3D Fibrous Molded Part Surface Patterning for Steam Venting

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Solution Overview

Problem

Molded parts made from fibrous materials often develop visually and tactually perceptible protrusions due to steam extraction during high-pressure and high-temperature processing, which are aesthetically disruptive and functionally limiting, particularly in applications like coffee capsules and drinking cups.

Innovation Solution

The molded parts incorporate protrusions as patterns that are integrated into designed surface sections with varying thickness or design elements, ensuring they are flush with the surrounding surface and do not interfere with functionality, while allowing steam extraction through mold tool openings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If steam extraction openings are provided in mold surfaces to remove steam during high-pressure and high-temperature pressing, then steam extraction is enabled, but protrusions are formed on the molded part surface which are visually and tactually perceptible

Engineering Contradiction:
Improvesteam extraction capabilityVSAvoidsurface flatness
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating recesses at specific locations on the mold surface where steam extraction openings are provided. These recesses are localized modifications that allow steam to be extracted without forming protrusions on the molded part surface. The recesses are positioned strategically to match the opening locations, ensuring that steam extraction occurs at these specific local areas while the rest of the surface remains flat and smooth.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements preliminary action by pre-forming recesses in the mold surface before the molding process. These recesses are prepared in advance at the locations where steam extraction openings will be provided, so that when steam extraction occurs during pressing, the fibrous material is directed into these pre-prepared recesses rather than forming protrusions on the surface. This preliminary preparation of the mold surface geometry ensures that the steam extraction function is achieved without compromising surface quality.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If the proportion of natural fibers in the pulp is increased to enhance sustainability, then environmental friendliness improves, but the formation of protrusions during pressing becomes more problematic

Engineering Contradiction:
ImprovesustainabilityVSAvoidsurface quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent addresses the surface quality issue with high natural fiber content by using local quality modifications on the mold surface. The recesses are strategically positioned at steam extraction opening locations to specifically manage the steam release behavior of high-fiber materials. This localized approach allows the bulk material composition to maintain high sustainability while the surface geometry is locally optimized to prevent protrusion formation during the pressing process.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If protrusions are formed on the molded part surface, then steam extraction is facilitated, but the molded part does not sit flush with contact surfaces preventing sufficient seal

Engineering Contradiction:
Improvesteam extraction efficiencyVSAvoidsealing performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies the inversion principle by reversing the conventional approach to steam extraction. Instead of allowing steam to force material outward to form protrusions, the mold surface is designed with recesses that invite material to move inward. The steam extraction openings are positioned within these recesses, so that steam escape creates a slight vacuum or reduced pressure zone that draws fibrous material into the recesses rather than pushing it outward. This inverted approach transforms the steam extraction process from a harmful protrusion-forming mechanism into a beneficial surface-flattening process.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent converts the harmful effect of steam extraction (which normally causes protrusions) into a beneficial effect. By providing recesses at the opening locations, the steam pressure that would normally force material outward is instead channeled to fill these recesses. The steam extraction process, which was previously a source of surface defects, is transformed into a mechanism that ensures surface flatness by directing material into the recesses and then allowing it to be compressed flush with the surrounding surface area.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 provides aesthetically appealing and functionally effective molded parts that maintain a flush surface, avoiding protrusions that disrupt design and functionality, using a simple mold tool design without complex components.

Implementation Method 1

during the manufacture of the molded part, were sucked and/or pressed into corresponding openings in a mold surface of a molding tool when steam escaping from the fibrous material during compression was removed

Methodology Applied
Scientific EffectSteam extraction: Evaporation

Data Source

PatentEP4667374A1Three-dimensional molded part made of fibrous material and molding tool for producing molded parts made of fibrous material
Publication Date: 2025.12.24 KIEFEL GMBH
  • EP4667374A1 patent drawingFigure 1
  • EP4667374A1 patent drawingFigure 2
  • EP4667374A1 patent drawingFigure 3a~4

AI summary

A three-dimensional molded part made of fibrous material and a molding tool for producing molded parts made of fibrous material are described, wherein the molded part made of fibrous material is produced in a manufacturing process under pressure and thermal influence, wherein a surface of the molded part has protrusions formed by fibrous material which, during the production of the molded part, were drawn into corresponding openings in a molding surface of a molding tool when steam escaping from the fibrous material during compression is removed, and wherein the protrusions form at least one pattern along a surface of the molded part.