Thermoplastic Container Plug-In Connection Without Wall Penetration

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Solution Overview

Problem

Existing methods for producing thermoplastic containers, such as fuel tanks, face challenges including the need for complex and costly piercing tools, potential damage to barrier layers, and inefficient use of space due to protruding connection elements, which complicate the integration of ventilation lines and increase production costs.

Innovation Solution

The method involves creating a connection element that is attached to the container wall without penetrating it, allowing for a plug-in connection that fits within the container's envelope, minimizing the required stroke and avoiding material loss, by separating the opening and joining processes and using a punching tool on the mold cavity side or tool side.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the wall of the container is pierced with a connection element during shaping, then the connection element can be integrated into the container wall, but the piercing tip must be removed after production which complicates the process

Engineering Contradiction:
Improveintegration of connection elementVSAvoidremoval of piercing tip
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The piercing tip is designed as a separate, removable component that is extracted from the container after the connection element is welded in place. This allows the piercing function to be performed during manufacturing while eliminating the need for the tip to remain in the final product, thus resolving the contradiction between integration and removal complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The piercing of the container wall is performed as a preliminary action before the final assembly is complete. The piercing tip serves its function during the welding process and is then removed, allowing subsequent steps (such as hose connection) to proceed without interference from the piercing mechanism.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If a large punching device is used to pierce the wall during production, then the connection element can be welded in one step, but the device requires relatively large space and stroke

Engineering Contradiction:
Improveone-step weldingVSAvoidspace for punching device
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The punching device is segmented into a piercing tip portion and a welding portion. The piercing tip is designed to be compact and can be integrated into the molding tool, while the welding mechanism operates separately. This segmentation allows the piercing function to be performed with minimal space requirements while maintaining the one-step welding capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The piercing tip is nested within or integrated into the molding tool structure, allowing it to occupy minimal space during the piercing operation. The welding mechanism then operates in the same or adjacent space, effectively nesting multiple functions within a compact footprint, thereby reducing the overall space and stroke requirements.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of operation

If the connection element protrudes from the container wall, then it can be easily connected to external lines, but it increases space usage and may damage barrier layers

Engineering Contradiction:
Improveconnection to external linesVSAvoidspace usage
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

Instead of having the connection element protrude outward from the container wall in the radial direction, the connection is established by piercing the wall and directing the connection path along the inner surface or through the wall thickness. This dimensional change allows external line connection while maintaining a compact external profile and preserving the container's envelope.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Rather than having the connection element protrude outward from the wall, the approach is inverted: the connection element is introduced from the outside, pierces through the wall, and is welded on the inside surface. This inversion allows external connection access while keeping the external profile smooth and compact, and prevents damage to outer barrier layers.

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

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 reduces the complexity and cost of production, minimizes space usage, and prevents damage to the container's barrier layers by ensuring the connection elements do not protrude, allowing for efficient integration of ventilation lines and built-in parts without compromising the container's integrity.

Implementation Method 1

application and shaping of the preforms in cavities of a multi-part mold using differential pressure

Methodology Applied
Scientific EffectDifferential pressure: Pressure Gradient

Implementation Method 2

the wall of the container being pierced with a part of the connection element in the still plasticized state

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Implementation Method 3

the connecting element enters into a material connection with the container wall at least in partial areas

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP3083193B1Method for producing a container from thermoplastic material and plastic container produced according to said method
Publication Date: 2019.10.16 KAUTEX TEXTRON GMBH & CO KG
  • EP3083193B1 patent drawingFigure 1A~1C
  • EP3083193B1 patent drawingFigure 2a~2b
  • EP3083193B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for producing a container, comprising the following steps: providing two web-shaped preforms (7); positioning and forming the preforms (7); punching out or cutting out in a circular shape at least one opening (18) in at least one dish-shaped intermediate product, wherein in a second method step, a first connection element of a line connection or a line arrangement is welded to the wall of the dish-shaped intermediated product on the mold-cavity side such that a circumferential welding collar (23) of the first connection element encloses the opening in a sealing manner; joining the dish-shaped intermediate products to a container, and removing the container from the blow molding tool (1), and connecting a second connection element (25), which is complementary with the first connection element in the manner of a plug-in connection, to the first connection element, wherein the plug-in connection is established within the contour of the container defined by the container wall.