In parts one and two of this multi-part blog series, we’ve gone over many of the most important terms to be aware of within the injection molding world. Whether you’re a client making an order from a molding company, a molding expert or anyone in between, a basic understanding of these terms will not only make the entire process easier, but will allow you to participate fully in any decisions being made.
At EnviroTech Custom Injection Molders, we’re proud to not only provide a wide range of custom injection molding services, but also expertise and product information for any of our clients looking to learn more. In today’s part three of our series, we’ll go over a couple other important terminology areas, including details on all three of the most common injection molding processes and the terms that define them.
Flash or Burrs
These two terms are used interchangeably to describe an occurrence of small, wafer-like protrusions that may appear on certain finished parts in the injection molding process. This is an error in setup, one that allows the melted resin to escape the mold cavity, most often along the parting line or an ejector pin.
In other cases, flash will be caused by excessive pressure or injection speed – in these cases, it can be removed simply by reducing the speed or pressure involved. In still other situations, flash will be caused by too high a mold temperature plus barrel heat that’s too high.
Various Processes
There are three common processes used in plastic injection molding:
- Hydraulic: The most common process, this involves machinery with hydraulic cylinders that clamp down together and push two halves of a mold together at high pressure. From here, plastic substrate pellets are melted, and the resulting liquid is injected into the mold cavity. Once the mold has cooled and hardened, it is separated, the part is removed, and the process can be done all over again.
- Electric: Only introduced in the 1980s, the electric molding process is quieter, faster and more accurate. It is powered by digital high-speed servo motors instead of hydraulics, which allows for better energy efficiency as well. However, this process is more expensive than hydraulic molding.
- Hybrid: This process actually combines both the hydraulic and electric formats to get the best of both worlds. It offers the clamping quality of hydraulics with the precision and energy savings of electric, plus the accuracy of the latter. Over the last several years, these hybrid molding machines have become extremely popular on the market.
For more on various terms to be aware of in the plastic injection molding world, or to learn about any of our bulk molding, slab stock molding or other services, speak to the staff at EnviroTech Custom Injection Molders today.
