With the increase in domestic demand for high-end automotive sheets and high-end home appliance sheets, especially high-end industries such as automobiles, the requirements for sheet product quality continue to increase. How can iron and steel companies eliminate surface impurity marks and small bright spots during the production of galvanized sheets to improve product quality?  It has become a problem that an enterprise has to study hard and urgently need to be solved.

•Special Fiber Cloth for Hot-dip Galvanizing Top Roller

       Hot-dip galvanizing cannot guarantee the same quality of galvanizing on both sides of the strip in the production process. The main reason is that the upper surface of the strip is in contact with the sinking roller during the galvanizing process, and the fluidity of the upper surface of the zinc liquid is not good, so the upper surface of the strip.  There is a lot of zinc dross, which is easy to produce defects such as sunken roller marks. 

       In addition, the upper surface of the strip steel often runs above, and dust and oil stains are also easy to adhere to the upper surface, which will also affect the quality of the coating on the upper surface of the strip steel.  Therefore, it is very important to ensure the quality of the coating on the lower surface of the strip. All galvanized sheets used in the outer panels of automobiles and home appliances have the lower surface facing outward, and the function of the top roll covering is to better guarantee and improve the galvanized strip.  The quality of the bottom surface. 

      Prior to this, some companies used asbestos and other fabrics to cover the surface of the top roller to solve the above problems, but it is not ideal from the perspective of environmental protection and hygiene.  Therefore, steel companies urgently need a new product that can eliminate impurity marks and small bright spots, improve product quality, and meet environmental and sanitary requirements.

• The Development of  Kevlar

        For this reason, we adopts foreign mature and advanced technology, and after long-term exploration and experimentation, successfully developed the top roller covering Kevlar of the galvanized line-PT1100.  The new high-tech special fiber used in this product has excellent characteristics such as ultra-high strength, high modulus, acid and soil resistance, flame retardancy, and high temperature resistance. It is an important national defense and military material and is widely used in military, aviation, aerospace,  Mechanical and electrical, construction, automobile, etc. 

       The Kevlar top roll cloth is also used because of its excellent characteristics.  After using this product on the galvanized sheet production line, it can not only avoid the bright spots and impurity marks on the inner side of the galvanized sheet, improve product quality, but also reduce the wear of the top roller and extend the life of the top roller.

•The Superior Performance of PT1100 Top Roller Cloth

①Avoid top tension roller creases

         Due to the high tension of the strip steel in the zinc pot section, in order to ensure the stability of the strip steel tension in the zinc pot section and prevent the top roll from slipping and causing the strip to be scratched, the top roll has a relatively large roughness, so that the top roll often adheres to zinc slag during production.  Impurities such as zinc and zinc particles often cause imprinting defects on the surface of the strip.  Although a scraper can be installed to remove the adhesions on the surface of the top roller, it is not a good guarantee to eliminate the defects of the top roller embossing, and this defect can be eliminated by using the top roller wrapping cloth. 

       Because the surface of the wrapping cloth is dense and clean, has no melting point, does not generate static electricity, and has no adhesion to metals such as lead and zinc, even small zinc dross will fall off, preventing the occurrence of top roller imprinting defects and improving the quality of galvanized sheets.

② Eliminate physical highlights 

        When the strip steel comes out of the zinc pot after galvanizing, the temperature is as high as 460°C, and the temperature is 180-280°C when it reaches the top roller for about 20 seconds through the air knife and the first cooling section. 

       At this time, the strip steel coating has solidified, but the internal structure of the strip steel is not stable.  The temperature difference between the strip steel and the surface of the top roll increases the temperature gradient between the inside and the surface of the strip, which increases the internal stress of the coating.

       Therefore, when the lower surface of the strip is under the control of tension, it will inevitably cause friction when contacting the surface of the top roll.  Damage or slippage produces physical bright spot defects, which cannot be concealed even after finishing.  The use of smooth, low thermal conductivity top roll cloth can eliminate this defect and improve the surface quality of the galvanized sheet.

③ Environmental protection and safety

     Since the wrapping fabric is made of special high-temperature resistant materials, it has strong thermal stability and will not produce harmful gases and wastes in the production of galvanized sheets.

 ④ Easy to install

      Enterprises only need to make a slight modification on the existing equipment and prepare some simple accessories, then they can be installed and used.

 ⑤ Easy to replace

      There is no need to disassemble the top roller, it can be replaced as long as each stop time is used, and each roller is about 20 minutes.

 ⑥ Professional value

       During the use of the wrapping cloth, there is no need for maintenance, less one-time investment, and low cost to improve product quality and corporate image, and win unlimited value space.

•Top Roller Cloth Specification Sheet

*The above data is a test value and not a guaranteed value

*The specific size is designed according to the size of the top roller.

Note: 

Because the coefficient of friction between the top roller and the galvanized sheet is changed after using the wrapping cloth, it is necessary to appropriately adjust the top roller speed to keep the original tension of the galvanized sheet production line unchanged.