Demystifying the production technology of mica tube

Mica tube is a cross-sectional round bar made of alkali-free glass fiber cloth dipped in epoxy resin, baked in a mold, and hot pressed. The glass cloth rod has high mechanical properties. The surface of the mica tube should be smooth and free of bubbles, oil and impurities. Uneven color, a little rubbing, etc. are within the allowable range. Epoxy resin pipes are used for insulating parts of electrical equipment, humid environments and transformer oil.

As we all know, the performance of epoxy resin pipe is excellent, so what is the manufacturing process of this excellent epoxy resin pipe?

1. Heat the epoxy resin in a water bath to 85-90°C, add the curing agent according to resin/curing agent (mass ratio)=100/45, stir to dissolve, and store in the glue tank at 80-85°C.

2. The glass fiber is wound on the metal core mold, the longitudinal winding angle is 45°, and the width of the fiber yarn is 2.5mm. The fiber layer is composed of 3.5mm longitudinal winding + 2 layers of circumferential winding + 3.5mm thick longitudinal winding + 2 layers of circumferential winding.

3. Scrape the resin solution so that the glue content of the layer around the fiber is calculated to be 26%.

4. Put a short heat-shrinkable plastic tube on the outer layer, blow it short with hot air and wrap it tightly, then wrap the outer layer with a 0.2 mm thick and 20 mm wide glass cloth tape and send it to the curing furnace for curing.

5. Curing control: first raise the room temperature from room temperature to 95°C at a rate of 3°C/10min, then heat it up to 160°C at the same temperature rise rate for 4h, and then cool it out of the oven to room temperature.

6. The mica tube is demoulded, the glass cloth tape on the surface is removed, and then processed as required.