3 calendering law
The rubber material is made into a certain specification film or tape by a calender, and sometimes it is necessary to make a semi-finished product of a certain shape and thickness after necessary bonding, such as various tape products (air bed, air cushion, motorboat…) or a thickness exceeding 8 mm. A thick pad with a higher density is required. For film for forming, if the thickness accuracy is required to be low, the film can be produced by an open mill. Films with high precision requirements for forming must be supplied by the calender operation. There are two types of calendering equipment commonly used, one operated by a three-roll calender; the other is operated by a four-roll calender. The thickness of the rolling of the four-roll calender is 0. 04~lmm. When the film thickness is required to exceed 6 mm, it must be laminated with a calender. In addition, when the film thickness is about 3 to 7 mm, a two-roll calender can be used for tableting. The film rolling process includes a medium-injection coating method and a medium-roller non-encapsulation method. The medium-rolling rubber-cladding method has a compact density and a small number of bubbles, but the calendering effect is large, and is mainly used for compressing natural rubber-based rubber compounds. . However, the medium-spray non-encapsulated rubber compound has a small calendering effect, but has low compactness and many bubbles, and is mainly used for compressing the main rubber as a main rubber.
Synthetic rubber is more suitable for natural rubber than for natural rubber because of the large shrinkage after film rolling, the surface is not smooth, the bubbles are numerous, the specifications are difficult to control, and the performance of the wrapping roll is poor. The rolling roll temperature should be properly controlled. When the thickness of the rubber compound needs to be more than 7 mm, or the airtightness is required or two different rubber materials are required to be put together, a three-roll calender is used for lamination.
The main points of operation of the post-cooperation industry are as follows: the adhesion between the bonding surfaces should be maintained, and the film should be bonded immediately after one rolling. The plasticity of the other two types of adhesives should be the same. When the different types of film are bonded, the shrinkage rate and vulcanization rate should be the same. It is best to use continuous operation when pressing and contracting, so as to avoid wrinkles of bubbles and surfaces, maintain a fresh calendered surface, and have strong adhesion and good fit. However, the film has a large calendering effect.
4 cutting machine method
The film made of the open mill or the calender is replaced by a slitting machine by hand to cut into a strip of a certain width, and can also be used to cut the extruded hose of the extruder directly into a circular semi-finished product. The method has high production efficiency, uniform width of the cut strip, convenient width adjustment and low labor intensity.
5 precision preforming machine method
The precision pre-forming machine adopts advanced manufacturing technology such as hydraulic, pneumatic, vacuum, circulating heating and automatic control. It is an ideal semi-finished molding production machine for the rubber industry. It has the characteristics of high efficiency and energy saving. The quality of the produced rubber is high and the apron has no joint. The surface is smooth. The precision pre-forming machine is composed of an extrusion device, a cutting device, a hydraulic control system, etc. The extrusion device is a plunger type extrusion, and thus can also be used for a filter rubber and a rubber strip. The pressure extrusion material is dense and dimensionally stable. There are two kinds of cutters: single knife and double knife. The speed can realize step speed regulation and stepless speed regulation. The size and quality of the semi-finished product are adjusted by the shape of the mouth and the speed of the cut. The rubber compound is heated to 60~80 °C on the open mill, and is rolled according to the specified size, pushed into the glue injection cylinder, and turned off.
Precision Preformer is mainly used to prepare rubberized embryos for various ring, round, rectangular and other shaped products used in the production of rubber molded products. It can be applied to various hardnesses of butyl rubber, natural rubber, neoprene, and fluororubber.
6 mechanical punching method
This method uses a punching machine and a cutter of a certain shape to punch out a semi-finished product from a film or a hose, for example, punching a disc rubber pad from a fluororubber film to solve the problem of difficulty in the fluororubber joint.