Manufacturing Process of Plastic Caps & Closures

People interact with millions of bottle caps every day and everywhere in the world. Some carry life-saving medications on children’s-proof pharmaceutical bottles, while others are on water bottles necessary to quench someone in thirst. Each of these bottle caps has to be created, and their production is a considerable effort. Plastics may be found everywhere, even in everyday life, but many people do not realize that it is for commercial or industrial purposes different techniques of forming it.

Plastic caps: Manufacturing process

The initial stage in the manufacture of plastic products is to extract the natural gas or raw oil raw material. Heavy machinery is used for boiling to collect raw material from the subsurface. The raw material gathered is transferred to the refinery through the pipelines. Heating oil and gas is done to manufacture pellets of pure plastic.


Thermoplastic closures molded by injection are mostly manufactured from polypropylene, polythene, or styrene. These closures are non-rigid, provide design freedom, and are cost-effective. Injection-molded closures are conveniently designed to save on liner costs and installation.


These fittings are very tough and provide great dimensional stability and chemical resistance. Compression-molded locks at high temperatures are stable and are often used for autoclaving. Compressive molded closures are often heavier and substantially costly than molded closures using injection.


The plastic powder is placed into the mold cavity, and the rest of the mold is then fastened, and the chamber is closed for warming.


The mold is heated until the plastic powder is melted and attached to the walls of the mold. The mold is rotated along two pivoting axes to provide for a consistent plastics coating.


As long as the mold continues in motion, the mold is progressively cooled to guarantee that the component skin does not shrink or collapse before crystallization.

Removal of part

The part is detached from the mold, and all flashes are cut off.

The Bottom line

Finally, solid components are painted, sprayed, and the final color. The smooth ending is done by automatic equipment or by hand means. The quality control process is followed by the implementation of and disposal of damaged products. The finished manufactured Plastic Cap items are packaged and sent to Retailers or Bottle Manufacturing companies.


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