22 inch open rubber refinery-550 open refiner
Rubber mix process/rubber mix production process
Main process flow: processing of compound → weighing of rubber and compound → mixing → cooling and storage of lower sheet → quick inspection of rubber.
1、 Processing and weighing of compounding agent:
The process of preparing and processing the rubber and compounding agent used in rubber products, and weighing and matching according to the technical formula is called processing and batching process.
1. Processing of raw materials:
(1) The natural glue shall be baked and equipped with a glue drying room. The large pieces shall be cut into small pieces.
(2) The purpose of processing and preparation of compounding agent: to ensure the quality of compounding agent, facilitate the process operation of mixing, improve the mixing and dispersion effect, achieve automatic conditions, and manufacture good rubber.
(3) Processing method of compounding agent:
--Crushing: Crush or grind large particles according to certain quality standards.
Objective: To increase the contact area between the formulation and raw rubber, so as to facilitate uniform mixing and dispersion of the formulation.
 
--Drying: the mixture is heated and dried in a specially designed heating chamber or dryer.
Objective: To remove and reduce the moisture and low volatile impurities in the formulation and ensure the quality of the formulation. Because too much water is easy to agglomerate, it is not conducive to dispersion in the mixing process, and finally leads to uneven mixing.
--Screening: use various screening equipment to screen the ingredients.  
Objective: To remove large particles of debris.  
--Melting, filtering and evaporative dehydration: heat and melt the easily melted solids and viscous liquids, remove impurities through the screen, and evaporate and dehydrate the softened liquids.
Purpose: To remove water.
 
2. Weighing and matching of the preparation agent:
(1) Weigh according to the type, specification and quantity of the formulation and the requirements of the formulation.
This process is very important to the quality of rubber mixture. In case of missing or wrong matching, the weighing tolerance is not met. More, less, etc.
(2) Operating requirements for symmetry and fit.  
A. The material type is accurate.
B. The weighing is accurate.
C. No missing or wrong matching.
D. Not more or less.
For example, the accuracy of the weighing balance for vulcanizing agent and accelerator is required to be 1-5g.
(3) Notes for batching process:
A. Pay attention to moisture-proof, and store the ingredients in a dry area.
B Some coordination agents, such as magnesium oxide (MgO) and calcium oxide (CaO), will react with water and change the performance of the coordination agent itself. Therefore, attention must be paid to waterproof in the process of batching and storage. In case of agglomeration, it cannot be used.
C. Fire prevention, such as sulfur, shall be paid special attention. It is not allowed to store under the electrical switch, and the raw rubber and CB shall also pay attention to fire prevention. Pay special attention to electric welding.
D. Anti mixing, because there are many raw materials in the matching room, and some of them are similar in appearance, so they are easy to mix, so they must be stored in a fixed place with obvious signs. Drugs without marks cannot be used, and must be determined by sampling test before use.
 
2、 Mixing process:
1. The process of mixing raw rubber and various ingredients into a whole through a special rubber mixing machine is called mixing process. The compound made by mixing and processing is called rubber mix.
Purposes of rubber mixture:
(1) The physical and mechanical properties of the preparation are uniform and consistent, meeting the requirements of the formula.
(2) Improve the processing performance of the rubber compound to meet the processing requirements of the subsequent process.
(3) Reduce cost and meet product quality requirements.
(4) Improve the use performance of rubber products.  
2. Quality requirements for rubber mixture:
(1) Ensure that all quick inspection indexes of rubber are qualified.
(2) It has good processing performance.
(3) Ensure that the finished products have good physical and mechanical properties.
3. The qualified rubber mixture shall meet the following requirements:
(1) The compounding agent shall be evenly dispersed to avoid agglomeration.
(2) The rubber material has a specific viscosity and scorch value to ensure the safety and smooth progress of various processes.
(3) The raw rubber and reinforcing agent should produce a certain amount of bonding rubber with good reinforcement effect. Reinforcing agents mainly include CB, SiO2.nH2O (white carbon black).
(4) On the premise of ensuring the quality of the rubber mix, shorten the mixing time as much as possible, reduce power consumption and avoid over refining.
4. The rubber mixing production line consists of internal mixer, upper auxiliary machine and lower auxiliary machine.
(1) The upper auxiliary machine is a device to store, weigh and transport raw materials such as powder, liquid, granule and block into the internal mixer.
(2) The lower auxiliary machine is a series of devices that press the rubber discharged from mixing of the internal mixer until cutting the lamination.  
The upper auxiliary machine is a complete set for the internal mixer, including carbon black, oil, powder and raw rubber weighing and conveying devices, mainly including a carbon black conveying device, namely CB unpacking room. CB is driven into the storage tank by air pressure, and then put into the suspended automatic scale according to the type, and then put into the internal mixer. B Liquid softener delivery system. C Small drug weighing system, using low melting point polyethylene packaging bags, packaging, and then put into the internal mixer. The lower auxiliary machine has two forms, A: open mill; B: Twin screw extruder is generally used for extruding rubber.