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Title:
METHOD AND APPARATUS FOR PRODUCING A MULTI-LAYER MOLDED ARTICLE HAVING CONTROLLABLY-POSITIONED CORE LAYER
Document Type and Number:
WIPO Patent Application WO/2019/140506
Kind Code:
A1
Abstract:
There are disclosed a method (500) of molding a molded article (202) using a molding system and the molding system implementing same. The molding system includes a mold (114, 116); a molding-material distributor associated with the mold, the molding-material distributor being configured to convey a first molten material and a second molten material to the at least molding cavity. The system also includes a controller (140) for controlling operation of the system. The controller is configured to cause execution of: injecting (502) the first material into the at least one molding cavity to define the outer layer; injecting (504) the second material into the at least one molding cavity to form a combined flow with the core layer encapsulated by the outer layer; selectively (506) controlling surface temperatures of at least one of the core insert and the cavity insert to selectively position the core layer.

Inventors:
HALTER, Christophe (58 rue Hamelius, 6700 Arlon, 6700 Arlon, 6700, BE)
YANKOV, Peter (30 Loontail Street, Bolton, Ontario L7E 2X1, L7E 2X1, CA)
WEATHERALL, Douglas James (12 Cornerstone Court, Bolton, Ontario L7E 1T4, L7E 1T4, CA)
Application Number:
CA2019/050003
Publication Date:
July 25, 2019
Filing Date:
January 03, 2019
Export Citation:
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Assignee:
HUSKY INJECTION MOLDING SYSTEMS LTD. (500 Queen Street South, Bolton, Ontario L7E 5S5, L7E 5S5, CA)
International Classes:
B29C45/14; B29C45/16; B29C45/72; B29C45/76
Foreign References:
US6497569B22002-12-24
US7568906B22009-08-04
US8551589B22013-10-08
Attorney, Agent or Firm:
GOW, Geoffrey (500 Queen Street SouthBolton, Ontario L7E 5S5, L7E 5S5, CA)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. A method (500) of molding a molded article (202) using a molding system (100), the molding system including: a mold (114, 116) defining at least one molding cavity for forming the molded article therein, the at least one molding cavity being defined between a respective mold core insert (120) and a respective mold cavity insert (118) of the mold; a molding-material distributor associated with the mold, the molding-material distributor being configured to convey a first molten material from a first molten material source and a second molten material from a second molten material source to the at least molding cavity; the molding-material distributor configured to convey the first molten material (406) and the second molten material (408) such that the second molten material forms a core layer (208) of the molded article that is surrounded by an outer layer (206) formed by the first molten material; a controller (140) for controlling operation of at least some of the mold and the molding-material distributor, the controller storing machine-executable instructions, which instructions when executed cause execution of: injecting (502) the first material into the at least one molding cavity to define the outer layer; injecting (504) the second material into the at least one molding cavity during the injecting of the first material to form a combined flow with the core layer encapsulated by the outer layer; selectively (506) controlling surface temperatures of at least one of the core insert and the cavity insert to selectively position the core layer. 2. The method of claim 1 , wherein the selective position of the core layer is relative to an outline of an associated one of the at least one molding cavity.

3. The method of claim 1, wherein the selective position of the core layer is a relative positioning of the core layer within the outer layer.

4. The method of claim 3, wherein the outer layer comprises an inner-skin outer layer and an outer-skin outer layer, and wherein the relative positioning is relative to the inner-skin outer layer and the outer- skin outer layer.

5. The method of claim 1, wherein the selectively controlling surface temperatures of at least one of the core insert and the cavity insert comprises: controlling at least one of cooling and heating of an associated one of the at least one of the core insert and the cavity insert.

6. The method of claim 5, wherein controlling cooling comprises at least one of controlling cooling temperature of a cooling fluid and controlling flow-rate of the cooling fluid. 7. The method of claim 1, wherein the selectively controlling surface temperatures further comprises receiving an indication of a target control temperature.

8. The method of claim 1, wherein the selectively controlling surface temperatures comprises creating a thermal difference between two sidewalls defining the molded article causing the core layer to be biased towards the hotter of the two sidewalls. 9. The method of claim 1, further comprising: dividing the combined flow in the at least one molding cavity to define multiple flow fronts; combining the multiple flow fronts in a combination region (610) of the at least one molding cavity, the combining defining a weld line (608); and wherein the selectively controlling surface temperatures comprises: selectively controlling the surface temperatures at least in a vicinity of the of the combination region to selectively position the core layer in the multiple flow fronts such that they overlap.

10. The method of claim 1, wherein the molded article is one of: a flip-top closure, a preform, a pouch fitment, a carton closure, food container, food container closure and a coffee capsule.

11. A molding system (100) configured to produce a molded article (202), the molding system comprising: a mold (114, 116) defining at least one molding cavity for forming the molded article therein, the at least one molding cavity being defined between a respective mold core insert (120) and a respective mold cavity insert (118) of the mold; a molding-material distributor associated with the mold, the molding-material distributor being configured to convey a first molten material from a first molten material source and a second molten material from a second molten material source to the at least molding cavity; the molding-material distributor configured to convey the first molten material (406) and the second molten material (408) such that the second molten material forms a core layer (208) of the molded article that is surrounded by an outer layer (206) formed by the first molten material; a controller (140) for controlling operation of at least some of the mold and the molding- material distributor, the controller storing machine-executable instructions, which instructions when executed cause execution of: injecting (502) the first material into the at least one molding cavity to define the outer layer; injecting (504) the second material into the at least one molding cavity during the injecting of the first material to form a combined flow with the core layer encapsulated by the outer layer; selectively (506) controlling surface temperatures of at least one of the core insert and the cavity insert to selectively position the core layer.

Description:
METHOD AND APPARATUS FOR PRODUCING A MULTI-LAYER MOLDED ARTICLE HAVING CONTROLLABLY-POSITIONED CORE LAYER

TECHNICAL FIELD

The non-limiting embodiments disclosed herein generally relate to injection molding, and more particularly to a method and an apparatus for producing a multi-layer molded article having a controllably-positioned core layer.

BACKGROUND

Molding is a process by virtue of which a molded article can be formed from molding material by using a molding system. Various molded articles can be formed by using the molding process, such as an injection molding process. One example of a molded article that can be formed is a closure for a container, such as a bottle. Several types of closures can be made, depending on the type of the container that the closure is to be used with. Depending on the type of the container the closure is destined to be used with, the closure is designed with specific design considerations in mind. For example, a closure for a carbonated beverage is different in design from a closure for still water (at least in the sealing features used for the closure for the carbonated beverage).

Another example of a molded article that can be formed, for example, from Polyethylene Terephthalate (PET) material is a preform that is capable of being subsequently blown into a beverage container, such as, a bottle and the like. As an illustration, injection molding of PET material involves heating the molding material (ex. PET pellets, etc.) to a homogeneous molten state and injecting, under pressure, the so-melted PET material into a molding cavity defined, at least in part, by a female cavity piece and a male core piece mounted respectively on a cavity plate and a core plate of the mold. The cavity plate and the core plate are urged together and are held together by clamp force, the clamp force being sufficient enough to keep the cavity and the core pieces together against the pressure of the injected PET material. The molding cavity has a shape that substantially corresponds to a final cold-state shape of the molded article to be molded. The so-injected PET material is then cooled to a temperature sufficient to enable ejection of the so-formed molded article from the mold. When cooled, the molded article shrinks inside of the molding cavity and, as such, when the cavity and core plates are urged apart, the molded article tends to remain associated with the core piece. Accordingly, by urging the core plate away from the cavity plate, the molded article can be demolded, i.e. ejected off of the core piece. Ejection structures are known to assist in removing the molded articles from the core halves. Examples of the ejection structures include stripper plates, ejector pins, etc.

A plethora of additional molded articles can be produced using the molding process, including: thin walled containers, specialty closures, coffee pods, medical appliances and devices, etc.

Some of the molded articles are made of a single material. For example, the aforementioned preforms that are stretch blow-molded into beverage container for still or sparkling beverages are typically made from a single material - PET. PET is well suited for such applications. However, PET is not suited ideally for other applications. For that matter, for certain applications, no single material is a viable option (either because it lacks certain properties or because it would be commercially non-viable). It is, thus, also known to create multi-material preforms, where another material (typically called a“core material” or a “barrier material”) is added and“sandwiched” between the main material. The core material is selected such as to enhance a particular characteristic that is lacking (or is weak) in the main (skin) material. As an example, certain materials can be chosen as the core layer to enhance oxygen im-permiability, to enhance light im-permiability, or the like.

US 2015/0209988 discloses methods and systems for co-injection molding multilayer articles having one or more molded apertures disposed between a gate region and a peripheral region of the article. The articles include an interior layer disposed between an inner layer and an outer layer. An article has interior layer coverage over at least 98% of a perimeter of a cross-section of the article downstream of the one or more molded apertures. A method includes modifying fluid flowing past an aperture-forming region of a mold cavity to compensate for the drag of the aperture-forming region on the velocity of the fluid flowing proximal to the aperture-forming region. SUMMARY

It is an object of the present invention to ameliorate at least some of the inconveniences present in the prior art.

Without wishing to be bound to any specific theory, embodiments of the present technology have been developed based on developers’ appreciation that it may be desirable to selectively position the core layer within the outer layer. Embodiments of the present technology are further based on a premise that positioning of the core layer within the outer layer can be achieved by creating a temperature difference between the various mold portions defining the molded article. In particular, the temperature difference can be created by selectively controlling the temperature of at least one of the core insert and the cavity insert.

According to a broad aspect of the present technology, there is provided a method of molding a molded article using a molding system, the molding system including:

• a mold defining at least one molding cavity for forming the molded article therein, the at least one molding cavity being defined between a respective mold core insert and a respective mold cavity insert of the mold;

• a molding-material distributor associated with the mold, the molding-material distributor being configured to convey a first molten material from a first molten material source and a second molten material from a second molten material source to the at least molding cavity; the molding-material distributor configured to convey the first molten material and the second molten material such that the second molten material forms a core layer of the molded article that is surrounded by an outer layer formed by the first molten material;

• a controller for controlling operation of at least some of the mold and the molding- material distributor, the controller storing machine-executable instructions, which instructions when executed cause execution of:

• injecting the first material into the at least one molding cavity to define the outer layer;

• injecting the second material into the at least one molding cavity during the injecting of the first material to form a combined flow with the core layer encapsulated by the outer layer;

• selectively controlling surface temperatures of at least one of the core insert and the cavity insert to selectively position the core layer. According to another broad aspect of the present technology, there is provided a molding system configured to produce a molded article.

The molding system comprising a mold defining at least one molding cavity for forming the molded article therein, the at least one molding cavity being defined between a respective mold core insert and a respective mold cavity insert of the mold. The molding system also includes a molding-material distributor associated with the mold, the molding-material distributor being configured to convey a first molten material from a first molten material source and a second molten material from a second molten material source to the at least molding cavity. The molding-material distributor configured to convey the first molten material and the second molten material such that the second molten material forms a core layer of the molded article that is surrounded by an outer layer formed by the first molten material. The molding system further includes a controller for controlling operation of at least some of the mold and the molding- material distributor, the controller storing machine-executable instructions, which instructions when executed cause execution of: · injecting the first material into the at least one molding cavity to define the outer layer;

• injecting the second material into the at least one molding cavity during the injecting of the first material to form a combined flow with the core layer encapsulated by the outer layer;

• selectively controlling surface temperatures of at least one of the core insert and the cavity insert to selectively position the core layer.

These and other aspects and features will now become apparent to those skilled in the art upon review of the following description of specific non- limiting embodiments in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

The detailed description of illustrative (non-limiting) embodiments will be more fully appreciated when taken in conjunction with the accompanying drawings, in which:

Figure 1 depicts a non-limiting embodiment of a molding system which can be adapted to implement embodiments of the present technology.

Figure 2 depicts a cross section view of a molded article implemented as a multi-layer preform, the molded article that can be produced by the molding system of Figure 1.

Figure 3 depicts a cross section of a non-limiting embodiment of a co-injection nozzle of the molding system of Figure 1, the co-injection nozzle being implemented in accordance with the non- limiting embodiments of the present technology. Figure 4 depicts a schematic representation of two molding surfaces - a first molding surface and a second molding surface, the two molding surfaces illustrating working principles of at least some non-limiting embodiments of the present technology.

Figure 5 depicts a flow chart of a non-limiting embodiment of a method, the method 500 being executed in accordance with embodiments of the present technology.

Figure 6 depicts a cross section of a melt flow in accordance with another non-limiting embodiment for implementations of the present technology.

The drawings are not necessarily to scale and may be illustrated by phantom lines, diagrammatic representations and fragmentary views. In certain instances, details that are not necessary for an understanding of the embodiments or that render other details difficult to perceive may have been omitted.

DETAILED DESCRIPTION OF THE NON-LIMITING EMBODIMENTS

Reference will now be made in detail to various non-limiting implementations for an injection molding machine, components thereof and methods for producing molded articles. It should be understood that other non-limiting implementations, modifications and equivalents will be evident to one of ordinary skill in the art in view of the non-limiting implementations disclosed herein and that these variants should be considered to be within scope of the appended claims. Furthermore, it will be recognized by one of ordinary skill in the art that certain structural and operational details of the non-limiting implementations discussed hereafter may be modified or omitted (i.e. non-essential) altogether. In other instances, well known methods, procedures, and components have not been described in detail.

It is to be further expressly understood that the injection molding machine and its components are depicted merely as an illustrative implementation of the present technology. Thus, the description thereof that follows is intended to be only a description of illustrative examples of the present technology. This description is not intended to define the scope or set forth the bounds of the present technology. In some cases, what are believed to be helpful examples of modifications to the injection mold and/or its components may also be set forth below. This is done merely as an aid to understanding, and, again, not to define the scope or set forth the bounds of the present technology. These modifications are not an exhaustive list, and, as a person skilled in the art would understand, other modifications are likely possible. Further, where this has not been done (i.e. where no examples of modifications have been set forth), it should not be interpreted that no modifications are possible and/or that what is described is the sole manner of implementing that element of the present technology. As a person skilled in the art would understand, this is likely not the case. In addition, it is to be understood that the injection mold and/or its components may provide in certain instances simple implementations of the present technology, and that where such is the case they have been presented in this manner as an aid to understanding. As persons skilled in the art would understand, various implementations of the present technology may be of a greater complexity. Furthermore, where specific details of the different implementations are presented with reference to discrete implementations, a person skilled in the art is expected to combine specific implementational details of one discrete implementation with specific implementational details of another discrete implementation, even though such a combination may not be expressly disclosed herein below.

Molding System

With reference to Figure 1, there is depicted a non-limiting embodiment of a molding system 100 which can be adapted to implement embodiments of the present technology. The type of the molding system 100 is not particularly limited and, as such, the molding system 100 can be an injection molding system, compression molding systems, compression injection molding systems, transfer molding systems, and the like. It should be further understood that embodiments of the present technology are applicable to the molding system 100 incorporating any multi-cavitation mold for producing any type of preforms. In the non- limiting embodiment of Figure 1, the molding system 100 comprises a fixed platen 102 and a movable platen 104. In some embodiments of the present technology, the molding system 100 may include a third non-movable platen (not depicted). Alternatively, or additionally, the molding system may include turret blocks, rotating cubes, turning tables and the like (all not depicted but known to those of skill in the art). The molding system 100 further comprises an injection unit 106 for plasticizing and injection of molding material. The injection unit 106 can be implemented as a single stage or a two-stage injection unit. In some embodiments of the present technology, the molding system 100 can include two instances of the injection unit 106, each of the two instances of the injection unit 106 for producing a different type of melt (for example, from a different resin, as will be described in greater detail herein below).

In operation, the movable platen 104 is moved towards and away from the fixed platen 102 by means of stroke cylinders (not shown) or any other suitable means. Clamp force (also referred to as closure or mold closure tonnage) can be developed within the molding system 100, for example, by using tie bars 108, 110 (typically, four tie bars 108, 110 are present in the molding system 100) and a tie-bar clamping mechanism 112, as well as (typically) an associated hydraulic system (not depicted) that is usually associated with the tie-bar clamping mechanism 112. It will be appreciated that clamp tonnage can be generated using alternative means, such as, for example, using a column-based clamping mechanism, a toggle-clamp arrangement (not depicted) or the like.

A first mold half 114 can be associated with the fixed platen 102 and a second mold half 116 can be associated with the movable platen 104. In the non- limiting embodiment of Figure 1, the first mold half 114 comprises one or more mold cavity inserts 118. As will be appreciated by those of skill in the art, the one or more mold cavity inserts 118 may be formed by using suitable mold inserts (such as a cavity insert, a gate insert and the like) or any other suitable means. As such, the first mold half 114 can be generally thought of as a“mold cavity half’.

The second mold half 116 comprises one or more mold core inserts 120 complementary to the one or more mold cavity inserts 118. As will be appreciated by those of skill in the art, the one or more mold core inserts 120 may be formed by using suitable mold inserts or any other suitable means. As such, the second mold half 116 can be generally thought of as a“mold core half’. Even though not depicted in Figure 1, the first mold half 114 may be further associated with a “melt distribution network” or a“molding-material distributor”, commonly known as a“hot runner”, for distributing molding material from the injection unit 106 to each of the one or more mold cavity inserts 118. Also, in those embodiments where the molding system 100 is configured to produce preforms, the second mold half 116 can be provided with neck rings (not depicted).

The first mold half 114 can be coupled to the fixed platen 102 by any suitable means, such as a suitable fastener (not depicted) or the like. The second mold half 116 can be coupled to the movable platen 104 by any suitable means, such as a suitable fastener (not depicted) or the like. It should be understood that in an alternative non- limiting embodiment of the present technology, the position of the first mold half 114 and the second mold half 116 can be reversed and, as such, the first mold half 114 can be associated with the movable platen 104 and the second mold half 116 can be associated with the fixed platen 102. In an alternative non- limiting embodiment of the present technology, the fixed platen 102 need not be stationary and may be movable in relation to other components of the molding system 100. Figure 1 depicts the first mold half 114 and the second mold half 116 in a so-called“mold open position” where the movable platen 104 is positioned generally away from the fixed platen 102 and, accordingly, the first mold half 114 is positioned generally away from the second mold half 116. For example, in the mold open position, a molded article (not depicted) can be removed from the first mold half 114 and/or the second mold half 116. In a so-called“mold closed position” (not depicted), the first mold half 114 and the second mold half 116 are urged together (by means of movement of the movable platen 104 towards the fixed platen 102) and cooperate to define (at least in part) a molding cavity (not depicted) into which the molten plastic (or other suitable molding material) can be injected, as is known to those of skill in the art. It should be appreciated that one of the first mold half 114 and the second mold half 116 can be associated with a number of additional mold elements, such as for example, one or more leader pins (not depicted) and one or more leader bushings (not depicted), the one or more leader pins cooperating with one more leader bushings to assist in alignment of the first mold half 114 with the second mold half 116 in the mold closed position, as is known to those of skill in the art. The molding system 100 can further comprise a robot 122 (also referred to as an“end of arm tool”) operatively coupled to the fixed platen 102. Those skilled in the art will readily appreciate how the robot 122 can be operatively coupled to the fixed platen 102 and, as such, it will not be described here in any detail. The robot 122 comprises a mounting structure 124, an actuating arm 126 coupled to the mounting structure 124 and a take-off plate 128 coupled to the actuating arm 126. The take-off plate 128 comprises a plurality of molded article receptacles 130.

Generally speaking, the purpose of the plurality of molded article receptacles 130 is to remove molded articles from the one or more mold core inserts 120 (or the one or more mold cavity inserts 118) and/or to implement post mold cooling of the molded articles. In the non- limiting example illustrated herein, the plurality of molded article receptacles 130 comprises a plurality of cooling tubes for receiving a plurality of molded preforms. Flowever, it should be expressly understood that the plurality of molded article receptacles 130 may have other configurations. The exact number of the plurality of molded article receptacles 130 is not particularly limited.

Schematically depicted in Figure 1 is the robot 122 of a side-entry type. Flowever, it should be understood that in alternative non-limiting embodiments of the present technology, the robot 122 can be of a top-entry type. It should also be expressly understood that the term“robot” is meant to encompass structures that perform a single operation, as well as structures that perform multiple operations. The molding system 100 further comprises a post-mold treatment device 132 operatively coupled to the movable platen 104. Those skilled in the art will readily appreciate how the post- mold treatment device 132 can be operatively coupled to the movable platen 104 and, as such, it will not be described here in any detail. The post- mold treatment device 132 comprises a mounting structure 134 used for coupling the post-mold treatment device 132 to the movable platen 104. The post- mold treatment device 132 further comprises a plenum 129 coupled to the mounting structure 134. Coupled to the plenum 129 is a plurality of treatment pins 133. The number of treatment pins within the plurality of treatment pins 133 generally corresponds to the number of receptacles within the plurality of molded article receptacles 130. The molding system 100 further comprises a controller 140, the controller including a human- machine interface (not separately numbered) or an HMI, for short. Generally speaking, the controller 140 is configured to control one or more operations of the molding system 100. The HMI of the controller 140 can be implemented in any suitable interface. As an example, the HMI of the controller 140 can be implemented in a multi-functional touch screen. An example of the HMI that can be used for implementing non-limiting embodiments of the present technology is disclosed in co-owned United States Patent No. 6,684,264, content of which is incorporated herein by reference, in its entirety.

Those skilled in the art will appreciate that the controller 140 may be implemented using pre programmed hardware or firmware elements (e.g., application specific integrated circuits (ASICs), electrically erasable programmable read-only memories (EEPROMs), etc.), or other related components. In other embodiments, the functionality of the controller 140 may be achieved using a processor that has access to a code memory (not shown) which stores computer- readable program code for operation of the computing apparatus, in which case the computer- readable program code could be stored on a medium which is fixed, tangible and readable directly by the various network entities, (e.g., removable diskette, CD-ROM, ROM, fixed disk, USB drive), or the computer-readable program code could be stored remotely but transmittable to the controller 140 via a modem or other interface device (e.g., a communications adapter) connected to a network (including, without limitation, the Internet) over a transmission medium, which may be either a non-wireless medium (e.g., optical or analog communications lines) or a wireless medium (e.g., microwave, infrared or other transmission schemes) or a combination thereof.

In alternative non-limiting embodiments of the present technology, the HMI does not have to be physically attached to the controller 140. As a matter of fact, the HMI for the controller 140 can be implemented as a separate device. In some embodiments, the HMI can be implemented as a wireless communication device (such as a smartphone, for example) that is“paired” or otherwise communicatively coupled to the controller 140.

Mold temperature management subsystem In accordance with the non-limiting embodiments of the present technology, the molding system 100 comprises a mold temperature management subsystem 170. The mold temperature management subsystem 170 comprises a core half temperature management portion 180 and a cavity half temperature management portion 190.

The core half temperature management portion 180 is associated with the one or more mold core inserts 120. Thus, the core half temperature management portion 180 is configured (under control of the controller 140) to change temperature of the one or more mold core inserts 120. The core half temperature management portion 180 can include (i) one or more cooling channels for circulating cooling fluid inside the one or more mold core inserts 120 and/or (ii) one or more heaters for heating the molding surface of the one or more mold core inserts 120. The cavity half temperature management portion 190 is associated with the one or more mold cavity inserts 118. Thus, cavity half temperature management portion 190 is configured (under control of the controller 140) to change temperature of the one or more mold cavity inserts 118. The cavity half temperature management portion 190 can include (i) one or more cooling channels for circulating cooling fluid around the one or more mold cavity inserts 118 and/or (ii) one or more heaters for heating the molding surface of the one or more mold cavity inserts 118.

Molded article

The type of the molded article that the molding system 100 can produce is not limited. Examples of the molded articles that can be produced in the molding system 100 include but are not limited to: a flip-top closure, a preform, a pouch fitment, a carton closure, food container, food container closure and a coffee capsule.

In accordance with the embodiments of the present technology, the molded article is of a laminated structure produced using one or more materials (which materials can be different resins or different states of the same resin, such as a virgin raw material and regrind same raw material). In other words, the molded article produced in the molding system 100 is of a multi-material type. An example of a molded article 200 is depicted in Figure 2, which Figure depicts a cross section view of the molded article 200 implemented as a multi-layer preform.

The molded article 202 comprises a first material main body portion 206 and a second material core layer portion 208. In this example, the first material main body portion 206 can be said to be “overmolded” over the second material core layer portion 208. In other words, it can be said that the first material main body portion 206 can be said to encapsulate the second material core layer portion 208

Broadly speaking, the second material core layer portion 208 can be made of a particular second material to provide certain functional characteristics. In a specific example, the second material core layer portion 208 can be selected to enhance one or more properties or to provide one or more functions: provide a barrier for light or oxygen, provide additional rigidity to the structure of the molded article 200, be a regrind material that is cheaper or more environmentally friendly (but that cannot“touch” a consumer and, thus, needs to be encapsulated).

The implementations of the first material and the second material are not particular limited. Just as a non- limiting example, (i) the first material can be Polypropylene (PP), High-Density Polyethylene (HDPE) and the like; and (ii) the second material can be any Thermoplastic Elastomer (TPE), Polypropylene (PP), High-Density Polyethylene (HDPE). It is noted that the exact implementation of the first material and the second material; as well as the inter combination of the first material and the second material can be selected by the operator (not depicted) of the molding system 100 based on the specification for the molded article 202.

Multi-material nozzle

Figure 3 depicts a non-limiting embodiment of a co-injection nozzle 300, the co-injection nozzle 300 being implemented in accordance with the non-limiting embodiments of the present technology. It is noted that the co-injection nozzle 300 forms part of the above-mentioned molding-material distributor. The molding-material distributor will comprise several instances of the co-injection nozzle 300, the several instances to the number of the molding cavities defined between the first mold half 114 and the second mold half 116. Broadly speaking, the purpose of the co-injection nozzle 300 is to convey the molten material distributed by the molding-material distributor into an associated one of the molding cavities. As shown in Figure 3, the co-injection nozzle 300 includes an inner melt channel 302, an annular outer melt channel 304, and an annular intermediate melt channel 306 disposed in between the inner melt channel 302 and the annular outer melt channel 304.

As will be appreciated, although only one annular intermediate melt channel 306 is shown in this embodiment, in other embodiments, the co-injection nozzle 300may include more than one annular intermediate melt channel 306. For example, the co-injection nozzle 300 may include two or more intermediate melt channels in between the inner melt channel 302 and annular outer melt channel 304. As will be further appreciated, each of these channels feeds melt to the same mold molding cavity.

As illustrated in Figure 3, the inner melt channel 302, the annular intermediate melt channel 306, and annular outer melt channel 304 are positioned adjacent to one another. That is, the respective outlets (not separately numbered) of the inner melt channel 302, the annular intermediate melt channel 306, and annular outer melt channel 304 are positioned immediately next to one another such that there is no appreciable space between them.

In some embodiments, the outlets of the inner melt channel 302, the annular intermediate melt channel 306, and annular outer melt channel 304 may intersect one another at a combination area 310. In such embodiments, the melt exiting the inner melt channel 302, the annular intermediate melt channel 306, and annular outer melt channel 304 may intersect each other in this combination area 310. In some embodiments, the melt exiting the inner melt channel 302, the annular intermediate melt channel 306, and annular outer melt channel 304 may be arranged concentrically with respect to one another. For purposes herein, a concentric arrangement may mean that the inner melt channel 302 is substantially frustoconical and nested inside of the annular intermediate melt channel 306, which, in turn, is substantially semi-hemispherical and nested inside the annular outer melt channel 304, which is also substantially semi-hemispherical.

As will be appreciated, one or more of the melt channels also may have different arrangements in other embodiments. Once combined in the combination area 310, the first material and the second material flow into the molding cavity.

Therefore, it can be said that the molding-material distributor is configured to convey the first molten material and the second molten material such that: the second molten material that forms a core layer of the molded article 202 is surrounded by an outer layer formed by the second molten material.

In accordance with the non- limiting embodiments of the present technology, the controller 140 causes: injecting the first material into the at least one molding cavity to define the outer layer; and injecting the second material into the at least one molding cavity during the injecting of the first material to form a combined flow with the core layer encapsulated by the outer layer. As has been alluded to above, the combined flow can be formed either in the combination area 310 or downstream in the molding cavity.

It should be noted that the structure of the co-injection nozzle 300 depicted in Figure 3 is provided as an illustration only. It should be expressly understood that the non-limiting embodiments of the present technology can be implemented with other types of the co-injection nozzle 300. Selective positioning of the core layer

In accordance with the non-limiting embodiments of the present technology, the controller 140 is further configured to selectively control surface temperatures of at least one of: (i) one or more mold core inserts 120 and (ii) one or more mold cavity inserts 118 to selectively position the core layer. Broadly speaking, the controller 140 is configured to cause one or more of the core half temperature management portion 180 and the cavity half temperature management portion 190 to control surface temperature of the molding surface of the respective ones of the (i) one or more mold core inserts 120 and (ii) one or more mold cavity inserts 118.

Figure 4 depicts a schematic representation of two molding surfaces - a first molding surface 402 and a second molding surface 404. Without wishing to be bound to any specific theory, the depiction of the Figure 4 is for illustrating principles on which the controller 140 selectively controls surface temperatures of at least one of: (i) one or more mold core inserts 120 and (ii) one or more mold cavity inserts 118 to selectively position the core layer (at least in accordance with some non-limiting embodiments of the present technology). To that end and as an illustration one of the first molding surface 402 and the second molding surface 404 can be the molding surface of one of the one or more mold core inserts 120 and (ii) one or more mold cavity inserts 118. The other one of the first molding surface 402 and the second molding surface 404 can be the molding surface of one of the one or more mold core inserts 120 and (ii) one or more mold cavity inserts 118. Positioned between the first molding surface 402 and the second molding surface 404 is an outer molten material 406 and a core molten material 408. A first portion 410 of the first molding surface 402 is relatively hotter and a second portion 412 of the first molding surface 402 is relatively cooler. A first portion 414 of the second molding surface 404 is relatively cooler, while a second portion 416 of the second molding surface 404 is relatively hotter. The relative temperatures that are illustrated here can be controlled by the controller 140 that executes selective controlling of the mold temperature management subsystem 170 as described herein.

As a result, a portion of the core molten material 408 positioned between the first portion 410 and the first portion 414 is biased in a direction 420 (i.e. towards a relatively hotter portion), while a portion of the core molten material 408 positioned between the second portion 412 and the second portion 416 is biased in a direction 422 (i.e. towards a relatively hotter portion). In other way, by selectively controlling relative temperature of the (i) the first portion 410 and the first portion 414 and/or (ii) second portion 412 and the second portion 416, the controller 140 can selectively position the core molten material 408.

Given the illustration of Figure 4, it should become apparent that the selective position of the core molten material 408 is relative to an outline of an associated one of the at least one molding cavity (with the illustration of the first molding surface 402 and the second molding surface 404 being used as proxies for illustrating the outline of the at least one molding cavity). By the same token, it should be clear that the relative positioning of the core molten material 408 is within the outer molten material 406. Put another way, the outer molten material 406 comprises an inner- skin outer layer and an outer-skin outer layer, and the relative positioning is relative to the inner- skin outer layer and the outer-skin outer layer.

It should be recalled that the core half temperature management portion 180 is associated with the one or more mold core inserts 120. Thus, the core half temperature management portion 180 is configured (under control of the controller 140) to change temperature of the one or more mold core inserts 120. The core half temperature management portion 180 can include (i) one or more cooling channels for circulating cooling fluid inside the one or more mold core inserts 120 and/or (ii) one or more heaters for heating the molding surface of the one or more mold core inserts 120.

It should be also recalled that the cavity half temperature management portion 190 is associated with the one or more mold cavity inserts 118. Thus, cavity half temperature management portion 190 is configured (under control of the controller 140) to change temperature of the one or more mold cavity inserts 118. The cavity half temperature management portion 190 can include (i) one or more cooling channels for circulating cooling fluid around the one or more mold cavity inserts 118 and/or (ii) one or more heaters for heating the molding surface of the one or more mold cavity inserts 118.

To that end, the controller 140 can execute the selectively controlling surface temperatures of at least one of the core insert by: controlling at least one of cooling and heating of an associated one of the at least one of the core insert and the cavity insert. The controller 140 can execute the selectively controlling surface temperatures further by receiving an indication of a target control temperature. The target control temperature can be inputted by an operator via an HMI of the controller 140.

In some embodiments of the present technology, it can be said that the selectively controlling surface temperatures comprises creating a thermal difference between two sidewalls defining the molded article 212 causing the core layer to be biased towards the hotter of the two.

It should be apparent from the above, the controlling cooling temperature can be implemented as controlling one of a temperature of a cooling fluid and controlling flow-rate of the cooling fluid.

Given the architecture of the molding system 100 described above, the controller 140 is configured to execute a method of molding the molded article 202. With reference to Figure 5, there is depicted a flow chart of a non-limiting embodiment of a method 500, the method 500 being executed in accordance with embodiments of the present technology. The method 500 can executable by the controller 140 of the molding system 100, which molding system 100 includes:

• a mold defining at least one molding cavity for forming the molded article therein, the at least one molding cavity being defined between a respective core insert and a respective cavity insert of the mold;

• a molding-material distributor associated with the mold, the molding-material distributor being configured to convey a first molten material from a first molten material source and a second molten material from a second molten material source to the at least molding cavity;

• the molding-material distributor configured to convey the first molten material and the second molten material such that the second molten material forms a core layer of the molded article that is surrounded by an outer layer formed by the first material; • a controller for controlling operation of at least some of the mold and the molding-material distributor, the controller storing machine-executable instructions, which instructions when executed cause execution of the method 500.

Step 502 - injecting the first material into the at least one molding cavity to define the outer layer

The method 500 starts at step 502, there the controller 140 causes injecting the first material into the at least one molding cavity to define the outer layer.

Step 504 - injecting the second material into the at least one molding cavity during the injecting of the first material to form a combined flow with the core layer encapsulated by the outer layer

At step 504, the controller 140 causes injecting the second material into the at least one molding cavity during the injecting of the first material to form a combined flow with the core layer encapsulated by the outer layer

Step 506 - selectively controlling surface temperatures of at least one of the core insert and the cavity insert to selectively position the core layer.

At step 506, the controller executes selectively controlling surface temperatures of at least one of the core insert and the cavity insert to selectively position the core layer.

In some implementations of the method 500, the selective position of the core layer is relative to an outline of an associated one of the at least one molding cavity. In some implementations of the method 500, the selective position of the core layer is a relative positioning of the core layer within the outer layer.

In some implementations of the method 500, the outer layer comprises an inner-skin outer layer and an outer-skin outer layer, and wherein the relative positioning is relative to the inner-skin outer layer and the outer- skin outer layer. In some implementations of the method 500, the selectively controlling surface temperatures of at least one of the core insert comprises: controlling at least one of cooling and heating of an associated one of the at least one of the core insert and the cavity insert.

In some implementations of the method 500, controlling cooling comprises at least one of controlling cooling temperature of a cooling fluid and controlling flow-rate of the cooling fluid. In some implementations of the method 500, the selectively controlling surface temperatures further comprises receiving an indication of a target control temperature.

In some implementations of the method 500, the selectively controlling surface temperatures comprises creating a thermal difference between two sidewalls defining the molded article causing the core layer to be biased towards the hotter of the two.

Alternative embodiments

With reference to Figure 6, there is illustrated another non-limiting embodiment for implementations of the present technology. There is schematically depicted a cross-section of a melt flow 602. There is depicted an injection point 604 and an obstruction 606 (which obstruction 606 can be, for example, a void to be defined in the molded article 202). To that end, the melt flow 602 can be said to be associated with a weld line 608. As such, some embodiments of the present technology may address proper position of the core layer around the weld line 608.

In these embodiments of the present technology, the method 500 further comprises:

• dividing the combined flow of the melt flow 602 in the at least one molding cavity to define multiple flow fronts (i.e. the two flow fronts that meet at the weld line 608);

• combining the multiple flow fronts in a combination region (around the weld line 608, the combination region being depicted at 610) of the at least one molding cavity, the combining defining the weld line 608; and wherein the selectively controlling surface temperatures comprises:

• selectively controlling the surface temperatures at least in a vicinity of the of the combination region 610 to selectively position the core layer in the multiple flow fronts such that they overlap.

Specific technical effect attributable to at least the embodiments depicted in Figure 6 is more even distribution of the core layer material around the weld line 608. This, in turn, ensures that there are no “gaps” in the core layer material, which can be very important for certain applications (for example, where the core layer material is used for barrier properties or the like).

It is noted that the foregoing has outlined some of the more pertinent non-limiting embodiments. These non-limiting embodiments may be used for many applications. Thus, although the description is made for particular arrangements and methods, the intent and concept of these non- limiting embodiments may be suitable and applicable to other arrangements and applications. It will be clear to those skilled in the art that modifications to the disclosed non-limiting embodiments can be affected. The described non-limiting embodiments ought to be construed to be merely illustrative of some of the more prominent features and applications thereof. Other beneficial results can be realized by applying these non-limiting embodiments in a different manner or modifying them in ways known to those familiar with the art. This includes the mixing and matching of features, elements and/or functions between various non-limiting embodiments is expressly contemplated herein, unless described otherwise, above.




 
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