Moulding plastics: how it works

Increasingly advanced technology has allowed for a decisive evolution in the moulding of plastics, which now allows for the production of the widest range of products and components made from polymer materials. Both machinery and materials have evolved over time, expanding the variety of shapes, designs and applications that can be obtained from the process.


GB S.r.l. currently has constructive skills that allow it to satisfy the demands of clients from the widest range of industrial sectors. But how does the moulding of plastics work, and what type of processes can be carried out?


A range of production processes for the moulding of plastics.

Moulding processes have differentiated in line with market demands and the characteristics of the materials to be processed. This type of process is based on thermoplastic materials (such as ABS, PA6, PA6.6, PA6.6 FG, PBT, PC, POM, TPE, TPU, which we use at GB S.r.l.), i.e. raw materials that react at high temperatures, becoming malleable and allowing for efficient moulding, to then regain rigidity on cooling.


The most widespread plastic moulding methods include injection.


Injection moulding of plastics

Injection moulding is the most commonly used process, and it has been highly optimised to obtain the widest range of manufacturing results. How does it work? This is a summary of the stages of the process.


  • The moulds required to model the items desired are created with software such as CAD, and they are then sent to the production department, where they are milled to obtain the moulding shape, design and size as dictated by the project. They can be made from either steel or aluminium, depending on the material to be processed and the steps to be carried out.


  • The raw material (plastic polymers) generally comes in granular form, and is melted in the injection chamber, compressed and then injected into the sealed moulds via dedicated channels that serve as access points.
  • The item is moulded in accordance with the projects prepared together with the client.
  • Once the process is complete, the mould is opened and dedicated expulsion tools assist with the removal of the finished product.
  • Once the production cycle is complete, the items obtained are immediately packaged and sent to the final destination.


The machinery used for injection plastic moulding is known as an injection press, and it is made up of:

  • an injection unit, which heats the raw material to melting point and injects it into the mould,
  • a hydraulic or mechanical sealing unit that ensures that the mould is properly sealed.

Inside the machine, temperatures and pressures reach extremely high levels, rendering moulding a process characterised by decidedly delicate precision.

GB’s experience in the moulding of plastics

The GB S.r.l. brand was founded in 1976, and since then it has evolved constantly, meaning that it can now create items to design and serve as a leader for the moulding of items both in rubber and in thermoplastic material. In our various departments, we process elastomers, materials overprinted with metals, nylon, rubberised cotton fabrics, high-tech fibres and thermoplastic materials, relying on the performance of an avant-garde machine inventory composed of vertical and horizontal presses of varying tonnage that operate with injection, compression and injection-compression systems.


GB S.r.l. is IATF 16949 and ISO 9001 certified, and guarantees constant commitment to quality, which is founded on investments into the skills of human resources and on better performing technological instrumentation.

Contact us to lend form to your industrial projects!