Coextruded Polyolefin Foam With KEE Cap Layer
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Solution Overview
Problem
The existing methods for achieving satisfactory adhesion between polyolefin foam and polyvinyl chloride (PVC) require surface modification treatments like corona, plasma, or chemicals, which are costly and may not be stable over time, especially when stored for extended periods.
Innovation Solution
Coextruding a polyolefin foam layer with a ketone-ethylene-ester (KEE) terpolymer cap layer, which is highly compatible with PVC, allowing for direct heat bonding without the need for surface treatments or adhesives, thereby eliminating the need for additional processing steps and ensuring long-term adhesion stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If surface modification treatment (corona, plasma, or chemical) is applied to polyolefin foam, then adhesion to PVC is improved, but processing complexity and cost increase
Solution Approach 1:
The patent combines the foam core material and adhesion-promoting cap layer into a single coextruded product. The cap layer containing polar groups (carboxyl, hydroxyl, or amine groups) is integrated directly with the polyolefin foam during the extrusion process, eliminating the need for separate surface modification treatments and adhesive applications.
Solution Approach 2:
The adhesion-promoting cap layer is incorporated into the foam structure during manufacturing, before the product reaches the end user. This preliminary inclusion of adhesion functionality ensures that no additional surface treatment or adhesive application is needed at the time of installation or bonding to PVC.
2Strength
If corona treatment is applied to polyolefin foam surface, then adhesion is improved, but adhesion stability deteriorates over time
Solution Approach 1:
The patent creates a composite structure where a cap layer with polar groups (carboxyl, hydroxyl, or amine groups) is bonded to the polyolefin foam core. This composite design provides both the adhesion strength needed for PVC bonding and the long-term stability required for durable applications, as the polar groups in the cap layer maintain their adhesion properties over time.
3Strength
If adhesion primer and adhesive are applied to surface modified foam, then adhesion is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges the functions of the foam core, adhesion promoter, and bonding interface into a single coextruded product. The cap layer containing polar groups serves both as part of the structural foam and as the adhesion-promoting surface, eliminating the need for separate primer and adhesive materials and their associated application processes.
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 KEE cap layer enables reliable bonding to PVC without surface treatments, reducing costs and maintaining adhesion over time, even when stored for extended periods, thus enhancing the economic viability and performance of polyolefin foam applications.
Implementation Method 1
a coextruded polyolefin foam with a KEE cap layer is expected to readily heat bond to PVC without the need for a surface treatment, a primer, and/or an adhesive
Implementation Method 2
a physically crosslinked, closed cell continuous multilayer foam structure comprising a KEE cap layer
Data Source
AI summary
The present disclosure is directed to a physically crosslinked, closed cell continuous multilayer foam structure comprising at least one foam polypropylene/polyethylene layer with a KEE cap layer. The multilayer foam structure can be obtained by coextruding a multilayer structure comprising at least one foam layer composition layer with at least one cap layer composition layer, irradiating the coextruded structure with ionizing radiation, and continuously foaming the irradiated structure.