HPPE Composite Sheet Resin Optimization for Ballistic Rigidity

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Solution Overview

Problem

Existing composite materials for ballistic-resistant articles face challenges in reducing back face deformation, improving bullet stopping characteristics, and maintaining rigidity, especially at elevated temperatures, while also requiring more environmentally friendly and efficient manufacturing processes.

Innovation Solution

A composite sheet comprising unidirectionally aligned high performance polyethylene fibers and a polymeric resin with specific density and melting temperature ranges, manufactured using an aqueous suspension application method that reduces environmental impact and enhances delamination resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional polymeric resins are used in composite sheets, then bullet stopping ability is achieved, but back face deformation increases and rigidity decreases at elevated temperatures

Engineering Contradiction:
Improvebullet stopping abilityVSAvoidrigidity at elevated temperatures
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The patent applies parameter changes by selecting a polymeric resin with a specific melting temperature range (115-140°C) and density range (930-980 kg/m³). This optimized parameter selection allows the resin to maintain appropriate rigidity at elevated temperatures while still providing effective bullet stopping ability, resolving the contradiction between strength and temperature-dependent rigidity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining high performance polyethylene fibers with a specifically selected polymeric resin matrix. This composite structure leverages the high strength and ballistic resistance of the fibers while the optimized resin provides thermal stability and rigidity at elevated temperatures, achieving both bullet stopping ability and temperature-resistant rigidity simultaneously.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If organic solvent-based resin application methods are used, then resin coating is effective, but environmental impact increases due to emissions and energy consumption

Engineering Contradiction:
Improveresin coating effectivenessVSAvoidorganic solvent emissions
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent applies the extraction principle by removing organic solvents from the resin application process entirely. By using a solvent-free polymeric resin system, the method eliminates harmful organic solvent emissions while maintaining effective resin coating and bonding, thus resolving the contradiction between manufacturing effectiveness and environmental impact.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the potential harm of requiring solvent-based application into a benefit by developing a solvent-free resin system. This approach not only eliminates environmental pollution from solvent emissions but also simplifies the manufacturing process, reduces energy consumption for solvent evaporation, and improves worker safety, turning a harmful necessity into an advantageous solution.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The composite sheet exhibits improved delamination behavior, reduced back face deformation, and increased rigidity at elevated temperatures, effectively addressing the limitations of existing materials in ballistic-resistant applications.

Implementation Method 1

a composite sheet comprising unidirectionally aligned high performance polyethylene (HPPE) fibers and a polymeric resin

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

applying an aqueous suspension of the polymeric resin to the HPPE fibers before, during or after assembling; at least partially drying the aqueous suspension of the polymeric resin applied in step c)

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

said polymeric resin has a density as measured according to ISO1183 of between 930 and 980 kg/m3, and a peak melting temperature of from 115 to 140° C.

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentUS11661485B2High performance fibers composite sheet
Publication Date: 2023.05.30 AVIENT PROTECTIVE MATERIALS BV

AI summary

The invention relates to a composite sheet, and a ballistic resistant article, comprising unidirectionally aligned high performance polyethylene (HPPE) fibers and a polymeric resin, wherein said polymeric resin comprises a homopolymer or copolymer of ethylene and wherein said polymeric resin has a density as measured according to ISO1183 of between 930 and 980 kg/m3, and a peak melting temperature of from 115 to 140° C.; and said polymeric resin is present in an amount of from 5 to 25% by weight based on the total weight of the composite sheet. It further relates to a method for manufacturing a composite sheet comprising assembling HPPE fibers to a sheet, applying an aqueous suspension of a polymeric resin to the HPPE fibers, partially drying the aqueous suspension, optionally applying a temperature and/or a pressure treatment to the composite sheet.