GB/T 5399-1985 Rapid method for determination of pulp concentration GB/T5399-1985 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of stock concentration-Rapid method
Pulp--Determination of stock concentration-Rapid method
UDC 676.1.017
GB5399—85
This standard specifies a method for rapid determination of the concentration of a stock water suspension. In principle, this method can be used for all kinds of raw pulp or pulp that has been beaten and is ready for papermaking.
This standard refers to the international standard ISO4119-1978 "Pulp - Determination of stock concentration (rapid method). 1 Definition
1.1 Stock: A suspension of one or more fibrous materials in water, which may contain fillers and additives. 1.2 Stock concentration: The ratio of the absolute dry weight of the filtered material to the weight of the filtered sample in the stock suspension. The stock concentration is expressed as a percentage by weight. Www.bzxZ.net
2 Instruments
General laboratory instruments, including:
2.1 Measuring cylinder: The scale error is less than 0.5%.
2.2 Balance
Medical balance: weighing range 0~1000g, sensitivity 0.1g, fast balance: weighing range 0~150g, sensitivity 0.01g. 2.3 True Air pump and suction device
Medium 100mm or @150mm Buchner funnel,
1500~2000ml suction bottle,
Quick filter paper.
2.4 Beaker.
2.5 Device for drying samples
Drying oven with a drying temperature of 105~150℃ (preferably with a small fan), infrared drying oven or electric heating plate (glazing machine). 3 Sample preparation
3.1 General method
According to regulations, samples taken from the process system are thoroughly mixed and sampled while stirring. The sample must be quickly retained in an appropriate container to reduce the separation of fiber and water. The sample can be retained at one time or by combining small amounts of pulp obtained several times. In the case of higher concentration pulp and long fiber pulp In some cases, incorrect sampling methods can cause large errors. Note that the weighed or measured samples should be within the range of 1 to 5g of absolute dry pulp.
Note: For pulps with a concentration greater than 1%, the dilution sampling method can be used, or direct sampling can be performed according to the characteristics of the pulp. 3.2 The specific gravity of pulps with a concentration less than 0.3% can be approximately regarded as equal to that of water, so a measuring cylinder can be used to measure the sample. National Bureau of Standards 1985-09-28 Issued
198605-01 Implementation
GB5399-85
3.3 For pulps with a concentration greater than 0.3%, a beaker of known weight should be used to weigh the sample. The weighing should be accurate to 0.1g. 4 Test steps
4.1 Constant weight filter paper
Use an oven or other electric heating equipment at a temperature of 105 Dry the filter paper at 150℃ to constant weight. The filter paper can be weighed directly. All weighings must be accurate to 0.01g. When the difference between two consecutive weighings of the filter paper is no more than 0.01g, it is considered to have reached constant weight. In all cases, the drying time between two consecutive weighings is at least one-fourth of the total drying time used for the previous time, but not less than 15min. Mark the filter paper that has been weighed to a constant weight and dry it, and store it for future use. 4.2 Preparation of Concentrated Pulp
Put the filter paper that has been weighed to a constant weight in a Büchner funnel, wet the filter paper with water, filter the measured pulp sample, rinse the inner wall of the measuring cylinder or beaker, and pour the rinse liquid into the funnel. When filtering, pay attention to check the filtrate to ensure that it does not contain any visible fiber fragments. If there are missing fibers in the filtrate, it should be filtered again through the same filter. If the sample contains a certain amount of water-soluble substances that can affect the accuracy of the test, wash the pulp with distilled water or desalted water one by one. After the pulp is filtered dry, carefully remove the filter paper from the funnel. Note that all solids including those on the funnel wall should be removed.
4.3 Drying and constant weight of pulp
Perform constant weight according to 4.1. Note that the pulp should be dried using the same equipment and conditions as the filter paper. 4.4 Each pulp sample should be measured at least twice. The number of measurements should be appropriately increased for long-fiber pulp or high-concentration pulp. 5 Result expression
The measurement results are expressed as the arithmetic mean of the measured values. The concentration X of the pulp is calculated using the following formula and expressed as a weight percentage: X (%) =m=m2×100
Where: m
-weight of pulp sample, g,
weight of pulp and filter paper after drying, nom, weight of constant weight filter paper, g.
Report the results as the average value of each measurement, rounded to two significant figures, and rounded to three significant figures for concentrations above 10%. Additional remarks:
This standard was proposed by the Ministry of Light Industry of the People's Republic of China and is under the jurisdiction of the Paper Industry Research Institute of the Ministry of Light Industry. This standard was drafted by the Paper Industry Research Institute of the Ministry of Light Industry. The main drafter of this standard is Zhang Shaoling.
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