橡胶硫化过程的四个阶段（Four stages of vulcanization process of rubber）.docVIP

橡胶硫化过程的四个阶段（Four stages of vulcanization process of rubber） When the gum is vulcanized, its properties change with the change of vulcanization time, which is called vulcanization curve. From the process of curing time affect the glue material tensile strength of the curing time can be divided into four stages: initial stage, less sulfur curing stage, sulfur and sulfur are stage stage 1) vulcanization starting stage (also known as scorch or vulcanization induction period) curing start means that the curing time, rubber began to harden, and then can not conduct thermoplastic flow that point of time. The sulfur start stage, i.e., the previous vulcanization time. In this stage, the crosslinking has not yet started and the adhesive has good fluidity in the model. The starting speed of the vulcanization of the rubber compound directly affects the scorch and operation safety of the rubber compound. The length of this phase depends on the type of complexing agent used, especially the promoter. With a speeding accelerator of the rubber material, its Scorch is relatively short, at this time the rubber material more prone to scorch, poor operation safety. In the use of delayed action accelerator (such as sulphenamide) or with little thiuram accelerator, can obtain longer scorch time and good operation safety. However, different curing methods and products have different requirements for focusing time. In the curing of molded products, always hope to have a longer scorch period, so that the glue has sufficient time to flow in the model, without causing products to appear unclear or lack of glue, until the defects. In the non model curing, the vulcanization should be started as early as possible, because the material starts quickly and hardens rapidly, and it is helpful to prevent the products from being deformed due to the softening of the heating. In most cases, however, a longer scorch time is desired to ensure operation 2) the stage of sulfide starting stage (also called pre