Granulation is a key process in the production of standard glues. The granulation method is divided into several types such as grinding, shearing, pressing and hammer grinding. Practice has shown that the hammer grinding method has many advantages such as high efficiency and wide adaptability, and thus has become a mainstream process. The whole process is as follows: latex centrifugation de-mixing-water mixing-dilution-solidification-extrusion dehydration-creping-granulation-grading-granule glue.
Performance
The biggest advantage of standard glue is that it eliminates the method of grading by appearance. These methods often determine the grade of glue by hand or visual inspection, so there is no objective and strict basis. The SMR (English Standard for Malaysian Standard Natural Rubber) adopted and published in 1979 has a small grade but consistent quality requirements. It is divided into 5 grades for dry glue, namely SMR丄, SMR-5.SMR-10.SMR·20, SMR-50. The control range is clearly defined for each grade, for example, the impurity content is 0.05% for SMR-5 and 0.5% for SMR-50:
1 impurity content) 0.05%~0.5%;
2 ash content is 0.6%~1.5%;
3 The highest ammonia content is 0. 65%;
4 volatile matter <1.0%;
5 Antioxidation index PI (plastic retention rate) > 0·4%~0·6%;
6 Wallace plasticity P0=60.