Solventless Extrusion Release Layers for Duct Tape
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional duct tapes with melt blown polyethylene films lack effective release materials, leading to high unwind forces due to aggressive adhesives and poor adhesion levels, while solvent-based release coatings pose environmental concerns and require additional steps.
Innovation Solution
A single-step extrusion process using alkyl dimethicone compositions combined with polyolefins to form release layers without post-treatments, ensuring tailored release forces and preventing material transfer to adhesives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If low molecular weight release materials (e.g., waxes) are used in melt blown polyethylene films, then unwind forces are reduced, but the release material transfers to the adhesive surface when the tape roll is unwound, resulting in reduced adhesion levels
Solution Approach 1:
The patent changes the molecular weight parameter of the release material from low (waxes) to high (polymer-grade release composition), and changes the chemical composition parameter by using a polymer matrix with dispersed release agents. This resolves the contradiction by providing sufficient release capability through the polymer structure while preventing transfer to the adhesive surface.
2Reliability
If solvent-based release coatings are used, then release properties are achieved, but additional coating steps are required and volatile organic compounds (VOCs) must be used
Solution Approach 1:
The patent combines the release function with the backing film manufacturing process itself. The release composition is incorporated into the melt blown polyethylene film during extrusion, merging the release layer application with the backing film formation into a single integrated process, thereby eliminating separate coating steps and VOC usage.
3Device complexity
If no release material is used in melt blown polyethylene films, then the film structure remains simple, but unwind forces become extremely high due to aggressive pressure sensitive adhesive
Solution Approach 1:
The patent creates a composite material structure within the backing film by incorporating a polymer-grade release composition (containing release agents like erucic acid, oleic acid, and metal soaps) into the polyethylene matrix. This composite structure provides the necessary release capability to reduce unwind forces while maintaining film integrity.
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 process provides stable, efficient release layers with customizable release forces and maintains adhesive properties, eliminating the need for solvent coatings and additional additives, thus enhancing tape unwinding and adhesion performance.
Implementation Method 1
the release material is mixed with an extrudable polymer to form a release layer... the blend must be post-treated, for example by heating the coated substrate for a period of 20 minutes, to cause the silicone to 'bleed' to the surface
Implementation Method 2
combining polyolefins with alkyl dimethicones... in a single step extrusion process
Data Source
AI summary
Described herein are release layers formed via solventless extrusion. The release layers include a polyolefin and an alkyl dimethicone. The release layers exhibit tailorable release properties from pressure-sensitive adhesives. The release layers are simple to make and require no post-treatment in order to impart the observed release properties. The release layers are adaptable to multilayer extrusion, blown film formation, and cast film formation techniques.