After the NBR wrapping roller, an appropriate amount of stacking glue must be left on the roller, and then the compounding agent is added to the stacking glue, and the wrinkle entraining agent of the stacking glue enters the roll gap and generates radial mixing action, thereby accelerating the mixing powder of the compounding agent. . Otherwise, only the circumferential shearing, no radial mixing, the compounding agent can not enter the inside of the wrapping roller rubber. However, the effect of the build-up glue can only reach 2/3 of the thickness of the roll rubber. On the side of the film close to the surface of the roll, there is about 1/3 of the thickness without the compounding agent entering. This is called the sluggish layer. At this time, the mixed state of the rubber is better in circumferential uniformity, poor axial uniformity, and the worst radial uniformity.

The radial mixing of the cut refining glue is limited, and in order to make the mixing of the NBR parts uniform, a cutting and refining operation must be performed. Such as the triangle package method, the bevel method (the oblique knife method, eight knife method), the twist method and the thin method. It is usually used in several ways, which not only improves the mixing uniformity, but also speeds up the mixing. No matter what, in the end, you have to thin through 3 to 5 times to finish the mixing and release. It must be noted that the cutting and retort operation can only be carried out after the compounding agent has been mixed into the rubber compound (after the powder is consumed), otherwise the NBR will be unrolled and cannot be operated normally.