Water-based Hot Melt Adhesive for Healthcare Packaging

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Solution Overview

Problem

Existing hot-melt adhesives for healthcare device packaging often provide excessive seal strength, leading to fiber tear when peeling open the packaging, which can contaminate the devices, and require complex multi-step preparation processes.

Innovation Solution

A water-based hot-melt adhesive comprising 100 weight parts of water-base polyolefin resin, 40 weight parts to 85 weight parts of wax particles, and 25 weight parts to 85 weight parts of tackifier particles, which forms a coating layer on medical polyolefin spunbonded nonwoven fabric for heat sealing, providing sufficient gas-permeability, seal strength, and peelability without the need for a blending step.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional hot-melt adhesive is used to provide sufficient seal strength, then the packaging seal strength is improved, but fiber tear occurs when peeling open the packaging causing contamination

Engineering Contradiction:
Improveseal strengthVSAvoidfiber tear contamination
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the adhesive by incorporating specific ratios of polyolefin resin (60-85 wt%), wax (10-30 wt%), and tackifier (5-20 wt%), along with controlling adhesive thickness (5-20 micrometers). These parameter changes optimize the balance between seal strength and peelability, allowing the adhesive to provide sufficient sealing force while cleanly splitting upon peeling to prevent fiber tear contamination.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If complex multi-step preparation process is used to prepare hot-melt adhesive, then adhesive performance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveadhesive performanceVSAvoidpreparation process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple adhesive components (polyolefin resin, wax, and tackifier) into a single integrated formulation that can be applied in one step. Instead of using separate primer layers and surface adhesive layers as in conventional processes, this invention combines all necessary adhesive functions into one coating layer, simplifying the manufacturing process while maintaining reliable adhesive performance through optimized component ratios and a single-application process.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If adhesive coating is applied to medical packaging material, then heat seal strength is improved, but gas-permeability may be affected

Engineering Contradiction:
Improveheat seal strengthVSAvoidgas-permeability
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The patent applies local quality by controlling the adhesive coating to be thin (5-20 micrometers) and uniformly distributed only on the sealing surfaces of the packaging material. This localized application ensures that the adhesive provides sufficient heat seal strength at the sealing edges while maintaining gas-permeability in the bulk packaging material, allowing steam and ethylene oxide gas to pass through during sterilization processes.

Inventive Principle:
Principle #3Local quality

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 water-based hot-melt adhesive coating layer ensures reliable seal strength and gas-permeability for steam and ethylene oxide sterilization, while cleanly splitting upon peeling to prevent fiber tear and contamination, and simplifies the manufacturing process by eliminating the blending step.

Implementation Method 1

The present hot-melt adhesive coating layer provides sufficient seal strength without affecting the gas-permeability required by the healthcare device packaging

Methodology Applied
Scientific EffectHeat sealing: Welding

Implementation Method 2

the packaging material for EO sterilization and steam sterilization has to provide gas-permeability to assure the steam and EO gas passing through the packaging material to reach the healthcare devices for sterilization

Methodology Applied
Scientific EffectGas permeability: Permeation

Data Source

PatentUS20250154383A1Water-based hot melt adhesive and nonwoven coated with the water-based hot melt adhesive
Publication Date: 2025.05.15 BENQ MATERIALS CORP

AI summary

The present disclosure is to provide a water-based hot melt adhesive for healthcare packaging. The water-based hot melt adhesive includes 100 weight parts of water-based polyolefin resin; 40 to 85 weight parts of wax particles; and 25 to 85 parts by weight of tackifier particles; wherein a total weight of the wax particles and the tackifier particles is from 45 wt % to 60 wt % of a total weight of the water-based hot melt adhesive. The coating layer coated by the water-based hot melt adhesive of the present disclosure on the healthcare packaging substrate has great gas-permeability, and satisfied seal strength and peelability after sealing with the periphery part of a flexible sheet or a blister container.