Composition and material selection of silicone rubber heaters

1. The basic structure of a silicone rubber heater consists of a lead out rod, insulating filler (magnesium powder), resistance wire, and a metal outer tube. The heating element of a 3D printer is stacked layer by layer to create a 3D model. Its operation process is similar to that of a traditional printer, except that traditional printers print ink onto paper to form a two-dimensional flat drawing, while 3D printers use liquid photosensitive resin materials, molten plastic fibers, gypsum powder and other materials to achieve layer by layer stacking and forming a 3D solid through spraying adhesives or extrusion. In recent years, due to the greenhouse effect, the temperature of the cabinet dehumidifier heater has been increasing year by year, and the atmospheric environmental factors have gradually deteriorated, such as high temperature, high humidity and other variable climates, making the threat to indoor power distribution facilities increasingly apparent. Silicone rubber heating belt is a particularly soft heating belt composed of nickel chromium alloy wire and insulation material. Its design has high power density, fast heating, high thermal efficiency, and long service life. In addition to being used for heat tracing and insulation in general constant power bands, it can also be used in places that require heating in some cases.

The diameter of the silicone rubber heater can be selected as 3 ー 25mm according to needs. It can also be bent into various shapes as needed. According to the different usage status, safety, and installation requirements of silicone rubber heaters, they will also include sealing structures, terminal structures, flanges, temperature control or fuses, and other structures.

2, Material selection of silicone rubber heater

Among the factors that have a serious impact on the quality management of silicone rubber heaters, the quality of materials plays a crucial role. Reasonable selection of raw materials for silicone rubber heaters is a prerequisite for ensuring the improvement of the working quality of silicone rubber heaters.

The main content is as follows: 1. Principles for selecting pipes: high temperature resistance and corrosion resistance.

For low-temperature pipes, aluminum and copper pipes are generally used. High temperature pipes are generally made of stainless steel, while quartz pipes have good oxidation resistance and corrosion resistance under high temperature working conditions.

The selection of resistance wire is commonly used in silicone rubber heaters, including nickel chromium wire and iron chromium wire. Using Beijing silicone rubber heating belt with iron chromium wire, the melting point is higher than that of ordinary iron chromium wire, and the service life is better.

3. Selection of magnesium oxide powder: Magnesium oxide powder is located between the resistance wire and the pipe wall, used for insulation between the resistance wire and the pipe wall. Meanwhile, mgo talcum powder has excellent thermal conductivity. Magnesium oxide powder has strong hygroscopicity, so it can be moisture-proof treated according to the temperature range (modified with magnesium oxide powder or sealed with a silicone rubber heater), and can be divided into two types: low-temperature powder and high-temperature powder. Low temperature powder can only be used below 400 ° C, usually modified magnesium oxide powder. Magnesium powder appears in granular form. The magnesium oxide powder used in silicone rubber heating furnace is composed of different particle sizes of magnesium oxide powder in a certain proportion.

Figure 4. Selection of sealing materials: The function of sealing materials is to prevent moisture from the atmosphere from entering the magnesium powder through the pipe opening, making the magnesium powder damp, reducing insulation performance, and causing the silicone rubber heater to fail due to leakage. Modified magnesium oxide powder cannot be sealed. The sealing materials for silicone rubber heaters mainly include glass, epoxy resin, silicone oil, etc. A silicone rubber heater sealed with silicone oil will evaporate the silicone oil at the nozzle after heating, causing the insulation of the silicone rubber heater to fall off. Epoxy resin materials are not heat-resistant and cannot be used for silicone rubber high-temperature heaters such as barbecues and microwave ovens. Glass is resistant to high temperatures, but at a higher price, and is often used for sealing high-temperature pipelines. In addition, there will be components such as silicone tubes, silicone sleeves, ceramic beads, plastic insulators, etc., mainly to increase the electrical gap and creepage distance between the lead rod and the metal tube wall. Silicone rubber can serve as a filler and adhesive.

The quality of silicone rubber heaters

The quality of silicone rubber heaters mainly depends on the following aspects: electrical design strength, insulation, leakage current, power accuracy, lifespan, corrosion resistance, size, etc.