Cold Seal Adhesive Packaging for Medical Articles

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing packaging structures for medical articles, such as adhesive plasters, often suffer from stringiness issues when peeling the sheet base materials, leading to inadequate adhesive strength and difficulty in separating them without damage.

Innovation Solution

A method involving coating sheet base materials with synthetic polyisoprene latex or styrene-isoprene-styrene block copolymer, sandwiching the medical article, and pressing the coated surfaces together at a temperature of 100°C or less, followed by sterilization to enhance adhesive strength and prevent stringiness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If cold seal layers composed of rubber and acrylic resin are used to adhere sheet base materials, then the sheet base materials can be easily peeled from the article to be packaged, but stringiness occurs at the adhered portion when peeling the sheet base materials

Engineering Contradiction:
Improvepeeling easeVSAvoidstringiness
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the adhesive layer by specifying precise proportions of acrylic resin (30-70 parts), rubber (10-40 parts), and plasticizer (5-20 parts). This parameter optimization resolves the contradiction by achieving both easy peeling and preventing stringiness through balanced adhesive properties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite adhesive layer combining acrylic resin, rubber, and plasticizer in specific ratios. This composite formulation resolves the technical contradiction by integrating the benefits of different materials: acrylic resin provides adhesion control, rubber provides flexibility, and plasticizer prevents stringiness while maintaining peeling ease.

Inventive Principle:
Principle #40Composite materials

2Reliability

If adhesive strength between sheet base materials is increased to prevent separation, then peeling difficulty increases and stringiness occurs, but if adhesive strength is decreased for easy peeling, then adhesion reliability deteriorates

Engineering Contradiction:
Improveadhesion reliabilityVSAvoidpeeling ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent optimizes adhesive strength parameters by controlling the ratio of adhesive components and specifying thickness (1-10 μm). This parameter tuning achieves the balance between adhesion reliability and peeling ease by ensuring sufficient bonding strength while maintaining removable adhesion.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies adhesive material at controlled thickness (1-10 μm), which is sufficient to ensure adhesion reliability but not excessive to cause peeling difficulty. This partial action principle resolves the contradiction by providing just enough adhesion needed for reliability without over-adhering.

Inventive Principle:
Principle #16Partial or excessive action

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

This method effectively prevents stringiness and ensures suitable adhesive strength between the sheet base materials, allowing for easy peeling and maintaining adhesion even in high-temperature and high-humidity environments.

Implementation Method 1

a self-seal adhesive containing no natural rubber. The self-seal adhesive system is comprised of a transfer adhesive disposed on a transfer web and an anchor adhesive disposed on an anchor web with the two adhesives forming the seal for the package. The self-seal adhesives bond to themselves when pressure is applied to close or seal the packaging material.

Methodology Applied
Scientific EffectSelf-adhesion: Adhesive

Implementation Method 2

pressing the portions where at least the sheet base materials of the laminated body are in direct contact at a temperature of 100°C or less

Methodology Applied
Scientific EffectThermal activation of adhesive: Heating

Implementation Method 3

performing a sterilization treatment on the pressed laminated body

Methodology Applied
Scientific EffectSterilization:

Data Source

PatentEP3520750B1Method of manufacturing package structure
Publication Date: 2023.05.24 ZEON CORP

AI summary

A method of producing a packaging structure, including a step of coating at least one surface of a first sheet base material and/or a second sheet base material with a latex of a synthetic polyisoprene having a weight average molecular weight of 500,000 to 5,000,000 and/or a styrene-isoprene-styrene block copolymer having a weight average molecular weight of 100,000 to 300,000, a step of sandwiching an article to be packaged in a state in which the first sheet base material and the second sheet base material are in contact with each other via a latex coated surface formed on the first sheet base material and/or the second sheet base material to thereby obtain a laminated body, a step of pressing a portion where at least the first sheet base material and the second sheet base material of the laminated body are in contact with each other via the latex coated surface at a temperature of 100°C or less to thereby obtain a pressed laminated body, and a step of performing a sterilization treatment on the pressed laminated body.