Plastic Bottle Manufacturing
Plastic bottles, especially those made from PET, are produced through a process called blow moulding. The overall process can be broken down into several steps:
Raw Material Preparation
- The process starts with PET resin (small plastic pellets or granules).
- The pellets are melted into a viscous liquid by heating them to a high temperature.
Injection Moulding (Preform Stage)
- The melted PET is then injected into a mould to form a preform. This is a test-tube-shaped piece of plastic with the neck and screw threads of the final bottle already moulded.
- The performance is cooled and solidified before moving on to the next stage. At this point, it looks like a small, thick plastic tube.
Blow Moulding
- The preform is heated again to soften it, making it ready for stretching and shaping.
- The preform is placed inside a blow mould that defines the final shape of the bottle.
- Compressed air is blown into the preform, causing it to expand and take the shape of the mould. The preform stretches both vertically and horizontally, forming the bottle.
- The mould is cooled so that the bottle solidifies quickly into its final shape.
Trimming and Finishing
- After blow moulding, excess plastic from the bottle’s neck or base is trimmed off.
- The bottles are then inspected for defects like cracks or uneven walls.
Labelling and Packaging
- Once formed and cooled, the bottles are labelled, capped, and packaged for transportation to bottling plants or directly to consumers.
Types of Blow Moulding
Extrusion Blow Moulding: This process involves extruding a tube of molten plastic into the mould, then blowing air into it.
Injection Blow Moulding (IBM): Uses injection moulding to create the preform, which is then blown into its final shape. This is the most common method for PET bottles.
Stretch Blow Moulding (SBM): A variation of IBM, used for PET bottles, where the preform is stretched vertically and horizontally during blow moulding, increasing the bottle’s strength.
This entire process is efficient, cost-effective, and produces lightweight, durable plastic bottles suitable for a wide range of products.
How Are Plastic Bottles Disposed Of?
Plastic bottles made from PET are recyclable with the help of our team. We collect a range of PET products from businesses nationwide, allowing them to safely dispose of materials. Get in touch today to book a collection for your plastic waste, and ensure these recycled materials are reintroduced back into the market.
