TECHNICAL FIELD

Disclosed invention relates to 2-layer insulation material where first fabric layer is connected lengthwise to the second fabric layer at predetermined intervals forming multiplicity of bundle channels which are simultaneously or immediately after con nection individually filled through nozzles with insulation material which expands af ter removing the nozzle and pressurizes the bundle channels to contact adjacent bundle channels and form an airtight connection. The invention also relates to a method and an arrangement for producing such 2-layer insulation material.

BACKGROUND OF THE INVENTION

The invention relates to thermal insulation structures and materials and products made from these just as jackets, pants, blankets, sleeping bags and the like.

The problem in conventional garment insulation is the stitching lines which permit air to get through and where the insulation is thinner than in insulated areas. These areas form cold bridges which have been tried to be covered with different solutions.

UK Patent GB 2159050 B 22 May 1984 describes a quilt which has first and second fabric layer having different covering area. The insulation is introduced between fab ric layers as sheet material and sandwiched and stitched together with fabric layers. When quilt is draped over a convex object, the edges of the compartments come together to obstruct the passage of air.

European Patent application EP 3205222 A1 describes an insulation structure with first and second insulation element with an initially different shape and where the second insulation element is deformed when wearing the garment by a pressure on an interior side of the heat insulation structure such that a contact area, in which the first insulation element contacts the second insulation element is increased. How ever, the insulation needs pressure from outside to flatten the second compartment over the first compartment to seal the gap between the compartments.

Both above-mentioned insulation structures need either special curved condition or pressure against the structure from outside to connect the compartments and seal the passage of air at connect point In PCT application PCT/FI2018/050319 a 3-layer insulation material and a method and an arrangement for producing the same is described. However, the present invention simplifies the product and the method to make it and makes the arrange ments of production, e.g. production machinery more economical to produce.

In garment manufacturing there are two elements that are important in protecting from the cold: stopping the wind from penetrating and maintaining the layer of warm air close to the body by using fibers to create a layer of still air which serves as an insulation. Air is commonly used non-conducting insulator.

Traditionally insulation material in garments is introduced to the quilting machine as sheet material. Insulation is instructed between the face layer and the lining layer and sewn together with an array of needles. Needle holes produce cold bridges, i.e. thermal bridges. Cold bridges form weak spots in the insulation, causing cold air from outside of the garment to migrate inside of the garment.

In one embodiment of the present invention a laser welding is used, which makes it possible to attach two fabric layers together without needle holes. Additionally, laser welded seams provide barrier to particles, liquids and gases. The fabrics are welded together from only interconnections and therefore the surface of the fabric stays intact.

The present invention describes a material with two layers of fabric; both layers have substantially low air permeability, preventing air from traveling through fabric layers. This stops warm air from escaping out of insulation and prevents occupation of cold air inside of insulation. An expanding fiber sliver, e.g. a continuous crimped tow, or compressed down or insulation particles are directed to inside the bundle channels between the fabric layers to keep the layers separate, trapping in warm air emitted from the user’s body. Pressure of the insulation inside the bundle channels causes the bundle channels to expand and therefore the adjacent bundle channels walls are pressed against each others and the bundle channels come together to obstruct the passage of air.

The manufacturing of the continuous insulation sheet material involves specially en gineered methods and processes, which adds expenses to the price of insulation. Instead of using traditional sheet material as insulation layer, present invention uses continuous fiber-bundle insulation, i.e. the sliver of fiber, a strand of loose, untwisted rope of fibers, continuous, possibly crimped tow, directly extruded from spinneret as multiplicity of continuous filament strands. The spinneret has tiny holes through which a chemical solution is extruded to produce continuous filaments, as of poly propylene, nylon or polyester. Multiple fiber filaments form a continuous bundle tow.

The sliver can also be made via a carding process, which forms a lightly coiled, puffy strand of fibers can be a product of the fiber combing process. The sliver could be introduced directly from collection barrels to fill the fabric lengthwise, running longi tudinal along bundle channels. The sliver is attached inside of a bundle channel possibly only by friction. Eventually it will be anchored in its place from its longitudi nal ends, when the insulating material is cut and sewn to be a garment. This direct method skips the manufacturing processes, which then simplifies whole process making insulation more economical.

Expending insulation particles can also be extruded to the individual bundle chan nels from nozzles of insulation conduits. Insulation particles can be down or poly meric fiber aggregates for example similar than described in US Patent 5329868.

Quilting fabric with needles is a slow and a labor-intensive process, which has made quilting uneconomical in many parts of the world. The bonding of layers with an adhesive is a process where two or more dissimilar substances are united by mo lecular force acting in the area of contact. This process requires the melting and cooling of adhesive is production which is a time-consuming process. Due to the limited peel strength, the adhesive-bonded seams often determinate when continu ous bending and washing. Laser welding on the other hand is economical and highly productive. Compared to traditional quilting methods by stitching or adhesive bond ing, laser welding could easily multi fold the speed. Increased production would have a remarkable economic impact.

To produce good quality seams using laser welding requires an infra-red absorbing textile, and another textile which does not absorb infra-red radiation. Laser energy percolates through the non-IR absorbing layer of textile and is absorbed by the un derlying IR-absorbing textile. The fabric layers are melted together on a molecular level under pressure from pressure roller. In the laser welding process, the outer surface of the fabric is not affected, only the thin layers of the fabric in interconnec tion is melted. Therefore, the surface or fabric is not affected.

Laser-welded seams do not use additional adhesive in the joint. Laser welding re sults in a joint which has greater flexibility and a softer feel compared to adhesive bonding. The IR-absorbency of the fabric can be reached by having the fabric itself being IR-absorbent. The fabric can also be dyed or printed to be IR-absorbent, or IR-absorbent can be applied to a seam before welding e.g. by spraying. Welding requires equal thermoplastic properties, so therefore e.g. polyester fabric is the most suitable to be welded with polyester; polypropylene with polypropylene; and poly amide with polyamide. Suitable laser welding heads, which can be adopted to use in fabric welding, are developed for example by Leister Technologies AG, CH-6056 Kaegiswil, Switzerland and TWI Ltd, Cambridge, United Kingdom. Alternatively, in other embodiment of the present invention, ultrasonic seaming could be used, how ever that method would melt the seam throughout.

SUMMARY OF THE INVENTION

The present invention describes a novel insulation material where two fabrics form longitudinal bundle channels. The first fabric is substantially flat, the second fabric is wider and having larger surface area in order to form bundle channels for insula tion. The bundle channels are formed between longitudinally running seams from predetermined intervals. The seams are formed by laser welding, ultrasonic weld ing, adhesive bonding, stitching or other means.

The bundle channels are filled with pressurized insulation. Pressure of the insulation inside the bundle channels causes the bundle channels to expand and causes ad jacent bundle channels walls to press against each other and the bundle channels come together to obstruct the passage of air through the material.

The method of producing the 2-layer insulation material comprises the steps of in troduction of the first and the second fabric layer and attaching the fabric layers together with longitudinal seams with predetermined intervals to form a plurality of longitudinal channels. The seams are formed by laser welding, ultrasonic welding, adhesive bonding, stitching or other means. The channels are individually filled with pressurized insulation simultaneously or immediately after forming the longitudinal seams. Pressure of the insulation inside the bundle channels results the bundle channels to expand and causes adjacent bundle channels walls press against each others and the bundle channels come together to obstruct the passage of air through the material.

The arrangement according to the invention is disclosing how to manufacture the insulation material where the fabric is guided through the upper and the lower guide element to the point where they are attached together to form the longitudinal bundle channels. Between the attaching points there are multiplicity of insulation conduits introducing the insulation material individually to each bundle channel. The bundle channels are filled with the insulation material which expands after in troduction causing the bundle channels expand wider to meet the adjacent bundle channel wall and close the gap between the adjacent bundle channels and covering the cold bridge caused by the seam.

In the following the invention is described in more detail.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a perspective view of the insulation material according to an em bodiment of the invention,

Figure 2 shows a side elevational view of an arrangement to produce the insulation material according to an embodiment of the invention,

Figure 3 shows an elevational view of the insulation conduits according to an em bodiment of the invention,

Figure 4a, 4b shows a perspective view of an arrangement to make the 2-layer in sulation according to an embodiment of the invention, and

Figure 5 shows a perspective view of a laser-welded seam according to an embod iment of the invention.

DETAILED DESCRIPTION

Fig. 1 shows a 2-layer insulation material 10 according to an embodiment of the invention. The first fabric layer 12 is attached to the second fabric layer 14 by multi plicity of laser welded seams 18a-18n. The first fabric layer 12 is substantially flat. The second fabric layer 14 form the bundle channels 20a-20n between the parallel running adjacent welded seams 18a-18n. The fabric layer 14 of the bundle channel wall 15 between the adjacent welded seams 18a-18n has enough coverage to ex pand the bundle channel 20a-20n wider than distance between the two adjacent welded seams 18a and 18b and enable to the adjacent bundle channels to connect to each others and close the air gap between the two adjacent bundle channels when the bundle channels are individually filled with the expanding or pressurized insulation material 22. The insulation material 22 can also be pressure packed. The pressure 16 of the insulation material inside of the bundle channel 20 is oriented towards the bundle channel 20 walls 15 of the second fabric layer 14 and the first fabric layer 12. The fabric layer 12 and the fabric layer 14 can be same thickness and weight but also the weight and the material or the material structure can be different. For ex ample, selecting the first fabric layer 12 to be thicker and possibly to have some additional protective features, it could be used as an outer layer of a garment. The second fabric layers 14 can be thinner, softer and resilient to provide comfort for the user.

Fig. 2 shows an elevation view of an arrangement to produce the insulation material according to the embodiment of the invention. The first fabric 12 and the second fabric 14 are running longitudinally to warp direction 27. The first fabric layer 12 is supported by the upper guide elements 32. The second fabric layer 14 is guided and run between the lower guide element 36 and the assisting guide element 34 in order to support the second fabric layer 14 to form the bundle channels 20.

Alternatively, the insulation conduit 42 is acting as an assisting guide element 34 and pressing the second fabric layer 14 against the lower guide element 36.

The second fabric layer 14 runs between the lower guide elements 36 and the con duits 42 and forms a multiplicity fabric loops for a multiplicity of bundle channels 20. The first fabric layer 12 and the second fabric layer 14 are welded together from the seams 18 and simultaneously or immediately after welding the bundle channels 20 are individually filled with the insulation material 22.

The arrangement comprises one or more upper guide elements 32 for the first fabric layer 12, one or more lower guide elements 36 for the second fabric layer 14 and one or more lower guide elements 36 and assisting guide elements 34 guiding fabric layer 14 to the point where the first fabric layer 12 and the second fabric layer 14 are attached by the attaching means 38 for forming the longitudinal bundle channels 20a-20n.

Welding stations 24a-24n have laser welding heads 38 to weld the first fabric layer 12 and the second fabric layer 14 to each others and form the multiplicity of welding seams 18 under pressure 25a and 25b between the pressure rollers 23a-23n and the laser sources 38a-38n.

Depending from the laser welding method the pressure can be formed between the rotary head laser source (in pressure sphere welding) and the anvil roller 23 or be tween the laser beam transparent pressure plate (in mask welding or quasi simulta neous welding) (not shown) above the first fabric layer 12 and the anvil roller 23. Alternatively, ultrasonic welding, adhesive bonding or stitching method can be used to connect the first fabric layer 12 and the second fabric layer 14 from the multiple seams 18.

Fig 3 shows a perspective view of an arrangement according to an embodiment of the invention to make the 2-layer insulation material 10.

The insulation material 22 is individually introduced to the bundle channels 20 through the multiplicity of insulation conduits 42. The insulation material can be for example polyester fiber or hollow fiber filament, which can be pulled inside of the bundle channels by the process flow. The fabric and the ready product are moved on the production line with the motor behind the welding station. Simultaneously, when pulling the fabric through the process the insulation material 22 is pulled through the conduits 42. After releasing from the nozzle 30 the material compressed by the conduit 42 expands and fills the bundle channel 20.

Alternatively, insulation can also be down, lose synthetic insulation balls or particles which are pressed inside of the bundle channels 20 by pressurized air from the conduits 42 or the piston (not shown) simultaneously or intermediately after forming the bundle channels 20.

Next the used terms are discussed more closely to open the used terms and used language.

Pressure ball

In preferred embodiment the pressure can be applied through the laser light trans parent sphere which can be supported by an air bearing which enables a frictionless rotation. The advantage of employing the roller or the sphere instead of the plate is having less friction and therefore less heat between the pressure means and the fabric when the fabric is moved thorough the welding station.

For example, in the laser welding Rotating Globo welding head produced by Leister Technologies AG of Switzerland can be used. In the Globo welding a laser beam is focused at a point on the joining plane through a freely rotating glass sphere. The glass sphere rolls along the fabric and provides a continuous pressure to the point of welding. The rotating glass sphere opposes a rotating support on the reverse side of the first fabrid 2 and the second fabric 14. In other embodiments of the invention the pressure can be applied to the fabric with different methods, such as:

Pressure roller

In one embodiment the pressure can be applied by a laser beam transparent glass ball roller. When using pressure ball or pressure roller upper guide element 32 and lower guide element have respective opening 33 for upper rotational laser source 38 and lower guide element have opening 35 for pressure roller 23.

Pressure plates

In one embodiment the fusible fabric layers, 12 and 14 are passing through and pressed between the pressure roller 23 (Fig. 3) and the IR-transparent pressure plate (not shown). Laser light is applied to the welding positions through the laser light transparent pressure plates.

The pressure for the welding stations can be produced mechanically, or as an alter native, hydro statically or pneumatically either blowing positive pressure or by suc tion.

The function, the design, the use and the mode of operation of the pressure forming, have already been disclosed in a variety of publications of the prior art with respect to the laser transmission welding method, which is known per se, and are therefore common knowledge to the person skilled in the art, such they need not be described in more detail here. Different pressure sources in context of laser welding are de scribed for example in US patent application US 2014/0363636 A1 for Leister Tech nologies AG.

Scanner welding

In scanner welding the beam guidance is performed by using mobile mirrors in cluded to the laser source 38. The laser beam is directed by changing the angles of the mirrors. The beam continuously scans the welding areas 18a-18n at very high speed. The fabrics passing through the welding areas will be melted and fused from the joint areas quasi-simultaneously manner. Mask welding

Mask welding method utilizes wide beams that moves over the entire surface being welded. Mask shields are protecting areas where the welding is not desired. The predetermined welding seam areas 18a-18n will be melted and fused. The function, the design, the use and the mode of operation of mask welding, dif fractive welding and scanner welding have already been disclosed in a variety of publications of the prior art with respect to the laser transmission welding method, which is known per se, and are therefore common knowledge to the person skilled in the art, such they need not be described in more detail here. Ultrasonic welding

In one alternative embodiment the ultrasonic welding can be done efficiently without friction by a rotating discoidal sonotrode horn. The rotating sonotrode opposes the rotating support pressure rollers 23 to form the needed pressure between the weld able fabrics. The discoidal sonotrode and the pressure roller 23 are running friction- less on the bearings on the both side of the welded fabrics. The ultrasonic vibration created by the sonotrode heats the first fabric 12 and the second fabric 14 which are fused together with vibrational energy under the pressure between the sono trode and the pressure roller 23.

When using pressure ball or pressure roller upper guide element 32 and lower guide element have respective opening 33 for upper discoidal sonotrone horn and lower guide element have opening 35 for pressure roller 23.

Welding, either by laser or ultrasonic method, can be done on the first fabric side, but also on the second fabric side.

Fig. 4a and Fig. 4b show an elevational view of the insulation conduits material ac- cording to an embodiment of the invention. In Figure 4a an insulation material tow 22 is compressed to an insulation conduit 42. Simultaneously, or right after forming of the bundle channel, the insulation is released from the nozzle 30 to the bundle channel 20 and expands to fill the channel. The expanded insulation material presses against the bundle channel wall 15. When the bundle channel 20 expands, it meets the adjacent bundle channel wall and closes the air gap between the bundle channels. In figure 4b the plurality of insulation particles 29 e.g. down or synthetic insulation balls are compressed through the insulation conduits 42 e.g. by the air or by the piston (not shown). When the particles 29 are released from the nozzle 30 they are expanding, occupying the bundle channel 20 and creating the pressure 16 against the bundle channel walls 15. The pressure causes the bundle channel to expand and reach the adjacent bundle channel.

Fig. 5 shows a laser-welded seam according to an embodiment of the invention, where the fabric layer 12 is percolating IR radiation, and where the IR absorbent middle layer of the fabric 14 is applied and absorbed with IR radiation 40, then heated, melted and pressed together with pressure the 25a and 25b. A controlled amount of heat is applied to the fabric joint. Laser energy passes through the IR percolating fabric layer 12, heats the surface of IR-absorbent fabric layer 14, melts the surface of the layer 14, and seals the interface area together under the pressure 25, hence forming a welded seam 18, when the fabric is moved to direction 27. The pressure is forced between the pressure rollers 23 (Fig 2 and 3) and the laser beam transparent welding sphere 38 (Fig. 3), or alternatively the transparent pressure plate (not shown).

These presented embodiments are in no way restricting the scope of the invention and the scope of the invention is defined in the following set of claims.

LIST OF REFERENCE NUMERALS

10 insulation material

12 first fabric layer

14 second fabric layer

15 bundle channel wall

16 pressure against the second fabric layer 18a-18n welding seams (lengthwise connections) 20a-20n bundle channels

22 insulation material

23a-23n pressure rollers, (i.e. anvils)

24a-24n welding stations

25a-25b pressure

26 rotation direction

27 welding / fabric running direction

28 fiber tow

29 insulation particles

30 nozzle

32 upper guide element (i.e. support plate)

33 opening in upper guide element

34 assisting guide element

35 opening in lower guide element

36 lower guide element

38a-38n laser source 40 IR radiation

42a-42n multiplicities of insulation conduits