Description

Band heaters are the heating devices that are ring shaped and can be clamped around the cylindrical heating elements. The band heaters are clamped on the outside of the heating elements and transfers heat from the outside. The mode of heat transfer in band heaters is conduction. Some band heaters are clamped on the inner diameter of the heating elements. Usually, they are equipped with ceramic or mineral insulation that helps in heat loss reduction to the environment.

Band heater for hot runner system is the ideal solution for high power density and high operating temperature applications, especially in the plastics industry. We can produce various shapes to suit different applications and industries.

The band heater for hot runner system is a key element in plastic injection molds. Its function is to provide stable temperature control in the mold to ensure the melting and flow of plastic materials during the injection molding process. The design and application of this band heater has a significant impact on the quality and production efficiency of mold manufacturing.

This heater uses resistance wire to generates heat,under normal circumstances, the hot runner band heater is installed around the mold cavity, transferring heat energy to the plastic material through heat conduction to bring it to a molten state. It is generally composed of two parts, the heating element and the shell. Heating elements are usually made of nickel-chromium alloy materials, which have a high resistivity and can generate a considerable amount of heat. The shell serves to fix the heating elements and protect the mold.

The design of the band heater needs to take into account multiple factors, including the shape and size of the mold cavity, the melting point and fluidity of the plastic material, etc. Firstly, determine the layout of the hot runner based on the shape and size of the mold to ensure that the plastic material can flow evenly during the injection molding process. Secondly, determine the heating power and working temperature range based on the characteristics and melting point of the plastic material. During the design process, it is also necessary to consider the matching of the thermal expansion coefficient between the band heater for hot runner and the mold to avoid dimensional deformation caused by temperature changes.

Mica band heater

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Construction

Hot runner heater is fabricated by encapsulating precision-wound nickel-chromium resistance tape within a specially treated steel jacket. Mica is used to insulate the resistance tape to short circuit with the outer steel sheath.

The mica band heater is designed with nickel-chromium resistance wire precisely wrapped around a mica sheet, which is then placed between two additional corrosion-resistant outer mica steel sheets. Mica is used because it provides good thermal conductivity and dielectric strength. It can withstand voltage spikes, resist moisture, and is flexible enough to conform to the curvature of a plastic molding machine barrel. Since mica is also a thermal insulator, only high-grade mica that is inorganic, has high temperature stability, and is "paper-thin" is used. This "paper-thin" property enables rapid transfer of heat through the mica to the outer steel sheath, which transfers heat away from the red-hot inner resistance band winding.

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The four basic parts or components of a heater are the resistive element, insulation, sheath and termination. The resistive element is the "heart" of the electric heater. Resistive elements typically take the form of small diameter metal alloy wires or flat thin strips. When the heater is connected to a power source (voltage) or current flows through the resistance wire. The wire blocks current flow through it, which converts electrical energy into heat, causing the resistive element to get very hot. This is how heat is generated in an electric heater.

Application

Plastic mass injection machines, heating for liquid containers, etc.

industrial sites where temperatures reach up 400°C.

Necklace electric heating element with small for heating the nozzles and cylinders of injection machines and extruders.

The resistance of the necklace with low insulation allows solving all the problems of heating cylindrical shapes. Allow up to 6.5w/cm² with 450C.

Features

– Available in Premium, Economy & Power Saving Options Available
– Conserves Energy with improved Heating Efficiency Up to 30 Watts per square inch.
– Superior Thermal Conductivity and die electric strength.
– Available in various Lead Terminations & Clampings

Band heater