Many plastic manufacturers are committed to proactively addressing customer demands for rapid turnaround on molded plastic parts. The benefits of low volume production are significant in the plastic molding process. Recognizing this, producing low volume plastic molding parts requires utilizing various manufacturing methods. Short-run injection molding can be employed to produce actual injection molded pieces based on the specified quantity of elements, serving as an initial production run.
Also known as low-volume injection moulding, it involves the rapid production of high-quality, high-precision parts. It is the preferred method for producing large quantities of finished plastic parts for industrial and commercial applications. Molten resin is injected into the cavity of a metal mould under high pressure and immediately cools to form a solid shape. A single process to produce a complete part can take from a few seconds to a few minutes, depending on the complexity and size of the part.
Before you start the injection moulding process, you should first prepare all the tools required for the process. All steps must be followed to ensure an accurate end product. The first step is to dry the resin in the form of raw pellets to the correct moisture content and then mix with colourants or masterbatches as required. Next, the dried pellets are poured into the casting machine’s bowl and the alternating spirals inside the casting machine’s container move the pellets towards the mould.
The third step is to mix and heat the solid pellets in the barrel to completely melt them into liquid resin. At this point, the heated mould closes automatically and the resin is injected through an orifice into the mould cavity under high pressure. The mould is then cooled to cure the internal parts and the mould is opened to remove the parts and start a new series.
Also known as Prototype Injection Moulding, it is used to produce injection moulded parts in quantities dependent on your requirements and only as a one-off product. It is ideal for operational prototypes, bridge moulds and short runs. Short-run injection moulding can also be used to produce small batches of plastic parts. Various companies use this process to produce parts based on their quantity requirements. The short-run injection moulding process first requires the loading of a 3D computer-aided design file to obtain a quick mould. After the design file is loaded, moulding and processing take place. Engineers can evaluate the model to ensure you get a model that meets your specifications. Once the engineer has approved your design, mould production begins. You will have time to inspect your samples and give your approval. When all these processes are complete, production of the part begins.
Generally referred to as vacuum forming or thermoforming, it is the process of covering a hollow or elongated tool with a layer of hot plastic material. The material is first stretched, a vacuum is passed through a specific device, and then pressure is applied to the back of the layer to fill the cavity with the desired shape. After the production is completed, the excess material of the formed part is trimmed using a CNC cutting machine.
This rapid injection molding method injects a liquid thermosetting material and then mixes it under very low pressure. The material has a hard, dense structure, and various reaction molding materials are created for specific uses. Reaction molding is usually made with epoxy aluminum composites, which are low-cost and can maintain a high number of injections. The base material can be colored in the correct order, but the appearance parts need to be painted and sanded. For large plastic parts with intricate details, reaction molding is the best choice.
This molding method injects plastic resin in short bursts and then uses natural or synthetic blowing forces to expand the material within the mold. The resulting part has closed interior areas but a hard outer skin. Bubbles that burst on the outer surface as the mold is filled create a curled appearance on the outside. Sanding and painting are excellent ways to correct this effect. Other tooling upgrades are available. Structural foaming is less expensive than other procedures and will create a smoother molding process.
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