GB 8290-1987 Sampling of natural concentrated latex

This standard specifies the sampling procedures and methods for natural concentrated latex. This standard is only applicable to natural concentrated latex from Hevea brasiliensis, and is not applicable to compound latex or vulcanized latex. GB 8290-1987 Natural Concentrated Latex Sampling GB8290-1987 Standard Download Decompression Password: www.bzxz.net

Application Procedure
National Standard of the People's Republic of China
Sampling of Natural Concentrated Rubber Latex
Natural Rubber Latex Coacentrale Sampllng4 The standard adopts the international standard IS0128-195 Latex-Sampling. UDC.ot
GB6290-87
This standard specifies the sampling procedure and method of natural concentrated rubber latex. This standard is only applicable to natural concentrated rubber latex from Trifolium brasiliensis, and is not applicable to compound latex and vulcanized latex. 2 Reference Standards
GB829B-7 Determination of Total Volume Content of Natural Concentrated Rubber Latex. Definition (This standard adopts the following definition) 3.Batch: A certain amount of latex processed or produced under uniform conditions, from which samples need to be taken (see 3.4). A batch of latex can be contained in one or more containers, or it can be composed of several samples of latex. 3. Sample: a certain number of latexes are drawn from a batch of latexes. 3.3 Laboratory sample: a certain number of latexes are inspected and tested by a laboratory, and the laboratory selects a representative of the batch of latexes. 3. Test: a certain number of latexes are drawn from the laboratory, and suitable for testing. Note: the test results are the laboratory products. No test specimens are used. 4 Equipment
1 Mixing: used to make the latex uniform. Latex in large barrels can be mixed with the tools described in 1.1.1 or 1.1.2. Latex in barrels can be mixed with the tools described in 4.1.3. 4.1.1 Stainless steel mixer with mesh disk, the diameter of the disk is about 150mm, the disk has holes, the diameter of the holes is about 10mm, 4.1.2 Electric mixer with 100-7001/in, foldable double-blade stainless steel mixer on the shaft, the vertical length is at least 110m when fully raised, the distance between the paddle and the bottom of the barrel is about one tenth of the height of the latex, and the mixing shaft can also be equipped with double-layer screws. The speed can make the latex flow, but it will not cause misflow, and the part in the latex should not be mixed.
4.1.3 The speed of the electric mixer is about 10s/min; 4.2 The sampling tube for barreled latex uses the tools described in 1.2.1 or 4.2.2, 4.2.! The inner diameter of the glass tube is 10~16mm, the length is at least 1 meter, and the two ends are open. There are doors, so that the glass tube can be pulled out through the holes.
.2.2, the inner diameter of the stainless steel sampling tube is about 25mm, the length is at least 1 meter, and the seat of the tube can be opened or closed by a control device. The attached figure is a schematic diagram of the sampling tube
Approved by the Ministry of Agriculture, Animal Husbandry and Fisheries of the People's Republic of China on July 10, 1988 and implemented on June 1, 1988
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Sampling tubes for latex barrels, latex trucks and relatively open ones (according to the proportion of the technology) 4. Equipment for extracting latex samples from latex trucks or production plants. For latex at a depth of 3 m or more, the equipment described in 1.3.1 shall be used. For latex at a depth of less than m, the equipment described in 4.3.2 in 1.3.1 shall be used: 4. The sampling vessel shall be a large, heavy container of the same size, with a capacity of about 1 m, and a plug which can be removed from the vessel. The vessel shall be heavy enough to allow the plug to sink into the latex. The vessel shall have at least two places to tighten around the vessel, if the rope is made of material that is not affected by the latex, and the length shall not exceed the depth of the latex to be sampled. 3.2 The stainless steel sampling tube shall have an inner diameter of 25 m and a length of 3 m, and shall be accessible by means of a control device or a closed tube. The attached figure is a schematic diagram of the sampling device:
4.4 The container is 21 m, and the latex sampling device or sampler is connected to the latex sampling device 1. The beaker should be resistant to impact, light and not react chemically with the latex.
4.5 The sample bottle should have a capacity of 1L, a screw cap, a smooth inner surface, and should be made of plastic or other materials that can react chemically with the latex. However, thin or brittle containers should not be used. 46 Stainless steel wire cloth. Width of wire cloth should be 18 to 10m: 5 Sampling
In all sampling procedures, the latex should be filled with large air. 5.1 Preliminary inspection
And the method of using the most advanced technology in the latex is to check whether there are large blocks, crusts and impurities in the latex. GB8290-87
5.2 Take 1% of the total number of pieces from the drum sampling machine as a minimum sample. 5.2.1 Homogenization
Homogenize the latex in one of the methods specified in 5.2.1.1, 5.2.1.2, and 5.2.1.3. 5.2.1.1 For small 11, if there is a drum, place it in the drum and roll it at a continuous rate of 10 rpm. If there is no drum roller, roll the drum on the ground briskly for at least 10 minutes, then turn it over to 1600 meters, repeat the hydraulic operation for at least 10 minutes, then stand it upright and take samples immediately. 5.2,1.2 If it is a large 1! Remove the lid and use a steel plunger stirrer with a temperature of 100 °C (4.1.1) to stir the milk thoroughly for 10 minutes. 5.2.1. Use an electric stirrer (4.1.2) to stir the milk for 10 minutes. Avoid over-stirring. 5.2.2 Take a laboratory sample from the milk. After homogenization (5.2.1), use a glass tube (4.2.1) to remove the sample and then take a laboratory sample (4.2.3). When using a glass tube, it must be clean and dry. Slowly push the latex into the tube until it reaches the bottom of the barrel, then remove the upper end of the glass tube with a needle, and then pull the tube out of the tube, and repeat the above operation until there is enough latex to fill the sample. There should be 2% to 5% space in the sample bottle to allow for thermal expansion. Tighten the bottle cap on the bottle.
If a stainless steel sample tube is used, press the tube with your hand to open the handle until the sample tube reaches the bottom of the barrel. Then loosen the handle, close the bottom of the sample tube, and then pull the tube out of the handle. Use the cup (1.1) to release the latex in the sample bottle. Repeat this operation until enough latex is sucked into the sample bottle (<4.5). There should be 2% to 5% space in the sample bottle. Put the bottle sampler on the bottle. 6.2.8 Sampling from several samples
If it is necessary to sample the same batch from several samples, for example, a smaller sample can be taken within 10 seconds, then the amount of lavandrine drawn from each barrel can be reduced accordingly. Combine the individual samples and stir them, then put the resulting experimental sample into the bottle. 6.3 Sampling from latex peaks and storage ends
5.3.1 Sampling operation
You can use .3.1 or (4.3.2) sampling.
When using the sampler (4.3.1), use a cold water bottle to ensure that it sinks into the latex to the required depth, then pull the sampler out and let it sit in the latex for several minutes until it is full of latex, then take out the sampler and put the latex in the beaker [4.4]: Put the latex in the beaker (4.5) ) Leave 2% to 5% of the sample space in the sample bottle to allow for thermal expansion. Tighten the bottle cap. When using the sampler (4, 3.2), first unclog the sample tube, then insert the sample tube into the latex to the required depth, then pull the handle to make the bottom of the tube level. When the sample tube is filled with latex, release the handle to make the bottom of the tube level, then push the sample tube out from the back, put the filled latex into the beaker (4.4), and then pour the latex in the beaker into the sample bottle (4.5). There should be 2% to 5% of the sample space in the bottle. 5.3.2 Homogenization test Take samples from 100 mm below the latex surface and 3100 mm from the bottom of the latex, and determine the total solid content according to the method specified in GB8298-87 Determination of total solid content of natural latex. If the difference in total solid content between the top sample and the bottom sample exceeds 0.5 μm (m), the latex manufacturer needs to verify the initial results of the product. 5.3 Take the test sample from the latex
When the degree of homogenization specified in 3.2 has been achieved, take three small samples of similar volume. The first sample is taken halfway between the center of the latex surface and the center of the middle. The second sample is taken from the center of the middle of the latex. The third sample is taken halfway between the center of the middle of the latex and the center of the bottom. Combine the samples and put them into the sample bottle (4.5). If the sampling method (4.3.2), then only one sample can be taken. The sampling method is to open the bottom of the sampling tube, insert the sampling tube into the bottom of the latex, close the bottom of the sampling tube, and then take the sample out of the latex. Note: The content of the block is determined by the real sample, not the test sample. a
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Sample preparation
GB A298-JT
Finely stir the test sample, and filter it through a stainless steel mesh (4.8). Move the filtered latex into another sample bottle (4.5). Leave 2% to 5% of the space in the bottle, tighten the bottle cap, and add additional instructions.
This standard is issued by the Agricultural Bureau of the Ministry of Agriculture and Animal Husbandry of the People's Republic of China. This standard was drafted by the South China Tropical Crops Product Design Institute. The promoter of this standard is Zhou Hongqing.
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