Blow-Molded Part with Integrated Support Structure for Strength

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Solution Overview

Problem

Existing blow-molded parts, particularly expansion tanks, face challenges in meeting structural strength and dimensional accuracy requirements due to overpressures and underpressures, necessitating separate structural components that limit design flexibility.

Innovation Solution

A support structure is integrated into the blow mold, with a preform enclosing it, allowing a material-bonded connection during blow molding to create a base body, which can include weld ribs for reinforcement and interface geometries, eliminating the need for additional sealing elements and simplifying production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If separate structural components are incorporated into the expansion tank to meet structural strength requirements, then the structural strength is improved, but the device complexity increases and design flexibility is limited

Engineering Contradiction:
Improvestructural strengthVSAvoiddevice complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent combines the support structure with the base body by integrating it directly into the blow molding process. The support structure is formed simultaneously with the base body from the preform material, creating a unified component rather than assembling separate parts. This merging approach maintains structural strength while reducing device complexity and improving design flexibility.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The support structure serves multiple functions: it provides structural reinforcement, defines cavity geometry, and creates integrated mounting points. By designing the support structure to fulfill multiple roles within the single blow molding process, the patent eliminates the need for additional separate components, thereby reducing complexity while maintaining strength.

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

2Adaptability or versatility

If additional interface elements such as screw caps and valves are integrated into the expansion tank, then the functional requirements are met, but the device complexity increases and design freedom is restricted

Engineering Contradiction:
Improvefunctional requirementsVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Interface elements such as screw caps, valves, and mounting points are integrated directly into the base body during the blow molding process. The support structure is formed with built-in interface geometries that provide threading, sealing surfaces, and mounting features, eliminating the need for separate interface components and reducing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If the preform is pressed against the cavity edges during blow molding, then the base body is formed, but seams are created on the blow molded part

Engineering Contradiction:
Improvebase body formationVSAvoidseam formation
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The support structure is strategically positioned within the cavity to control the molding process. It provides localized support and guidance for the preform during pressing, ensuring proper alignment and distribution of material flow. This local structural intervention helps prevent seam formation at critical areas while maintaining ease of manufacture.

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 method enables cost-effective production of blow-molded parts with highly accurate interface geometries and structural reinforcement, reducing manufacturing steps and components while ensuring media-tight connections and improved mechanical strength.

Implementation Method 1

the preform is inserted into the blow mold in such a way that the support structure is at least partially enclosed by the preform, then the blow mold is closed and a base body surrounding the support structure is produced from the preform by blow molding

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

the blow mold is closed and a base body surrounding the support structure is produced from the preform by blow molding

Methodology Applied
Scientific EffectPressure Increase: Pressure Increase

Implementation Method 3

the base body connects with the support structure in a material-bonded and/or form-bonded manner during blow molding

Methodology Applied
Scientific EffectMaterial bonding: Welding

Data Source

PatentEP4667186A1Method for producing a blow-moulded part, and blow-moulded part
Publication Date: 2025.12.24 TI AUTOMOTIVE TECHNOLOGY CENTER GMBH
  • EP4667186A1 patent drawingFigure 1
  • EP4667186A1 patent drawingFigure 2
  • EP4667186A1 patent drawingFigure 3

AI summary

A method for producing a blow-molded part (1) in which a support structure (2) is provided and arranged in a blow mold (3), a preform (4) is inserted into the blow mold (3) such that the support structure (2) is at least partially enclosed by the preform (4), the blow mold (3) is then closed, and a base body (5) surrounding the support structure (2) is produced from the preform (4) by blow molding, wherein the base body (5) bonds to the support structure (2) during blow molding by a material bond and/or a form-fit bond. The invention further relates to a blow-molded part (1) comprising a base body (5) enclosing a cavity (15) and a support structure (2) arranged within the base body (5), wherein the base body (5) and the support structure (2) define the cavity (15), and wherein the base body (5) and the support structure (2) are materially bonded to one another.