Characteristics and advantages of mixer mixing
Time: 2019-01-23 09:53:46Copyfrom: Wuxi Tengyu Environmental Protection Technology Co
Characteristics of mixer mixing
Plastic rubber and various compounding agents are put into high temperature and high pressure secret refining chamber. After short time of kneading, dispersing and mixing, the required mixtures can be obtained.
The mixing process is as follows: lifting of the top bolt feeding falling of the top bolt pressurized mixing end of mixing opening of the bottom bolt turning over discharging turning back closing of the bottom bolt.
The advantages of mixer mixing are:
(1) The mixing time is short, the production efficiency is high and the quality of the mixing gum is good;
(2) Large glue loading capacity, high degree of automation in mixing, low labor intensity and safe operation;
(3) Mixture flying loss is small, pollution is small, workplace sanitation.
The shortcomings of mixer mixing are as follows:
It is difficult to control the mixing temperature accurately because of the slow heat dissipation of the mixer. When mixing the temperature-sensitive rubber, it is easy to produce burning phenomenon and consume large amount of cooling water
(2) The shape of the blend is irregular and massive, so it must be processed by pressing and other supplementary processing.
Mixing by internal mixer is not suitable for mixing light-colored compound, special compound, compound with frequent variety and temperature-sensitive compound.
Mixing process of internal mixer
The mixing process of internal mixer includes one stage mixing method, two stage mixing method, feeding method and reverse sequence mixing method.
(1) The working stage of mixer mixing is divided into three stages: wetting, dispersing and kneading.
(2) In the mixing process of internal mixer, wetting and dispersion are the two dominant stages of BIT value. In production, judging the mixing performance of the compound is usually measured by the time required for the mixture to be evenly dispersed. Generally, the second power peak on the mixing time-power diagram is used as the end time of the dispersion, which is called the BIT value of carbon black mixing time. The smaller the BIT value is, the better the mixing performance of the compound is, that is, it is easy to mix.
(3) Cooling and parking
A. Cooling is to avoid burning and bonding caused by high temperature of mixtures, usually through strong cooling to below 35 C.
B. Parking can relax the stress of rubber molecules and reduce shrinkage. It can also make the mixture disperse, further combine carbon black with rubber, and improve the physical-mechanical properties of the compound.
Rapid Inspection of Mixer
Controlling and guaranteeing the quality of rubber mixtures is one of the key links in the production of rubber products. Rapid inspection is to carry out rapid quality inspection of rubber mixtures. The method of rapid inspection is to take a sample at the front, middle and rear parts of each vehicle after mixing. The plasticity, vulcanization characteristics, hardness, tensile strength, elongation at break, permanent deformation at break and density of each vehicle are measured. The measured results are compared with the specified standard values to determine whether the quality is in line with the requirements.
The inspection methods of the related items can be found in the corresponding national standards.