Crosslinked Polyolefin Foam Sheet Balancing Softness and Shear Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing crosslinked olefin foams often sacrifice one desired property (softness, haptics, moldability, thermal stability, or shear strength) for another, failing to achieve a balance that is essential for various commercial applications, particularly in automotive, furniture, and adhesive industries.
Innovation Solution
A foam composition comprising 15-75 parts by weight of olefin block copolymer with controlled block sequence, 25-85 parts by weight of polypropylene-based polymer, and crosslinks formed from divinylbenzene, blended and crosslinked to achieve a balance of softness, haptics, moldability, thermal stability, and exceptional shear strength, with specific properties such as compressive strength, durometer hardness, haptic factor, and shear strength across varying temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the foam is made softer to improve comfort and haptics, then the initial resistance increases and thermal stability decreases
Solution Approach 1:
The patent applies parameter changes by carefully controlling the crosslinking degree (20-75%) and using specific olefin block copolymer compositions with controlled block sequences. This allows the foam to achieve softness and good haptics while maintaining thermal stability through optimized chemical structure and crosslinking parameters.
Solution Approach 2:
The patent uses composite materials by combining olefin block copolymer with controlled block sequence and polypropylene-based materials in specific weight ratios (15-75 parts OBC to 25-85 parts polypropylene). This composite structure enables the foam to simultaneously achieve softness, haptics, and thermal stability that neither material could provide alone.
2Ease of operation
If the foam is made softer to improve comfort, then the shear strength decreases
Solution Approach 1:
The patent resolves this contradiction by changing the crosslinking parameter to a specific degree (20-75%), which allows the foam to remain soft while developing sufficient shear strength through the crosslinked network structure.
Solution Approach 2:
The combination of olefin block copolymer and polypropylene-based materials in specific proportions creates a composite structure where the softer OBC provides comfort and the crosslinked network provides shear strength.
3Ease of manufacture
If the foam is made more moldable to form complex shapes, then the thermal stability decreases
Solution Approach 1:
The patent achieves both moldability and thermal stability by controlling the crosslinking degree (20-75%) and using olefin block copolymer with specific block sequences. The controlled crosslinking provides thermal stability while the polymer structure maintains moldability.
Solution Approach 2:
The composite of olefin block copolymer and polypropylene-based materials provides complementary properties: the OBC contributes to moldability and the crosslinked structure contributes to thermal stability.
4Temperature
If crosslinking is increased to improve thermal stability, then the softness and haptics deteriorate
Solution Approach 1:
The patent optimizes the crosslinking degree parameter to a specific range (20-75%) rather than maximizing it. This controlled parameter change ensures thermal stability is achieved while softness and haptics are preserved.
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 provides a foam with enhanced softness, haptics, moldability, thermal stability, and exceptional shear strength, allowing for complex shape formation and deep draws without compromising on any single property, thus expanding its commercial applications and usability.
Implementation Method 1
crosslinks to a crosslinking degree of about 20 to about 75%
Implementation Method 2
closed cells; wherein the density of the foam composition is about 20 to about 250 kg/m3
Data Source
AI summary
A crosslinked, closed cell polyolefin foam sheet has exceptional softness, haptics, moldability, thermal stability and shear strength as well as a laminate and uses thereof.