Curl-Resistant PSA Tape for Recyclable Resealable Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing resealable packaging solutions face challenges with curling issues when the pressure-sensitive adhesive tape is repeatedly strained, leading to compromised sealing integrity, and most solutions are not recyclable, making them unsuitable for retail recycling programs.
Innovation Solution
A curl-resistant, polyethylene-based pressure-sensitive adhesive tape is developed, compatible with the packaging material, featuring a machine-direction-oriented film structure with a specific blend of metallocene LLDPE and HDPE, and a non-adhesive grip strip, which minimizes curling and ensures recyclability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional pressure-sensitive adhesive tape is used for resealable packaging, then the package allows repeated opening and closing, but the tape curls significantly after repetitive strain, compromising sealing integrity
Solution Approach 1:
The patent changes the physical and chemical parameters of the tape material by using a specific blend of metallocene LLDPE and HDPE polymers with controlled molecular weight distributions. This parameter change reduces the tape's curling tendency while maintaining its adhesive properties and resealability functionality.
Solution Approach 2:
The patent employs a composite material system combining metallocene LLDPE and HDPE polymers in specific ratios. This composite approach leverages the complementary properties of each polymer to achieve reduced curling while maintaining adhesive performance and recyclability.
2Reliability
If non-polyethylene materials are used for PSA tape, then the tape provides adequate adhesive performance, but the package cannot be recycled in polyethylene streams
Solution Approach 1:
The patent uses polyethylene-based materials for the tape that are homogeneous with the polyethylene packaging material. This homogeneity ensures that the tape can be recycled together with the package in polyethylene streams without contaminating the recycle stream or requiring separate processing.
Solution Approach 2:
The patent modifies the material composition parameters to use polyethylene-based polymers instead of conventional non-recyclable materials. This parameter change maintains adhesive performance while enabling recyclability in polyethylene streams.
3Object-generated harmful factors
If the tape is made from multilayer polyethylene films, then the package becomes recyclable, but the tape exhibits significant curling when strained
Solution Approach 1:
The patent changes the material parameters by using specific blends of metallocene LLDPE and HDPE with controlled molecular weight distributions. This parameter modification achieves both recyclability and reduced curling, resolving the contradiction between these two properties.
Solution Approach 2:
The patent creates a composite polyethylene material system that combines the recyclability of polyethylene with the curl resistance provided by specific polymer blends. This composite approach allows both requirements to be satisfied simultaneously.
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 effectively reduces curling by less than 10% and maintains sealing integrity, allowing the entire package to be recycled, as it is compatible with polyethylene-based materials, thus meeting recyclability standards.
Implementation Method 1
pressure-sensitive adhesion tape ('PSA tape') that covers an opening
Implementation Method 2
The PSA tape resists curling when it is strained by pulling it away from the first panel to unseal the slit
Data Source
AI summary
A flexible package formed from a film of polymer packaging material having a first and second panels sealed at a top portion and a bottom portion, an elongate slit in the first panel, and an elongate strip of pressure-sensitive-adhesion, re-closing tape (“PSA tape strip”) applied to the surface of said first panel over the slit. The PSA tape strip has an adhesive edge portion abridging and releasably sealing the slit and a non-adhesive edge portion arranged on one side of said slit and lying against the first panel. The PSA tape strip is adapted so that the slit can be unsealed by gripping the non-adhesive edge portion and pulling the PSA tape strip away from the first panel until the adhesive edge portion no longer abridges the slit. The PSA tape strip comprises a base material of polymer film that is compatibly recyclable with said packaging material The PSA tape strip also resists curling when it is strained by pulling it away from said first panel to unseal the slit. Preferably, the PSA tape has secant modulus ratio (machine direction to cross direction) greater than 90%.