Plastics are generally the polymers that are further categorized into two basic types: Thermoplastics and Thermosets.
Thermoplastics: Thermoplastics are a kind of plastic that can be melted and re-formed again and again. Some of the key features of thermoplastics include highly recyclable, high impact resistance, chemical resistant, eco-friendly manufacturing, remolding or reshaping capabilities, aesthetically superior finishes, etc.
Thermosets: Thermosets are a kind of plastic that can only be heated and shaped once as they get harden when they are heated. If heated further, they will break down chemically and lose their properties. Some of the key features of thermosets plastics include highly flexible design, more resistant to high temperatures than thermoplastics, excellent aesthetic appearance, high levels of dimensional stability, cost-effective, etc.
There are a number of options available to form different types of finished custom plastic components. Each method has its advantages and disadvantages and is best suited for specific applications. Before choosing any particular plastic processing method for our next project, you must be aware about the major techniques so that you’ll be able to make an informed decision. Here are some of the top methods of processing plastics, have a look:
Injection Molding: Plastic injection molding is one of the most popular methods for mass producing plastic parts. Under this method, plastic pallets are placed into a hopper where they are heated until molten. The molten plastic is then pushed through a long chamber with a reciprocating screw wherein the core is pressed to form the final shape. Once cooled, the now-solid part is ejected and the process repeated.
Blow Molding: Blow molding method is mainly used when the plastic product that needs to be created should be hollow such as bottles, containers and light globes. A molten tube is formed with blow molding with the help of compressed air that blows up the tube and forces it to conform to the chilled mold. The two most-common types of blow molding are: Injection Blow Molding, Injection-Stretch Blow Molding, and Extrusion Blow Molding.
1.In injection blow molding, the plastic is taken to a blow mold and filled with compressed air. As a result, it conforms to the interior design of the blow mold.
2.In injection-stretch blow molding, the plastic is stretched prior to being formed. Otherwise, it is basically the same as the injection process.
3.In extrusion blow molding, a molten plastic tube is created and is pinched between two mold halves. Then, a needle or a blow pin is inserted into the tube and blows compressed air up the part in order to force it to conform to the mold interior.
Rotational or Roto Molding: Plastics that are generally used for rotational molding include nylon, ABS, polyethylene and PVC. The key steps involved under rotational molding are:
1.Preparing the mold- In this step, plastic in the form of powder along with other additives such as colorants or UV stabilizers is placed inside the mold, which goes into a pre-heated oven.
2.Heating and fusion-Within the oven, the mold is rotated slowly on two axes. Instead of using centrifugal force to displace the material, it is allowed to combine onto the mold walls under gravitational pressure. The temperature and timing must be controlled precisely during this stage.
3.Cooling- The mold is removed from the oven and allowed to cool down either naturally or with the help of forced air, water or a combination.
4.Unloading- Once cooled, the part is removed from the mold and the process is repeated.
These are some of the key methods used to process plastic. It is important to note that each method has its advantages and disadvantages and are suited for specific applications. Choose the one that you feel is right for your next project.