Plastic Moulding Companies - Source a moulder

Which plastic manufacturing process do I need?

There are six main categories of 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 (molding in the US)? 

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 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 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 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 Chess Plastics showing the manufacturing process
• To make an enquiry and acquire quotes from the UK & IE’s best 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 & IE’s best extrusion companies visit our ‘Source A Moulder’ – Extrusion section here

What is Blow Moulding?

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 & IE’s best 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. Rotational moulding 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 this manufacturing process and typical products.
• To make an enquiry and acquire quotes from the UK & IE’s best companies visit our ‘Source A Moulder’ – Rotational Moulding here

What is Thermoforming?

Thermoforming is the primary process of heating thermoplastic sheet to a temperature where the sheet reaches a pliable/ malleable state. Heating is normally done by convection however some thermoforming machines use quartz heaters for a greater focus of heat. Once the plastic sheet reaches elasticity the sheet is then draped or moulded over a male or female form.

Thermoforming is a process often used in packaging and cup manufacturing applications. In most cases the products have a thinner gauge wall section (film) and the process is often associated with more automated production lines.

• Example products: clamshells, plant trays, disposable cups

What is Vacuum forming?

Vacuum forming is a secondary process after thermoforming. The air between the male/female form and the malleable sheet is purposefully removed by vacuum. This process provides greater material displacement and results in finer detail. Vacuum forming is widely used to manufacture large surface area components where low to medium volume parts are required. Vacuum forming is a competitive alternative to other processes such as injection moulding where part dimensions are greater than 500mm x 500mm. Lower tooling and engineering costs make the process ideal for lower volume production runs. Typical batch sizes range from l00’s to 10,000 plus.

• Example products: Shower trays, signage, machine covers, display units
• Here is a video from Toolcraft Plastics showing the process
• To make an enquiry and acquire quotes from the UK & IE’s best 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 & IE’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 applications that may be more suitable to your requirements. These include:

• Low Volume production (typical annual volumes 50 - 1000 components)
• Medical & Cleanroom
• Structural Foam (Can be a less expensive option for large injection moulded components)
• Insert loading / overmoulding (typically injecting plastic around a metal insert e.g. to incorporate brass inserts)
• Multi material & Multi Colour
• Liquid Silicone Rubber
• Gas Injection & Mucell®
• Compression & Intrusion
• Reactive Injection (RIM)
• Polyurethane (PU)
• Rubber

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.