less than the length of Psi. In an embodiment, flare segment Fs ₄ and Fs ₂ have the same length and peak segments Psi and Ps ₂ have the same length. The length of Fsi (or Fs ₂ ) is less than the length of Ps ₄ (or Ps ₂ ). In an embodiment, flare segments Fsi and Fs ₂ have the same length and the length of Fsi (or Fs ₂ ) is the same as mid-segment Msi.

[00104] Figure 7B shows inner surface 108 and flare segment Fs ₃ has a length less than the length of peak segment Ps ₃ . In an embodiment, flare segments Fs ₃ and Fs ₄ have the same length and peak segments Ps ₃ and Ps ₄ have the same length. The length of Fs ₃ (or Fs ₄ ) is less than the length of Ps ₃ (or Ps ₄ ). In an embodiment, flare segments Fs ₃ and Fs ₄ have the same length and the length of Fs ₃ (or Fs ₄ ) is the same as the length as mid-segment MS ₂ .

[00105] Although Figure 7B shows each peak point 114a-114d as a sharp, pointed intersect between the tapered surface and the flare surface, it is understood that the transition between each tapered surface and its respective flare surface can be a smooth transition whereby a curved surface extends between, and connects, each tapered surface to its respective flare surface.

[00106] Figures 7D and 7E show an embodiment wherein first outlet plate 56a has an inner face (or first inner face) 206 and second outlet plate 56b has an inner face (or second inner face) 208. First inner face 206 is the same as first inner face 106 with the addition that first inner face 206 includes a plurality of ridges 226a. Second inner face 208 is the same as second inner face 108 with the addition that second inner face 208 includes a plurality of ridges 226b. Ridges 226a are in mirror-image relation with ridges 226b. The purpose of ridges is to counter the bulging effect of microcapillary channels at the processing temperature, which is caused by the air pressure inside the microcapillary channels. The ridges will enable us to make films with more flat surfaces. Bounded by no particular theory, it is believed the ridges contribute to (i) the production of microcapillary films with flat surfaces, (ii) the reduction of edge effect, (iii) the reduction of neck-in, and (iv) any combination of (i)-(iii).

[00107] The ridges also can be used to apply surface texture to the microcapillary film. The surface texture can be the same size as (i) the capillaries or (ii) the spaces between the capillaries. Alternatively, the surface texture can be on the same length scale as the microcapillaries and produce a scalloped structure. The surface texture is beneficial when aesthetics and/or tactile sensation is desired for the microcapillary film.

[00108] In an embodiment, the first outlet plate 56a moves, or is otherwise moveable, with respect to the second outlet plate 56b. Restrictor bar adjustment, shape of outlet plates, and positioning of outlet plate (adjusting its gap) all influence polymer flow and die pressure.

[00109] The elongate outlet 57 extends along at least a portion of the width, W, of the die plates (12, 28), as shown in Figure 7A. The elongate outlet 57 is positioned below the manifold 36 and is defined by a gap between the first die plate 12 and the second die plate 28, as shown in Figure 2.

[00110] The elongate outlet 57 has a width, M, as shown in Figure 7A. In an embodiment, the width, M, of the elongate outlet 57 is from 50 cm, or 55 cm, or 56 cm, or 57 cm, or 58 cm, or 59 cm, or 60 cm to 61 cm, or 62 cm, or 63 cm, or 64 cm, or 65 cm, or 70 cm, or 100 cm, or 150 cm, or 200 cm. In an embodiment, the width, M, of the elongate outlet 57 is 60.96 cm (24 inches). In another embodiment, the width, M, of the elongate outlet 57 is 152.40 cm (60 inches). [00111] The elongate outlet 57 may comprise two or more embodiments disclosed herein.

E. Plurality of Nozzles

[00112] The present die assembly includes a plurality of nozzles.

[00113] A "nozzle" refers to a structure with a fluid channel, the structure having a tapered outer surface that extends to a nose. A "fluid channel" is an elongated void through which a channel fluid may flow. Figure 10 depicts a plurality of nozzles 58, each nozzle 58 having a fluid channel 60 and a tapered outer surface 62 that extends to a nose 64. Figure 2 shows the plurality of nozzles 58 positioned between the plurality of film channels 38, below the manifold 36, and above the elongate outlet. The plurality of nozzles 58 are positioned between the first die plate 12 and the second die plate 28, as shown in Figure 2.

[00114] The nozzles 58 may or may not be integral with one another. Figures 8 and 10 depict a plurality of nozzles 58 that are integral. In other words, the nozzles 58 are formed from a single structure.

[00115] A fluid channel 60 extends through each nozzle 58 such that channel fluid 68 may flow through the fluid channel 60 and out the nose 64, as shown by Arrow F of Figure

9. The nose 64 is adjacent the elongate outlet 52. Figure 9 depicts a plurality of nozzles 58 arranged in a linear configuration.

[00116] In an embodiment, each fluid channel 60 has a diameter, D, as shown in Figure

10. In an embodiment, each fluid channel 60 has a diameter, D, from 250 pm, or 300 pm, or 350 pm, or 375 pm, or 380 pm to 385 pm, or 390 pm, or 400 pm, or 450 pm, or 500 pm, or 550 pm, or 600 pm, or 650 pm, or 700 pm, or 750 pm, or 800 pm, or 850 pm, or 900 pm, or 1000 pm. In an embodiment, each fluid channel 60 has a diameter, D, of 381 pm.

[00117] The plurality of nozzles 58 are located between the plurality of film channels 38.

[00118] In an embodiment, the die assembly 10 includes from 5, or 10, or 15, or 20, or 50, or 100, or 200, or 300, or 400, or 500 to 600, or 700, or 800, or 900, or 1000 nozzles 58. In an embodiment, the die assembly 10 includes 532 nozzles 58. [00119] The plurality of nozzles 58 are operatively connected to a source of channel fluid 66 for emitting the channel fluid 66 between layers of the microcapillary film 54, whereby a plurality of microcapillary channels 68 are formed in the microcapillary film 54, as shown in Figures 9 and 13. In an embodiment, the channel fluid 66 is air or a gas. In another embodiment, the channel fluid 66 is a melted thermoplastic material that is different than the melted thermoplastic material 4 flowing through the extruder 2 and the film channels 38. The channel fluid 66 that is a melted thermoplastic material and the melted thermoplastic material 4 flowing through the extruder 2 and the film channels 38 may differ in composition, structure, and/or properties.

[00120] Figure 8 shows the plurality of nozzles 58 are connected to the manifold 36. In an embodiment, the plurality of nozzles 58 are connected to the manifold 36 via a plurality of fasteners 50.

[00121] The elongate outlet 52 may comprise two or more embodiments disclosed herein.

[00122] The plurality of nozzles 58 may comprise two or more embodiments disclosed herein.

F. Adjustment Mounting Brackets

[00123] In an embodiment, the present die assembly includes a first adjustment mounting bracket 70 and a second adjustment mounting bracket 72 positioned on opposite sides of the manifold 36, as shown in Figure 2. An "adjustment mounting bracket" is an elongated rigid structure to which adjustment assemblies 90 are secured.

[00124] The pair of adjustment mounting brackets includes the first adjustment mounting bracket 70 and the second adjustment mounting bracket 72, as shown in Figures 1, 2 and 4.

[00125] Each adjustment mounting bracket (70, 72) has an outer surface 76 and an inner surface 78, as shown in Figure 3. The inner surface 78 of the adjustment mounting bracket (70, 72) is in connection with the outer surface of the die plate (12, 28).

[00126] A plurality of adjustment mounting bracket adjustment openings 74 extend through each adjustment mounting bracket (70, 72), as shown in Figure 3. Each adjustment mounting bracket adjustment opening 74 extends from the outer surface 76 of the adjustment mounting bracket (70, 72) to the inner surface 78 of the adjustment mounting bracket (70, 72).

[00127] In an embodiment, each adjustment mounting bracket adjustment opening 74 is parallel to one another. Figures 2 and 8 depict parallel adjustment mounting bracket adjustment openings 74.

[00128] In an embodiment, each adjustment mounting bracket adjustment opening 74 extends at an angle, J, from the inner surface 78 of the adjustment mounting bracket (70, 72), as shown in Figure 3. In an embodiment, the angle, J, between the inner surface 78 of the adjustment mounting bracket (70, 72) and the adjustment mounting bracket adjustment opening 74 is from 20°, or 25° to 30°, or 35°, or 40°, or 45°, or 50°, or 60°, or 70°, or 80°, or 90°. In an embodiment, the angle, J, between the inner surface 78 of the adjustment mounting bracket (70, 72) and the adjustment mounting bracket adjustment opening 74 is 30°. The angle, G, between the inner surface 20 of the die plate (12, 28) and the adjustment opening 24 is the same as the angle, J, between the inner surface 78 of the adjustment mounting bracket (70, 72) and the adjustment mounting bracket adjustment opening 74.

[00129] Each adjustment mounting bracket adjustment opening 74 is positioned to align with an adjustment opening 42 in a die plate (12, 28), such that an adjustment assembly may extend through an adjustment mounting bracket (70, 72) and a die plate (12, 28), as shown in Figure 2.

[00130] Each adjustment mounting bracket (70, 72) and each die plate (12, 28) includes the same number of adjustment openings (42, 74). In an embodiment, each adjustment mounting bracket (70, 72) includes ten restrictor bar adjustment openings 74.

[00131] The first adjustment mounting bracket 70 and the second adjustment mounting bracket 72 may comprise two or more embodiments disclosed herein.

G. Adjustment Plates

[00132] In an embodiment, the present die assembly 10 includes a first adjustment plate 80 and a second adjustment plate 82 connected to the outer surface 76 of each adjustment mounting bracket (70, 72), as shown in Figure 2. An "adjustment plate" is an elongated rigid structure sized to be positioned on and connected to the outer surface of a restrictor bar. The adjustment plate enables manipulation of the adjustment assemblies to pull or push on a restrictor bar, thereby adjusting the profile of the flow of the melted thermoplastic material. The adjustment plate (80, 82) also enables a smooth transition along the restrictor bar (92, 93) to create a parabolic profile for adjusting the thickness of the film channel 38 between the manifold 36 and the die plates (12, 28).

[00133] The pair of adjustment plates includes the first adjustment plate 80 and the second adjustment plate 82, as shown in Figures 1, 2 and 4.

[00134] Each adjustment plate (80, 82) has an outer surface 86 and an inner surface 88, as shown in Figure 3. The inner surface 88 of the adjustment plate (80, 82) is in connection with the outer surface 76 of the adjustment mounting bracket (70, 72).

[00135] A plurality of adjustment plate adjustment openings 84 extend through each adjustment plate (80, 82), as shown in Figure 3. Each adjustment plate adjustment opening 84 extends from the outer surface 86 of the adjustment plate (80, 82) to the inner surface 88 of the adjustment plate (80, 82).

[00136] In an embodiment, each adjustment plate adjustment opening 84 is parallel to one another. Figures 2 and 8 depict parallel adjustment plate adjustment openings 84.

[00137] In an embodiment, each adjustment plate adjustment opening 84 extends at an angle, K, from the inner surface 88 of the adjustment plate (80, 82), as shown in Figure 3. In an embodiment, the angle, K, between the inner surface 88 of the adjustment plate (80, 82) and the adjustment plate adjustment opening 84 is from 20°, or 25° to 30°, or 35°, or 40°, or 45°, or 50°, or 60°, or 70°, or 80°, or 90°. In an embodiment, the angle, K, between the inner surface 88 of the adjustment plate (80, 82) and the adjustment plate adjustment opening 84 is 30°. The angle, K, between the inner surface 88 of the adjustment plate (80, 82) and the adjustment plate adjustment opening 84 is the same as the angle, G, between the inner surface 20 of the die plate (12, 28) and the adjustment opening 24, which is the same as the angle, J, between the inner surface 78 of the adjustment mounting bracket (70, 72) and the adjustment mounting bracket adjustment opening 74. [00138] Each adjustment plate adjustment opening 84 is positioned to align with an adjustment mounting bracket adjustment opening 74 in an adjustment mounting bracket (70, 72) and an adjustment opening 42 in a die plate (12, 28), such that an adjustment assembly may extend through an adjustment plate (80, 82), an adjustment mounting bracket (70, 72), and a die plate (12, 28), as shown in Figure 2.

[00139] Each adjustment plate (80, 82), each adjustment mounting bracket (70, 72), and each die plate (12, 28) includes the same number of adjustment openings (42, 74, 84). In an embodiment, each adjustment plate (80, 82) includes ten adjustment plate adjustment openings 84.

[00140] The first adjustment plate 80 and the second adjustment plate 82 may comprise two or more embodiments disclosed herein.

H. Adjustment Assemblies

[00141] In an embodiment, the present die assembly 10 includes a plurality of adjustment assemblies 90. An "adjustment assembly" is an apparatus that applies variable pressure on the first restrictor bar 92 or the second restrictor bar 93, and thereby on a respective die plate (12, 28). A nonlimiting example of a suitable adjustment assembly 90 is depicted in Figures 1, 2 and 3.

[00142] By tightening one or more adjustment assemblies 90, the pressure applied to a die plate (12, 28) may be increased along the width, W, of the die plate (12, 28). Additionally, pressure may be adjusted at a fine level along the width, W, of the die plate (12, 28) such that pressure may be increased in areas known to exhibit the most vertical deformation (e.g, the middle-most point along the width, W, of the die plate (12, 28)), relative to other points along the width, W, of the die plate (12, 28). Bounded by no particular theory, it is believed that increasing pressure at the middle-most point along the width, W, of the die plate (12, 28) with the adjustment assemblies 90 results in increased flow of the thermoplastic material 4 towards the first end 102 and the second end 104 of the die assembly, as shown in Figure 1. This is believed to result in a more homogenized flow of thermoplastic material 4 through the die assembly 10 and, in turn, in a film with less variation in thickness. [00143] In an embodiment, the adjustment assemblies 90 are connected to a first restrictor bar 92 or a second restrictor bar 93, as shown in Figures 2 and 3. A "restrictor bar" is an elongated structure operably connected to one or more adjustment assemblies and positioned within a die plate. The restrictor bar (92, 93) extends along a portion of the width, W, of the die plate (12, 28). In other words, the restrictor bar (92, 93) does not extend the entire width, W, of the die plate (12, 28). The restrictor bar (92, 93) bends, or deforms, due to the application of pressure by one or more adjustment assemblies 90. The restrictor bar (92, 93) can be deformed, or bent, its full length using the adjustment assemblies 90 to alter the thickness of the area of the film channel 38 between the restrictor bar (92, 93) and the manifold 36 (e.g., to reduce flow of melted thermoplastic material in the center of the die assembly by tightening the center adjustment assemblies and not the outside adjustment assemblies).The number of adjustment assemblies 90 is equal to the combined number of adjustment openings (42, 74, 84) in each adjustment plate (80, 82), or in each adjustment mounting bracket (70, 72), or in each die plate (12, 28). In an embodiment, the die assembly 10 includes twenty adjustment assemblies 90.

[00144] The adjustment assembly 90 may comprise two or more embodiments disclosed herein.

I. Cartridge Heaters

[00145] In an embodiment, the present die assembly 10 includes a plurality of cartridge heaters 100. A "cartridge heater" is a cylindrical heating element.

[00146] In an embodiment, the first die plate 12 includes a plurality of cartridge heaters 100.

[00147] In an embodiment, the second die plate 28 includes a plurality of cartridge heaters 100.

[00148] Each cartridge heater 100 is positioned within, or substantially within, a cartridge heater opening 26 in a die plate (12, 28), as shown in Figure 4.

[00149] The number of cartridge heaters 100 is equal to the combined number of cartridge heater opening 26 in the first die plate 12 and the second die plate 28. In an embodiment, the die assembly 10 includes 24 cartridge heaters 100. [00150] Each cartridge heater 100 is electrically connected to a power source and a controller (not shown). Each cartridge heater 100 may be set at the same temperature, or at a different temperature.

[00151] Bounded by no particular theory, it is believed that the use of cartridge heaters 100 placed within, or substantially within, a die plate (12, 28) allows for more efficient heating of the die assembly and better control over the temperature of the die assembly compared to die assemblies that utilize an external heating source. Additionally, the cartridge heaters 100 allow the die assembly 10 to include multiple heating zones, with each zone set at a different temperature.

[00152] The cartridge heaters 100 may comprise two or more embodiments disclosed herein.

J. Mounting Plate

[00153] In an embodiment, the present die assembly 10 includes a mounting plate 94, as shown in Figure 1. A "mounting plate" is a structure connected to the first die plate and the second die plate, to which an extruder may be connected.

[00154] In an embodiment, the mounting plate is connected to the first die plate 12 and the second die plate 28 with a plurality of fasteners 50.

K. Hoist Arm and Hoist Ring

[00155] In an embodiment, the present die assembly 10 includes a plurality of hoist arms 96 connected to the outer surface 18 of the die plate (12, 28), as shown in Figures 1 and 2. The hoist arms 96 are connected to hoist rings 98. A "hoist ring" is a structure that facilitates the connection of the present die assembly 10 with an extruder 2.

L. Microcapillary Film

[00156] Figure 13 shows the microcapillary film 54 formed by the present die assembly 10 containing a plurality of microcapillary channels 68 extending therethrough. The microcapillary film 54 includes a number of microcapillary channels 68 that is equal to the number of nozzles 58 of the die assembly 10.

[00157] The microcapillary film 54 has a width, B, as shown in Figure 13. In an embodiment, the width, B, of the microcapillary film 54 is less than, or equal to, the width, M, of the elongate outlet 52. In an embodiment, the width, B, of the microcapillary film 54 is from 50 cm, or 55 cm, or 56 cm, or 57 cm, or 58 cm, or 59 cm, or 60 cm to 61 cm, or 62 cm, or 63 cm, or 64 cm, or 65 cm, or 70 cm. In an embodiment, the width, B, of the microcapillary film 54 is 60.96 cm (24 inches).

[00158] The microcapillary film 54 has a thickness, C, as shown in Figure 13. In an embodiment, the maximum thickness, C, of the microcapillary film 54 is from 25.4 pm, or 40 pm, or 45 pm to 46 pm, or 50 pm, or 55 pm, or 60 pm, or 70 pm, or 80 pm, or 100 pm, or 150 pm, or 200 pm, or 500 pm, or 1000 pm, or 1500 pm, or 1524 pm, or 1600 pm. In an embodiment, the maximum thickness, C, of the microcapillary film 54 is 45.72 pm (1.8 mil).

[00159] In an embodiment, the variation of film thickness of the microcapillary film 54 across its width, B, is less than ±10%, or less than ±5%, or less than or equal to ±3%. In an embodiment, the variation of thickness of the microcapillary film is from -10%, or -5% to 2%, or 3%, or 4%, or 5%, or 10%. Variation in film thickness is calculated in accordance with the following Equations 1 and 2.

upper limit variation in film thickness

maximum film thickness— average film thickness

x 100 average film thickness

Equation 1 lower limit variation in film thickness

minimum film thickness— average film thickness

X 100 average film thickness

Equation 2 wherein average film thickness is the mean average of thickness values measured across the width, B, of the microcapillary film 54; maximum film thickness is the maximum thickness value measured across the width, B, of the microcapillary film 54; and minimum film thickness is the minimum thickness value measured across the width, B, of the microcapillary film 54. [00160] In an embodiment, the upper limit variation in film thickness is from 0%, or 0.1% to 1.4%, or 1.5%, or 2.0%, or 3.0%, or 4.0%, or 5.0%, or 6.0%, or 7.0%, or 8.0%, or 9.0%, or 10.0%.

[00161] In an embodiment, the lower limit variation in film thickness is from -10.0%, or - 9.0%, or -8.0%, or -7.0%, or -6.0%, or -5.0%, or -4.5%, or -4.2% to -4.0%, or -3.0%, or -2.0%, or -1.0%, or -0.5%, or -0.1%, or 0%.

[00162] In an embodiment, the microcapillary film 54 is a multilayer film. The multilayer film contains two layers, or more than two layers. For example, the multilayer film can have two, three, four, five, six, seven, eight, nine, ten, eleven, or more layers. In an embodiment, the multilayer film contains only two layers, or only three layers. Figure 13 depicts a microcapillary film 54 that is a multilayer film with two layers, including a first layer 53a and a second layer 53b. The microcapillary channels 68 are located between the first layer 53a and the second layer 53b.

[00163] In an embodiment, the die assembly 10 includes:

the first die plate 12 and the second die plate 28;

the manifold 36 located between the pair of die plates (12, 28) and defining a plurality of film channels 38 therebetween, the plurality of film channels 38 converging into the outlet assembly 52, the thermoplastic material 4 extrudable through the plurality of film channels 38 and the outlet assembly 52 to form the microcapillary film 54;

the outlet assembly 52 including the first outlet plate 56a and the second outlet plate 56b, each outlet plate 56a, 56b located along the bottom surface of respective first die plate 12 and second die plate 28;

the first outlet plate 56a and the second outlet plate 56b each having a respective inner face 106, 108, the first inner face 106 in mirror-image relation to the second inner face 108 along the axis of symmetry 56c, the first inner face 106 and the second inner face 108 together forming the elongate outlet 57 through which the microcapillary film 54 exits the die assembly 10;

each inner face (106, 108) has two tapered surfaces extending in opposite directions from a respective midpoint (112a, 112b), first inner face 106 having tapered surfaces 110a,

BO 110b with midpoint 112a therebetween, second inner face 108 having tapered surfaces 110c, llOd with midpoint 112b therebetween;

each tapered surface HOa-llOd extending between the respective midpoint (112a, 112b) and a respective peak point 114a-114d;

for each respective first and second inner face (106,108) a mid-segment (Msi, Ms ₂ ) extends between the midpoint (112a, 112b) and the axis of symmetry;

for each respective first and second inner face (106, 108) a peak segment (Psi, Ps ₂ , Ps ₃ , Ps ₄ ) extends between a respective peak point (114a-114d) and the axis of symmetry; for each respective first and second inner face (106, 108) the mid-segment length (Msi for inner face 106 and Ms ₂ for inner face 108) is less than the peak segment length (Psi for inner face 106 and Ps ₃ for inner face 108);

a plurality of nozzles 58 located between the plurality of film channels 38, the plurality of nozzles 58 operatively connected to a source of channel fluid 66 for emitting the channel fluid 66 between layers of the microcapillary film 54 whereby a plurality of microcapillary channels 68 are formed in the microcapillary film 54; and

the microcapillary film 54 has a variation of thickness of ±10%, or ±5%, or ±4.2%, or ±3%; or from -10%, or -5%, or -3%, or -2%, or 0, to 2%, or 3%, or 4%, or 5%, or 10%.

[00164] The die assembly 10 may comprise two or more embodiments disclosed herein.

[00165] While the present disclosure is directed to a microcapillary film 54 that is a multilayer film with two layers, each layer formed from the same thermoplastic material 4, it is understood that each layer may alternatively be formed from a different thermoplastic material 4, the thermoplastic materials differing in composition, structure, and/or properties.

[00166] In an embodiment, the die assembly is operatively connected to a plurality (e.g., 2) of extruders, each extruder having a thermoplastic material passing therethrough. The die assembly includes a manifold spacer with a plurality (e.g., 2) of manifold spacer intakes and a corresponding number of manifold spacer outtakes; a manifold with a plurality (e.g., 2) of manifold intakes and a corresponding number of manifold outtakes; and a plurality of film channels (e.g., 2). In an embodiment, a first thermoplastic material flows through the first extruder into the first manifold spacer intake and out the first manifold spacer outtake, into the first manifold intake and out the first manifold outtake, into the first film channel. In an embodiment, a second thermoplastic material flows through the second extruder into the second manifold spacer intake and out the second manifold spacer outtake, into the second manifold intake and out the second manifold outtake, into the second film channel. The first film channel and the second film channel converge into an elongate outlet, the first thermoplastic material and the second thermoplastic material extrudable through the respective first film channel and second film channel, and the elongate outlet to form a microcapillary film.

[00167] By way of example, and not limitation, examples of the present disclosure are provided.

EXAMPLE

[00168] The die assembly 10 of Figures 1-7 A-C, 11, and 12 is provided. The die assembly 10 is operatively connected to [i.e., is in fluid communication with) an extruder 2 having a thermoplastic material 4 passing therethrough. The thermoplastic material 4 is Dow™ LDPE 5011 (a LDPE with a density of 0.922 g/cc and a melt index of 1.9 g/10 min). The extruder 2 is a 1.25-inch (3.175 cm) diameter Killion single-screw extruder that feed a gear pump operated at a speed commensurate with the desired output rate (here, the gear pump speed is 50 rotations per minute). While the present example utilizes a gear pump, it is understood that a gear pump is not required to produce a microcapillary film with the present die assembly. The extrusion temperature is 200°C and the air flow rate is 150 ml/min. The line speed is 59.2 ft/min (18.0 meters/min).

[00169] The die assembly 10 includes a first die plate 12, a second die plate 28, twelve SUPERBOLT™ bolt-style S8 multi-jackbolt tensioners (available from Nord-Lock, Inc) connecting the first die plate 12 to the second die plate 28, a manifold 36, and a plurality of nozzles 58. The manifold 36 is located between the pair of die plates (12, 28) and defines a plurality of film channels 38 therebetween. The plurality of film channels 38 converge into an elongate outlet 52, the thermoplastic material 4 extrudable through the plurality of film channels 38 and the elongate outlet 52 to form a microcapillary film 54. The plurality of nozzles 58 are located between the plurality of film channels 38. The plurality of nozzles 58 are operatively connected to a source of channel fluid 66 for emitting the channel fluid 66 between layers of the microcapillary film 54, whereby a plurality of microcapillary channels 68 are formed in the microcapillary film 54.

[00170] A first adjustment mounting bracket 70 and a second adjustment mounting bracket 72 are positioned on opposite sides of the manifold 36. Ten adjustment assemblies 90 are in contact with each adjustment mounting bracket (70, 72). The ten adjustment assemblies 90 in contact with the first adjustment mounting bracket 70 are capable of applying pressure on the first restrictor bar 92 positioned within the first die plate 12. The ten adjustment assemblies 90 in contact with the second adjustment mounting bracket 72 are capable of applying pressure on the second restrictor bar 93 within the second die plate 28.

[00171] The first die plate 56a and the second die plate 56b (e.g. dog bone shape) are used to manually counteract the die deflection caused by the pressure of polymer melt flow across the die width.

[00172] This present outlet assembly 52 (first die plate 56a in mirror image relation with second die plate 56b, and hereafter referred to as "inventive outlet assembly") counteracts the die deflection. Conventional flexible die lip control has the potential of damaging the delicate microcapillary nozzles.

[00173] As an example of the inventive outlet assembly the length of each tapered surface is 10.5 inches (266.7 mm), and the length for each flare surface is 1.5 inches (38.1 mm). The die opening (MSI+MS ₂ ) in the center (midpoint) of the die width is 60 mil (1.52 mm) (60 mil = MSI+MS ₂ ) and the die opening gradually increases to 72 mil (1.83 mm), at the peak points (72 mil=Psi+Ps ₃ and 72 mil=Ps ₂ +Ps ₄ ) at a distance of 1.5 inch (38.1 mm) from the edge. The die opening then reduces to 60 mil (1.52 mm) (60 mil=Fsi+Fs ₃ and 60 mil=Fs ₂ +Fs ₄ ) at the edge for minimizing the edge effects.

[00174] A flat die lip design with a uniform die opening of 60 mil (1.52 mm) along the entire length of the outlet was used as a comparative sample. All the heating zones in the die were set to 392°F (200°C). The gear pump speed was fixed at 50 rpm for LDPE 5011. For the flat die lip design (comparative sample), the percent deviation from average film thickness was approximately ±20%. In contrast, the percent deviation from average film thickness was about ±10% using the die with the present outlet assembly 52 (first die plate 56a in mirror image relation with second die plate 56b).

[00175] The microcapillary film thickness deviation data is shown in Table 1 below.

Table 1. Data for film thickness and percent deviation from average film thickness versus percentage of film width by using a flat die lip (comparative) and inventive outlet assembly.

[00176] In order to further improve the film thickness uniformity to within ±5% for the microcapillary die with a flat die lip (comparative), the adjustment of restrictor bars must be coupled with the control over die temperature profiles. As shown in Table 2, the die temperatures in the center of the die is 380°F (193°C), whereas the temperature at both edges is 410°F (210°C).

[00177] Table 2. Temperature profiles of microcapillary die with a flat die lip (comparative).

[00178] In the flat die lip (comparative), the non-uniform temperature profiles across the zones are required to push more polymer flow toward the edges by reducing the viscosity of polymer melt on both edges. The adjustments of restrictor bars for the flat die lip (comparative) are shown in Table 3. The adjustment of restrictor bars in the center of the die is about 1 revolution. Under these conditions, film thickness variation is within ±5% for LDPE 501I microcapillary films.

[00179] In contrast, all the heating zones were set to 392°F (200°C) for the microcapillary die with the inventive outlet assembly. The adjustments of restrictor bars (e.g. 0.5 revolution in the center) for the microcapillary die with the inventive outlet assembly were also less than those with a flat die lip comparative. Using the inventive outlet assembly, the LDPE 5011 microcapillary film thickness variation was within ±3% and actually less than ±3%. and is summarized in Table 4. To summarize, the inventive outlet assembly enabled easier process control for achieving uniform film thickness. The inventive outlet assembly advantageously enabled (1) uniform temperature across all the heating zones, (2) required less adjustment of the restrictor bars and (3) achieved less thickness variance (inventive ±3%, comparative ±5%) when compared to the flat die lip. Table 3.

Table 4. Raw data of film thickness and percent deviation from average film thickness versus percentage of film width by using a flat die lip (comparative) and inventive outlet assembly under the adjustment of restrictor bars and/or die temperature profiles.

[00180] It is specifically intended that the present disclosure not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.