Process flow of rubber products
Process flow of rubber products
1、 Basic process flow
There are various types of rubber products, but the production process is basically the same. The basic process of rubber products made from general solid rubber (raw rubber) includes six basic processes: molding, mixing, rolling, extrusion, forming, and vulcanization.
2、 Raw material preparation:
01. The main raw material of rubber products is raw rubber, which grows in tropical and subtropical Hevea brasiliensis and is collected by manually cutting the bark.
02. Various compounding agents: auxiliary materials added to improve certain properties of rubber products. 3. Fiber materials include (cotton, hemp, wool and various artificial fibers, Synthetic fiber) and metal materials (steel wire, copper wire) as the skeleton materials of rubber products to enhance mechanical strength and limit product deformation. During the raw material preparation process, the ingredients must be accurately weighed according to the formula. In order for the raw rubber and the compounding agent to mix evenly with each other, it is necessary to process the material:
Raw rubber should be softened in a drying room at 60-70 ℃, then cut and broken into small pieces; The compounding agents include: block like, such as paraffin, stearic acid, rosin, etc., which need to be crushed;
If the powder contains mechanical impurities or coarse particles, it needs to be screened and removed;
Liquid, such as pine tar and coumarone, require heating, melting, evaporating water, and filtering impurities
Quality;
The compounding agent should be dried, otherwise it is prone to clumping. If it cannot be evenly dispersed during mixing, bubbles will be generated during vulcanization, which will affect product quality;
3、 Molding
Raw rubber is elastic and lacks the necessary plasticity during processing, making it difficult to process. In order to improve its plasticity, it is necessary to refine the raw rubber; In this way, the compounding agent is easily evenly dispersed in the raw rubber during mixing; At the same time, during the rolling and forming processes, it also helps to improve the permeability of the adhesive material (penetrating into the fiber fabric) and the molding fluidity.
4、 Mixing
In order to adapt to various usage conditions, obtain various properties, and improve the performance of rubber products and reduce costs, it is necessary to add different additives to the raw rubber.
Mixing is the process of mixing the raw rubber after molding with the compounding agent and placing it in a rubber mixer. Through mechanical mixing, the compounding agent is completely and evenly dispersed in the raw rubber.
5、 Forming
In the production process of rubber products, the use of a calender or extruder to pre make various shapes and sizes is called molding. The methods of forming include:
01. Rolling forming:
Suitable for manufacturing simple sheet and plate shaped products. It is a method of pressing mixed rubber into a certain shape and size of film through a rubber rolling machine, called rolling forming.
Some textile fiber materials used in rubber products (such as tires, tape, hose, etc.) must be coated with a thin layer of adhesive (also known as gluing or wiping on the fibers), and the gluing process is usually completed on a rubber calender. Fiber materials need to be dried and soaked before rolling. The purpose of drying is to reduce the moisture content of the fiber material (to avoid evaporation and foaming) and increase the temperature of the fiber material to ensure the quality of the rolling process. Dipping is a necessary process before hanging the adhesive, with the aim of improving the bonding performance between the fiber material and the adhesive.
02. Press out molding:
For more complex rubber products, such as tire tread, rubber tube, and metal wire surface coating, it needs to be manufactured using extrusion molding method. It is a method of continuously shaping rubber blends with a certain degree of plasticity by placing them into the hopper of the extruder and using various mouth shapes (also known as templates) under the extrusion of the screw. Before pressing out, the rubber material must be preheated to make it soft and easy to extrude, in order to obtain a smooth surface and accurately sized rubber product.
03. Molding
Some rubber products with complex shapes (such as leather cups and sealing rings) can also be made by molding. With the help of the shaped male and female molds, the rubber material can be placed in the mold for heating and forming.
