GB/T 21331-2021 English PDF (GBT21331-2021)
GB/T 21331-2021 English PDF (GBT21331-2021)
GB/T 21331-2021: Fluff pulp
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
CCS Y 31
Replacing GB/T 21331-2008
ISSUED ON: MARCH 09, 2021
IMPLEMENTED ON: APRIL 01, 2022
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Terms and definitions ... 6
4 Product classification ... 6
5 Technical requirements ... 6
6 Test methods ... 7
7 Inspection rules ... 9
8 Marks, packaging, transportation and storage ... 10
Annex A (normative) Dispersion method for fluff pulp board ... 12
Annex B (normative) Determination of dry bulkiness, water absorption time and water absorption amount of fluff pulp ... 14
This Standard specifies the terms and definitions, product classification, technical requirements, test methods, inspection rules and marks, packaging, transportation, storage for fluff pulp.
This Standard is applicable to raw fluff pulp for the production of disposable sanitary products.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 451.2, Paper and board - Determination of grammage
GB/T 451.3, Paper and board - Determination of thickness
GB/T 462, Paper, board and pulp - Determination of moisture content of
GB/T 740, Pulps - Sampling for testing
GB/T 1539, Paperboard; Determination of bursting strength
GB/T 2828.1, Sampling procedures for inspection by attributea - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
GB/T 7974, Paper, board and pulps - Measurement of diffuse blue
reflectance factor - D65 brightness (Diff/Geometry, Outdoor daylight
GB/T 10739, Paper, board and pulps - STANDARD atmosphere for
conditioning and testing
GB/T 10740, Pulp - Estimation of dirt and shives
GB 15979, Hygienic Standard for Disposable Sanitary Products
GB/T 22804, Pulp, paper and board - Determination of mercury content
GB/T 22902, Pulps - Determination of acetone-soluble matter
GB/T 24991, Paper, board and pulps - Determination of lead content -
Graphite furnace atomic absorption spectrometry method
GB/T 24992, Paper, board and pulps - Determination of arsenic
GB/T 24997, Paper, board and pulps - Determination of cadmium content - Atomic absorption spectrometric method
GB/T 27741-2018, Paper and board - Determination of migratable
fluorescent whitening agents
GB/T 34845, Tissue paper - Determination of absorbable organic halogen
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. 3.1 treated fluff pulp
the fluff pulp that has been chemically treated and has significantly reduced burst resistance
3.2 untreated pulp
the fluff pulp that has not been chemically treated
4 Product classification
Fluff pulp is divided into treated fluff pulp and untreated pulp according to whether it has been chemically treated.
5 Technical requirements
5.1 The indicators of physical and chemical properties of fluff pulp shall meet the requirements of Table 1.
6.3 Quantitative deviation
Quantitative deviation is determined according to GB/T 451.2.
Tightness is measured according to GB/T 451.3.
6.5 Burst resistance
Burst strength is measured according to GB/T 1539.
6.6 D65 brightness
D65 brightness is measured according to GB/T 7974.
6.7 Dry bulkiness
Dry bulkiness is measured in accordance with Annex B. The fluff pulp board is dispersed according to Annex A.
6.8 Water absorption time
Water absorption time is measured in accordance with Annex B.
6.9 Water absorption amount
Water absorption amount is measured in accordance with Annex B.
6.10 Movable fluorescent substance
Movable fluorescent substance is qualitatively measured according to the method given in Clause 5 of GB/T 27741-2018.
6.11 Acetone extract
Acetone extract is determined measured to GB/T 22902.
6.12 Absorbable organic halogen (AOX)
AOX is measured according to GB/T 34845.
6.13 Heavy metal
The content of heavy metal lead (Pb) is determined according to GB/T 24991. The content of heavy metal arsenic (As) is determined according to GB/T 24992. The content of heavy metal cadmium (Cd) is determined according to GB/T 24997. The content of heavy metal mercury (Hg) is determined according to GB/T 22804.
7.4 When sampling, the external packaging of the sample shall be checked first. Then take a specimen from it for inspection.
7.5 Acceptability determination: The number of samples inspected for the first time shall be equal to the first sample size given in the plan. If the number of nonconforming products found in the first sample is less than or equal to the first acceptance number, the batch shall be considered acceptable. If the number of nonconforming products found in the first sample is greater than or equal to the first rejected number, the batch shall be considered unacceptable. If the number of nonconforming products found in the first sample is between the first acceptance number and the first rejection number, the second sample of the sample size given by the plan shall be inspected and the number of nonconforming products found in the first sample and the second sample shall be accumulated. If the cumulative number of nonconforming products is less than or equal to the second acceptance number, then the batch is determined as acceptable. If the cumulative number of nonconforming products is greater than or equal to the second rejected number, the batch is determined as unacceptable.
7.6 If the buyer has objections to the quality of the product, the batch of products shall be sealed up and notified to the supplier within three months after arrival (or as stipulated in the contract). The supplier and the buyer shall jointly conduct sampling inspection to this batch of products. If it does not meet the
requirements of this Standard, the batch will be rejected. It shall be dealt with by the supplier. If it meets the requirements of this Standard, the batch shall be accepted and dealt with by the buyer.
8 Marks, packaging, transportation and storage
8.1 Each batch of fluff pulp shall be marked with the product name,
implementation standard number, production date, batch number, manufacturer name, manufacturer address, product specifications, product type and other information, accompanying with a product certificate.
8.2 Each roll (piece) of the product shall be wrapped tightly with plastic film. 8.3 When the products are shipped, clean transportation tools with protective measures shall be used. They shall not be co-transported with polluting substances.
8.4 During the handling process, the products shall be handled with care, kept from rain and moisture. They shall not be thrown away.
Dispersion method for fluff pulp board
A.1.1 Paper cutter;
A.1.2 Laboratory fluff pulp board disperser: The schematic diagram is shown in Figure A.1. In the middle of the nail-shaped diffuser is a metal drum with a diameter of 150mm and about 500 nails on the outside. It is driven by an electric motor with a speed of 6000r/min~8000r/min. There is a protective casing outside the drum. There are feeding rollers [speed can be constant within the range of (4±1) cm/s] and a discharge port on the casing.
A.2 Sampling method
After removing the two-layer pulp board on the outer layer of the fluff pulp board, conduct sampling. Use a paper cutter to cut into strips of fluff pulp board samples with a width of about 30mm and a length of not less than 100mm. A.3 Dispersion method
Start the disperser power supply. After the motor reaches the rated number of revolutions, insert the strip-shaped fluff pulp board sample between the two feeding rollers. The dispersed fluff pulp is collected from the discharge port with negative pressure.
NOTE 1: To prevent the tail end of the strip fluff pulp board sample from entering the disperser and rotating with the metal drum then it cannot be effectively dispersed, discard the sample at the end of 1cm~2cm.
NOTE 2: To prevent the long-term work of the equipment from heating up and affecting the performance of the sample, the equipment shall not continuously work for more than 15min. NOTE 3: If the fluff pulp sample after dispersion is blocked in the disperser, discard this part of the sample.
B.4.1.2 Weigh about 3.05g of fluff pulp sample that is completely dispersed and balanced under standard atmospheric conditions. Use a tweezer to put them in the fluff pulp inlet several times. Make them sucked into the plastic molding tube for molding. The molded lump fluff pulp specimen remains in the test module. Use the balance to weigh the total mass of the test module and specimen, recorded as dry weight mdry.
NOTE: If the upper end of the formed specimen is not flat, it may use a needle or pointed tweezers to carefully adjust it to roughly level. Then weigh the dry weight. B.4.2 Determination of dry bulkiness and water absorption performance
B.4.2.1 Place the test module and the specimen on the dry bulkiness and water absorption performance tester (B.1.2). Gently place a pressure block with a mass of (500±5) g on the top of the specimen. After 30s, read the bulky height h of the specimen through the height gauge on the inner surface of the plastic molding tube.
B.4.2.2 Start the pumping system. Inject normal saline at (23.0±1.0)°C into the dry bulkiness and water absorption performance tester. When the surface of the normal saline contacts the 80-mesh metal filter, start the timer. After the saline is completely soaked in the specimen, the built-in electrode of the pressure block is turned on. The timer shall stop timing. The timer reading at this time is the water absorption time of the specimen.
B.4.2.3 After the water absorption time is measured, the pumping system continues to pump water for 30s. Then the pump shuts down. The water level drops. After the liquid level of the saline drops below the 80-mesh metal filter, the wet specimen starts to drain under the action of the briquette. After the wet specimen is drained for 30s, remove the pressure block. Use the balance to weigh the total mass of the test module and the wet specimen, recorded as wet weight mwet.
NOTE: If after removing the briquette, the bottom of the briquette is stained with fluff pulp, this test shall be invalid.
B.4.2.4 Take another set of dry test modules. Repeat B.4.2.2 and B.4.2.3 to conduct blank test. Use the balance to weigh the wet empty weight of the test module after the blank test is over, m’0.
B.4.2.5 Conduct at least 3 parallel tests. Calculate the average of dry bulkiness, water absorption time and water absorption amount respectively.
B.5 Result calculation
B.5.1 The dry bulkiness X of fluff pulp is calculated according to formula (B.1) and formula (B.2), to the nearest of 0.5cm3/g.