Injection moulding is a process used to produce moulded products by injecting heat-melted plastic materials into a mould, followed by the cooling and solidification of the material. This process is used for the mass production of plastic products of different and complex shapes.
Traditionally, in the injection moulding process plastic granules are fed into the hollow container where they are converted into the slurry. This slurry feeds into the moulds through screwing and cools down by supplying chilled water or using a chiller to take the desired shape.
Water Chillers are generally used for cooling plastic melts. However, when chilled water is used for cooling the molten plastic, the moisture present in the air in the vicinity of the chilled mould surface condenses, leading to the formation of water droplets on the mould surface. It not only reduces the quality but also impacts the structure and tensile strength of the product.
Also, this cooling time is longer and during this process, the screw recovers and waits for the ejection of mould. It increases the cycle time and reduces productivity.
Thus, the surrounding air near the mould has to be lower than the chilled water supplied to the mould.
Effects of Mould Sweating
- Condensation on mould, low cycle time, high scrap rate
- Short lifespan of the mould
- Low part/product quality
- Streaks, bubbles and other structural defects
- Loss in tensile and impact strength
Ideal Solution for Mould Sweating: Bry-Air EcoDry Mould Dehumidification System
Bry-Air EcoDry Mould Dehumidification System – MDS Series is designed exclusively to prevent mould sweating, providing an envelope of dry air. This system ensures increased production through reduced cycle times and is installed in critical applications where PET preforms and various plastic caps are manufactured.