Plastic Manufacturing Processes

Involves the heating of plastic granules until soft within the hopper, these are then injected under pressure into moulds, where the molten plastic hardens into the desired shape.

Advantages:

• Detailed features
• Complex geometry
• High efficiency
• Enhanced strength
• Automatic process, humans only needed for quality check

Disadvantages:

• High tooling costs
• Long set up times
• Design restrictions within the product
• Small parts of runs can cost alot of money
• Up-front costs are high

Injection Moulding can be used to make:

• Wire spools
• Packaging
• Bottle caps
• Automotive parts
• Components

Blow molding is a manufacturing process that is used to create hollow plastic parts by inflating a heated plastic tube until it fills a mold and forms the desired shape. Parts made from blow molding are plastic, hollow, and thin-walled, such as bottles and containers that are available in a variety of shapes and sizes.

Advantages:

• Costs are not as expensive as other processes
• Machinery costs are also low
• Easy to mould external threads
• Production can happen in large quantities
• Automatic process

Disadvantages:

• Petroleum usage
• Affects the environment
• Requirement of precision makes waste

Blow moulding can be used to make:

• Plastic bottles
• Containers
• Storage tanks

Vacuum forming is a simplified version of thermoforming, a sheet of plastic is heated to a forming temperature, stretched onto a single-surface mold, and forced against the mold by a vacuum.

Advantages:

• Fast prototyping
• Fast production time frames
• Ability to create huge pieces
• Lower start-up costs

Disadvantages:

• Wall thickness can be inconsistant
• Deeper areas are harder to achieve
• Intricacy of parts is restricted

Vacuum forming can be used to make:

• Plastic containers
• Tubs
• Sink Units
• Electrical enclosures

Compression molding is a forming process in which a plastic material is placed directly into a heated metal mold then is softened by the heat and therefore forced to conform to the shape of the mold, as the mold closes.

Advantages: 

• Low costs
• Little waste is produced
• Suitable to make large parts
• No gates, sprues or runners

Disadvantages:

• Very slow
• High labour costs
• Slow processor times

Compression Moulding can be used to make:

• Ceramics
• Kitchenware
• Switches
• Handles