Fluorine Rubber Ten Kinds Of Production Problems And Solve!

Fluorine rubber ten kinds of production problems and solve!

Fluorine rubber has been developed since the mid-1950s and has been in industrial production for more than 60 years. Due to its small swelling in oil, hydrocarbons and solvents, it has excellent oil resistance, high temperature resistance and high resistance. Acid, alkali, radiation resistance, corrosion resistance, strong oxidizing agent, strong chemical resistance, good air tightness, and good physical and mechanical properties, and electrical insulation, low compression characteristics of low, as a special synthetic rubber, Widely used in chemical, aerospace, automotive, petroleum industry, machinery, electronics and other fields. Fluorine rubber is excellent performance, has a broad application prospects. By China's independent research and development of low temperature fluoride ether rubber has been successfully used in the manufacture of Long March series of carrier rocket servo seals, and assembled in the fighter, the new tank on the tubing, electrical wiring sheath and other accessories. In the civilian sector for the automotive parts, increasing, in the industrial sector to gradually promote the use of fluorine rubber.

Although the fluorine rubber has excellent resistance to medium and high temperature performance as described above, there are some abnormalities and difficulties in the process of producing and producing fluoro-plastic products. Among them, there are common scorch burns during kneading, , After the film cut off the inspection, and sometimes found a small white point, the product easy to tear, shrink, burning edge, there are traces of joints, lack of plastic, product deformation, mold pollution and other phenomena, affecting product quality.

In view of the above production process abnormalities, make the following solutions:

1, the mixing of fluoride glue appears dead material, the reason for the accessory glue contact with sulfur or sulfur-containing products, many companies do not have special fluoride plastic machine, often refining other sulfur-containing rubber, the cleaning is not in place, or Ingredients are not careful to stain the sulfur or water, which can be combined with fluoride in the accelerator caused by scorch, or due to the role of water to make the surface activation of fluorine plastic decomposition. Solution, the best special plane, such as can not do, should also be in the conversion of fluoride before the glue, be sure to baffle and Sheng Pan completely clean, and absolutely avoid contact with water and sulfur, ingredients for the application of special tools, a A spoonful of food to prevent cross-contamination. Calcium hydroxide and magnesium oxide to keep the seal, that is, with the match.

2, the phenomenon of sticky roller, mainly in the mixing machine on the mixing process, the rubber tight package in the rear roll, or before and after the package before and after the two rollers, resulting in the former rubber compound can not be refined, while the latter also added to join the agent easy to pressure Into a sheet and drop, resulting in uneven dispersion. The main cause of the flocculation of the flocculant is caused by the excessive amount of fluoroelitomorphic or low molecular weight. The solution to this problem is to use the selection of Mooney viscosity 70 left in the raw rubber is good, while the use of narrow molecular weight distribution of raw rubber, and then add a small amount of Brazilian wax or fluoride wax, or low molecular weight poly Ethylene, but also to solve the phenomenon of sticky roller.

3, the white spots on the compound, which is due to the presence of some powder powder dispersion of non-uniform, or because of powder moisture particles, such as sour agent calcium hydroxide, magnesium oxide and diatomaceous earth, sulfuric acid Barium, etc., to prevent the complex with moisture and strengthen the thin through the process.

4, the product is easy to tear. Caused by the reasons may be too thick hair, trim when the tear, or mold with too tight, the mold when the burr was stuck by the mold, easy to tear from the product and burr before, from the mold when the force is not uniform, Easy to tear products. Sometimes the mold cavity processing rough, or rubber sticky mold, curing finished mold, resulting in stripping difficult, easy to tear products. In addition, the vulcanization temperature is too high, will make the product brittle, easy to tear. For the above anomalies, can be resolved from the following aspects: mold processing accuracy to master the cavity roughness Ra is less than 0.8, with the gap should not be too large, the curing temperature control between the left 170 degrees as well, while the material weighing to be accurate.

5, the problem of shrinkage is due to the mold when the pressure was removed, the occurrence of shrinkage of fluorine rubber, and burr parts are stuck in the mold between the surface, so the product parts and burrs to produce a tensile force between the product and the burr Split, when the crack expanded to the product site, it caused the phenomenon of shrinkage. The solution is to reduce the vulcanization temperature, the choice of Mooney viscosity of 70 or so [ML1 +4] 121 degrees, while the mold with the degree of fit, not too loose too tight,

6, burning edge, is the vulcanization temperature is too high, especially thick products, appropriate to reduce the curing temperature can be overcome.

7, there are traces of joints. Is due to the overlapping parts of the compound is not fully integrated together due to, or because there are impurities in the tape or oil, the solution is to keep the preformed tape in the storage, transportation, plastic cleaning, to prevent pollution.

8, lack of plastic. This is related to the mold structure and the fluidity of the compound. Closed mold than the open mold more prone to lack of glue phenomenon. The solution, the appropriate adjustment of rubber fluidity, and open the cavity in the mold cavity.

9, product deformation. This is due to the larger shrinkage of fluorine plastic, molded products shrink anisotropy, rubber different thermal expansion coefficient in different directions, the second phase of the vulcanization process will form additional cross-linking, especially a vulcanization of sulfur, two Products, will be a significant deformation, so in a period of time to give full cross-linking, to avoid the second paragraph after the product deformation occurs.

10, mold pollution serious phenomenon. We commonly used 26 kinds of fluorine plastic, with phenolic vulcanization system, in the curing process will have HF, it is a very strong acidic substances, the mold has a great corrosion effect, the formula is added to the sour agent is to The resulting HF is absorbed to prevent contamination of the mold. The solution is based on the combination of calcium hydroxide and magnesium oxide, the amount is generally 6 and 3, the formula can be added Brazil wax, in the vulcanization can be moved to the rubber surface, forming a layer of film to prevent the mold is contaminated, with the exception of Mold to plating, but also can use fluoride release agent to protect the mold from pollution.