MULTILAYER COMPOSITE COMPRISING A BACKBONE FILM

Abstract

The present invention relates to a multilayer composite comprising a first monolayer comprising high-performance fibers, aligned in a first direction and a first matrix material and a second monolayer comprising high-performance fibers, aligned in a second direction and a second matrix material and a third polymeric film located in between the first and the second monolayer, with the third polymeric film having a tensile modulus of at least 0.75 GPa measured by ASTM D882. Preferably the high-performance fibers comprise UHMWPE fibers. A thermoplastic polyurethane is in contact with the first monolayer to form a first outer layer of the composite and in contact with the second monolayer to form a second outer layer of the composite, opposite to the first outer layer. The present invention further relates to the use of the multilayer composite in backpacks, packs, bags, medical gear, outdoor products, sail cloths, tents, tarps, shelters, clothing, ponchos, foul weather gear, mats, outerwear, jackets, sleeping bags, lift bags, parachutes, large kites, inflatable structures, beams, balloons, backraft, inflatable gear, liferaft, inflatable sculptures, airship (HAA: High Altitude Airships), space applications, flexible circuits, footwear and umbrella's.

Claims

1. A multilayer composite comprising: a first monolayer comprising high-performance fibers, aligned in a first direction and a first matrix material and a second monolayer comprising high-performance fibers, aligned in a second direction and a second matrix material and an inner polymeric film located in between the first and the second monolayer, with the inner polymeric film having a tensile modulus of at least 0.75 GPa measured by ASTM D882.

2. Multilayer composite according to claim 1 wherein the second fiber direction is offset relative to the first fiber direction by up to 90 degrees.

3. Multilayer composite according to claim 1 wherein the high-performance fibers comprise polyethylene fibers.

4. Multilayer composite according to claim 3 wherein the high-performance fibers comprise UHMWPE fibers.

5. Multilayer composite according to claim 1, wherein the inner polymeric film has a thickness from 1 μm-100 μm.

6. Multilayer composite according to claim 1 wherein the inner polymeric film is chosen from the group consisting of a polyester, polyethylene, polyamide or polyvinyl fluoride.

7. Multilayer composite according to claim 6 wherein the inner polymeric film is chosen from polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or polyethylene naphtalate (PEN).

8. Multilayer composite according to claim 1 wherein the inner polymeric film is in the form of a woven or non-woven fabric.

9. Multilayer composite according to claim 1 wherein the inner polymeric film is a waterproof and/or (non)-breathable film.

10. A multilayer composite according to claim 1 wherein at least one matrix material is chosen form the group of polyacrylates, polyurethanes, polyesters, silicones, polyolefins, modified polyolefins, ethylene copolymers, polyamide, polypropylene.

11. A multilayer composite according to claim 10 wherein the first and second matrix material comprise polyurethane.

12. Multilayer composite according to claim 1 wherein the first monolayer optionally comprises a first polymeric film and the second monolayer optionally comprises a second polymeric film.

13. Multilayer composite according to claim 12 wherein the first polymeric film is in contact with the first monolayer to form a first outer layer of the composite and wherein the second polymeric film is in contact with the second monolayer to form a second outer layer of the composite, opposite to the first outer layer.

14. Multilayer composite according to claim 12 wherein the first and second polymeric film is chosen from polyurethane.

15. Use of the multilayer composite of claim 1 in backpacks, packs, bags, medical gear, outdoor products, sail cloths, tents, tarps, shelters, clothing, ponchos, foul weather gear, mats, outerwear, jackets, sleeping bags, lift bags, parachutes, large kites, inflatable structures, beams, balloons, backraft, inflatable gear, liferaft, inflatable sculptures, airship (HAA: High Altitude Airships), space applications, flexible circuits, footwear, sports apparel, luggage; leather goods, jackets, wallets, purses, upholstery, gloves.

Description

EXAMPLES

[0040] A composite laminate is manufactured comprising a first monolayer comprising high performance fibers (ultra-high molecular weight polyethylene (UHMWPE)) in a polyurethane (PUR) matrix oriented in a 0° direction and a second monolayer comprising UHMWPE fibers in a PUR matrix oriented in a 90° direction with an inner polymeric film in between the first and second monolayer of high performance fibers, further optionally comprising a first outer polymeric film on top laminate surface and an identical second polymeric film on the bottom laminate surface. The composite is cut into target 1 inch width strips and 26 inches length, with the length running parallel to the 0° direction. The actual width of each sample is measured and recorded. Each lengthwise end of the sample is gripped by bollard style grips, with a resulting gage length of the test sample of 10 inches. The sample is pre-tensioned to 5% of the expected laminate failure load by a mechanical test frame. The sample is tested for tensile strength at a constant rate of extension of 3 inches/minute until sample failure. The maximum tensile load of the sample during the duration of the test is recorded and divided by the width of the sample to determine a tensile strength in terms of Load/Width.

From table 1 it is clear that there is a balance between the inner polymeric film thickness, weight, and modulus.
In table 2 comparatives are presented; multilayer composites without inner or backbone film.

TABLE-US-00001 TABLE 1 First and Inner second Film % Increase % First and monolayer Thickness Mean TSTensile Increase second with fiber UHMW Inner Film in mil Tensile Laminate Strength vs Weight outer film orientation PE Fiber Inner Modulus (1 mil = 25. Strength Weight Standard (no vs degrees Type film (GPa) 4 μm) (lbf/in) (gsm) backbone) Standard 1.TPU/TPU 0/90 SK75 PEN 12.2 0.08 191.63 119.92 2.74 2.29 2.TPU/TPU 0/90 2640 PEN 12.2 0.16 237.10 122.60 27.12 4.57 3.TPU/TPU 0/90 dtex PEN 12.2 0.24 254.03 125.27 36.19 6.85 4.TPU/TPU 0/90 PET 4.5 0.18 222.48 123.52 19.28 5.36 5.TPU/TPU 0/90 Perforated 4.5 0.18 223.17 123.52 19.65 5.36 PET 6.TPU/TPU 0/90 Tedlar 2.6 1.5 252.47 172.44 35.36 47.08 7.N/A 0/90 SK99 PET 4.5 0.18 689.10 73.95 28.04 9.27 dtex 8.N/A 0/90 880 PET 4.5 0.18 661.10 73.95 22.83 9.27 TPU= thermoplastic polyurethane PEN= polyethylene naphtalate PET= polyethylene terephthalate Tedlar= polyvinylfluoride

TABLE-US-00002 TABLE 2 Comparative experiments First Mean and Fiber Tensile Laminate second reinforcem UHMWPE Inner Strength Weight Film orientation Fiber Type Matrix film (lbf/in) (gsm) I TPU/ 0/90 SK75 2640 PUR None 186.52 117.24 TPU dtex II N/A 0/90 SK99 880 PUR None 538.21  67.68 dtex