Tube Head Insert Overmolding for Barrier Continuity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional tube heads made by injection of plastic material are unsatisfactory for reactive products and prone to gas and liquid penetration or leakage, leading to product degradation and visual alteration, and existing solutions with inserts are complex, expensive, and difficult to position correctly, causing discontinuity in the barrier effect.
Innovation Solution
A tube head assembly with a shoulder and neck featuring a flat insert with a peripheral extension parallel to the longitudinal axis, a central deformation for centering, and a multilayer material including a metallic or EVOH barrier layer, which improves positioning and continuity of the barrier effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an insert is placed in the tube head area to form a protective barrier, then the infiltration and leakage of unwanted components is limited and both the tube head and its contents are protected, but the tube head structure becomes complex and expensive to manufacture
Solution Approach 1:
The insert is integrated with the tube head through overmolding, merging two previously separate components into a unified structure. This reduces assembly complexity while maintaining the barrier protection function, directly addressing the contradiction between reliability and device complexity.
Solution Approach 2:
The tube head assembly uses composite materials including metallic layers and ethylene vinyl alcohol (EVOH) layers within the insert to achieve superior barrier properties. This allows the structure to provide enhanced protection without requiring increased complexity, as the barrier function is achieved through material composition rather than structural complexity.
2Reliability
If an insert is placed in the tube head area to form a protective barrier, then the infiltration and leakage of unwanted components is limited, but it is difficult to position and center the insert correctly
Solution Approach 1:
The insert is pre-positioned and centered within the tube head during the overmolding process before final assembly. This preliminary positioning action ensures correct alignment is achieved during manufacturing, eliminating subsequent positioning difficulties and ensuring the barrier protection function operates as intended.
Solution Approach 2:
The mechanical positioning system is replaced by integrating the insert directly into the molded tube head structure. The overmolding process inherently positions and secures the insert through material flow and bonding, eliminating the need for separate mechanical positioning mechanisms and reducing positioning errors.
3Reliability
If a metallic insert is used to limit corrosion, then the tube head is protected, but incorrect positioning could lead to significant plastic deformation of the insert and reduce its barrier properties
Solution Approach 1:
The insert is merged with the tube head through overmolding, creating a unified structure where the insert is surrounded and supported by the molded material. This integration provides mechanical support that prevents plastic deformation while maintaining corrosion protection, resolving the contradiction between reliability and strength.
Solution Approach 2:
The overmolded material acts as a cushioning layer that surrounds and protects the metallic insert from forces that could cause deformation. This beforehand cushioning ensures the insert maintains its structural integrity and barrier properties throughout the product lifecycle.
4Manufacturing precision
If the insert is made flat with height-to-depth ratio less than 0.1, then the positioning and centering is improved, but the barrier effect continuity between skirt and tube head may be disrupted
Solution Approach 1:
The barrier continuity is maintained by extending the insert's protective function into the longitudinal dimension through the overmolded tube head structure. While the insert itself remains flat for positioning purposes, the overmolding creates a three-dimensional barrier that connects the skirt to the tube head, preserving barrier effect continuity in the vertical dimension.
Solution Approach 2:
The insert and tube head are merged through overmolding, creating a continuous barrier structure that spans from the skirt through the tube head. This merging ensures barrier effect continuity is maintained despite the insert's flat geometry, as the overmolded material bridges any potential gaps and maintains the protective barrier throughout the assembly.
Data Source
Figure 1~2
AI summary
An assembly of a tube head (1) and a skirt, said tube head being capable of being associated with the skirt (4) in such a way as to form an inner volume of the tube, the tube head (1) comprising a body (11), said body comprising a neck (3) and a shoulder (2) connected to the neck (3), the tube head (1) further comprising an insert (6) arranged in contact with said shoulder (2), so as to form a barrier between the body (11) and the product contained in the inner volume, said insert (6) closing the neck (3), the shoulder (2) having a peripheral portion (70) orientated along a longitudinal axis of the skirt (4), the insert (6) comprising a peripheral extension (72) orientated parallel to said longitudinal axis.