Plastic Injection Molding & Other Molding Types
October 26, 2018
We are frequently asked about different molding types and how each effect the process of part design and production. At Xcentric Mold & Engineering, we specialize in plastic injection molding. Below briefly highlights some of the more popular molding types:
Plastic injection molding
Injection molding is a manufacturing process process for producing parts by injecting molten material into a mold. Material for the part is fed into a heated barrel, mixed (using a helical shaped screw), and injected into a mold cavity, where it cools and hardens to the configuration of the cavity.
Material selection is critical for plastic injection molding, which can be performed with a host of materials including plastic, metals (for which the process is called die-casting), glasses, elastomers, confections, and most commonly thermoplastic and thermosetting polymers.
Common examples of plastic injection-molded parts include medical equipment and medical devices, automotive, marine, industrial, agriculture, aerospace and tight tolerance parts.
Other Molding Types
Below are some molding types which are not specialties of Xcentric Mold & Engineering however we may be able to provide you with recommendations of other suppliers who specialize in the following:
Blow molding is a specific manufacturing process by which hollow plastic parts are formed and can be joined together. In general, there are three main types of blow molding: extrusion blow molding, injection blow molding, and injection stretch blow molding. The blow molding process begins with melting down the plastic and forming it into a parison or in the case of injection and injection stretch blow molding (ISB) a preform. The parison is a tube-like piece of plastic with a hole in one end through which compressed air can pass.
The parison is then clamped into a mold and air is blown into it. The air pressure then pushes the plastic out to match the mold. Once the plastic has cooled and hardened the mold opens up and the part is ejected.
Common examples of blow molding products include bottles, containers and other hollow shapes.
Rotational molding is comprised of a heated hollow mold which is filled with a charge or shot weight of material. It is then slowly rotated (usually around two perpendicular axes), 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.
Common examples of rotational molding include parts larger than 2’ such as containers, utility carts, storage bins, car parts, tanks (oil, septic, water) and leisure products such as kayaks.
Vacuum forming is a process by which a sheet of plastic is heated until it becomes pliable, stretched onto a single-surface mold and forced against the mold by a vacuum to create a shape.
This process can also include thick-gauge thermoforming, a type of vacuum molding, that is known for producing a variety of products including disposable cups, containers, lids, trays, blisters, clam shells, and other products for the food, medical, and general retail industries.
Common products produced with the vacuum forming application include industrial containers and crates, pallets, exterior door panels, plastic totes, plastic trailers, passenger cabin window canopies for winged aircraft, and lawn mower hoods.
Would you like additional information about the plastic injection molding process and its capabilities? Contact our Technical Specialists today at 586-598-4636 or email@example.com.