Industrial injection, or plastic injection molding, is a process used to consistently create uniform products of plastic or similar material for a wide variety of uses. Simply, a mold made of aluminum, steel, or other metal alloy is created to specifications prescribed for the end product. A molten synthetic material is then forced into the mold and allowed to cool before being removed.
Machines used for industrial injection molding range from simple one-person operations with a small shop footprint to large multi-stage machines. A small injection molding machine, while very affordable for the small entrepreneur, is limited in scope in terms of product configuration and production rates. Larger and more sophisticated injection molding companies can produce a vast array of products in large numbers to meet the needs of major end-use companies.
Versatility is a strong argument for industrial injection. Injection molding companies offer products ranging from large, high-voltage electrical components and industrial machinery to tiny parts for computers and medical applications. Injection-molded plastics can be used for limited product numbers and prototypes to runs of production of an identical piece numbering in the thousands per month.
For limited production and prototypes, rapid injection molding has become an industry unto itself. While steel molding and setup for large production numbers might take months to come on line, rapid injection molding might typically have a limited number of products ready in a matter of days. Colors, materials,and design are consistent with specifications, but the molds used are essentially temporary and good only for small production runs.
Materials used in industrial injection depend upon a number of factors, including cosmetics, durability, cost, and other, more specialized, factors such as resistance to electrical current and fire resistance. Products such as acrylonitrile butadiene styrene (ABS) are commonly used where toughness and durability are desirable. As an example, ABS is in common use for residential waste and soil pipes because it is tough, durable, and low cost.
Other materials, such as synthetic resins, nylon blends, and thermoplastic elastomers, are used in applications able to absorb a higher cost. Chemists and engineers collaborate to determine the optimum synthetic for injection-molded parts. Many injection-molded plastics can be recycled.
In many industrial injection applications, cosmetics play a major role. Injection-molded plastics used in health clubs or furniture, for instance, have to be durable and attractive. An advantage of using injection-molded plastics for these uses is the capability to add color during the molten stage so that coloration is integral to the product and not a superficially applied coating. Wear and tear are not readily seen even when items are deeply scratched.