Injection moulding is a manufacturing process for producing parts by injecting molten material into a mould, or mold. Injection moulding can be performed with a host of materials mainly including metals, glasses, elastomers, confections, and most commonly thermoplastic and thermosetting polymers. Material for the part is fed into a heated barrel, mixed, and injected into a mould cavity, where it cools and hardens to the configuration of the cavity. After a product is designed, usually by an industrial designer or an engineer, moulds are made by a mould-maker from metal, usually either steel or aluminium, and precision-machined to form the features of the desired part. Injection moulding is widely used for manufacturing a variety of parts, from the smallest components to entire body panels of cars. Advances in 3D printing technology, using photopolymers that do not melt during the injection moulding of some lower-temperature thermoplastics, can be used for some simple injection moulds.
A moldmaker or molder is a skilled tradesperson who fabricates moulds for use in casting metal products.
Thermoforming is a manufacturing process where a plastic sheet is heated to a pliable forming temperature, formed to a specific shape in a mold, and trimmed to create a usable product. The sheet, or "film" when referring to thinner gauges and certain material types, is heated in an oven to a high-enough temperature that permits it to be stretched into or onto a mold and cooled to a finished shape. Its simplified version is vacuum forming.
Vacuum forming is a simplified version of thermoforming, where a sheet of plastic is heated to a forming temperature, stretched onto a single-surface mould, and forced against the mould by a vacuum. This process can be used to form plastic into permanent objects such as turnpike signs and protective covers. Normally draft angles are present in the design of the mould to ease removal of the formed plastic part from the mould.
Blow molding is a manufacturing process for forming and joining together hollow plastic parts. It is also used for forming glass bottles or other hollow shapes.
Microcellular plastics, otherwise known as microcellular foam, is a form of manufactured plastic fabricated to contain billions of tiny bubbles less than 50 microns wide. It is formed by dissolving gas under high pressure into various polymers, relying on the phenomenon of thermodynamic instability to cause the uniform arrangement of the gas bubbles, otherwise known as nucleation. Its main purpose was to reduce material usage while maintaining valuable mechanical properties. the density of the finished product is determined by the gas used. Depending on the gas, the foam's density can be between 5% and 99% of the pre-processed plastic. Design parameters, focused on the foam's final form and the molding process afterward, include the type of die or mold to be used, as well as the dimensions of the bubbles, or cells, that classify the material as a foam. Since the cells' size is close to the wavelength of light, to the casual observer the foam retains the appearance of a solid, light-colored plastic.
Rotational molding involves a heated hollow mold which is filled with a charge or shot weight of material. It is then slowly rotated, causing the softened material to disperse and stick to the walls of the mold. In order to maintain even thickness throughout the part, the mold continues to rotate at all times during the heating phase and to avoid sagging or deformation also during the cooling phase. The process was applied to plastics in the 1950s but in the early years was little used because it was a slow process restricted to a small number of plastics. Over time, improvements in process control and developments with plastic powders have resulted in increased use.
Mack Group is a privately held corporation providing contract manufacturing with specialties in plastics design, prototyping, molding, sheet metal fabrication and full product assembly.
Fusible core injection molding, also known as lost core injection molding, is a specialized plastic injection molding process used to mold internal cavities or undercuts that are not possible to mold with demoldable cores. Strictly speaking the term "fusible core injection molding" refers to the use of a fusible alloy as the core material; when the core material is made from a soluble plastic the process is known as soluble core injection molding. This process is often used for automotive parts, such as intake manifolds and brake housings, however it is also used for aerospace parts, plumbing parts, bicycle wheels, and footwear.
A threaded insert, also known as a threaded bushing, is a fastener element that is inserted into an object to add a threaded hole. They may be used to repair a stripped threaded hole, provide a durable threaded hole in a soft material, place a thread on a material too thin to accept it, mold or cast threads into a work piece thereby eliminating a machining operation, or simplify changeover from unified to metric threads or vice versa.
An injection molding machine, also known as an injection press, is a machine for manufacturing plastic products by the injection molding process. It consists of two main parts, an injection unit and a clamping unit.
The Bemis Manufacturing Company is an American manufacturing company based in Sheboygan Falls, Wisconsin, and is best known for its toilet seat products. Bemis also manufactures plastic lawn, commercial, and indoor furniture, suction canisters, sharps containers, fluid management systems, gas caps, gauges and various contracted extrusion and injection molded plastic parts for companies such as John Deere and Whirlpool Corporation. The company is a pioneer of co-injection molding, a process in which virgin resin is injected with scrap plastic.
Chen Hsong Holdings Limited is a manufacturer and supplier of plastic injection moulding equipment and systems. The company was established by Dr. Chiang Chen in a small village workshop in Hong Kong in 1958. The following half-century has been a period of growth and expansion both locally and internationally. Today Chen Hsong has a customer base covering more than 80 countries worldwide including China, Taiwan, the United States, Canada, France, the United Kingdom, Brazil, Argentina, Mexico and most Southeast Asian countries.
HARBEC manufactures prototypes, highly toleranced tooling, machined components, and injection molded parts. They produce engineered custom plastic parts for customers in the medical, automotive, electronic, telecommunications, consumer goods, and other industries. HARBEC performs initial design and concept molding; production tooling; low and high volume production injection molding and secondary processes.
Gemini Group, Inc. is a supplier of engineered plastic and metal products to OEM's and Tier 1 suppliers. The company operates internationally from its headquarters in Bad Axe, Michigan in the United States.
Thin wall injection molding is a specialized form of conventional injection molding that focuses on mass-producing plastic parts that are thin and light so that material cost savings can be made and cycle times can be as short as possible. Shorter cycle times means higher productivity and lower costs per part.
Solid Concepts, Inc. is a custom manufacturing company engaged in engineering, manufacturing, production, and prototyping. The company is headquartered in Valencia, California, in the Los Angeles County area, with six other facilities located around the United States. Solid Concepts is an additive manufacturing service provider as well as a major manufacturer of business products, aerospace, unmanned systems, medical equipment and devices, foundry cast patterns, industrial equipment and design, and transportation parts.
Cast Urethanes are similar to injection molding. During the process of injection molding, a hard tool is created. The hard tool, made of an A side and a B side, forms a void within and that void is injected with plastics ranging in material property, durability, and consistency. Plastic cups, dishware, and toys are most commonly made using the process of injection molding because they are common consumer items that need to be produced on a mass scale, and injection molding is designed for mass production.
Protolabs is a company that provides rapid manufacturing of low-volume 3D printed, CNC-machined, sheet metal, and injection-molded custom parts for prototyping and short-run production. Markets like medical devices, electronics, appliances, automotive and consumer products use these parts. Protolabs' headquarters and manufacturing facilities are located in Maple Plain, Minnesota. The company also has manufacturing facilities in England, Germany, and Japan.
Core Molding Technologies, Inc. was founded in 1988 and now based in Columbus, Ohio. The company manufactures sheet molding compounds (SMC), and molds fiberglass reinforced plastics. It occupies over 1,000,000 square feet of manufacturing space and its main subsidiaries are in Matamoros, Mexico, Gaffney, South Carolina, and Cincinnati, Ohio. In 2011, Core Molding Technologies formed Core Specialty Composites, LLC.
