Disposable Injection Mold Shell and Reinforcement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current injection molding processes are uneconomical for producing small quantities of custom-made products due to high costs associated with individually manufactured disposable molds, which limits the use of injection molding technology for one-off or low-volume production.
Innovation Solution
A disposable injection mold with a shell and shell reinforcement, where the shell is partially or completely created using additive manufacturing, and is made of a soluble material that dissolves in a solvent not affecting the injection molding material, and a reinforcement material with a lower melting point than the molding material, allowing for cost-effective production and easy demolding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If individually manufactured disposable molds are used for one-off production, then manufacturing precision and adaptability are improved, but production cost increases significantly
Solution Approach 1:
The disposable mold is segmented into two functional parts: a thin-walled shell (0.5-5mm) made of soluble material and a reinforcement structure made of fusible material. This segmentation allows the shell to provide precise cavity definition while the reinforcement provides structural strength, enabling the mold to be manufactured at lower cost through additive manufacturing while maintaining injection molding precision.
Solution Approach 2:
The invention changes the material parameters by selecting soluble materials for the shell and fusible materials for reinforcement, with specifically controlled melting points and solubility characteristics. The shell material dissolves in solvents at temperatures below the injection molding material's melting point, while the reinforcement material melts at temperatures below the injection molding material but above the shell dissolution temperature. This parameter control enables cost-effective one-off production while maintaining precision.
2Manufacturing precision
If traditional injection molding processes are used for small batches, then manufacturing precision is maintained, but economic viability deteriorates due to high mold costs
Solution Approach 1:
The invention implements a disposable mold concept where the shell and reinforcement are designed for single-use. The shell is made inexpensive through additive manufacturing with thin walls (0.5-5mm) using soluble materials, and the reinforcement is made of fusible material that can be melted and reused. This disposable approach makes small-batch production economically viable while maintaining precision, as the low cost of each disposable mold offsets the lack of volume discounts.
Solution Approach 2:
The reinforcement material is designed to be recoverable - it melts at a controlled temperature below the injection molding material's melting point, allowing the molten reinforcement to be drained and the solidified material to be collected and reused for subsequent molds. This recovery process significantly reduces material costs for each production cycle, improving economic viability for small batches while maintaining precision through reusable reinforcement material.
3Ease of manufacture
If shell thickness is reduced to minimize material usage, then production cost decreases, but mold strength deteriorates
Solution Approach 1:
The disposable mold uses a composite structure combining two materials with complementary properties: a thin-walled shell (0.5-5mm) made of soluble material provides the cavity shape and dissolves easily, while an outer reinforcement layer made of fusible material provides structural strength to withstand injection pressures. This composite approach allows the shell to be thin (reducing material cost) while the reinforcement compensates for the reduced strength, maintaining overall mold strength.
4Ease of operation
If soluble material is used for the shell, then ease of demoulding is improved, but material selection constraints increase
Solution Approach 1:
The invention systematically addresses material selection constraints by establishing specific parameter ranges: the shell material must have solubility in solvents at temperatures below the injection molding material's melting point, while the reinforcement material must have a melting point below the injection molding material but above the shell dissolution temperature. This parameter-based approach provides clear selection criteria, making the process easier to manage despite the apparent complexity of material constraints.
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
Enables the production of fully or partially customized injection molded components at low cost by minimizing material usage and allowing for the reuse of reinforcement material, making injection molding economically viable for small batch sizes.
Implementation Method 1
the shell being completely or partially individually created, preferably using an additive manufacturing process. The injection molded component is produced using this injection mold. The component is then demoulded. Similar to the two-stage structure of the injection mold, demoulding is also carried out in two stages. In this case, the shell reinforcement is first removed, specifically by melting the reinforcement material, before the shell or partial shell is subsequently removed, specifically by dissolving the shell material in a solvent.
Implementation Method 2
the reinforcing material has a lower melting point than the injection molding material. This ensures that the injection molded component is not damaged during the demolding process. The material used for hull reinforcement can be collected and reused after melting.
Data Source
Figure 1~7
Figure 3~6
AI summary
The invention relates to the production of injection-molded components (3) in disposable molds (1). To produce individual injection-molded components (3) cost-effectively, the use of an injection mold 1 composed of two elements (shell 6, 9 and shell reinforcement 12) is proposed. Both elements of the injection mold (1) are made of materials (4, 11) that must possess certain material properties (solubility and melting point). The selection of these materials (4, 11) depends on the material properties of the injection molding material (2) used.