Ⅰ. What are the key characteristics of mica tape?
The low binder content of mica tapes is one of the first principles of mica tapes. In addition, the permeability of the mica tape and the compatibility with the impregnating resin are also important principles of selection. Mica tapes have a low binder content. After the insulating layer is treated with VPI, the impregnating resin can fully penetrate, the air gap is small, and the thermal conductivity of the insulating layer is improved.
The medium material of the low-glue mica tape is large-scale uncalcined muscovite paper, and the reinforcing material is an alkali-free glass cloth for electrical use and polyester film, polyimide film or resistance halogen polyimide. Among the components of low-viscosity mica tapes, the binder is the most important component.
Professional manufacturers will use bisphenol A epoxy resin as the main component of the adhesive, mainly because the epoxy resin has good adhesion after curing. Low shrinkage and good electrical and mechanical properties as well as moisture and chemical resistance. Especially in H-type or C-type mica tape adhesives, epoxy resins are converted with diphenyl ether epoxy adhesives or high-performance imines to improve the adhesion and flexibility of epoxy adhesives, and at the same time greatly improve heat resistance Sexual mica tape.
The plastic-free mica tape has sufficient softness at room temperature, which is conducive to wrapping the coil, and at the same time has good air permeability, which is beneficial to the insulating layer during the impregnation process of air and volatilized VPI. The extraction of material and the penetration of resin can ensure the integrity of the coil. performance.
Ⅱ. What are the preparations for the production of mica tapes?
Mica tape can be divided into: synthetic mica tape, phlogopite tape, muscovite tape. Has excellent high temperature resistance and combustion resistance. Powder mica tape has good flexibility under normal conditions and is suitable for the main fire-resistant insulating layer in various fire-resistant cables. When burning in an open flame, there is basically no volatilization of harmful fumes, so mica tape is not only effective but also safe when used in cables.
Composition and application of mica tape: Mica tape is suitable for fire-resistant mica tape and motor components of fire-resistant wire and cable.
Preparations before the production of mica tape:
1. Put the tools and measuring tools on the workbench and check whether the measuring tools are zeroed;
2. Check whether the mica tape is normal. If there is any abnormality, please report mica sheet uses to the maintenance personnel immediately for maintenance;
3. Prepare semi-finished products and materials according to the production plan, and check whether the semi-finished products and materials are qualified by experience and meet the process requirements, and install the qualified copper wire on the pay-off rack and adjust the tension;
4. Hang the gear according to the hemming distance required by the process, and select the hemming die according to the process requirements;
5. According to the mica tape required by the process, install the mica tape on the wrapping head in turn according to the number of wrapping layers, adjust the tension of the mica tape, and pull the wrapping guide rod of the mica tape to the front mold of the wrapping head in sequence;
6. Prepare the delivery reel as required, check whether the delivery reel is in good condition, and install the delivery reel on the delivery rack;
7. Pull the traction wire and wrap it around the traction wheel for 3-4 turns, fix one end of the traction wire on the take-up reel, and pull the other end to the front end of the winding die.