What's the best way to open the mixer when mixing? Next, I'll introduce it to you from the small editor of kaichi:
Mixing with open mill is an early mixing method in rubber industry. Compared with the internal mixer, the open mixer has the advantages of high labor intensity, low production efficiency, insecurity, environmental pollution, and poor mixing uniformity, so it has been gradually eliminated. However, it is more flexible to use the open mill for mixing, which is suitable for factories with small production scale, small batch size of rubber materials and many varieties. For the production of some special rubber materials, such as sponge rubber, hard rubber, color rubber, etc., it is particularly suitable to use the open mixer for mixing, so at present, the use of open mixer for mixing in small rubber factories still accounts for a certain proportion.
The third stage of refining and mixing is refining. Due to the high viscosity of rubber, during mixing, the rubber material only flows in the circumferential direction along the rotation direction of the open mill roller, but there is no axial flow, and the rubber flowing in the circumferential direction is only laminar flow, so the rubber layer close to the front roller surface at about 1 / 3 of the film thickness can not generate flow and become a "dead layer" or "dead layer". In addition, the stacking glue on the upper part of the roll gap will form a part of wedge-shaped "return area". All of the above causes make the admixture in the compound disperse unevenly.
Because of the high viscosity of rubber, the fluidity of rubber near the roller surface is poor, and the shear force makes the rubber flow only laminar. About 1 / 3 of the inner layer of the film in contact with the roller surface cannot be fed in, forming a "dead layer".
Mixing operation method of open mill during mixing operation of open mill, raw rubber, mother rubber or compound rubber are generally added along one end of the big gear, and then various admixtures are added according to the specified dosing sequence for mixing. There are two kinds of dosing methods in mixing according to the formula rubber content: the one with high raw rubber content, the admixture is added in the middle of the roller, the mixer is opened and the method of extracting glue and dosing is adopted to keep the proper amount of stacking glue between the two rollers; the one with low raw rubber content, the admixture is added at one end and the method of changing glue and dosing is adopted. The admixture with less amount of compound and carbon black with high pollution are usually added in the form of masterbatch or paste.
Generally, one-stage mixing method is used for mixing, but if natural rubber is used and a large amount of synthetic rubber and carbon black is used for filling, two-stage mixing method can be used to make rubber and admixture mix more evenly.
After all the compounding agents are added, it is necessary to conduct re mixing to further mix the rubber. There are two methods of mixing: manual cutting and mechanical cutting. The manual cutting method generally uses left and right cutters, twists and turns, triangle packs and cutter rolls. The mechanical cutter method is to install a mechanical cutter near the front roller, cut along the roller surface to make the glue fall in the plate, and then send it to the roller room for several times. After the completion of the turning, the roll spacing shall be widened (4-5mm), and then the cutting method shall be used to supplement the turning for 2-3 times and then lower the plate.