Filter Paper Insert with Differential Slit Widths to Reduce Clogging

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Solution Overview

Problem

Existing filter paper inserts for brewing beverages suffer from permeability issues, leading to clogging and reduced extraction efficiency, particularly with coffee oils, due to slit designs that either close or entangle during the brewing process.

Innovation Solution

A filter paper insert with two layers of filter paper joined at the base and sides, featuring slits with varying opening widths and wedge-shaped cross-sections to enhance permeability, allowing for optimized coffee oil extraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If slits are formed by incisions in filter paper, then permeability is increased, but cut edges become entangled and blockages occur

Engineering Contradiction:
ImprovepermeabilityVSAvoidblockages
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The filter paper is divided into multiple layers (first layer and second layer) with slits in each layer having different opening widths. This segmentation prevents complete blockage because coffee grounds can pass through the layer with wider slits even if blocked in the other layer, maintaining reliable permeability while reducing entanglement issues.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions (layers) of the filter paper have different slit opening widths tailored to local requirements. The first layer has slits with a first opening width while the second layer has slits with a second opening width, creating local quality variations that optimize both permeability and prevent blockages at different levels.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If slits are made with uniform opening width, then manufacturing is simplified, but coffee oil extraction is reduced

Engineering Contradiction:
Improveslit uniformityVSAvoidcoffee oil permeability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention applies local quality by creating two distinct layers with different slit opening widths. The first layer has wider slits optimized for coffee oil passage while the second layer has narrower slits for filtration, thereby improving coffee oil extraction without complicating manufacturing since both layers use the same basic slit formation process.

Inventive Principle:
Principle #3Local quality

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 design ensures improved brewing results by preventing clogging and enhancing the coffee oil content in the beverage through differential slit widths and orientations, facilitating efficient manufacturing with a single cutting tool.

Implementation Method 1

the slots with different opening widths create areas in the filter paper that are more permeable during extraction, especially for coffee oil

Methodology Applied
Scientific EffectPermeability: Permeation

Data Source

PatentEP4659634A1Filter paper insert and method for producing a filter paper insert
Publication Date: 2025.12.10 MELITTA EUROPA
  • EP4659634A1 patent drawingFigure 1A~1B
  • EP4659634A1 patent drawingFigure 2
  • EP4659634A1 patent drawing

AI summary

A filter paper insert (1) for brewing beverages, comprising two layers (2a, 2b) of filter paper joined at a base (3) and at two opposite sides (4, 5) to form a fillable interior, wherein the layers (2a, 2b) of filter paper are movable at an opening side (6) opposite the base (3) from a superimposed position to a spaced-apart filling position, and wherein a plurality of slots (9a, 9b) are provided in the two layers (2a, 2b) of filter paper, is designed such that the smallest opening width (B, b) of the slots (9a, 9b) differs perpendicular to their longitudinal direction in the two layers (2a, 2b) of filter paper. This improves the extraction result of the brewed beverage. Furthermore, a method for manufacturing a filter paper insert (1) is provided.