A plastic material that can be melted, cool and solidify
diecastingpartsupplier
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2017-04-05 20:02:01
A sprue is simply the channel that guides molten plastic from the nozzle of the injection molding machine to the entry point for the entire injection mold tool. It is a separate part from the mold tool itself.
A runner is a system of channels that meet up with the sprue, typically within or as part of the mold tool, that guides the molten plastic into the part cavities within the mold tool. There are two principal categories of runners (hot and cold) which you can read about here. Lastly, the gate is the part of the channel after the runner that leads directly into the part cavity. After an injection mold cycle the entirety of the molten plastic will cool leaving solid plastic in the sprue, runners, gates, part cavities themselves, as well as a little bit of overflow potentially on the edges of the parts. In the case of thermosetA thermoset material, such as an epoxy resin that cures once exposed to air, is a material that cures and would burn after curing if one attempted to melt it.
Thermoplastic material by contrast, is a plastic material that can be melted, cool and solidify, and then be melted again without burning. materials, all of the material (except the parts themselves) is eventually discarded as waste. With thermoplastic materials the material can be recycled are used again. Sometimes this happens right on the factory floor. They grind up the sprues/runners and any reject parts. Then they add that material back into the raw material that goes into the injection molding press.