Plastic Fuel Tank Pre-blowing Obstacle Element

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing manufacturing techniques for plastic fuel tanks result in a projecting weld on the outer periphery, which interferes with the fixation to the vehicle chassis, limits the attachment of components, and increases production costs and weight due to excess material.

Innovation Solution

Introducing an obstacle element between the mold cavities during the pre-blowing process to prevent the parison from being pinched, creating an outer perimeter zone free of welds, allowing for a recess or area devoid of protruding welds, which can be used for attaching accessories and reducing material usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the mold cavities are closed without an obstacle element, then the parison is pinched between the cavities forming a projecting weld, but this weld interferes with strap fixation and component attachment

Engineering Contradiction:
Improvetank formationVSAvoidstrap fixation and component attachment
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

An obstacle element is introduced as an intermediary component between the mold cavities and the parison during the blowing process. This obstacle element prevents the parison from being pinched between the cavities, thereby eliminating the projecting weld that would otherwise interfere with strap fixation and component attachment on the tank outer periphery.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If the parison is pinched between the mold cavities, then the tank structure is formed, but excess material is created forming a projecting weld that increases weight and production cost

Engineering Contradiction:
Improvetank structure formationVSAvoidexcess material
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The obstacle element is used to extract or prevent the formation of excess material during the blowing process. By positioning the obstacle element between the mold cavities, the parison is guided to conform to the cavity shape without being pinched, thereby eliminating the projecting weld and reducing material waste.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If no obstacle element is used during pre-blowing, then the manufacturing process is simpler, but the outer periphery of the tank cannot be used for attaching components

Engineering Contradiction:
Improvemold structureVSAvoidcomponent attachment capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The obstacle element is introduced during the pre-blowing stage, before the final molding is completed. This preliminary action ensures that the parison is properly positioned and prevents weld formation on the outer periphery, creating a smooth surface that enables subsequent component attachment while maintaining mold structure simplicity.

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

The method eliminates the need for excess material, enhances the attachment of straps and components, reduces production costs, and maintains the tank's balance by preventing weld formation, resulting in a lighter and more efficiently manufactured fuel tank.

Implementation Method 1

a pressurized fluid (i.e. gas) is introduced inside the parison to perform pre-blowing of the parison

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP3049233B1Method for producing a fuel tank from plastic material
Publication Date: 2017.11.08 PLASTIC OMNIUM ADVANCED INNOVATION & RES SA
  • EP3049233B1 patent drawingFigure 1~5
  • EP3049233B1 patent drawingFigure 2a~2b
  • EP3049233B1 patent drawingFigure 3~7

AI summary

The invention concerns a method for producing a fuel tank from plastic material comprising the following steps: - inserting a plastic parison (1) into an open mould comprising mould cavities (3, 4); - introducing at least one obstacle element between the mould cavities; and - introducing a pressurised fluid into the parison in order to perform pre-blowing of the parison and applying a part of the parison against the obstacle element (5, 6), in such a way as to prevent said part of the parison from being clamped between the mould cavities.