Procedure

Plastic injection moulding is not witchcraft, but a high-pressure process. This means that we process thermoplastics.

There are two groups of plastics, thermoplastics and thermosetting plastics. The main difference between the two groups of plastics? It lies in the basic chemical structure: thermoplastics are reversible - in other words, they can be melted again without restriction when heat is applied. Thermoset moulding compounds, on the other hand, undergo a change in their chemical structure after the moulding process during the cooling process - which means that these plastics can no longer be melted.

At PRONTOPLAST, we mainly process thermoplastics. We melt the plastic mass in a heated cylinder and then press it into a mould under high pressure and sometimes at very high speeds. Typical specific filling pressures are between 800 and 2000 bar. The mould consists of two halves and contains at least one cavity - the negative mould of the component. We operate injection moulds with up to 32 cavities. Per cycle - mould closes, plastic is injected, moulded part cools in the closed mould, mould opens and moulded part is ejected - we therefore produce 32 exactly identical parts. The cycle time is mainly influenced by the size of the components and their wall thicknesses and can vary greatly. The manufacturing process is usually fully automated. This process is well suited to series production.

We process thermoplastics using state-of-the-art production machinery and robotics. The variety of material properties and the unique freedom of geometry in production offer us a wide range of possibilities.

Our injection moulding machinery consists of all-electric injection moulding machines with clamping forces of 150 - 650 kN. We produce high-precision, technically sophisticated parts, but we are also happy to produce simple, uncomplicated plastic articles, e.g. game chips for a game developer of MGMT games.

With our machines in the lower clamping force range, we work with minimal screw diameters. Micro injection moulding is one of our core competencies. Part weights of less than 0.01 g are one of our specialities. It goes without saying that tolerances of less than ± 0.01 mm are required in this area - we master them perfectly.

We have a 2-component injection moulding machine with a clamping force of 600 kN and injection units with small screw diameters. This machine technology offers an exciting extension to one of our in-house specialities - the overmoulding of inserts. The overmoulding of inserts has a long tradition at PRONTOPLAST. Today, four machines are specially designed for manual insert moulding and overmoulding. They all have a rotary table to ensure manual or automatic loading of the injection moulds without extending the cycle time. The injection moulding process therefore runs without restrictions or interruptions - enabling us to guarantee the highest quality standards.