This standard specifies the method for determining the coagulum content of natural concentrated latex. This method is only applicable to natural concentrated latex from Hevea brasiliensis, and is not applicable to compound latex, vulcanized latex, and cationic latex. GB 8291-1987 Determination of coagulum content of natural concentrated latex GB8291-1987 Standard download decompression password: www.bzxz.net

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National Standard of the People's Republic of China
Natural concentrated latex
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Determination of coagulation content
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of congulun content1
This standard refers to the international standard IS07UB-1985 rubber type: coagulation content (determination of sieve residue>3UDC 678.031bZxz.net
CE 8291-: 87
This standard specifies the method for determining the content of natural latex in blocks. This method is applicable to natural concentrated latex from Hevea brasiliensis, not to latex from rubber trees, chemical latex, and other latexes. 2 Reference standard
GB825-8 Natural latex bottle sampling,
3 Sampling
Sampling shall be carried out in accordance with the method specified in GB8290. '4 Definition
The content of the block is the number of grams of dry material contained in every 10g of latex, including coagulated rubber pieces, latex knots and twisted foreign impurities, reagents
5.1 Potassium oleate or ammonium laurate: surfactant batch, 5% (m/m), pH = 10.5.2 Calcium test paper.
E Instrument
6.1 Test filter, a 180 ± 10m stainless steel wire full of holes, 6.2 Two stainless steel rings: the inner color is equal, the inner diameter is 1m: use a Class D filter. 6.3 The container is 600mL,
For the test procedure
Specially take 20D11g of laboratory latex sample into the beaker (6.3), according to the actual situation, add 200mL of surface contaminant solvent (5.1) to filter thoroughly. Put the filter (6.1) Dry in an oven at 1 ± 5 °C until constant temperature, weigh again (accurate to 1 mg) and record: Place the filter between two stainless steel rings (6.2). Use the same surfactant solution to filter (8.1). Pour the latex and surfactant mixture into a concentrator. Wash the residue on the stainless steel cloth with the same surfactant solution until there is no latex in the filter. Then wash with water until the residue is neutral. Take the stainless steel cloth with obvious condensation from the filter paper and wipe the bottom of the cloth with filter paper. Heat the steel cloth and the filter paper in a clean oven at 100 °C for 30 minutes. , and then put it in a dryer to cool, weigh it, and then put it back into the oven for 15 minutes, cool it again, and then weigh it. The calculation of the content of the agglomerate (expressed as a percentage of latex) is: one × 100. In the formula, mr is the mass of the latex sample. ,
The quality of some cloth blocks is more doubtful,
due to uneven distribution of blocks in latex: three parallel shakes are made for each sample station, and the average is taken for estimation. Additional notes:
This standard is issued by the Ministry of Agriculture and Animal Husbandry of the People's Republic of China, and the Ministry of Agriculture and Animal Husbandry of the People's Republic of China. The main drafter of this standard is Zhou Hongyan.
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