First, the basic process flow

There are many kinds of rubber products, but the production process is basically the same. The basic process of rubber products using general solid rubber (raw rubber) as raw material includes: plasticization, mixing, calendering, extrusion, molding and vulcanization 6 basic processes.

2. Preparation of raw materials:

1. The main raw material of rubber products is raw rubber as the basic material, and raw rubber is grown on tropical and subtropical rubber trees by artificially cutting the bark and collecting.

2. Various compounds: auxiliary materials added to improve certain properties of rubber products. 3. Fiber materials include (cotton, linen, wool and various artificial fibers, synthetic fibers) and metal materials (steel wire, copper wire) are used as skeleton materials for rubber products to enhance mechanical strength and limit product variation. During the preparation of raw materials, ingredients must be weighed accurately according to the recipe. In order for the raw rubber and the compound to be evenly mixed with each other, the material needs to be processed:

The raw rubber should be softened in the oven at 60--70 °C, and then cut and broken into small pieces; The compound is: lumpy, such as paraffin, stearic acid, rosin, etc. to be crushed;

If the powder contains mechanical impurities or coarse particles, it needs to be screened and removed;

Liquid, such as (pine tar, couron) need to be heated, melted, evaporated water, and filtered impurities;

The compound should be dried, otherwise it is easy to agglomerate, if it cannot be evenly dispersed during mixing, bubbles will be generated during vulcanization, which will affect product quality;

3. Plasticization

Raw rubber is elastic and lacks the necessary plasticity properties for processing, so it is not easy to process. In order to improve its plasticity, it is necessary to plasticize raw rubber; In this way, the compound is easy to be evenly dispersed in the raw rubber during mixing; At the same time, during the calendering and molding process, it also helps to improve the permeability (penetration into the fiber fabric) and molding fluidity of the compound.

4. Mixing

In order to adapt to a variety of different use conditions, obtain a variety of different performance, but also in order to improve the performance of rubber products and reduce costs, it is necessary to add different compounding agents to the raw rubber.

Mixing is a process in which the plastic raw rubber is mixed with the compound, placed in the rubber mixer, and completely and uniformly dispersed in the raw rubber through mechanical mixing.

5. Molding

In the production process of rubber products, the use of calenders or extruders to pre-make a process of various shapes and sizes, called molding. The molding methods are:

1. Calendering:

It is suitable for the manufacture of simple sheet and plate products. It is a method of pressing the mixed rubber into a certain shape and size of film through a rubber calender called calendering.

The textile fiber materials used in some rubber products (such as tires, tape, hoses, etc.) must be coated with a thin layer of glue (glue on the fiber is also called glue or rubbing), and the glue coating process is generally completed on the rubber calender. The purpose of drying is to reduce the moisture content of the fiber material (so as not to avoid water evaporation and foaming) and increase the temperature of the fiber material to ensure the quality of the calendering process. Glue dipping is a necessary process before glue hanging, in order to improve the bonding performance of fiber material and rubber material.

2. Extrusion molding:

For more complex rubber products, such as tire tread, hose, wire surface coating needs to be manufactured by extrusion molding method. It is a method of continuously modeling the mixed rubber with certain plasticity into the hopper of the extruder, and under the extrusion of the screw, through various mouth shapes (also called samples). Before extrusion, the rubber must be preheated to make the rubber soft and easy to extrude, so as to obtain a rubber product with a smooth surface and accurate dimensions.

3. Compression molding

It is also possible to use the molding method to manufacture certain rubber products with complex shapes (such as leather bowls, sealing rings), and with the help of the formed yin and yang molds, the rubber material is placed in the mold and heated to form.