Injection Mold Extension Cylinder Resin Waste Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional three-plate injection molds used for producing LED lead frames result in a significant amount of resin being wasted due to the hardening of molten resin within the mold, as they cannot accommodate extension cylinders, leading to 90% or more of the injected resin being discarded.
Innovation Solution
An injection mold design that includes extension cylinders with heaters to maintain molten resin in a fluid state, coupled with a nozzle positioner and gate-lock-pin holder system that allows for the separation of gate molded parts from injection-molded parts, reducing waste by preventing resin hardening within the mold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a three-plate injection mold is used to produce LED lead frames, then gate molded parts can be separated from injection-molded parts, but a large amount of resin hardens in runners and is wasted
Solution Approach 1:
The mold is divided into multiple plates including a first clamp plate, second clamp plate, and intermediate plate, creating distinct separation zones. This segmentation allows different functional areas: extension cylinders in one zone keep resin molten, while other zones enable gate part separation, thus reducing waste while maintaining manufacturability
Solution Approach 2:
Extension cylinders act as intermediary components between the injection system and the mold cavity. These cylinders maintain resin in a molten state through heating, serving as a mediator that prevents premature hardening in runners, thereby reducing resin waste while allowing the three-plate structure to perform its gate separation function
2Loss of substance
If extension cylinders are installed within the injection mold, then resin can be kept in a molten state, but the mold structure becomes more complex
Solution Approach 1:
The intermediate plate serves multiple functions: it provides structural support for the extension cylinders, creates parting lines for gate separation, and maintains the overall mold architecture. This multi-functionality allows the mold to accommodate extension cylinders for waste reduction while using the same structural element to enable gate part separation, thus managing complexity
3Device complexity
If a two-plate injection mold is used, then the structure is simple, but gate molded parts are attached to injection-molded parts requiring additional separation processes
Solution Approach 1:
The mold is segmented into three or more plates instead of two, creating an additional parting line between the intermediate plate and second clamp plate. This segmentation enables automatic separation of gate molded parts from injection-molded parts during the opening sequence, eliminating the need for additional separation processes and improving productivity while maintaining reasonable structural complexity
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
Significantly reduces the amount of hardened resin waste by keeping resin molten within the extension cylinders and enabling efficient separation of gate molded parts from injection-molded parts, thereby minimizing material loss during the production process.
Implementation Method 1
extension cylinders with heaters to maintain molten resin in a fluid state
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Provided is an injection mold which can reduce the amount of resin that is separated from injection-molded parts and then thrown away. The injection mold includes for an embodiment an extension cylinder coupled to an upper clamp plate and having a nozzle at an end thereof; a nozzle positioner disposed under the nozzle, the nozzle positioner having a nozzle insertion groove adapted to receive the nozzle; a gate-lock-pin holder disposed under the extension cylinder and the nozzle positioner , comprising a gate lock pin which has a first end coupled to a gate molded part and a second end coupled to the gate-lock-pin holder, and adapted to separate the gate molded part from an injection-molded part; a gate stripper plate disposed under the gate-lock-pin holder and adapted to separate the gate molded part from the nozzle; and a cavity plate and a core plate disposed under the gate stripper plate and having a cavity which is shaped like the injection-molded part.