There are several kinds of plastic raw material used for manufacturing the plastic bags or any other plastic items like bottles, switches, buttons et al. However, the thermosetting plastic, elastomers and the polymers or resins that are widely used in the production process due to the presence of greater viscosity in these materials.
Plastics are incredibly versatile and are widely used in everyday life ranging from common household items to their various uses in building and agricultural products
Plastic is a synthetic substance made from small organic molecules generally containing carbon and hydrogen with a mixture of other elements like oxygen and nitrogen. These molecules join together to form polymers which can then be moulded into any shape. Plastics fall under two distinct categories, thermoplastics and thermosets. Thermoplastics are plastics which, once prepared, can be heated and reformed continuously, thus facilitating the recycling process. Thermosets, however, cannot be reformed and once set, cannot be remoulded. Depending on the type of products to be manufactured, different plastic manufacturing processes are employed. There are three types of processes used for plastic manufacturing, according to the product requirements, these are injection moulding, extrusion moulding and thermoforming. All these types have their own importance.
When it comes to moulding, there are many moulding processes performed by plastic suppliers including the plastic injection moulding and the plastic extrusion moulding processes. Injection moulding is the most common process whereby plastic PVC pellets are fed into a largely heated barrel where they are crushed and turned into liquid. The liquid is then propelled through a nozzle and into the mould and left to cool into its correct shape whilst pressure is applied to keep the plastic in place. This form of plastic manufacture results in everyday items such as household containers, bottle caps, one-piece chairs and tables and mechanical gears.
The plastic raw material is also used to create large heavy duty items such as aircraft and car windscreens, vehicle doors and dash panels. The process of producing these large plastic sheets is through thermoforming. This is a far less forceful process then the injection or extrusion moulding. The plastic is heated and moulded much like clay and is left to cool into the required position once finished. Although this method is a lot less expensive it is fairly limited as fewer shapes are possible to create.