Molding, in the simplest terms, is the process of shaping plastic and other liquid materials using a mold. Plastic molding involves using liquid or a powdered polymer for creating desired articles with specific sizes and shapes. There are various kinds of plastic molding techniques, and five of the most popular ones are discussed below.
- Rotational Molding
Rotational molding also known as rotomolding, is mainly used to make large hollow parts for products. Unlike other techniques, this method does not involve using extreme pressure on the mold, and therefore, a wider range of products can be made. There are companies that specialize in custom plastic molding using this technique, which is more like casting. The powder or liquid resin is placed in a mold, which is then rotated so that the material covers the mold. Once the cooling process is completed, the hardened plastic product is taken out. The wasted produced from this process is considerably low.
- Injection Molding
This is the most traditional technique of molding plastic. The process involves injecting molten material into a metal mold, which is then cooled to get the required product. If you need large volumes of custom plastic parts, this is probably the most effective technique. The molds are, however, expensive and are usually made from steel and aluminum. The molds must be good quality, and the amount of production time can run into weeks.
- Blow molding
This kind of molding is used for creating thin plastic products, mainly when the shape is important. If you know the principle behind glassblowing, then this method follows the same technique, where the plastic is heated up by using injected air. The plastic is blown into a mold, and as it presses against the walls of the mold, the desired shape is formed. Blow molding is used for making many products and is more effective than injection molding in terms of pricing, but it is still more expensive than rotational molding.
- Compression Molding
This process is rather simple. The plastic material is heated up and placed in a heated mold and then pressed accordingly to get the right shape. The plastic is further compressed to the required density, after which it is cooled and trimmed as needed. This kind of molding is effective when there’s a need to replace metal parts with plastic ones. It is mostly used for making smaller items, and the focus is on strength and durability.
- Extrusion Molding
It is almost same as injection molding, except that the process involves the use of something called ‘die’, instead of a mold. The products are made by passing heated material through a die. The simplest example of products made of such molding is PVC piping. This is a costly process, but is often needed in many industries.
You can check online to find companies that specialize in manufacturing custom products. For a number of products, you can minimize the cost by opting for rotomolding, which one of the most cost-effective techniques available in the industry.