Mold hot runner heating which way is good 

Mold heating ensures that the plastic plastic melt has good fluidity in the mold cavity, so the temperature of the mold directly affects the molding, quality and performance of the products to be processed. 

A hot runner is a heating element used in an injection mold to inject molten plastic particles into the mold cavity. Flow channel is also called no flow channel. Through the heating of the runner and the runner, the plastic in the runner has been kept in a molten state from the nozzle of the injection machine to the entrance of the cavity, so that only the plastic parts need to be taken out when the mold is opened, without taking out the runner and runner condensate. This not only shortens the molding cycle, saves raw materials, greatly improves production efficiency, reduces costs, but also ensures the transmission of injection pressure in the flow channel. To a certain extent, it overcomes the defects of depression and shrinkage caused by insufficient feeding of plastic parts.

Hot runner mold relative to the traditional mold or three-plate mold, is a new structure, hot runner is generally composed of a hot nozzle, the main splitter plate, temperature control box and accessories and other parts. However, there are many ways to mold heating, not for direct heating of electric heating pipe, steam heating, electromagnetic heating, heat transfer oil heating, which heating method is more appropriate, but also depends on the specific application environment 

There are two commonly used heating methods, one is electric heating, and the other is to pass the hot medium inside the mold, which is often heated by hot water or hot oil. This heating method is more convenient. And the price is low, if the injection machine with mold temperature machine, adjust the temperature of the thermal medium is also more convenient. 

There are two types of electric heating devices used in mold electric heating, one is resistance heating, and the other is induction heating. The structure of the induction heating device is complex and the volume is large. Almost all GSM molding molds are heated by resistance. Electric heating components are set around or inside the mold to heat the mold. 

In general, electric heating is used for molds that need to provide sufficient heat energy and have high temperature requirements, such as thermosetting plastic molds and hot runner plates of hot runner molds. In order to achieve mold heating uniformity, ensure molding temperature requirements, and reduce the loss of electric heating power, when designing an electric heating system, electric heating has the advantages of large temperature adjustment range, convenient installation, convenient maintenance, cleanliness, no pollution, high efficiency and energy saving. Therefore, it is widely used.

Type of mould electric heating pipe 

Single head electric heating tube, double head electric heating tube, spring heating ring, flexible and freely deformable electric heating tube. 

General injection mold, commonly used is a single head electric heating tube. 

Lead Outlet Mode of Electric Heating Pipe 

The inner outlet wire is drawn from the inside of the electric heat pipe. The lead wire is not easy to break, but the cost is high. 

External wiring terminal pin extended from the electric heat pipe welding high temperature lead, relatively low cost, more widely used. 

Use of Mold Electric Heating Pipe 

Plug-in 

Winding 

Insertion 

Hot runner mold 

The central component of the hot runner system of the splitter plate, the splitter plate one mold multi-cavity or multi-point feeding, which transmits the plastic melt from the main channel nozzle to each injection point nozzle through the splitter plate. The split plate can make the cavity of the mold evenly filled, the plastic balance flow, and the system heat balance. Splitter plate series are X type, H type, I type, Y type, K type. 

Heating method of hot runner splitter plate 

There are two kinds, one is internal heating, that is, set the heating rod in the flow channel, and heat the plastic from the inside of the flow channel. The other is external heating, which generally opens a heating hole in the direction parallel to the flow channel, inserts a heating rod or installs a heating ring to heat the flow channel from the outside of the flow channel. Compared with the two methods, the internal heating method has higher thermal efficiency, but it is easy to cause local overheating in the hot runner system and increase the flow resistance of the melt. Although the external heating method does not produce local overheating and the flow resistance in the flow channel is small, the flow channel is easy to process, the heating device is easy to purchase, and the maintenance is convenient, but the heating efficiency is low.

Hot nozzle divided into 

Open hot nozzle and needle valve hot nozzle. As the hot nozzle form directly determines the hot runner system selection and mold manufacturing. 

Therefore, the hot runner system is often divided into open hot runner system and needle valve hot runner system. Generally spring heating ring, flexible deformation tube. 

Advantages of hot runner mold 

Save raw materials, reduce costs, shorten the molding cycle, improve machine efficiency, improve product surface quality and mechanical properties, improve the injection molding products surface aesthetics, can be cost-effective side gate molding single product, multi-cavity mold injection parts quality consistent, improve the degree of automation. 

However, while each innovative technology brings advantages, it also has shortcomings. Hot runner mold technology is no exception. 

Hot runner mold structure is complex, high cost, high maintenance costs, start-up time product process can be stable 

Annai Electric Heating Pipe Characteristics 

Annai electric heating pipe is mainly composed of high quality imported seamless stainless steel tube shell, high quality electric wire, temperature can reach 1100 °C, high purity, high temperature resistance, good thermal insulation of imported magnesium oxide powder, and then through the shrink tube, both ends of the tube with silica gel or ceramic seal, refined by other processes.

Features of Annai electric heating tubes : 

Small size 

Slender to needle tip matchstick size 

High power 

Density : 

Heating up fast 

Small size, high power, high energy, in a relatively short period of time into sufficient heat ; 

High efficiency 

High heat conversion rate 

Easy installation 

Plug-in, winding, sleeve-in 

Easy wiring 

There are outlet interfaces suitable for various machinery and installation environments. 

Complete specifications 

Product specifications and types can be non-standard customization, flexible size. 

Non-standard customization 

Good mechanical performance 

As an outer protective shell, stainless steel is not easy to be damaged by mechanical vibration. 

Dry burning explosion-proof 

Configure temperature control self-power-off system 

Annai electric heating tube 

Quality assurance, safe and durable !

Selection of Electric Heating Pipe 

1.The material of the electric heating tube is determined according to the temperature, voltage and power of the environment. 

2.The diameter of the electric heating pipe is determined according to the hole diameter of the mold, and it is recommended that the gap between the two is between 0.1-0.2mm, which is fully heated and does not waste heat 

3.The length of the electric heating pipe is determined according to the length of the hole 

4.The shape of the electric heating tube, according to the temperature, power requirements, equipment environment to determine 

5.Accurate calculation of mold heating power, to prevent power is not enough to meet the mold temperature requirements, or overpower the mold overheating. 

6.Reasonable distribution of electric heating components, so that the cavity is heated evenly, the electric heating pipe must not be too close to the mold cavity, so as not to affect the stiffness and hardness of the cavity. 

7. Try to prevent the heat loss of electric heating pipe, ensure the efficiency of heating device, energy saving 

8.Electric heating pipe outlet mode, welding method, sealing method, outlet protective sleeve, fasteners, etc., the fundamental use cost to determine 

9 industry electric heat pipe customization solutions Advise annai Shenzhen Annai Electric Heat Technology Co., Ltd.