Some standard content:
GB8939—1999
This standard is a mandatory standard, of which the permeability, pH value in Article 4.1 and Article 4.3 are mandatory standard provisions, and the rest are recommended standard provisions.
This standard is a revision of GB8939--1988 "Sanitary Coin". The main technical differences between this standard and GB8939--1988 are as follows: This standard includes sanitary pads in the scope of assessment and makes specific provisions for their technical indicators; the test of sanitary napkin permeability is changed to the inclined plane method, and the test solution is changed from pig blood to standard synthetic test solution; the pH determination is adjusted accordingly according to the current widespread application of polymer additives; the provisions on product specifications emphasize the control of its fluctuation range to meet the requirements of market development. The sanitary indicators of this standard are no longer specified separately, and GB15979-1995 "Sanitary Standards for Disposable Sanitary Products" is uniformly implemented. This standard replaces GB8939-1988 from the date of implementation. Appendix A, Appendix B, and Appendix C of this standard are all standard appendices: Appendix D of this standard is a prompt appendix.
This standard is proposed by the State Bureau of Light Industry.
This standard is under the jurisdiction of the National Technical Committee for Standardization of Paper Industry. The responsible drafting unit of this standard: China Pulp and Paper Industry Research Institute; participating drafting units: Fujian Hengan Group, Guangzhou Procter & Gamble Company, Kimberly Clark Personal Hygiene Products Co., Ltd., Shandong Jinan Lu'ao Paper Company, Shanghai Weierfu Group, Tianjin Baihui Hygiene Products Company, Guangxi Qiaofeng Hygiene Products Company, Guangdong Shunde Fukang Hygiene Products Company. The main drafters of this standard: Zhang Xiaohui, Wang Huajia, Chen Qizhao, Wei Pengyue, Zhang Shaoling. This standard is entrusted to the National Technical Committee for Standardization of Paper Industry for interpretation. 283
1 Scope
National Standard of the People's Republic of China
Sanitary napkins (including sanitary pads)
Sanitary absorbent pads
GB 8939 --1999
Replaces GB8939-1988
This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, transportation, storage and other requirements for sanitary napkins and sanitary pads. This standard is applicable to external physiological hygiene products with specially designed structures, i.e., composed of outer covering materials, inner absorbent layers, impermeable bottom films, etc., and formed by special packaging machines for women during menstruation (sanitary napkins) and non-menstruation (sanitary pads). Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T462-1989 Determination of moisture content in paper and paperboard (eqvISO287:1978) GB/T2828-1987 Procedure for sampling by counting and sampling by batch inspection (applicable to inspection of continuous batches) GB/T10739-1989 Standard atmosphere for handling and testing of pulp, paper and paperboard samples (eqvISO187:1984) GB15979-1995-Sanitary standard for disposable sanitary products 3 Product classification
3.1 This standard is divided into sanitary napkins and sanitary pads according to product performance. 3.2 Generally, sanitary napkins are those with an effective length of not less than 160mm, and sanitary pads are those with an effective length of less than 160mm (effective length: the length of the built-in absorbent layer such as fluff pulp seen through the absorbent surface of the sanitary napkin). Manufacturers can also produce sanitary napkins and sanitary pads of different specifications according to market demand and enterprise standards. 3.3 Sanitary pads are not divided into grades. Sanitary napkins are divided into three grades according to technical quality: superior, first-class and qualified. 4 Technical requirements
4.1 The technical indicators of sanitary napkins and sanitary pads shall comply with the requirements of Table 1 or the provisions of the order contract. Table 1
Indicator name
Full length L
Water absorption
】Full width B
Bar mass G
Not less than
Approved by the State Administration of Quality and Technical Supervision on June 22, 1999 284
Superior product
G±10%
Sanitary napkin
First-class product
Sanitary pad
Qualified product
L±10%||t t||B±10%
G±15%
G±20%
L±10%
B±10%
2000-01-01 implementation
Permeability
Indicator name
Permeation volume
Front lateral penetration width 1
Adhesive strength
Delivery moisture
Not less than
Not more than
GB 8939—1999
Table 1 (end)
Superior products
Not full width
Sanitary city
First-class products
Qualified products
Qualitative assessment
Sanitary pads
1) If the sample absorbs all the test solution, take another sample to test its permeability without a net, and take its width and absorption without a net as its test result.
4.2 Sanitary napkins and sanitary pads should be clean and uniform, with intact anti-seepage bottom layer, no damage, no hard blocks, etc., soft to the touch, and reasonable structure. 4.3 The hygienic requirements for sanitary napkins and sanitary pads shall comply with the provisions of GB15979. 4.4 The seals at both ends of sanitary napkins and sanitary pads should be firm and not break during the water absorption rate test. 4.5 The adhesive strength of the back adhesive of sanitary napkins and sanitary pads should meet the requirements, that is, the spraying effect is good, the product does not move during normal use, and the clothing is not damaged when it is peeled off from the underwear and there should be no obvious residue. The anti-sticking paper should not fall off by itself and can be torn off naturally and completely. 5 Test method
5.1 Pretreatment of the sample before the test shall be carried out in accordance with the provisions of GB/T10739. 5.2 Full length, full width, and strip quality deviation
5.2.1 Full length
Measure the full length of the sample with a ruler (measured from the longest part of the sample), measure 10 samples of each specification, measure to 1mm, and calculate the difference between the maximum and minimum lengths of the 10 strips and the average value (L) of the 10 strips and the percentage of their average value as the measurement result of the full length deviation of the sample, accurate to 1%.
5.2.2 Full Width
Use a ruler to measure the full width of the sample (measured from the narrowest part of the sample). For each sample of the same specification, measure 10 strips, and push the measurement to 1mm. Calculate the difference between the maximum and minimum values of the width of the 10 strips and the average value (B) of the 10 strips and the percentage of the average value as the measurement result of the full width deviation of the sample, accurate to 1%.
5.2.3 Strip Mass
Use a 0.01g sensitive balance to weigh the net weight (including release paper) of 10 strips of the same specification, accurate to 0.1g, and calculate the difference between the maximum and minimum values of the mass of the 10 strips and the average value (G) of the 10 strips and the percentage of the average value as the measurement result of the mass deviation of the sample, accurate to 1%.
5.2.4 Calculation of the deviation of the total length, total width and strip mass Upper deviation (%) = Maximum volumetric average value × 100 Average value
Lower deviation (%) = Minimum average volumetric value × 100 Average value
5.3 Water absorption ratio
: (1)
....( 2)
Take a sample of known mass (excluding the mass of release paper), clamp one end with an iron clamp to seal it, and make the clamp mouth of the iron clamp perpendicular to the longitudinal direction of the sample, and do not clamp the built-in absorption layer. Immerse the sample together with the iron clamp into distilled water at a depth of about 10 cm and at (23 ± 1) ℃, with the use side of the sample facing up. Gently press the sample to make it completely submerged for 60 seconds, then lift the iron clamp to make the sample completely leave the water surface, hang it vertically for 90 seconds, and then weigh its mass. Calculate the ratio of the amount of water absorbed by the five samples to the weight of the strip (i.e., water absorption ratio) according to formula (3), and take the average value of the five samples as the test result, accurate to one decimal place.
GB 8939--1999
Mass after absorptionMass of a strip
Water absorption ratio
Mass of a strip
5.4 The permeability shall be measured according to Appendix A (Appendix to the standard). (3)
5.5 The delivery moisture shall be measured according to the provisions of Chapter 8 and Chapter 9 of GB/T462-1989. Sampling method: Take 2 strips of each sample of the same specification, and the sampling weight of each strip is 2g (it shall not contain the adhesive and release paper part). Take two groups of samples for parallel testing, and take their arithmetic mean to express the test result. The error between the two measured values shall not exceed 0.5%. 5.6 pH shall be measured in accordance with the provisions of Appendix C (Standard Appendix). During arbitration, it shall be measured in accordance with the surface method provisions of Appendix C C2.2. 5.7 The determination of sanitary indicators shall be carried out in accordance with the provisions of GB15979.8 The quantitative determination of adhesive strength of the back glue is recommended to be carried out in accordance with the provisions of Appendix D (Suggested Appendix). 6 Inspection rules
6.1 Type inspection
Type inspection is the first piece inspection, and the inspection items are all standard inspection items and hygiene indicators. Type inspection should be carried out in any of the following situations:
a) Trial production of new and old products; b) When the production process is changed or new raw materials are used in production, which may affect the product performance; c) Normal production, type inspection is carried out once a quarter; d) When production is resumed after suspension;
e) When the factory inspection results are significantly different from the last type inspection. 6.2 Delivery inspection
6.2.1 Take one delivery as a batch, and the delivery inspection sample unit is a box. A sufficient number of samples are randomly selected from the sample box as the sample of the box.
The manufacturer shall ensure that the product quality meets the requirements of this standard. The product can only be shipped after passing the inspection and attaching the quality certification mark. 6.2.3 Product delivery sampling inspection shall be carried out in accordance with GB/T2828, and the sampling plan, inspection level and acceptable quality level (AQL) shall be as specified in Table 2. Table 2
Sampling plan
151～3 200
6.2.4 Judgment rules
Normal inspection Secondary sampling plan Inspection level S-3 Sample size
13(26)
Class B nonconforming products
Class C nonconforming products
Nonconforming classification
Nonconforming
Swimmability
Nonconforming
Full length, full width, strip
quality, water absorption
rate, delivery moisture,
pH, appearance quality
If Class B and Class C nonconforming products appear at the same time, they shall be treated as Class B nonconforming products A. , R. Under the premise of meeting the judgment requirements, and only when the sum of Class B and Class C non-conforming products is less than or equal to the A value of Class C non-conforming products, the batch is judged to be qualified; if it is greater, it is judged to be unqualified. If it cannot be judged, the second sample shall be tested and judged, and the judgment method is the same as before. 6.2.5 If the purchaser raises any objection to the quality of the batch of products, it shall notify the supplier within three months after arrival and conduct a joint re-inspection of the batch of products. If it meets the requirements of this standard or the order contract, it shall be judged to be qualified and the purchaser shall be responsible for handling it; if it does not meet the requirements of this standard or the order contract, the supplier shall be responsible for handling it.
7 Marking, packaging, transportation, storage
7.1 Sales marking and packaging of products
GB 8939—1999
7.1.1 The sales packaging of products shall indicate the following: a) product name, implementation standard number, hygiene standard number, trademark; b) name and address of the manufacturer;
c) product variety and internal quantity;
d) production date or batch number of the product;
e) hygiene license number;
f) disinfection products shall also indicate the disinfection method and validity period, and the words "disinfection grade" shall be marked on the main surface of the packaging. 7.1.2 The sales packaging of products shall ensure that the products are not contaminated. Materials with moisture-proof, anti-seepage, good isolation performance and sealing properties, such as polyethylene film, shall be selected to ensure that the marking information can be clearly printed and not easily faded. 7.2 Transportation and storage of products
7.2.1 Finished products that have been packaged for sale should be placed in packaging boxes. Each packaging box should be accompanied by product qualification and product grade labels. 7.2.2 The packaging box should indicate the product name, name and address of the manufacturer (or distributor), content, production date (batch number) and shelf life (use-by date), health license number, and disinfection products should also indicate the disinfection unit and address, disinfection method, disinfection date (or batch number), validity period and disinfection mark. The packaging box should indicate the transportation and storage conditions. 7.2.3 During transportation, clean tools with protective measures should be used to prevent heavy pressure, collision with hard objects, and exposure to sunlight and rain. 7.2.4 Finished products should be stored in a dry and ventilated room that is not exposed to direct sunlight, and should be protected from rain, snow and ground moisture. They should not be placed together with polluted or toxic chemicals.
7.2.5 Products that have exceeded their shelf life can only be used within a limited period after re-inspection and passing the inspection. 287
A1 Instruments and test solutions
A7.1 Instruments
GB8939—1999bzxz.net
Appendix A
(Appendix to the standard)
Determination of permeability
a) 1 balance, maximum range 200g, sensitivity 0.01g, b) 1 sanitary napkin permeability tester (hereinafter referred to as the tester, see Figure A1); c) 1 60mL drain funnel (hereinafter referred to as the funnel); d) 1 standard test net;
e) 1 10mL graduated pipette;
f) 1 beaker,
g) 1 steel ruler.
Draining funnel
Standard test network
Sanitary
A1.2 Test solution
Schematic diagram of sanitary napkin permeability tester
The test solution is a standard synthetic test solution specially used for permeability test. The formula is shown in Appendix B (Standard Appendix). During the test, the test solution temperature should be maintained at (23±1)℃. During arbitration inspection, the specimens should be processed and tested under standard atmospheric conditions, i.e. (23±1)℃ and (50±2)% relative humidity.
A2 Test procedure
A2.1 First place the tester in a horizontal position, adjust the angle between the upper and lower panels to about 10°, and then adjust the lower opening of the draining funnel so that the projection of its center point is (140±2) mm from the lower edge of the inclined panel of the tester, and the lower opening of the funnel faces the operator. Pour an appropriate amount of test solution into the funnel to moisten the funnel, and wash the funnel twice with the solution, and drain the solution in the funnel. A2.2 Take a sanitary coin to be tested, weigh its mass (g), and weigh it to 0.01g. Place the sanitary napkin flatly on the inclined panel of the tester, align the lower edge of the effective length of the sanitary napkin with the lower edge of the inclined panel, and fold the extended edge back to the bottom of the inclined panel, and then press the standard test net on the sanitary napkin evenly and symmetrically. Adjust the height of the funnel so that the lower end of its lower opening is 5mm to 10mm away from the surface of the sample, and then place a beaker under the inclined panel of the tester to collect the solution that flows down after the sample penetrates. Some sanitary napkins are severely folded and cannot be placed flat. You can peel off the release paper behind it and put it aside, and gently stick the sanitary napkin to the panel below. After the test, stick the release paper back and weigh it together. A2.3 Use a graduated pipette to accurately transfer 5 mL of the test solution into the adjusted funnel, then quickly open the funnel valve to the maximum, allowing the solution to flow freely onto the surface of the sanitary napkin sample and flow down along the slope; after the solution has flowed out, close the funnel valve, press the standard test net lightly on the surface of the sanitary napkin and remove it, then use the sanitary napkin to lightly touch the solution at the bottom of the funnel, then remove the sanitary napkin and weigh it again on the balance. If the test solution flows away from the side of the sanitary napkin, the sample is invalid and another one is taken for retesting. A3 Calculation of test results
The permeability of the sanitary napkin is expressed in terms of the mass (g) of the absorbed test solution. 8 pieces of each sample are tested and the permeation amount of each sanitary napkin is calculated according to formula (A1).
Infiltration amount (g) - the mass of a sanitary napkin after absorption (g) - the mass of the sanitary napkin before absorption (g) .....(Al)
Remove the maximum and minimum values of the 8 test results, and take the arithmetic mean of the remaining 6 as the final test result, accurate to 0.1g. If 5mL of the test solution is completely infiltrated into the test sample, it is not necessary to weigh it again, and it can be directly recorded as 5.1g (due to the existence of the standard test net, the total absorption value may fluctuate around 5.1g, which is a normal phenomenon). A4 front lateral infiltration width
Take the sanitary napkin that has been infiltrated with the test solution, and immediately observe the front lateral infiltration width of the sanitary napkin (if the visible infiltration width of the built-in absorbent layer is wider than the surface layer, take the visible infiltration width of the built-in absorbent layer) for judgment. If more than 2 (not including 2) of the above 8 are full width, then the measurement result is judged to be full width. Appendix B
(Standard Appendix)
Formula of standard synthetic test solution for sanitary napkin penetration performance test B1 Principle
This standard synthetic test solution is prepared based on the main physical properties of animal blood (pig blood) and has similar flow and absorption characteristics. B2 Formula
a) Distilled water or deionized water: 860mL; b) Sodium chloride: 10.00g;
c) Sodium carbonate: 40.00g;
d) Glycerin: 140mL;
e) Sodium benzoate: 1.00g
f) Color (food coloring): appropriate amount;
g) Sodium carboxymethyl cellulose: about 5g,
h) Standard medium: 1% (V).
The above reagents are all chemically pure.
Physical properties of B3 standard synthetic test solution
At (23±1)℃:
Density: (1.05±0.05) g/cm2;
GB 8939 --1999
Viscosity: (11.9±0.7) s (measured with No. 4 paint cup); Surface tension: (36±4) mN/m.
Appendix C
(Subject Appendix)
Determination of pH
C1 Instruments and Reagents
C1.1 Instruments
a) 1 pH meter with a combined electrode;
b) 1 mercury thermometer with an accuracy of ±0.1℃;c) 2 beakers with a capacity of 100mL;
d) 1 volumetric cylinder with a capacity of 50mL;
e) 1 pair of stainless steel scissors;
f) 1 1000mL volumetric flask.
C1.2 Reagents
C1.2.1 Distilled water or deionized water, pH 6.5-7.2;C1.2.2 Standard buffer solution: buffer solution with a pH of 6.86 at 25℃ (mixture of potassium dihydrogen phosphate and disodium hydrogen phosphate). The reagents used should be analytically pure, and the buffer solution should be re-prepared at least once a month. Preparation method: Weigh 3.39g of potassium dihydrogen phosphate (KH,PO) and 3.54g of disodium hydrogen phosphate (Na2HPO4), place in a 1000mL volumetric flask, dissolve with distilled water and dilute to the scale, shake well. C2 Test steps
C2.1 Beaker immersion method
At room temperature, take a piece of sample, cut off the adhesive strip and weigh 1g (accurate to 0.001g) of the sample from the middle, place in a 100mL beaker, add 50mL of deionized water (or distilled water), stir vigorously with a glass rod for 10 minutes, and put the composite electrode in the beaker to read the pH value.
C2.2 Surface method (direct immersion method)
At room temperature, take a sample and lay it flat on the test bench with the self-adhesive surface facing down. Put 50 mL of deionized water (or distilled water) close to the middle surface of the sample and slowly immerse it into the sample within 1 minute. Start timing after 50 mL of water has completely penetrated. At 3 minutes, put the flat composite electrode close to the sample immersion surface. Read the pH value when the electrode is in contact with the sample for 1 minute. Note: For samples containing high molecular weight water-absorbing resin, add an appropriate amount of water within 1 minute until a small amount of free water appears, and start timing immediately. C3 Calculation of test results
Take two samples of each sample and measure them at the same time. Take the arithmetic mean as the measurement result, accurate to 0.1 pH unit. Precautions
Before using the pH meter each time, the instrument should be calibrated with a standard buffer solution. For details, see the instrument manual. After each sample is tested, the electrode should be rinsed with deionized water immediately, and the deionized water on the electrode should be absorbed with filter paper for the next sample test. 290
D1 Preface
GB8939—1999
Appendix D
(Suggested Appendix)
Method for Determination of Adhesive Strength of Back Adhesive (180° Peel Strength) Sanitary napkins and sanitary pads rely on adhesive backing to stick to underwear. There are many methods to evaluate their adhesive strength. This method provides examples of them for reference when evaluating the adhesive effect of adhesive. D2 Principle
Use the 180° peeling method to apply a certain stress to peel off the adhesive backing of the sample from the pure cotton jersey. By timing the time required to peel a certain length, its adhesive strength is reflected.
D3 Apparatus and Tools
a) Test clamp: The upper clamp should be able to hang on any bracket and ensure that the sample it clamps can be perpendicular to the horizontal and the gap is flush; the lower clamp has a weighted magnetic code to make its total weight reach 40g and the gap is flush. b) Counterweight bowl: area 62mm×80mm, weight 500g (glass of the same area can be used instead with a counterweight); c) Stopwatch: 1;
d) Constant temperature box: can maintain a temperature of (37±2)℃; e) Scissors, ruler, flat plate (can also be used instead of glass); f) Standard jersey: unbleached and dyed worsted 32 yarn, no post-treatment 120g/m2, standard brand, size 65mm×80mm. D4 Operation
D4.1 Cut off the bottom of the sample and take the section with the most glue sprayed, with a length of not less than 80 mm and a width of not less than 62mm. Clean the surface of the section connected to the fluff pulp (or the inner layer of the sample), gently scrape it flat, and it is best to peel off all layers except the last glue spraying layer, and use it as a sample for later use. Be careful not to peel off the release paper and do not touch the glue surface with your hands. D4.2 Draw two straight lines B and C 40mm apart perpendicular to the length direction of the prepared sample, and draw another straight line A 10mm apart on one side, as shown in Figure D1:
Length direction of sample
D4.3 Place the prepared sample on a flat plate, tear off the release paper, and gently place the standard jersey on the sample with the front side facing up (i.e., the back side facing the glue), without pressing with your hands, and then press the weight bowl flat on the jersey. D4.4 Immediately move the flat plate into the constant temperature box and start timing. The temperature in the box is (37±2)℃. After 1 hour, take it out and let it dry at room temperature for 20 minutes. 291
D5 Test
GB8939-
9—1999
Take the sample after D4.4, gently peel the jersey and the bottom layer of the sample to a certain distance to line A, clamp the upper clamp of the sample along line A, and hang it up so that the length direction of the sample is perpendicular to the horizontal plane; clamp the jersey with the lower clamp parallel to the upper clamp, and let go, so that the jersey is 180° peeled from the rubber surface under the gravity of the lower clamp, and start timing when the peeling point reaches line B, and stop timing when it is peeled to line C, and the peeling time of the sample is obtained.
D6 Test Result
The test result takes the maximum, minimum and arithmetic average of the test values of the 5 test pieces, and the time data is accurate to minutes if it is greater than 1h, and accurate to seconds if it is less than 1min.
Test Report
The test report should include the following contents:
a) sample name and manufacturer;
b) test date;
c) test conditions;
d) test phenomena;
e) test results;
f) other contents to be reported.2 Surface method (direct immersion method)
At room temperature, take a sample and lay it flat on the test bench with the self-adhesive surface facing down. Put 50 mL of deionized water (or distilled water) close to the middle surface of the sample and slowly immerse it into the sample within 1 minute. Start timing after 50 mL of water has completely penetrated. At 3 minutes, put the flat composite electrode close to the sample immersion surface. Read the pH value when the electrode is in contact with the sample for 1 minute. Note: For samples containing high molecular weight water-absorbing resin, add an appropriate amount of water within 1 minute until a small amount of free water appears, and start timing immediately. C3 Calculation of test results
Take two samples of each sample and measure them at the same time. Take the arithmetic mean as the measurement result, accurate to 0.1 pH unit. Precautions
Before using the pH meter each time, the instrument should be calibrated with a standard buffer solution. For details, see the instrument manual. After each sample is tested, the electrode should be rinsed with deionized water immediately, and the deionized water on the electrode should be absorbed with filter paper for the next sample test. 290
D1 Preface
GB8939—1999
Appendix D
(Suggested Appendix)
Method for Determination of Adhesive Strength of Back Adhesive (180° Peel Strength) Sanitary napkins and sanitary pads rely on adhesive backing to stick to underwear. There are many methods to evaluate their adhesive strength. This method provides examples of them for reference when evaluating the adhesive effect of adhesive. D2 Principle
Use the 180° peeling method to apply a certain stress to peel off the adhesive backing of the sample from the pure cotton jersey. By timing the time required to peel a certain length, its adhesive strength is reflected.
D3 Apparatus and Tools
a) Test clamp: The upper clamp should be able to hang on any bracket and ensure that the sample it clamps can be perpendicular to the horizontal and the gap is flush; the lower clamp has a weighted magnetic code to make its total weight reach 40g and the gap is flush. b) Counterweight bowl: area 62mm×80mm, weight 500g (glass of the same area can be used instead with a counterweight); c) Stopwatch: 1;
d) Constant temperature box: can maintain a temperature of (37±2)℃; e) Scissors, ruler, flat plate (can also be used instead of glass); f) Standard jersey: unbleached and dyed worsted 32 yarn, no post-treatment 120g/m2, standard brand, size 65mm×80mm. D4 Operation
D4.1 Cut off the bottom of the sample and take the section with the most glue sprayed, with a length of not less than 80 mm and a width of not less than 62mm. Clean the surface of the section connected to the fluff pulp (or the inner layer of the sample), gently scrape it flat, and it is best to peel off all layers except the last glue spraying layer, and use it as a sample for later use. Be careful not to peel off the release paper and do not touch the glue surface with your hands. D4.2 Draw two straight lines B and C 40mm apart perpendicular to the length direction of the prepared sample, and draw another straight line A 10mm apart on one side, as shown in Figure D1:
Length direction of sample
D4.3 Place the prepared sample on a flat plate, tear off the release paper, and gently place the standard jersey on the sample with the front side facing up (i.e., the back side facing the glue), without pressing with your hands, and then press the weight bowl flat on the jersey. D4.4 Immediately move the flat plate into the constant temperature box and start timing. The temperature in the box is (37±2)℃. After 1 hour, take it out and let it dry at room temperature for 20 minutes. 291
D5 Test
GB8939-
9—1999
Take the sample after D4.4, gently peel the jersey and the bottom layer of the sample to a certain distance to line A, clamp the upper clamp of the sample along line A, and hang it up so that the length direction of the sample is perpendicular to the horizontal plane; clamp the jersey with the lower clamp parallel to the upper clamp, and let go, so that the jersey is 180° peeled from the rubber surface under the gravity of the lower clamp, and start timing when the peeling point reaches line B, and stop timing when it is peeled to line C, and the peeling time of the sample is obtained.
D6 Test Result
The test result takes the maximum, minimum and arithmetic average of the test values of the 5 test pieces, and the time data is accurate to minutes if it is greater than 1h, and accurate to seconds if it is less than 1min.
Test Report
The test report should include the following contents:
a) sample name and manufacturer;
b) test date;
c) test conditions;
d) test phenomena;
e) test results;
f) other contents to be reported.2 Surface method (direct immersion method)
At room temperature, take a sample and lay it flat on the test bench with the self-adhesive surface facing down. Put 50 mL of deionized water (or distilled water) close to the middle surface of the sample and slowly immerse it into the sample within 1 minute. Start timing after 50 mL of water has completely penetrated. At 3 minutes, put the flat composite electrode close to the sample immersion surface. Read the pH value when the electrode is in contact with the sample for 1 minute. Note: For samples containing high molecular weight water-absorbing resin, add an appropriate amount of water within 1 minute until a small amount of free water appears, and start timing immediately. C3 Calculation of test results
Take two samples of each sample and measure them at the same time. Take the arithmetic mean as the measurement result, accurate to 0.1 pH unit. Precautions
Before using the pH meter each time, the instrument should be calibrated with a standard buffer solution. For details, see the instrument manual. After each sample is tested, the electrode should be rinsed with deionized water immediately, and the deionized water on the electrode should be absorbed with filter paper for the next sample test. 290
D1 Preface
GB8939—1999
Appendix D
(Suggested Appendix)
Method for Determination of Adhesive Strength of Back Adhesive (180° Peel Strength) Sanitary napkins and sanitary pads rely on adhesive backing to stick to underwear. There are many methods to evaluate their adhesive strength. This method provides examples of them for reference when evaluating the adhesive effect of adhesive. D2 Principle
Use the 180° peeling method to apply a certain stress to peel off the adhesive backing of the sample from the pure cotton jersey. By timing the time required to peel a certain length, its adhesive strength is reflected.
D3 Apparatus and Tools
a) Test clamp: The upper clamp should be able to hang on any bracket and ensure that the sample it clamps can be perpendicular to the horizontal and the gap is flush; the lower clamp has a weighted magnetic code to make its total weight reach 40g and the gap is flush. b) Counterweight bowl: area 62mm×80mm, weight 500g (glass of the same area can be used instead with a counterweight); c) Stopwatch: 1;
d) Constant temperature box: can maintain a temperature of (37±2)℃; e) Scissors, ruler, flat plate (can also be used instead of glass); f) Standard jersey: unbleached and dyed worsted 32 yarn, no post-treatment 120g/m2, standard brand, size 65mm×80mm. D4 Operation
D4.1 Cut off the bottom of the sample and take the section with the most glue sprayed, with a length of not less than 80 mm and a width of not less than 62mm. Clean the surface of the section connected to the fluff pulp (or the inner layer of the sample), gently scrape it flat, and it is best to peel off all layers except the last glue spraying layer, and use it as a sample for later use. Be careful not to peel off the release paper and do not touch the glue surface with your hands. D4.2 Draw two straight lines B and C 40mm apart perpendicular to the length direction of the prepared sample, and draw another straight line A 10mm apart on one side, as shown in Figure D1:
Length direction of sample
D4.3 Place the prepared sample on a flat plate, tear off the release paper, and gently place the standard jersey on the sample with the front side facing up (i.e., the back side facing the glue), without pressing with your hands, and then press the weight bowl flat on the jersey. D4.4 Immediately move the flat plate into the constant temperature box and start timing. The temperature in the box is (37±2)℃. After 1 hour, take it out and let it dry at room temperature for 20 minutes. 291
D5 Test
GB8939-
9—1999
Take the sample after D4.4, gently peel the jersey and the bottom layer of the sample to a certain distance to line A, clamp the upper clamp of the sample along line A, and hang it up so that the length direction of the sample is perpendicular to the horizontal plane; clamp the jersey with the lower clamp parallel to the upper clamp, and let go, so that the jersey is 180° peeled from the rubber surface under the gravity of the lower clamp, and start timing when the peeling point reaches line B, and stop timing when it is peeled to line C, and the peeling time of the sample is obtained.
D6 Test Result
The test result takes the maximum, minimum and arithmetic average of the test values of the 5 test pieces, and the time data is accurate to minutes if it is greater than 1h, and accurate to seconds if it is less than 1min.
Test Report
The test report should include the following contents:
a) sample name and manufacturer;
b) test date;
c) test conditions;
d) test phenomena;
e) test results;
f) other contents to be reported.
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