Plastic Processes

Plastics Processing involves 3 key stages:

Process selection depends on many factors including:

Process

Applications

Sponsor

Structural Foam

Structural Foam is a term commonly used to describe thermoplastic injection moulding components made by the injection moulding process which have a cellular core.

Rotational Moulding

Rotational moulding differs from all other processing methods in that the heating, melting, shaping, and cooling stages all occur after the polymer is placed in the mould, and no external pressure is applied during forming.

Injection Moulding

Most thermoplastics can be processed by Injection Moulding.

Injection Moulding (Gas Assisted)

Enhanced quality, reduced cycle times and component weight reductions can be achieved by gas assisted injection moulding.

Injection Blow Moulding

Injection blow moulding is used for the production of hollow objects in large quantities. The main applications are bottles, jars and other containers. The Injection blow moulding process produces bottles of superior visual and dimensional quality compared to extrusion blow moulding.

Injection stretch blow moulding is used for the production of high quality containers.

Thermoforming

Thermoforming has close similarities with Vacuum Forming except that greater use is made of air pressure and plug assisted forming of the softened sheet. Only thermoplastics sheet can be processed by this method.

Extrusion Blow Moulding

Used for the production of hollow objects in large quantities. Obvious application are bottles and similar containers.

Insert Moulding

Inserts can either be incorporated at the time of the moulding process, or be inserted as a post moulding operation.

Moulding Expanded Polystyrene (EPS)

Expanded polystyrene (EPS) is used for the production of a number of applications. However its major application is as a protective packaging for consumer electronic products and white goods.

Vacuum Forming

Vacuum formed products are all around us and play a major part in our daily lives. Virtually all thermoplastics can be supplied as sheet and vacuum formed. 

Blown Film

The process involves extrusion of a plastic through a circular die, followed by "bubble-like" expansion.

Machining of Plastics

Where a plastics component is specified and the numbers to be used are not large, then machining the component becomes more economical.

Process Cooling

Cooling is a critical element of the process and one of the areas that can be targeted for Energy Savings.

Moulding Expanded Polypropylene

Expanded Polypropylene (EPP) is used for energy absorbing applications, including automotive, packaging that requires multiple impact protection, and furniture requiring unique performance solutions.

Extrusion Profiles & Sheet

Along with Injection moulding, Pro-file Extrusion of plastics materials is a widely used method of forming plastics materials.

Cast Film

Currently no information

Post Processing Operations

Currently no information

Other Extrusion Processes

Various other extrusion processes not mentioned above:EXTRUSION OF CAST FILM, CALENDERING OF THIN SHEET/FILM, COEXTRUSION/ LAMINATING.

2. Thermoset Processes
Thermosetting materials start as liquids/syrups, often called "resins", as powders or partially cured products ("preforms") which need heat for the shaping phase. The shaping is accompanied by a chemical reaction, which means that the material does not soften on reheating. The reaction may be exothermic (giving heat out), in which case cooling is required.

Process

Applications

Sponsor

Resin Transfer Moulding

RTM is a low pressure moulding process, where a mixed resin and catalyst are injected into a closed mould containing a fibre pack or preform.

Pultrusion

Offshore, transport,
aerospace, building and Civil engineering Engineering applications.

SMC / DMC
Moulding

The materials are widely known as Dough or Bulk Moulding Compounds (DMC or BMC). In sheet form they are known as Sheet Moulding Compound (SMC).

Other GRP
Moulding Techniques

Usually involves impregnation of glass fibre mat with a liquid polyester mix. 'Gel Coat' provides a good surface on the mould side. Large mouldings e.g. boat hulls, lorry cabs.

Process

Applications

Sponsor

Welding

Design and tooling constraints sometimes make it more economical and/or advantageous to tool the product as two or more pieces. Post moulding joining of the parts provides a means of achieving an end solution.

Product Decoration

Currently no information

Recycling

All plastics can be recycled. The extent to which they are recycled depends upon both economic and logistic factors.