UK Plastic Manufacturers

Which plastic manufacturing process do I need?

There are six main categories of moulding / plastic manufacturing, each utilised according to a number of factors. Below is a summary of each process. If you remain unsure as to which process is suitable to manufacture your product just email us on info@plastikcity.co.uk with your requirements and we will be pleased to advise.

What is Injection Moulding? 

Injection moulding is a manufacturing process for producing parts by injecting material into a mould. Plastic material for the part is fed into a heated barrel, mixed, and forced into a mould cavity, where it cools and hardens to the configuration of the cavity. After a product is designed, usually by an industrial designer moulds (molds in USA) are made by a mouldmaker  (or toolmaker) from metal, usually either steel or aluminium, and machined to form the features of the desired part. Injection moulding is widely used for manufacturing a variety of parts, from the smallest components to entire car body panels. Parts to be injection moulded must be very carefully designed to facilitate the moulding process; the material used for the part, the desired shape and features of the part, the material of the mould, and the properties of the moulding machine must all be taken into account. The versatility of injection moulding is facilitated by this breadth of design considerations and possibilities.

• Example products: buttons, bumpers, containers, caps
• Here is a video from one of our partners, Chess Plastics showing the process
• To make an enquiry and acquire quotes from the UK’s best injection moulding companies visit our ‘Source A Moulder’ – Injection Moulding section here

What is Extrusion?

Plastic extrusion is a high volume process where material is melted and 'extruded' continuously through a tool (die) that forms a particular design of plastic profile or sheet in a continuous length. The product is then cut to the required length.

• Example products: window profiles, pipes, tubes, film
• Here is a video by Amut (represented in the UK by Renmar) showing the process.
• To make an enquiry and acquire quotes from the UK’s best extrusion companies visit our ‘Source A Moulder’ – Extrusion section here

What is Blow Moulding?

Blow moulding is a process by which hollow plastic parts are manufactured. The blow moulding process begins with melting down the plastic and forming it into a parison. The parison is a tube-like piece of plastic with a hole in one end through which compressed air can pass. The parison is then clamped into a mould and air is blown into it. The air pressure then pushes the plastic out to match the mould. Once the plastic has cooled and hardened the mould opens up and the part is ejected.

• Example products: plastic bottles, fuel tanks and watering cans.
• Here is a video from one of our partners High Profile showing the process.
• To make an enquiry and acquire quotes from the UK’s best blow moulding companies visit our ‘Source A Moulder’ – Blow Moulding section here

What is Rotational Moulding?

In essence, liquid or powdered plastic is poured into the gap between an inner and outer form, which is then heated then rotated /spun/inverted so that the plastic spreads evenly prior to cooling and setting. This is a slow process, but allows large hollow components with thick wall sections to be produced.

• Example products: industrial refuse bins, tanks, housings, large ornamental pots
• Here is a video showing typical products and the process of rotational moulding.
• To make an enquiry and acquire quotes from the UK’s best rotational moulding companies visit our ‘Source A Moulder’ – Rotational Moulding here

What is Vacuum forming / Thermoforming?

With this process, a sheet of plastic is heated and then drawn by vacuum over a profile to produce a three dimensional shape. Large surface areas can be produced, although wall thickness is limited.

• Example products: shower trays, disposable confectionary trays, clamshells, plant trays, disposable cups, decorative wall panels
• Here is a video from our partner Toolcraft Plastics showing the process
• To make an enquiry and acquire quotes from the UK’s best blow moulding companies visit our ‘Source A Moulder’ – Vacuum forming here

What is plastic machining and fabrication?

Sometimes it is not practical to mould components, for example, volumes are uneconomical, the ‘form’ is complex, wall sections are very thick, or components are very large. In these instances, machining components from solid plastic, or fabricating a solution by combining a number of individual items can be the best option.

Machining engineering grades of plastic using CNC lathes, milling equipment, routers, laser cutters etc. can rapidly produce complex components with difficult to ‘mould’ features such as internal threads.

Large and heavy items can be manufactured by invisibly bonding components such as laser cut acrylic or perspex sheet.
Example Products: display units, tanks and very low volume parts.

• To make an enquiry and acquire quotes from the UK’s best plastic machining and fabrication companies visit our ‘Source A Moulder’ – Machining and Fabrication here

What other specialised plastic manufacturing processes are there?

PlastikCity has partners that offer very specific moulding applications that may be more suitable to your requirements. These include:

• Low Volume production (typical annual volumes 50 - 1000 components)
• Medical & Cleanroom moulding
• Structural Foam moulding (Can be a less expensive option for large injection moulded components)
• Insert loading injection moulding (typical is moulding around a metal insert)
• Multi material & Multi Colour injection moulding
• Liquid Silicone Rubber moulding
• Gas Injection moulding
• Compression & Intrusion moulding
• Reactive Injection Moulding (RIM)
• Polyurethane Moulding (PU)

If your products apply to any of the above, please select the hyperlink to navigate direct to the section. After reading the processes that may be applicable to your product and you remain unsure just email us on info@plastikcity.co.uk with your requirements and we will be pleased to advise.