Thermoforming Coffee Capsule Hollow Bottom via Annular Gap

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Solution Overview

Problem

Current methods for thermoforming coffee capsules are not resource-efficient and lack material savings, with a need for more compact and environmentally friendly production processes.

Innovation Solution

The method involves using a molding tool with a molding chamber that can be pressurized, creating a circumferential annular gap on the mold base to form a hollow bottom with varying thicknesses, allowing for material redistribution and the formation of a circumferential web, which enhances dimensional stability and reduces material usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If conventional thermoforming methods are used to produce coffee capsules, then the manufacturing process is simple, but material usage is excessive and resource efficiency is low

Engineering Contradiction:
Improvematerial usageVSAvoidmolding tool complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The mold base is designed with a circumferential annular gap that creates localized variations in film thickness during forming. This allows different regions of the capsule body to have different wall thicknesses - thicker walls where structural strength is needed and thinner walls where material savings are possible, thereby optimizing material usage while maintaining necessary structural properties

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The molding process employs dynamic control of the mold base position, specifically a hollow bottom mold stroke of less than 5mm that moves counter to the main forming direction. This dynamic adjustment during the forming process redistributes material and creates the desired thickness variations in the capsule body wall

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If the film is pressed against the mold base to form a flat bottom region, then the forming process is straightforward, but the dimensional stability and structural strength are insufficient

Engineering Contradiction:
Improvedimensional stabilityVSAvoidforming process complexity
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The circumferential annular gap in the mold base creates localized structural features in the formed capsule body, including a circumferential web and hollow bottom region. These localized structural modifications enhance dimensional stability and structural strength at critical locations without requiring complete redesign of the entire forming process

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The mold base is pre-configured with the circumferential annular gap and hollow bottom geometry before the forming process begins. This preliminary structural preparation guides the film deformation and material distribution during forming, ensuring that the capsule body develops the necessary dimensional stability and structural features as part of the standard forming operation

Inventive Principle:
Principle #10Preliminary action

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 approach enables the production of coffee capsules with improved dimensional stability and material savings, achieving a more compact and environmentally friendly manufacturing process.

Implementation Method 1

the film is formed into a molding having a cavity by means of at least one forming punch and/or by means of an overpressure in an axial main forming direction into a molding chamber part of a molding tool

Methodology Applied
Scientific EffectOverpressure: Pressure Increase

Implementation Method 2

a thermoplastic film 6, in particular a blown film, is fed to a thermoforming tool 1

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP3700732B1Method for thermoforming a film, molding tool, thermoforming tool, installation for thermoforming, capsule body, brewing capsule and container
Publication Date: 2024.09.11 KIEFEL GMBH
  • EP3700732B1 patent drawingFigure 1
  • EP3700732B1 patent drawingFigure 2
  • EP3700732B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for thermoforming a film to a container, in particular to a container for a brewing capsule, especially for a coffee capsule, wherein the film is formed by means of a shaping punch and/or by means of an overpressure in an axial main shaping direction into a molding chamber part to form a molded article having a cavity, wherein the film is pressed against or at least up to a mold base of the molding chamber part in order to form a base region of the molded article, and wherein the method is characterized in that, in a further shaping step, when the base region of the molded article is pressed against the mold base of the molding chamber part, a circumferential annular gap is produced on the mold base at ambient pressure or overpressure, in which the base region of the molded article is further shaped into a hollow base.