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Processing technology of rubber fender
- 2019-06-04-

Rubber fenders are mainly produced by two processes, steel wire fabric with joint type and jointless type. The steel cord has a joint type process, which uses an extruder or a calender to prepare a steel cord, a flat plate vulcanizing machine vulcanizes the belt body, and then overlaps to form a ring body joint vulcanization. The advantages of this production process are high degree of equipment automation, high production efficiency, and low labor intensity. The disadvantages are that the thickness deviation of the overlapped parts of the track joints is large, and the steel cord and the belt rubber are liable to cause relative slippage at the joint parts. The steel cord non-joint process uses a single steel wire winding method to produce steel cord, and then uses a flat vulcanizing machine to vulcanize it in stages. The advantages of this production process are the small elongation of the rubber track, the good stability of the track pitch, the good cooperation between the core metal and the mechanical gear, and the high overall tensile strength of the track. The disadvantage is that there are many process factors that affect the quality of the track, and the vulcanization interface is vulcanized. The degree is not easy to control, the production efficiency is low, and the labor intensity is large. The processes of mixing, extruding, and calendering in the production of rubber tracks are basically the same as those in the production of conventional rubber products. This article only briefly introduces the issues that need attention in the surface treatment of core gold, wire coating, preforming, and vulcanization.

1 The surface treatment of core gold uses sand blasting to remove rust, clean, dry and dip the adhesive (automatically or manually) to make the core gold and rubber bond more firmly after vulcanization. The core gold blasting treatment should be standardized. Carefully check the core gold before blasting to avoid using core gold with defective quality. After sandblasting according to the specified quality and time, check whether the surface of the core gold is clean. Core cores with defects such as pores, slag inclusions, shrinkage holes and notches must be selected. For cores with unclean surfaces and other attachments, Gold should be reblasted. Wear clean gloves when touching the blasted core gold to prevent contamination of the core gold surface. After the core gold is blasted, the adhesive should be dipped within 60 minutes. After 60 minutes, the blasting should be repeated for 10 minutes. The core of the dip-coated adhesive should be stored in a dry and clean environment and used up within 1 week, otherwise it must be reblasted.

2 wire rubber

(1) Extruder rubber coating When using an extruder to prepare steel cord fabric, the rubber coating tension must be uniform, the rubber coating width and thickness must meet the construction standards, and the steel wires must be arranged neatly without bending or overlapping. If the steel cord is broken or missing during the extrusion operation, the steel cord should be supplemented according to the construction standards. When the steel cord is found to be rusted or the rubber is abnormal, it should be replaced in time. The steel cord should be stored in a sealed, desiccant box. The hanging time on the spindle rack should not exceed 72 hours. No water is allowed in the spindle room. The storage temperature of the rubber-coated steel cord should be below 40, and the storage time should not exceed 15 d. If it is stored for more than 15 d, the gasoline should be brushed before use, and then coated with a layer of glue.

(2) Winding machine coating When using a winding machine to produce steel cords, the glue concentration must be strictly controlled. The steel cords and strips are not allowed to suffer from lack of glue, yellowing, wire bending and overlap. Unevenness and looseness are not allowed when winding the steel wire. After the winding of the steel cord fabric, if local yellowing occurs, the glue should be applied in time. The glue should be applied evenly, and no accumulation of glue is allowed. After being wound and coated with glue, the steel cord should be reversed on the plate and removed after drying. The two sides of the film cannot overlap. After the steel cord is removed, it should be stored on a rack. Flooring, twisting, entanglement, etc. are not allowed to ensure the smoothness of the steel cord.

3 Pre-molding Place the extruded rubber material that meets the requirements on the core-gold pitch template, and insert the specified amount and specifications of core-gold. The process of making standard-quality molded parts is pre-forming. Extruded rubber, steel cord and core gold need to reach the prescribed parking time before being pre-formed, and all parts are not allowed to be placed on the ground. When pre-forming, the prescribed amount of core gold is placed symmetrically and equidistantly in the template hole, and the core gold is covered with a thin film and tamped in order with a special tool to fix the core gold. Cover the core gold tooth tips with soft film to prevent them from damaging the mold surface.

4 Vulcanization

(1) The steel cord has a joint-type process. First, the long mold is formed and vulcanized. The semi-finished parts are sequentially loaded into the mold in the order of wheel side rubber, tooth rubber, core gold, intermediate rubber and steel cord, quality adjustment rubber, and pattern side rubber. . Check whether the core gold is inserted into the hole, whether it is perpendicular to the mold center, and whether the steel cord is placed at the set position. The glue for quality adjustment is placed on both sides of the steel cord, and it must be filled uniformly over the entire length. The various rubber materials installed in the mold should be connected, and overlap is not allowed to avoid the extension of the pitch. The glue should be brushed at the joint and then connected with a thin film. After vulcanization, ensure that there are no quality defects such as bubbles on the surface of the pattern side rubber, and take care not to damage the ends of the belt.

After vulcanizing the long mold, vulcanize the ring joint. Remove the rubber edges at both ends of the unvulcanized or semi-vulcanized part of the belt, cut 5 to 6 mm in the length direction, cut out the bevel, apply glue to both ends, and connect. Glue butt. After the necessary repairs are made to the depressions caused during vulcanization and demoulding of the long mold or the cavity formed by the positioning of the core metal, the vulcanization of the joint is performed.

(2) The steel cord non-joint process adopts the steel cord non-joint process. During vulcanization, care should be taken to control the degree of vulcanization at the vulcanization junction to prevent excessive sulfur or undersulfurization at the vulcanization junction.