Fluid-Supported 3D-Printed Molds for Low-Volume Injection Molding
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Solution Overview
Problem
Existing injection molding processes require expensive metal molds and high volume production to be economical, limiting the feasibility of low-volume, customized mold manufacturing.
Innovation Solution
An apparatus and method utilizing an additively manufactured mold supported by a fluid within a pressure chamber, where a fluid injector generates pressure to resist mold deflection, allowing for thinner mold walls and enabling the use of dissolvable materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal molds are used to withstand high injection pressures, then mold strength is sufficient, but manufacturing cost increases and economy deteriorates for low-volume production
Solution Approach 1:
The patent employs disposable plastic molds instead of expensive metal molds. These molds are designed to be used for low-volume production and then discarded, eliminating the high manufacturing cost of metal molds while providing sufficient strength for the application. The mold is replaced after a limited number of uses or when wear occurs.
Solution Approach 2:
The patent changes the material parameter from metal to plastic, and adjusts the wall thickness parameter to optimize performance. By using plastic material with appropriate wall thickness (e.g., 2-5mm) and combining it with fluid support, the mold achieves sufficient strength at lower cost for low-volume production.
2Ease of manufacture
If mold wall thickness is decreased to reduce material cost, then manufacturing cost decreases, but mold deflection under pressure increases
Solution Approach 1:
The patent introduces a fluid medium as an intermediary between the mold and the external environment. This fluid provides support pressure that counteracts the injection pressure, preventing mold deflection even when wall thickness is reduced. The fluid acts as a mediator that distributes and balances the forces acting on the mold.
Solution Approach 2:
The patent applies counterpressure through the surrounding fluid to balance the injection pressure acting on the mold. This counterweight effect prevents the mold walls from deflecting inward during injection, maintaining mold integrity even with thinner walls.
3Adaptability or versatility
If customized molds are produced for low-volume production, then adaptability increases, but economy deteriorates without high-volume production
Solution Approach 1:
The patent makes customized molds economically viable for low-volume production by treating them as disposable or limited-life components. The low cost of plastic molds allows customization without the need for high-volume production to amortize the cost, enabling economical low-volume production of specialized parts.
Solution Approach 2:
The patent changes the production volume parameter from high-volume to low-volume, making customized molds economically feasible. By accepting lower production volumes, the system eliminates the need for expensive metal molds and achieves cost-effective customization through disposable plastic molds.
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 customized molds with reduced wall thickness and material costs, facilitating low-volume injection molding with efficient pressure control and mold support.
Implementation Method 1
the fluid injector apparatus is configured to generate a pressure within the fluid surrounding the mold to counteract and resist outward deflection of an outer surface of the mold
Data Source
AI summary
A manufacturing system includes an additive manufacturing (AM) system and a fluid supported molding system. The AM system is configured to produce a plastic mold. The fluid supported molding system includes a pressure vessel surrounding a pressure chamber. The pressure vessel is configured to contain a fluid surrounding the mold. The fluid supported molding system also includes a mold material injector configured to inject a mold material into the mold. During the injection of mold material into the mold, the fluid surrounding the mold is configured to resist defection of an outer surface of the mold.