Injection molding is a process where a molten material is injected at a high pressure into a mold, to form a certain shape or form. Different molten materials yield different properties of the final product, and also have different processes.
ABS, or Acrylonitrile Butadiene Styrene, is one of the materials that may be used in this process. ABS is a thermoplastic polymer, with properties that lend itself very well to the injection molding process. Many consumer products that we see and use today have been manufactured using ABS injection molding.
ABS is a plastic with a fairly low melting point in the world of injection molding. ABS melts at just above 100⁰C, and is typically injected at a temperature of just above 200⁰C. While this lower melting temperature makes the injection process cheaper and easier, it also limits the use of ABS in high temperature applications. ABS is a thermoplastic, which means that it can be melted again and reused in the process.
ABS has mechanical properties that makes the post processing thereof cheap and easy. It is highly machinable, and responds well to typical plastic processes such as glue fixing and polishing. The strength of ABS is not high enough to make it a prominent figure in engineering plastics, but it is sufficient to use in domestic end user products. It does however have a good impact strength and material resilience which it owes to its chemical composition.
The properties of ABS show a good marriage between in its constituents – butadiene provides ductility and resilience, nitrile bonds provide strength and the styrene components give an aesthetic finish.
ABS is a thermoplastic, meaning it can be melted down and used again
Energy required for melting down the plastic is low, and a lower mold temperature is needed which results in higher production speed
ABS provides a high quality surface finish with the correct process, making it suited for commercial end user products
Mechanical post processing is easy with ABS, owing this to its mechanical properties
Products made from ABS have good impact strength, due to the elasticity of the material
ABS material is abundant and requires a low energy molding process, greatly reducing the production cost
The natural transparency of ABS enables it to be used in see-through applications, but also makes it easy to add any colour to the final product
Even though the strength ABS is too low for hard wearing engineering applications, it is still high for domestic plastics, especially in regards to dimensional rigidity, resilience and wear resistance
The chemical composition of ABS makes it very receptive for chemical post processing such as gluing and painting
ABS is suited for many user products where a relatively low cost, good surface finish, colouration and low temperatures are involved. Applications may include plastic computer input devices such as keyboards, plastic toys and building blocks, electric tool enclosure, carrier bags and medical equipment. Another interesting one is bulletproof windows, where the transparency and impact strength comes to its full right.