Self-Supporting Sound-Absorbing Panel Without Perforated Sheets

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Solution Overview

Problem

Existing sound-absorbing panels made of rock wool deteriorate rapidly due to weathering, lose sound-absorbing properties with perforated metal sheets, and require difficult maintenance and additional support structures, which impair acoustic performance.

Innovation Solution

A sound-absorbing panel with an integrated self-supporting frame and resin-bonded fibres, such as cotton or polyester, is used, eliminating the need for perforated sheets and external support structures, and featuring a releasable bracket system for easy maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rock wool is used as sound-absorbing material, then excellent sound insulation properties are achieved, but the material deteriorates rapidly when exposed to weathering

Engineering Contradiction:
Improvesound insulation propertiesVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent uses resin-bonded fibres (cotton or polyester) as a replaceable sound-absorbing layer that can be easily replaced when deteriorated, while the frame structure remains reusable. This resolves the contradiction by making the short-lived sound-absorbing material easily replaceable rather than replacing the entire panel structure.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent creates a composite structure combining resin-bonded fibres with a rigid frame system. The frame provides structural durability and weather resistance, while the resin-bonded fibres provide sound absorption. This composite approach allows each component to address its specific function without the limitations of the other.

Inventive Principle:
Principle #40Composite materials

2Duration of action of stationary object

If perforated metal sheets are added to protect rock wool, then service life is extended, but sound-absorbing properties significantly decrease

Engineering Contradiction:
Improveservice lifeVSAvoidsound-absorbing properties
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent removes the perforated metal sheet from the design entirely. Instead, it uses a rigid frame that holds the resin-bonded fibres directly, eliminating the need for protective sheets that would block sound waves. The frame structure provides both protection and support without interfering with acoustic performance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The rigid frame acts as an intermediary structure that provides the protective and supportive functions previously requiring metal sheets. The frame holds the sound-absorbing material in place and provides structural integrity without blocking sound waves, mediating between the need for protection and the need for acoustic performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If glue or fixing means are used to attach sheets to rock wool, then structural stability is improved, but sound insulation properties are reduced

Engineering Contradiction:
Improvestructural stabilityVSAvoidsound insulation properties
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent replaces chemical bonding (glue) and mechanical fastening (nails or rivets) with a purely mechanical support system using a rigid frame. The frame holds the resin-bonded fibres through contact and gravity, eliminating the need for adhesives or fasteners that would create sound bridges and reduce insulation performance.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Strength

If additional support structures are added to arrange panels in series, then structural integrity is improved, but acoustic performance further decreases

Engineering Contradiction:
Improvestructural integrityVSAvoidacoustic performance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent merges the support structure functions into the panel itself by using a rigid frame that is integral to each panel. This self-supporting frame eliminates the need for separate supporting structures, thereby preventing additional sound bridges and maintaining acoustic performance while providing the necessary structural integrity for arranging panels in series.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rigid frame serves multiple functions simultaneously: it provides structural support, holds the sound-absorbing material in place, enables easy assembly and disassembly of panels, and maintains the required spacing between panels. This multi-functionality eliminates the need for separate support structures that would compromise acoustic performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

5Stability of the object's composition

If traditional fixing methods are used for maintenance, then structural stability is maintained, but maintenance difficulty increases

Engineering Contradiction:
Improvestructural stabilityVSAvoidmaintenance difficulty
Core Design Contradiction:
Stability of the object's compositionVSEase of repair

Solution Approach 1:

The patent segments the panel into a reusable rigid frame and a replaceable sound-absorbing layer. The layer can be independently removed and replaced by simply detaching it from the frame, eliminating the need to dismantle the entire panel structure. This segmentation makes maintenance straightforward while maintaining structural stability through the reusable frame.

Inventive Principle:
Principle #1Segmentation

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 panel maintains superior acoustic performance, extends service life, and simplifies maintenance, while enhancing sound insulation and stability without the drawbacks of traditional designs.

Implementation Method 1

a layer of sound-absorbing material (4) having: a front surface (6) designed to face an acoustic source (7) so as to be struck by sound waves (3) coming from the latter

Methodology Applied
Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentEP4223952B1Sound-absorbing panel with integrated self-supporting frame
Publication Date: 2026.04.22 STS ISOLAMENTI SRL
  • EP4223952B1 patent drawingFigure 1
  • EP4223952B1 patent drawingFigure 2
  • EP4223952B1 patent drawingFigure 3

AI summary

A sound-absorbing panel (1) is described comprising a layer of sound-absorbing material (4) and an integrated self-supporting frame (5) supporting the layer of sound-absorbing material (4), wherein the layer of sound-absorbing material (4) has a front surface (6) apt to be directly exposed to an acoustic source (7) for being struck by sound waves (3) without the interposition of grated elements or other parts, a rear surface (8) opposite the front surface (6), and a lateral surface (10) delimited between the front surface (6) and the rear surface (8); wherein the self-supporting frame (5) comprises: a support profile (11) laterally surrounding at least part of the layer of sound-absorbing material (4) and defining an abutment body for the lateral surface (10) of the layer of sound-absorbing material (4) itself; a protective sheet (12) fixed to the support profile (11) and defining an abutment element for said rear surface (8) of the layer of sound-absorbing material (4); and at least one containment bracket (13) having a first fixing portion (13a) fixed to the support profile (11) and a second containment portion (13b) cooperating with the layer of sound-absorbing material (4) at the front surface (6); wherein the sound-absorbing material is made of natural or artificial resin-bonded fibres; and wherein the layer of sound-absorbing material (4) is releasably interposed and fitted between the second containment portion (13b) and the protective sheet (12).