Movable Mould Parts Dynamic Cavity Injection Moulding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional injection moulding processes face challenges in producing articles with high flow-length: wall thickness ratios, requiring high injection pressures and complex machinery, which is costly and inefficient, especially for producing container preforms with low material stress.
Innovation Solution
A method involving a multi-step mould configuration change during the injection moulding process, where movable mould parts adjust to create successive cavity configurations with progressively increasing L/T ratios, reducing filling pressure and allowing for the production of articles with high L/T ratios using conventional machines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high injection pressure is used to fill the mould cavity, then the cavity can be filled with molten material, but the clamping force requirement increases and complex machinery is needed
Solution Approach 1:
The mould part is made movable instead of fixed, allowing dynamic adjustment of the cavity configuration during the injection process. The mould part moves from an initial position defining a first configuration to a final position defining a second configuration, enabling the system to adapt to different filling requirements without complex fixed structures
Solution Approach 2:
The invention changes the geometric parameters of the mould cavity during injection by moving the mould part between two positions. This transforms the cavity from a first configuration to a second configuration, altering the flow path and reducing the required injection pressure while maintaining effective cavity filling
2Manufacturing precision
If high injection pressure is used to fill the periphery of the mould cavity, then material can reach remote areas, but the clamping force requirement increases
Solution Approach 1:
The movable mould part dynamically reconfigures the cavity during injection, creating an evolving flow path that guides material to remote periphery areas. This dynamic adjustment reduces the pressure needed to reach distant regions compared to a static cavity configuration
Solution Approach 2:
The mould part is positioned in a first configuration before injection begins, creating an initial cavity shape that facilitates material flow. During injection, it moves to a second configuration that ensures complete periphery filling, preparing the path for material flow in advance
3Productivity
If fast fill rate is used to fill the cavity, then the cavity can be filled quickly, but the fill pressure and clamping force requirement increase
Solution Approach 1:
The movable mould part creates a dynamic cavity configuration that optimizes material flow during injection. By moving from first to second configuration during the filling process, it maintains favorable flow conditions that enable high fill rates without requiring excessive fill pressure
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 method effectively reduces the clamping force requirement, allows for the production of articles with high L/T ratios, and is cost-effective by utilizing conventional injection moulding machines, enhancing the efficiency and simplicity of the moulding process.
Implementation Method 1
injecting molten thermoplastic resin material into the first intermediate moulding cavity through the injection inlet to fill the first intermediate moulding cavity with the molten material
Implementation Method 2
moving the second movable mould part from the first forward position to a second rearward position; moving the first movable mould part from the first rearward position to a second forward position
Implementation Method 3
moving the second movable mould part from the second rearward position to a third forward position thereby to dispose the first and second movable mould parts in a final configuration so as to define a final moulding cavity of the injection mould filled with the molten material
Data Source
AI summary
A method of injection moulding an article, the method comprising the steps of: (a) providing an injection mould comprising a plurality of mould parts defining a mould cavity of the injection mould, the plurality of mould parts including first and second movable mould parts, the injection mould further comprising an injection inlet for injecting molten thermoplastic resin material into the mould cavity, wherein the injection inlet is located in the vicinity of the first movable mould part and the second movable mould part is remote from the injection inlet; (b) disposing the first and second movable mould parts in a first configuration so as to define a first intermediate moulding cavity, in which first configuration the first movable mould part is in a first rearward position and the second movable mould part is in a first forward position; (c) injecting molten thermoplastic resin material into the first intermediate moulding cavity through the injection inlet to fill the first intermediate moulding cavity with the molten material; (d) closing the injection inlet; (e) after commencement of the injecting step and at least partly after the closing step, moving the second movable mould part from the first forward position to a second rearward position; (f) moving the first movable mould part from the first rearward position to a second forward position; and (g) moving the second movable mould part from the second rearward position to a third forward position thereby to dispose the first and second movable mould parts in a final configuration so as to define a final moulding cavity of the injection mould filled with the molten material, the final moulding cavity defining a cavity outer surface which defines the outer shape of the article to be moulded.