Multipart Label Laminate Sterilization Adhesion

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Solution Overview

Problem

Existing multipart label laminates for single-use sterilization packs face challenges in manual dispensing and reliable application, particularly in maintaining adhesive properties during sterilization and ensuring easy recyclability.

Innovation Solution

A multipart label laminate structure comprising a face layer, two acrylic-based pressure sensitive adhesive layers, a carrier, and a liner, with on-site printing and specific layer compositions for opacity, shrinkage control, and release forces, allowing for easy manual application and removal of top labels while maintaining adhesion through sterilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a multipart label laminate structure is used for single-use sterilization packs, then the labeling process becomes more reliable and efficient, but the complexity of the label structure increases with multiple adhesive layers and components

Engineering Contradiction:
Improveadhesion reliability during sterilizationVSAvoidlabel structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The label laminate is divided into distinct functional layers: a face layer for printing, a first adhesive layer for top label adhesion, a carrier for structural support, a second adhesive layer for carrier attachment, and a liner for release. This segmentation allows each layer to be optimized for its specific function while maintaining overall system reliability during sterilization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs composite material construction with multiple adhesive layers (acrylic-based pressure sensitive adhesives) combined with a carrier material and face layer. This composite structure provides both the necessary adhesion properties for reliable labeling and the structural integrity required to withstand sterilization processes.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If the face layer has high opacity to ensure print visibility, then the labeling quality improves, but the material selection and manufacturing complexity increase

Engineering Contradiction:
Improveprint visibility and qualityVSAvoidface layer material selection
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The face layer is specifically engineered with high opacity properties (≥80% opacity per ISO 2471) to ensure optimal print visibility and quality. This localized quality enhancement is applied only where needed for labeling purposes, allowing the rest of the laminate structure to maintain standard manufacturing processes.

Inventive Principle:
Principle #3Local quality

3Reliability

If the adhesive layers are optimized for strong adhesion during sterilization, then the labeling reliability improves, but the ease of removing top labels after use decreases

Engineering Contradiction:
Improveadhesion strength during sterilizationVSAvoidtop label removal ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The adhesive system exhibits dynamic behavior: the first adhesive layer provides strong initial adhesion for top label application and maintains it during sterilization, while the second adhesive layer on the carrier enables controlled removal of the entire label assembly after use. This dynamic adhesion profile allows the system to adapt to different operational stages.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent specifies particular parameters for the acrylic-based pressure sensitive adhesives, including tack strength, shear strength, and temperature resistance properties. By carefully controlling these parameters, the adhesive layers provide strong bonding during sterilization (high temperature and moisture conditions) while still allowing for label removal after the sterilization process is complete.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If the carrier material has low shrinkage to maintain label dimensions during sterilization, then the labeling precision is improved, but the material selection becomes more restrictive

Engineering Contradiction:
Improvelabel dimension stabilityVSAvoidcarrier material selection
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The carrier material is selected and engineered to exhibit specific dimensional stability parameters, with shrinkage less than 4% when measured at 150°C for 30 minutes. This parameter control ensures that the label maintains its printed dimensions and positioning accuracy throughout the sterilization process, while still allowing for practical material selection from options like polyethylene terephthalate or polypropylene.

Inventive Principle:
Principle #35Parameter changes

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 enables reliable, easy, and efficient labeling of single-use sterilization packs with high opacity and low shrinkage, ensuring adhesion during sterilization and facilitating recyclability by optimizing the adhesive properties and layer composition.

Implementation Method 1

a first adhesive layer of acrylic based pressure sensitive adhesive; a second adhesive layer of acrylic based pressure sensitive adhesive

Methodology Applied
Scientific EffectPressure sensitive adhesion: Adhesive

Data Source

PatentEP3638502B1Multipart label laminate, labels and labelling
Publication Date: 2022.10.19 UPM RAFLATAC OY
  • EP3638502B1 patent drawingFigure 1~3
  • EP3638502B1 patent drawingFigure 4

AI summary

The invention relates to a multipart label laminate for labelling of single-use sterilization packs, the multipart label laminate comprising a face layer, a first adhesive layer of acrylic based pressure sensitive adhesive, a carrier, a second adhesive layer of acrylic based pressure sensitive adhesive, a liner, and a printing ink layer between the carrier and the second adhesive layer. The invention further relates to a method for application of a multipart label.