Cold shrink tube production process and process details
Formulation: including raw rubber, reinforcing agent, vulcanizing agent and other additives.
Mastication: Put the raw rubber on the open mill and pack it for use.
Thin pass: refers to the two rolls of rubber that pass through the machine with a very thin thickness. The purpose is three:
1. If it is pure natural rubber, it will use the mechanical shearing force of thin pass to break some long molecular chains in NR into small molecular chains to reduce the Mooney viscosity of NR and improve the process operation and processing performance. For mastication.
2. If it is a rubber compound, it is to improve the mixing effect of the rubber compound, so that the components in the rubber compound such as carbon black, vulcanizing agent and anti-aging agent are uniformly dispersed.
3. If the vulcanized rubber is regenerated, the vulcanized rubber of larger particles is pulverized into finer particles of vulcanized rubber powder by using the mechanical shearing force of the thin pass, which is convenient for recycling.
Mixing: Weighing and mixing the plasticized rubber, reinforcing agent and auxiliary agent, and then adding it to the internal mixer for mixing. After mixing, it is discharged into the internal mixer, and then opened and finished on the open mill. After parking, stand-by.
Filtration: After the parked rubber is heated, it is filtered to remove impurities, and then the film is cooled and parked.
Sulfurization: After the filtered rubber mixture is weighed, a vulcanizing agent is added to the mill, and after the vulcanizing agent is uniformly dispersed, a thin pass is performed.
Thin pass: In the open mill, the vulcanizing agent will be thinned and the strip will be extruded.
Extrusion: According to the requirements of the technical parameters of the process, select the appropriate die to adjust to meet the requirements of the technical parameters.
Vulcanization: The unvulcanized hose that meets the technical parameters of the process after extrusion shall be vulcanized according to the requirements of the technical parameters.
Cutting: The vulcanized hose is fixed and cut according to the requirements of the product and the technical parameters of the process. At the same time, check whether the surface of the vulcanized tube has impurities, bubbles, and whether there are pores in the section.
Extrusion, winding and welding of the support tube: support the strip with a plastic extruder, and then carry out the winding, welding, dressing and inspection on the winding machine according to the requirements of the technical parameters.
Expansion: The tube and the support tube that have been cut and fixed after vulcanization are expanded on the expansion machine, and the length after expansion is checked.
Finishing: Trimming, inspecting, surface wiping, and visual inspection of the expanded cold-shrink tubing.
Inspection: Check whether the cold-shrinkable tube after expansion has mechanical impurities, scratches, mechanical damage, bubbles, or deformation of the support tube, and perform sampling inspection at 100% to detect mechanical properties and retraction rate.
Packaging: Packed according to customer requirements.