The plastic injection molding method commonly employs two types of components for their molding process i.e. cold and hot runner system. The hot system is preferred over the cold system by many manufacturers. It’s also known as runner-less molding because it does not produce wasted plastic materials after the manufacturing process.
You can save a lot of time by using the hot runner mold. As there are no waste plastic materials, you will save money and time by faster production cycle. Earlier, with the cold system, it was quite costly to regrind and store the runners. They are prohibited from reuse in many cases that give them cost disadvantage from the manufacturing point of view.
They are originally developed in the 1960s, however, they only become popular once the technology evolved rapidly in the 90s. They do cost a lot in the beginning yet they offer better value for money due to their lower cycle time. In this system, the molten plastic material is injected into the cavities of the hot runner die smoothly compared to the cold system.
They are the preferred choice for molding larger size plastic materials. The system has two varieties i.e. internally heated and externally heated. The internally heated system allows us to better control the temperature and flow of plastics while the externally heated system helps us to easily mold temperature sensitive plastic materials.
The setup is quite complex compared to the cold system. The liquefied plastic material is heated inside the mold while the rest of the part is cooled in order to get the desired shape and size. The process requires quality products that can withstand several rounds of heating and cooling for a longer duration.
The hot runner mold is able to produce various plastic products with intricate design patterns. They are being used extensively in large factories. Most of the Indian manufacturers have started using advanced machines with this system. They know that no matter how much costly the machine at the beginning, they can easily recover that amount by manufacturing huge quantity of products in a short time with much-improved quality.