Many protective products in the Caplugs range are made by injection moulding, including fully-customised products. This blog post explains the injection moulding process, and introduces its advantages.
What is injection moulding?
Injection moulding is commonly used in industrial production to produce three-dimensional plastic parts and products on a large scale. Molten plastic is injected into a mould before it cools and solidifies to take on the desired shape. Injection moulding is used in several industries, including automotive, electronics, packaging and medical.
The plastic injection moulding
Each stage of the injection moulding process helps make a robust, high-quality plastic product. This affects the geometry, dimensions, colour, and the level of finishing of the product.
The injection moulding process consists of four stages:
1. Plasticising
Plastic pellets (granules) are the base material for injection moulding. The material goes from a storage hopper through a large loader. From there, the granulate is transported further via a screw. During this process, the plastic is heated until it melts. At the end of this step, the granulate has turned into a liquid and homogeneous mass.
2. Dosing
The molten plastic is transported through the screw and measured. The final dosage is determined by the size of the desired product.
3. Injecting
After the accurately dosed liquid plastic has been made from the granulate, about 95 to 98% of the cavity in the injection mould is filled with the liquid plastic under high pressure from the screw. The injection mould is not filled completely to enable venting and cooling. The high injection pressure ensures that the liquid plastic takes on the shape of the mould precisely – and thus the form of the finished product.
4. Cooling/pressing
After injection, the cooling process starts immediately. The plastic is gradually reduced to a solid form through cooling channels in the mould. Any air present is also squeezed out of the injection mould during cooling. To complete this phase, the final spaces in the mould cavity, created by air bubbles and plastic shrinkage during cooling, are filled with additional liquid plastic. This is called emphasising the injection mould. The solidification temperature can vary depending on the type of plastic, and is programmed before the injection moulding process begins. After the product has cooled sufficiently, the mould opens, and a robot gently removes the product. The injection-moulded products are placed in a tray or a box via a conveyor belt.
The advantages of injection moulding
Injection moulding offers several advantages:
- It is possible to produce highly accurate and detailed parts.
- Complex shapes with minimal deviations can be made, ensuring consistent quality.
- The injection moulding process is a very efficient method of producing large numbers of identical plastic parts and products.
- Once the parameters are optimised, the injection moulding process can be repeated many times, making it highly cost-effective.
- High production speed, minimal material wastage and automated processes also contribute to cost savings.
- Due to the precision and finishing quality of the injection-moulded products, only minimal post-processing is required.
Find out more about these advantages in our blog on the advantages of injection moulding for protective and masking products or contact us.
