Self-Adhesive Article with Dual PSA Layers for Rough Wallpaper

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Solution Overview

Problem

Existing self-adhesive strips struggle to provide high holding power and non-destructive removal on rough surfaces, particularly painted woodchip wallpaper, due to insufficient bonding strength and surface damage during removal.

Innovation Solution

The development of self-adhesive articles with specific PSA layer combinations and foam carrier materials, including polybutadiene-polyvinylaromatic block copolymers, hydrocarbon resins, and soft resins, which offer improved adaptability and tensile strength for bonding to rough surfaces while allowing for residue-free removal by stretching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If adhesive strips are used on rough surfaces like painted woodchip wallpaper, then bonding to the surface is achieved, but bonding strength is insufficient and surface damage occurs during removal

Engineering Contradiction:
Improvebonding strengthVSAvoidsurface damage
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent changes the physical parameters of the adhesive strip by introducing a foam carrier with specific density (20-500 kg/m³) and thickness (0.1-30 mm) parameters. This allows the adhesive to deform and adapt to rough surfaces while maintaining sufficient bonding strength and enabling damage-free removal through controlled elasticity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structure combining foam carrier material with pressure-sensitive adhesive layers. This composite structure provides both the adaptability needed for rough surfaces and the bonding strength required, while the foam's elastic properties enable non-destructive removal

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If foam carriers with low density are used to improve adaptability to rough surfaces, then bonding area increases, but tensile strength decreases

Engineering Contradiction:
Improveadaptability to rough surfacesVSAvoidtensile strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent optimizes the foam carrier parameters within specific ranges: density of 20-500 kg/m³ and thickness of 0.1-30 mm. This parameter optimization balances adaptability to rough surfaces with sufficient tensile strength for practical applications

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3362528B1Self-adhesive article and its use for adhering on ingrain wallpaper
Publication Date: 2021.09.29 TESA SE
  • EP3362528B1 patent drawingFigure 1

AI summary

A self-adhesive article comprising (i) at least one carrier material which comprises at least one foamed layer having a first surface A and a second surface B, the at least one foamed layer of the carrier material having a thickness of at least 500 µm und at most 1800 µm, a tensile strength in detachment direction of at least 500 kPa, a tensile elongation in detachment direction of at least 300 % and a compressive hardness of at least 50 kPa, (ii) a layer HKA of pressure-sensitive adhesive (PSA) assigned to the surface A, (iii) a PSA layer HKB assigned to the surface B, and (iv) optionally further layers; the PSA layers HKA and HKB may be two PSA layer combinations, in which case, for PSA layer combination 1, PSA layer HKA is a PSA layer HKA1 with particularly good properties for bonding to rough substrates, and PSA layer HKB is a PSA layer HKB1 with a tensile strength of at least 9 MPa, and, for PSA layer combination 2, PSA layer HKA is a PSA layer HKA2 and PSA layer HKB is a PSA layer HKB2, each of these layers, but independently of one another, featuring not only good properties of bonding to rough substrates but also sufficient tensile strength at the same time, is particularly suitable for bonding to rough substrates whilst possessing strippability.