Advantages and disadvantages of hot runner molds

Advantages and disadvantages of hot runner molds

Hot runner mold system, also known as hot runner system, is mainly composed of hot sprue sleeve, hot runner plate and temperature control electric box. Our common hot runner system has two types of single-point hot gate and multi-point hot gate. The single-point hot gate uses a single hot gate sleeve to directly inject the molten plastic into the cavity, which is suitable for plastic molds with a single cavity and a single gate; Divided into the sprue sleeve and then into the cavity, it is suitable for single-cavity multi-point feeding or multi-cavity molds.

◆Advantages of hot runner mold system

(1) No water mouth material, no post-processing is required, the entire molding process is fully automated, working time is saved, and work efficiency is improved.

(2) The pressure loss is small. The temperature of the hot runner is equal to the nozzle temperature of the injection molding machine, which avoids the condensation of the raw material on the surface of the runner, and the injection pressure loss is small.

(3) The repeated use of the nozzle material will degrade the plastic performance, and the use of the hot runner system without the nozzle material can reduce the loss of raw materials, thereby reducing the cost of the product. The temperature and pressure in the cavity are uniform, the stress of the plastic part is small, and the density is uniform. Under the smaller injection pressure and the shorter molding time, the injection molding system can produce better products than the general injection molding system. For transparent parts, thin parts, large plastic parts or high-demand plastic parts, it can show its advantages, and it can produce larger products with smaller models.

(4) The hot nozzle adopts standardized and serialized design, equipped with various optional nozzle heads, and has good interchangeability. The uniquely designed and processed electric heating ring can achieve uniform heating temperature and long service life. The hot runner system is equipped with hot runner plates, thermostats, etc., with exquisite design, various types, easy to use, and stable and reliable quality.

◆Inadequate application of hot runner mold system

(1) The closed height of the hot runner mold is increased, and the overall height of the mold is increased due to the addition of a hot runner plate.

(2) The heat radiation is difficult to control. The biggest problem of the hot runner is the heat loss of the runner, which is a major issue that needs to be solved.

(3) There is thermal expansion, and thermal expansion and cold contraction are issues to be considered in our design.

(4) The manufacturing cost of hot runner molds increases, and the price of standard accessories for hot runner systems is high, which affects the popularity of hot runner molds