They are specially designed for fast adaptation in moulds or surfaces where rivets cause problems or are not usable. Cuadrawatt cartridges are the best option in such cases. Low watt density cartridges are ideal for moderate heating up to 300°C. The square tube is made from high-quality stainless steel. All tubes are precisely calibrated inside and out, with a long-lasting ceramic core inside. The tube withstands continuous temperature variation and offers optimal thermal conductivity because the ceramic part is in direct contact with the tube wall, ensuring even heat distribution.
Maxiwatt Model SC The heating wire is located inside the ceramic element. The nickel-chromium heating wire is of premium quality and is the most recommended for cartridge heaters due to its high temperature tolerance. Everything is coated with verified magnesium oxide. The entire cartridge interior is also coated, ensuring excellent conductivity between the heating wire and the object to be heated.
The most important element in ensuring the long life of the cartridge heater is the heating wire used in its manufacture. Maxiwatt uses the best available on the market. After extensive research and years of experience, it has been proven that heating wire made from Ni-Cr 80/20 is effective and resistant to forming a metallic layer caused by oxidation. The austenitic combination of nickel and chromium, being free of iron, is the most recommended for heating wires.
A nickel cable (coated with fibreglass) is used for the induction of electricity. It is coated with silicone and fireproof glazing. The wires in the cable are twisted. Sometimes, the load of the cartridge prevents the use of this type of connection. Finally, special procedures are used: threaded outlets with bolts, opposite outlets, etc. The different types of connections are shown in the protections section.
Magnesium oxide is used as an insulator and is the most suitable for isolating the heating wire and conductor from the sheath current in the cartridge. When the space between the heating wire and the protective sheath is too narrow, an insulator is required, made from top-quality components: purity, high thermal resistance, maximum melting point, uniform compression, perfect thermal conductivity, etc., to ensure optimal insulation. Temperature control is essential and must not exceed operational limits. It's very important to store the cartridge in a dry place, as magnesium oxide is highly hygroscopic. Just a few drops of water can significantly reduce its insulation capacity. The different types of connections are shown in the protections section.
The stainless steel 321 casing offers the highest quality for the manufacture of cartridge heaters. The materials that can be used in their production are limited due to stress caused by constant expansion from the heating and cooling of the cartridge heater, the absence of a metal cover (which causes oxidation), and abrasive action. Stainless steel has proven to be the most suitable material for building cartridge heaters.
| Protective material | Stainless steel 1.4541 |
|---|---|
| Heating conductor material | NiCr 8020 |
| Max. storage temperature | 750 ºC / 1380 ºF |
| Max. voltage | 480 V |
| Power tolerance* | .+5% - 10% |
| High voltage resistance* | 1500 V AC at > 24 V operating voltage |
| 500 V at <= 24 V operating voltage | |
| Insulation resistance* | >= 5MW at 500 V DC |
| Leakage current* | <= 0.5 mA at 253 V AC |
| Length tolerance | A 1.5%, min A 1mm |
| Standard diameter tolerance | metric -0.02 / -0.06 mm |
| inch: A 0.79 mils [A 0.02 mm] |
