Plastic water bottles are found everywhere. The ease of production and low cost have made them a standard container for general consumption. Blow molding is the most common method for manufacturing plastic water bottles. It allows for great flexibility in design while minimizing cost. Thousands of bottles can be manufactured quickly and uniformly with high-speed injection blow-mold presses. The molding process typically takes place in an industrial setting with trained plastic technicians.
Dry the plastic resin before molding. The majority of plastic bottles are molded out of polyethylene terephthalate (PET). PET is hygroscopic, so it will absorb water out of the air. High moisture content in PET can effect the way it performs when processed.
Load plastic resin into the feed hopper. As most plastic bottle-molding processes run long cycles in an automated environment, vacuum feeders should be used to make sure the material hopper does not run out of resin.
Set the injection press to the appropriate temperature, pressure and cycle time for the specific part to be molded. As conditions are subject to the specific grade of PET, part size, wall thickness and equipment type, it is best to consult with a material supplier and a plastic engineer to determine the best conditions for a specific circumstance.
Start injection cycle once the dried material is loaded and the machine has reached appropriate temperatures. For a straightforward part like a water bottle, the machine should be able to operate in an automatic production setting. requiring typical oversight.
This is not a do-it-yourself project. Blow molding is an industrial process that should be done in an industrial setting for safety and to meet community guidelines for businesses. The heavy equipment used presents a risk, too. Only trained technicians should operate injection presses.