Some standard content:
Chemical Industry Standard of the People's Republic of China
Main contents and scope of application
HG/T2187-91
This standard specifies the technical requirements, test methods, acceptance rules and various requirements for packaging, marking, storage and transportation of powdered sesbania gum.
This standard does not apply to chemically modified sesbania gum. Cited standards
GB2794 Determination of viscosity of adhesives - Rotational viscometer method GB6438 Determination of crude ash in feed
GB5009.7 Determination of reducing sugar in food 3 Product classification
The products are divided into 1, 2, 3, and 4 types according to their viscosity (mPa.s): >3000, >1500~3000, 500~1500, <500
4 Technical requirements
4.1 Appearance: light yellow or milky white powder, no agglomeration, no impurities visible to the naked eye, 4.2 The quality indicators of various types of sesbania gum are listed in Table 1. Quality indicators of sesbania gum
Moisture, %
Sieving rate, %
Ash, %
Broken gel residue, %||tt ||Colloid content, %
Viscosity, mPa·s
Approved by the Ministry of Chemical Industry of the People’s Republic of China on December 23, 1991
Particle size, mm
1.50~2.00
1500~3000
2.00~2.50
500~1500
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Implementation on May 1, 1992
5 Test method
HG/T2187-91
The reagents and water used in this standard, unless otherwise specified, shall be purified reagents and distilled water or water of equivalent purity that meet the current national standards or professional standards.
5.1 Appearance inspection
Visual inspection method,
5.2 Moisture determination
5.2.1 Instruments and equipment
5.2.1.1 Weighing bottle d×h, mm40×25 or 50×25;5.2.1.2 Dryer: use color-changing silica gel as desiccant;5.2.1.3 Analytical balance: sensitivity 0.001g:5.2.1.4 Electric oven: temperature fluctuation range 1℃,5.2.2 Determination steps
Weigh 2g (accurate to 0.001g) Tianpu glue and spread it in a weighing bottle with constant weight in advance, open the cover and place it in a 105℃ oven, take it out after 4h, cover it Place in a desiccator to cool for 0.5h, weigh, place in a 105℃ oven for 0.5h, take out and place in a desiccator to cool for 0.5h, weigh to constant weight (the difference between the two weighings is less than 0.002g). Determine three times in parallel, and the absolute error of each measurement result is 0.20%.
5.2.3 Calculation
Moisture content (%)
Where: m—sample mass before drying, g;
—sample mass after drying, g.
5.3 Determination of screening rate
5.3.1 Main equipment
5.3.1.1 Standard sieve vibrating screen;
5.3.1.2 Standard sieve: aperture mm: 0.074, 0.100, 0.125; 5.3.1.3 Analytical balance: sensitivity 0.001g
5.3.2 Determination steps
Weigh about 50g of sesbania gum on a standard sieve (select a standard sieve with corresponding aperture according to the type of sesbania gum, 0.074mm, 0.100mm or 0.125mm), install the lid and the sieve bottom and place it on a vibrating sieve machine to vibrate for 0.5h, and weigh the mass of sesbania gum above and below the sieve respectively.
5.3.3 Calculation
Sieving rate (%)
Where: ml——mass of unscreened sesbania gum, g——mass of sieved sesbania gum Glue mass, g.
5.4 Determination of glue residue
5.4.1 Instruments and equipment
5.4.1.1 Centrifuge: can hold 50ml centrifuge tubes: 5.4.1.2 Glass centrifuge tubes: 50ml;
5.4.1.3 Constant temperature water bath: temperature fluctuation range ±0.5C; 2
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HG/T218791
5.4.1.4 Electric heating oven: temperature fluctuation range ±1℃; 5.4.1.5 Dryer: use color-changing silica gel as desiccant. 5.4.2 Preparation of cross-linking glue breaking solution
Add 1g borax, 0.1g potassium permanganate, and 0.25g potassium persulfate to 100ml water and mix to dissolve. 5.4.3 Determination steps
Weigh about 0.35g (accurate to 0.001g) of sesbania gum into a 100ml beaker, add 0.5ml ethanol to evenly moisten the sesbania gum, add 50ml 30℃ water, stir for 10min, cover with a watch glass and place in a 30℃ constant temperature water bath to swell for 4h. Take it out from the water bath, stir it evenly, add 2.5ml of cross-linking gel breaking solution, stir it evenly to form a frozen gel, cover the surface blood, break the gel in a constant temperature water bath at 70℃ for 24h, take it out from the water bath, stir it evenly, transfer the solution and precipitate into a 50ml centrifuge tube with constant weight in advance, wash the beaker with 10ml water several times, pour it into the centrifuge tube, place the centrifuge tube in a centrifuge, centrifuge at 2000r/min for 30min, discard the upper clear liquid, wash the beaker and precipitate with 50ml water (break the precipitate with a glass rod), wash the glass rod with a small amount of water, centrifuge for 20min, discard the supernatant, repeat the above operation, and finally place the centrifuge tube in a 105℃ oven to constant weight. The difference between the two weighed masses is less than 0.002g, which is constant weight.
5.4.4 Calculation
Broken gel residue (%)
Wherein, m is the mass of the sample, g;
m is the mass of the centrifuge tube, g
The total mass of the centrifuge tube and the residue, g.
5.5 Viscosity determination
5.5.1 Instruments and equipment
5.5.1.1 Beaker: tall type 250ml;
5.:5.1.2 Ground conical flask: 300ml;
5.5.1.3 Constant temperature water bath: the temperature fluctuation range is less than ±0.5℃; 5.5.1.4 NDJ-1 type rotational viscometer or similar products m
5.5.2 Determination steps
Weigh 2.5g (accurate to 0.001g) of sesbania gum into a dry ground-mouth conical flask. Tilt the conical flask to concentrate the sesbania gum on one side. Use a 200ml pipette to add 200ml of 25℃ water. Immediately add a stopper and shake vigorously until the solution is uniform. Then use a burette to add the insufficient amount of water and shake well. The amount of water is calculated according to formula (4): Additional water amount (ml) = sample weight (g) × (99-water %) - 200. (4)
About 5min, 30min, 1h, 1.5h, and 2h after adding water, shake vigorously again. After 2 hours, pour the solution into a tall beaker and place it in a constant temperature water bath at 25°C for 0.5 hours. After stirring, measure the viscosity on a viscometer. For sesbania gum with a viscosity below 1000mPa.s, use rotor No. 2 at a speed of 12r/min. For sesbania gum with a viscosity above 1000mPa.s, use rotor No. 3 at 12r/in. The basic method for determining viscosity is carried out in accordance with GB2794. 5.6 Ash determination
Determine in accordance with GB6438.
5.7 Determination of gum content
The main component of sesbania gum is galactomannan. The determination of total sugar can reflect the gum content. After the sample is deproteinized, galactomannan is hydrolyzed with hydrochloric acid to convert into reducing sugar. The total amount of reducing sugar is the gum content of sesbania gum. 5.7.1 Reagents
5.7.1.1 Hydrochloric acid (1+1);www.bzxz.net
Standard loss exchange network wwo.bzaoaoco m5.7.1.2 1g/L methyl red ethanol solution:
5.7.1.3 200g/L sodium hydroxide solution;
The other reagents are the same as GB5009.7.
5.7.2 Operation steps
HG/T2187-91
Weigh 2.5g (accurate to 0.001g) sesbania gum into a 250ml volumetric flask, add 50ml water, shake vigorously, then slowly add 5ml zinc acetate solution and 5ml (106g/L) potassium ferrocyanide solution, add water to the scale and mix well. Let stand for 30 minutes, filter with dry filter paper, discard the initial filtrate, draw 50ml of the filtrate into a 100ml volumetric flask, add 5m) hydrochloric acid (1+1), heat in a 68-70℃ water bath for 15min, add 2 drops of Scintillation Red indicator after cooling, neutralize with sodium hydroxide solution to neutrality, add water to the scale, mix well, and perform the following operations according to 7.2, 7.3, 7.4, and 7.5 of GB5009.7. 5.8 pH determination
Use the solution for viscosity determination in 5.5.2 to determine the pH value on a pH meter. 6 Inspection rules
6.1 Inspection classification
6.1.1 Factory inspection
6.1:1.1 This product is inspected by the quality inspection department of the manufacturer. The manufacturer shall ensure that all products shipped meet the requirements of this standard, and each batch of products shall be accompanied by a quality certificate. 6.1.1.2 Factory inspection items include appearance, moisture, sieving rate, and viscosity. 6.1.2 Type inspection
6.1.2.1 Type inspection shall be carried out in the following cases: a. When the variety of sesbania raw materials is changed;
b. During normal production, once a quarter;
C. When the national quality supervision agency proposes to conduct quality inspection. 6.1.2.2 Type inspection items are the items in Table 1 (items that cannot be measured by the manufacturer can be inspected externally). 6.2 Sampling
6.2.1 Number of samples
6.2.1.1 During factory inspection, one bag of the same type of sesbania gum shall be randomly taken from each ton (40 bags). 6.2.1.2 During type inspection, 1% of the output shall be randomly sampled. 6.2.2 Sampling method
6.2.2.1 The sampling shall be carried out using the sampler shown in Figure 1.
6.2.2.2 Sampling process
Open the sampling bag, scrape the sesbania gum on the surface flat, and insert the sampler vertically into the bag at the center point and any number of points around it until it reaches the bottom of the bag. After mixing the samples taken from the same bag evenly, use the quartering method to prepare two portions, each of which shall be no less than 50g, one for inspection and the other for duplicate sample.
6.2.2.3 The sample storage container shall be a clean, neat ground-mouth bottle or a plastic bottle with a double lid or a double-layer plastic bag; the sample shall be immediately sealed or capped after being placed in the storage container; a label shall be affixed to the sample storage container, indicating the product batch number, date, and name of the sampler. 6.2.2.4 When sampling, preparing, and storing samples, prevent the samples, samplers, and other containers from being contaminated by foreign matter. Standard exchange network wwo.bzaoaocome
HG/T2187-91
Figure 1 Sampler
a-Wooden handle; b-Stainless steel inserter
6.3 Judgment rules
6.3.1 According to the factory inspection items in 6.1.1.2 and the type inspection items in 6.1.2.2, each item shall comply with the product requirements of the corresponding model in Table 1. If one of the inspection results does not meet the requirements of the corresponding model in Table 1, the samples shall be re-taken for verification according to 6.2. If even only one of the verification results does not meet the requirements of the corresponding model in Table 1, the batch of products shall be downgraded. 6.3.2 If the supply and demand parties have disputes over product quality, arbitration shall be conducted by the arbitration unit. During arbitration, the inspection method shall be carried out in accordance with this standard.
7 Packaging, marking, storage and transportation
7.1 The product packaging is divided into two layers, the inner layer is a plastic bag, and the outer layer can be a chemical fiber woven bag, a multi-layer paper bag, a carton or a wooden box. The net weight of each piece is 25kg.
7.2 The packaging should indicate the manufacturer's name, product name, model, batch number, net weight, and the word "moisture-proof". The interlayer of the packaging bag should be attached with a product quality certificate.
7.3 This product should be placed in a clean and dry transport warehouse and warehouse during transportation and storage. It must not be mixed, transported or stacked with toxic and odorous substances during storage and transportation. It is strictly forbidden to be exposed to moisture and sunlight. 7.4 Under the above conditions, the storage period is 6 months from the date of production. Additional Notes:
This standard was proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Shanghai Rubber Products Research Institute. This standard was drafted by the Beijing Research Institute of Mining and Metallurgy and the Institute of Botany of the Chinese Academy of Sciences. The main drafters of this standard are Tang Yanxiang and Huang Qihua.
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