Plastics are commonly used in most of the things ranging from automobile body parts to human body parts. Plastic molding is a method of manufacturing which includes shaping of liquid or pliable materials using a firm frame called matrix or mold. This technique creates objects with vivid shapes and sizes involving both simple and complex designs. Car parts, sign boards, containers, high volume objects are some of the final products of plastic molding.
If you are looking for custom plastic molding, it is imperative to know different types of plastic molding. The list below briefs out the different materials used in different molding process.
- Blow molding
Blow molding is best suited for objects that are hollow such as bottles or thin walled containers. This process can manufacture high volume bottles uniformly. The basic steps involved in the process are: A heated tube or plastic mass is overblown by air. This blown air presses the plastic against the mold’s walls, to form desired shape. After complete cooling, plastic is ejected out of mold. Blow molding is one of the most economical molding processes when compared to other processes.
- Compression molding
In compression molding, heated plastic is positioned in heated mold and then compressed to desired shape. Compression molding is best suited for strong compounds like fibreglass and reinforced plastics. Compression molding produces poor consistency products and hence not suitable for automotive industry. Some of the common materials used in compression molding process are: Torlon, Vespel, Polyester fiberglass resin systems (SMC/BMC), Polyphenylene sulfide(PPS) and other grades of PEEK.
- Extrusion molding
Extrusion molding is best suited for long hollow objects like straws, tubes and pipes. This molding process forces out liquefied plastic straight into a die. The shape of final product is determined by the shape of die and not the mould. The extrusion is then allowed to cool and form a solid shape. Some of the shapes resulting from Extrusion include: U-sections, T-sections, L-sections, square sections, I-sections and circular sections.
- Injection molding
Injection molding is the most versatile form of molding process. The process includes injecting materials into moulds to produce different products. Some of the manufacturing materials used in the process include: glasses, metals, confections, elastomers, thermosetting and thermoplastic polymers. The process involves – injecting the moulding material into heated barrels and then pushing it into a mold cavity. It is then allowed to cool and harden and finally ejected by pins. Injection mold making cost is comparatively higher, but cost per part is quite economical.
- Rotational molding
Rotaional molding also known as Rotomolding is best suited for huge, hollow objects like tanks. Rotational molding process involves continuous rotational movements at relatively high temperature, to coat the mold’s inside. Continuous rotation creates constant centrifugal force resulting in uniform or even walled products. However, rotational molding is not a high-speed moving process. This type of molding is reasonable and ensures minimal wastage of materials during the process.
Each molding types listed above has its own set of advantages and disadvantages. But nevertheless, the above list of molding types is sure to help you decide the right one for your production process.