Multilayered Polymer Sheet for Ballistic Resistance

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Solution Overview

Problem

Existing multilayered material sheets for ballistic resistance, composed of ultra-high molecular weight polyethylene, suffer from non-uniform areal density and antiballistic performance due to overlapping tape edges, which complicates production and reduces effectiveness.

Innovation Solution

A multilayered material sheet with unidirectional monolayers of drawn polymer, where adjacent tapes do not overlap and have no elevated thickness along their longitudinal edges, allowing for a more homogeneous stack and improved ballistic properties, using polymers like polyolefins and polyamides, and produced through processes involving compression-moulding and uniaxial drawing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If tapes are positioned adjacent to each other with overlaps to form monolayers, then the monolayers can be produced and consolidated into multilayered material sheets, but the areal density becomes non-uniform and antiballistic performance is reduced

Engineering Contradiction:
Improveuniformity of areal densityVSAvoidproduction complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention removes the overlapping portions of adjacent tapes during the consolidation process, extracting the harmful elevated thickness areas that cause non-uniform areal density. This extraction principle directly addresses the contradiction by eliminating the defect (overlaps) while maintaining the structural integrity of the monolayers and their ability to be consolidated into multilayered sheets.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If overlaps are used to join adjacent tapes, then monolayers can be formed, but zones of increased areal density are created that reduce antiballistic performance

Engineering Contradiction:
Improveantiballistic performanceVSAvoidthickness uniformity
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The invention converts the potentially harmful overlaps into a beneficial process feature by deliberately creating controlled overlaps during tape positioning, then removing them in a subsequent consolidation step. This approach transforms what would normally be a manufacturing defect into a deliberate intermediate state that enables the final uniform thickness and improved antiballistic performance.

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

3Productivity

If tapes are positioned with gaps between them to simplify production, then production speed increases, but the monolayer coverage becomes non-uniform

Engineering Contradiction:
Improveproduction speedVSAvoidmonolayer coverage uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention applies preliminary action by positioning tapes with intentional gaps during the high-speed production phase, then subsequently filling or consolidating these gaps in a later step. This allows the initial taping process to proceed at high speed without compromising the final uniformity of coverage, as the gaps are addressed in a controlled subsequent operation.

Inventive Principle:
Principle #10Preliminary action

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 solution results in a more homogeneous antiballistic performance with improved resistance to ballistic threats at a lower weight, using less expensive materials and simplifying production, while maintaining or exceeding the performance of previous materials.

Implementation Method 1

a multilayered material sheet comprising a consolidated stack of unidirectional monolayers of drawn polymer

Methodology Applied
Scientific EffectPolymer drawing: Deformation

Implementation Method 2

the monolayers to be more readily stacked and compressed into a multilayered material sheet with uniform areal density

Methodology Applied
Scientific EffectCompression-moulding: Compression

Data Source

PatentEP2711661B1Multilayered material sheet and process for its preparation
Publication Date: 2018.10.10 DSM IP ASSETS BV
  • EP2711661B1 patent drawingFigure 1
  • EP2711661B1 patent drawingFigure 2
  • EP2711661B1 patent drawingFigure 3

AI summary

The invention relates to a multilayered material sheet comprising a consolidated stack of unidirectional monolayers of drawn polymer, whereby the draw direction of two subsequent monolayers in the stack differs. At least one monolayer comprises a plurality of unidirectional tapes of the drawn polymer, aligned in the same direction, whereby adjacent tapes do not overlap. The invention also relates to a process for the preparation of the multilayered material sheet, and to a ballistic resistant article comprising the multilayered material sheet.