Flexible Surface Element with Controlled Microsphere Expansion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for producing flexible surface elements with thermoplastic functional layers face challenges such as limited or uneven surface quality, micropores, and inconsistent dimensional accuracy due to the continued expansion of microhollow spheres after calendering.

Innovation Solution

A method involving a detachable pressure-resistant layer is applied over a thermoplastic functional layer containing microhollow spheres, which is heated to control their expansion within a specific temperature range using electromagnetic radiation, ensuring the expansion is limited by the pressure-resistant layer, and subsequently removed to achieve a smooth surface finish.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If expandable microhollow spheres are incorporated into the thermoplastic functional layer, then the surface element gains improved mechanical properties and comfort, but the surface quality becomes limited or uneven with micropores and voids

Engineering Contradiction:
Improvemechanical propertiesVSAvoidsurface quality
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

A pressure-resistant layer is applied to the functional layer before heating and expansion of the microhollow spheres. This preliminary action prevents the spheres from expanding beyond the desired thickness, ensuring uniform surface quality and eliminating micropores and voids that would otherwise form during expansion.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The pressure-resistant layer acts as a flexible constraint that allows controlled expansion of the microhollow spheres while maintaining surface integrity. This thin film structure enables the spheres to expand uniformly without creating surface defects, resolving the contradiction between mechanical properties and surface quality.

Inventive Principle:
Principle #30Flexible shells and thin films

2Manufacturing precision

If the microhollow spheres are expanded by heating the functional layer, then the desired thickness and porosity are achieved, but the expansion continues uncontrollably after calendering, reducing dimensional accuracy

Engineering Contradiction:
Improvethickness controlVSAvoiddimensional accuracy
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The pressure-resistant layer is applied before the expansion process to pre-establish the maximum expansion boundary. This preliminary constraint ensures that the spheres expand only to the desired thickness and stop expanding at the correct point, preventing continued expansion after calendering and maintaining dimensional accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The pressure-resistant layer changes the physical parameters of the expansion process by providing a counter-pressure that limits sphere expansion. This parameter change controls the expansion behavior, ensuring that the spheres achieve the desired porosity and thickness without excessive or uncontrolled expansion that would compromise dimensional accuracy.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If a pressure-resistant layer is applied to limit microhollow sphere expansion, then surface quality and thickness control are improved, but the process complexity increases

Engineering Contradiction:
Improvesurface qualityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The pressure-resistant layer is implemented as a simple flexible film or sheet that can be easily applied and removed. This approach minimizes process complexity while effectively controlling sphere expansion, as the layer does not require complex mechanisms for application or removal and can be integrated into existing calendering or lamination equipment.

Inventive Principle:
Principle #30Flexible shells and thin films

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 results in a surface element with high surface quality, precise thickness control, and improved dimensional accuracy, enabling applications with mirror-like finishes and customizable mechanical properties.

Implementation Method 1

at least one section of the surface element to be treated is heated, preferably uniformly, to a specific temperature within an expansion temperature range below an upper limit temperature of the microhollow spheres by the input of thermal energy, so that at least the microhollow spheres contained in the section to be treated and/or already partially expanded microhollow spheres are at least partially expanded

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

The energy input is achieved by electromagnetic radiation, particularly in the infrared spectrum, and is specifically adjusted such that at least individual areas and/or cross-sectional planes of the functional layer are heated

Methodology Applied
Scientific EffectInfrared radiation heating: Infrared Radiation

Implementation Method 3

the expansion of the microhollow spheres is limited by the pressure-resistant properties of the pressure-resistant layer

Methodology Applied
Scientific EffectMechanical pressure resistance: Mechanical Force

Data Source

PatentEP4328001B1Method for producing a flexible surface element and a surface element produced thereby
Publication Date: 2026.03.04 FORBO SIEGLING
  • EP4328001B1 patent drawingFigure 1
  • EP4328001B1 patent drawingFigure 2~3

AI summary

The invention relates to a method for producing a flexible surface element (1) with an inner or outer functional layer (3), wherein expandable hollow microspheres (4) with a preferably homogeneous distribution are introduced into a functional layer (6). At least one additional pressure-resistant layer (5) is detachably applied to the functional layer (3). By supplying thermal energy, the hollow microspheres (4) are preferably heated uniformly to a temperature above the expansion temperature and expand, the expansion of the hollow microspheres (4) being limited by the pressure-resistant properties of the pressure-resistant layer (5). The material thickness (D) of the functional layer (3) is reduced by the expansion, and the surface quality is significantly improved. The pressure-resistant layer (5) is then removed from the functional layer (3).