When we are trying to achieve the best result in the injection molding process , we often have to take into account all the details of this technology, including temperature control. In this article, we will try to explain why the correct temperature of the injection molding machine is so important and how it affects the finished product.
When we talk about the temperature of the mold , we usually mean the temperature readings on the very surface of the mold, which is in contact with the plastic parts during the molding process. In this article, we will consider only the temperature of the mold layer, and not the temperature of the gate channel, which can be heated by a spiral heater in the case of a hot runner mold. This criterion naturally affects the appearance, dimensional clarity and characteristics of molded plastic parts. In addition, it affects the production, further processing and final use of products.
Mold temperature is one of the main control factors in the injection molding process. The recommended mold temperature is from 130 C to 150 C.
#1 How Does Mold Temperature Affect The Quality Of Plastic Molded Parts?
- Product Appearance:The flow of a polymer can be improved by increasing the temperature, which generally results in a smooth and glossy surface for the component. The optimal temperature of the material during the molding process increases the strength and aesthetics of the lines.
- Internal stress of an already finished product:The development of internal stress during the cooling process is primarily associated with different levels of thermal shrinkage during the cooling process. After the creation of the product, the cooling process gradually takes place from the surface of the product inwards.
- Improving Product Warpage:Plastic components will stretch and warp due to insufficient cooling if the mold cooling system is not designed properly or if the mold temperature is not properly controlled.
- Product Shrinkage:Since low temperatures in the mold increase the rate at which molecules “freeze”, this will increase the thickness of the solidified melt layer in the mold cavity and reduce the rate of crystallization growth. In such a case, low mold temperature can reduce the mold shrinkage of the products.
- Thermal Deformation Temperature of Products:When crystalline plastic products are manufactured at low mold cavity temperature, molecular orientation and crystallization occur in an instant, which is especially important for crystalline plastics.
The correct way is to apply a temperature close to the crystallization temperature for the manufacture of plastic products, so that the product is fully crystallized during the injection molding stage and therefore avoid post-crystallization and additional shrinkage in high temperature conditions, which is the most common cause of product breakage.
#2 Injection Molding Heaters
On the Be-cu.com you can order any injection molding heaters directly from the manufacturer. We can offer you not only cartridge heating elements and spiral heaters for molds, but also ring and flat heaters for the injection molding machine cylinder, flexible heating elements , tubular metal heating elements molded to your requirements, as well as thermocouples to control the temperature of heaters and raw materials at all stages injection molding.