As a technology for thermoplastic injection molds, hot runner systems have been in use for 50 years.
Hundreds of companies in the market are supplying their respective hot runner systems. The application of hot runner systems continues to grow. It is estimated that one-quarter of injection molds in Europe and one-sixth in the United States utilize hot runner technology. Forecasts indicate that the proportion of applications using hot runner technology will continue to increase. The fundamental principles of hot runner technology were patented in the U.S. back in 1940. Today's evolved hot runner systems differ only slightly from the original principles. In Poland, the first hot runner molds were designed based on reports from BA Company and manufactured by PLASTIC Company in 1965.
In its early stages, the development of hot runner technology was slow with limited interest, and only a few companies were involved in designing and manufacturing hot runner systems.The oil crisis of 1973 brought about various economic factors that spurred the rapid development of hot runner systems. With raw material prices rising weekly, processing companies were forced to reduce base material costs. One method was the use of hot runner systems to eliminate waste materials formed in the main runner. Subsequently, manufacturers' hot runner nozzles and the corresponding runner systems appeared on the market. The sudden surge in demand for hot runner systems also had negative effects. Manufacturers had no time to upgrade existing systems; hot runner nozzles were prone to clogging; they were not adaptable to plastic flow properties; temperature control sensitivity was poor; there was no automatic adjustment control during initial heating. At that time, hot runner technology was not yet perfect. These factors led to a decline in demand and a stagnant phase. Later, increased investment in the development of hot runner technology improved quality.
Over the last 20 years, hot runner technology has matured significantly. Today, the scale of the hot runner system market is large, and effective systems are available for almost all thermoplastics and most applications.