High performance fibers composite sheet

Pending Publication Date: 2022-10-27
AVIENT PROTECTIVE MATERIALS BV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention provides composite sheets that can be used to make more robust and high-quality panels. These sheets can be stacked and compression molded with greater accuracy and consistency as compared to existing sheets. The resulting panels also show less gaseous inclusions and are less likely to have a negative impact on the human skull and brain after being hit by a stopped projectile. Overall, the invention improves the production process for composite panels and increases their quality.

Problems solved by technology

It was observed that typically improved generations of ballistic sheets become more demanding on handling and process control during the manufacture of molded ballistic resistant articles made therefrom, requiring amongst others long and accurately followed compression processes.
Typical quality issues encountered during manufacturing of molded ballistic resistant articles are displacement of sheets during the process or the presence of undesired bubbles in the molded article immediately or days after manufacturing.
Such imperfections in the molded articles represent aesthetic but also performance defects.

Method used

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  • High performance fibers composite sheet
  • High performance fibers composite sheet
  • High performance fibers composite sheet

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0076]Comparative Experiment A was repeated with the difference that a 28 wt % aqueous dispersion of an ethylene acrylic acid copolymer was used to impregnate the monolayers. The copolymer had an acrylic acid content of about 30 wt % and a melt flow index of >200 g / 10 min (21.6 kg, 190° C.). The EAA copolymer had a melting peak at 78° C., a heat of fusion of 29 J / g, and a modulus by DMTA of 280 MPa and 2 was obtained.

example 2

[0077]Comparative Experiment A was repeated with the difference that a 25 wt % aqueous dispersion of a neutralized ethylene acrylic acid copolymer was used. The acrylic acid level of the copolymer was about 10 wt % whereby the neutralization of the carboxylic acid exceeded 98% and consisted of about 17 mol % ammonia and 83 mol % potassium counter ions. The melt flow index of the dried neutralized copolymer was 4.5 g / 10 min (21.6 kg, 190° C.). The neutralized copolymer had a peak melting temperature at 85° C. a modulus by DMTA of 150 MPa and 0.7 MPA at 25° C. and 110° C. respectively. A composite sheet with a matrix content of about 13 wt % and an areal density of about 126 g / m2 was obtained.

[0078]Rectangular samples (10 cm×30 cm) of all above composite sheets where cut with the fiber orientation in the −45 / +45° direction of said rectangular samples. The samples were tested for in-plane shear properties according to ASTM D3518-94. The respective data are reported in Table 1.

TABLE 1No...

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PUM

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Abstract

Composite sheets include at least two adjacent fibrous monolayers of unidirectionally aligned high tenacity polyethylene fibers, whereby the direction of orientation between the polyethylene fibers of said two fibrous layers differs by at least 80° and up to 90°, the fibers having a tenacity of at least 1.5 N / tex, the fibers being in a matrix comprising a homopolymer or copolymer of ethylene and wherein the homopolymer or copolymer of ethylene has a density as measured according to ISO1183 of between 870 to 980 kg / m3. The composite sheets have an areal density of between 50 and 500 g / m2, wherein the composite sheets have an areal density normalized in-plane shear force measured at 25° C. evaluated according to a bias extension test method variant of ASTM D3518 of at least 0.40 N·m2·g−1 and lower than 5.0 N·m2·g−1 at 10 mm clamp displacement and an areal density normalized in-plane shear force measured at 110° C. and clamp displacement of 10 mm of at least 0.01 N·m2·g−1 and lower than 0.20 N·m2·g−1.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. application Ser. No. 16 / 956,094 filed on Jun. 19, 2020 (now U.S. Pat. No. ______), which in turn is the U.S. national phase of International Application No. PCT / EP2018 / 085264 filed Dec. 17, 2018 which designated the U.S. and claims priority to U.S. Provisional Patent Application No. 62 / 609,655 filed Dec. 22, 2017, and EP Patent Application No. 18153429.8 filed Jan. 25, 2018, the entire contents of each such prior filed application being expressly incorporated herein by reference.FIELD[0002]The present invention concerns a composite sheet comprising high tenacity polyethylene fibers and a polymeric resin, a ballistic resistant article comprising such a composite sheet and a method for producing such a composite sheet. These composite sheets are amongst others especially adapted to facilitate the manufacture of ballistic resistant articles, amongst which molded ballistic articles for example for ve...

Claims

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Application Information

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IPC IPC(8): B32B5/26B32B5/12C08F210/02F41H5/04B32B27/12B32B27/32
CPCB32B5/26B32B5/12C08F210/02F41H5/0485B32B27/12B32B27/32B32B2260/023B32B2260/046B32B2262/0253B32B2571/02B32B2307/72B32B2307/542B32B2307/546B32B2307/734B32B2307/718F41H1/08F41H5/04B32B2262/101B32B2262/0261B32B27/36B32B2262/0284B32B2262/0269B32B5/022B32B27/08B32B27/365B32B2262/106B32B2262/0223B32B5/28
InventorVAN ELBURG, JOHANNVAN DER WERFF, HARMMARISSEN, ROELOFHEISSERER, ULRICHPEREZ GRATEROL, RAUL MARCELINO
OwnerAVIENT PROTECTIVE MATERIALS BV