Layered Heater Tool Insert for Injection Molding Temperature Control
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Solution Overview
Problem
Current injection molding technologies face challenges in achieving fast and efficient temperature control of mold cavities, leading to defects such as voids, incomplete filling, and weld lines, especially in components with high aspect ratios, due to inefficient heating and cooling methods.
Innovation Solution
A tool insert with a thin layer heating system that directly heats the mold cavity surface using a heating conductor track and insulation layers, allowing for dynamic temperature control and rapid heating and cooling cycles, reducing the mass of the heated material and minimizing thermal influences on neighboring areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional heating methods (water channels, induction heating) are used to control mold plate temperature, then temperature control is achieved, but the heating and cooling cycles are slow and production efficiency is reduced
Solution Approach 1:
The patent applies a thin film heating element (heating foil) with a thickness of 10-500 micrometers directly on the mold cavity surface. This thin film structure has minimal thermal mass, enabling extremely rapid heating and cooling cycles. The heating foil can be quickly heated and just as quickly cooled, dramatically reducing production cycle times compared to conventional bulk heating methods.
Solution Approach 2:
The patent uses a fluid channel system with heat transfer medium (water or oil) flowing through channels in the mold plate to provide rapid cooling. The hydraulic cooling system efficiently removes heat from the thin heating layer, enabling fast cycle times by continuously circulating cooled fluid through the mold plate during and after the heating phase.
2Manufacturing precision
If high injection pressure is used to fill mold cavities with high aspect ratios, then filling is achieved, but defects such as voids, weld lines, and incomplete grain formation occur
Solution Approach 1:
The patent heats the mold cavity surface to a predetermined temperature (e.g., 150°C or higher) before introducing the flowable material. This preliminary heating action ensures the cavity walls are warm enough to prevent premature cooling of the injected material, allowing the material to flow completely into high aspect ratio cavities without forming voids, weld lines, or incomplete grain structures.
Solution Approach 2:
The patent dynamically changes the temperature parameter of the mold cavity surface by activating the thin film heating element only when needed. By controlling the heating timing and temperature, the system optimizes material flow characteristics during injection, enabling complete filling of complex geometries while avoiding defects that would otherwise require excessive injection pressure.
3Power
If a large mass of material is heated (as in induction heating), then heating power is achieved, but the thermal inertia causes slow cooling and extended production cycles
Solution Approach 1:
The patent uses a thin film heating element (10-500 micrometers thick) that has extremely low thermal mass. This thin structure can be rapidly heated to the required temperature and just as rapidly cooled by the fluid channels, eliminating the thermal inertia problem associated with bulk induction heating while maintaining high heating power at the cavity surface.
4Temperature
If infrared radiation heating is used on the mold cavity surface, then direct surface heating is achieved, but the tool must be open during irradiation which significantly extends production cycles
Solution Approach 1:
The patent integrates the thin film heating element directly into the closed mold cavity structure, allowing heating to occur while the tool is closed and the component is being formed. The hydraulic cooling system simultaneously or subsequently cools the cavity, enabling complete heating and cooling cycles without requiring the tool to be opened, thus maintaining high production efficiency.
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 enables faster production cycles, higher component quality, reduced injection pressures, and improved surface structures, while maintaining low unit costs and efficient temperature control, even for complex and thin-walled parts.
Implementation Method 1
a layer of heating (20) on its shaping front side (S1)... a heating conductor track (21)... transforming electrical energy into thermal energy
Implementation Method 2
conducting the thermal energy E of the flowable material M and the layer heater (20) through the base body (10) into the mold plate (101)... thermal energy transfer through contact
Implementation Method 3
passing a cooling medium through fluid channels (107) in the mold plate (101)... fluid flow carrying heat away
Data Source
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AI summary
Heated mould cavities of injection-moulding dies require long heating and cooling phases, with the result that the production unit numbers are low, the unit costs are high and the degree of efficiency is low as a result of the energy for temperature control. It is therefore a problem of the invention to eliminate or to reduce these disadvantages. According to the invention, this is solved by virtue of the fact that a die insert for delimiting, at least in sections, a mould cavity which is configured in a moulding plate of an injection-moulding die for producing components from a flowable material is provided with a main body which has a shaping front side for the mould cavity and a rear side which lies opposite the shaping front side, wherein the main body carries a layer heating means on the shaping front side thereof.