Some standard content:
National Standard of the People's Republic of China
Test methods for packaging materials
Contact corrosion
Test of packaging materials-Contact corrosivity1 Subject content and scope of application
This standard specifies the test method for the corrosion of packaging materials to the metal surfaces with which they are in close contact. This standard is applicable to the inspection of packaging materials that have been or have not been treated in the specified environment. 2 Reference standards
GB 678
GB 679
GB 699
Chemical reagents Ethanol (anhydrous ethanol)
Chemical reagents 95% ethanol
Glycerol (glycerol)
Chemical reagents
Technical conditions for high-quality carbon structural steel
GB1922
GB 3193Www.bzxZ.net
Solvent oil
Aluminum and aluminum alloy hot-rolled plates
GB10455 Silica gel desiccant for packaging
3 Terms
3.1 Corrosion
GB/T 162661996
Deterioration of materials caused by chemical reactions. This deterioration is usually caused by oxidation, acid or alkali, electrochemical effects, etc. In this test, as long as rust spots, corrosion spots or loose or granular products appear on the surface of the sample, it is considered to be corrosion. Single discoloration is not considered corrosion.
3.2 Stain
Only the color change occurs on the test surface without rust spots, corrosion spots or surface deterioration. Discoloration is not considered corrosion in this test. 3.3 Test surface
Refers to the surface of the material that has been specially processed. Its corrosion condition should be checked after the test. 4 Instruments, materials, reagents, test pieces and specimens 4.1 Instruments and materials
Electric constant temperature drying oven: (100~300)℃±1℃; Glass desiccator: about 320mm, upper diameter 280mm±5mm, height (without cover) 260mm±5mm Hair dryer: for both drinking and heating;
Evaporating dish: 500mL,
Tweezers: 300mm long
Medical gauze and absorbent cotton;
Embrane cloth: 180*, 200″, 220″, 240; Dry sandpaper: particle size 100 mesh.
Approved by the State Bureau of Technical Supervision on March 12, 1996 366
Implemented on September 1, 1996
4.2 Reagents
Anhydrous ethanol: in line with GB678;
95% ethanol: in line with GB679
Glycerol: in line with GB.687, GB/T 16266—1996
Washing oil: in line with NY190 silica gel in GB1922 standard: fine pore type, in line with GB10455.
4.3 Test pieces and samples
Low carbon steel sheet: in accordance with GB699, 100mm×50mm×(4～6)mm, four pieces of each, one piece is blankAluminum test piece: in accordance with GB3193, 100mm×50mm×(4～6)mm, four pieces of each, one piece is blankPackaging material sample: 75mm×50mmz
Glass slide: 75mm×25mm. Thickness 3~5mm; Rectangular steel block for fixing: 75mm×25mm×25mm, stainless steel. 5 Preparation of test pieces and samples
5.1 Grinding and cleaning of metal test pieces
Grind the processed steel sheet with 200*～240* emery cloth; grind the aluminum test piece with dry sandpaper with a particle size of 100 mesh. Then clean it in four evaporating blood bottles containing solvent oil (twice), 95% ethanol, and anhydrous ethanol respectively. When cleaning, use tweezers to hold absorbent cotton or gauze to scrub, then blow dry with hot air, and put it in a dryer containing fine-pored silica gel that meets GB10455 for use. The test piece prepared after grinding and cleaning shall not be stored for more than 8 hours, otherwise it should be re-grinded and cleaned. 5.2 Packaging material samples
Randomly select samples of coiled materials that are three turns away from the outer coil or the fourth sheet from the top of the flat plate, and cut them at least 100mm away from the edge. 5.2.1 For soft materials
According to the curling direction, select three pieces of 75mm×50mm materials from different parts. The surface of the sample should be flat, without holes, wrinkles, oil stains, deterioration, etc.
5.2.2 For harder or blocky materials, such as pads and plywood, select the flat surface of the material, with a size of 75mm×50mm, and the number is three pieces.
5.2.3 For granular materials, the sample should be 20g, ground to particles that can pass through a 40-mesh standard sieve but not through a No. 80 sieve. For bagged materials, such as desiccants, the sample should be a minimum unit of the bagged material. 5.2.4 Except for granular or bag-like materials or foam materials and packaging materials that cannot be cleaned, soft or hard packaging materials should be held with one tweezers and the other tweezers holding the gauze, and scrubbed in the order of solvent oil, 95% ethanol, and anhydrous ethanol, and then blown dry with cold air (or warm air below 60°C).
5.2.5 Sample pretreatment
The cleaned packaging material samples are placed in an environment of (25±1)°C and relative humidity of (50±3)% for a period of time, preferably not more than 24 hours.
5.2.6 Cleaning of other test pieces
Before use, the glass slide and the rectangular steel block for fixing should be cleaned or scrubbed in solvent oil and 95% ethanol in turn, blown dry with hot air, and placed in a dryer for standby use.
All It is forbidden to touch the cleaned test pieces or samples with bare hands. The packaging material sample should be flat. If necessary, a 75mm×75mm glass piece can be pressed on it during pretreatment, and then a rectangular steel block for fixing can be pressed on it. 6 Test procedure
6.1 Record the surface condition of the metal test piece in detail, such as scratches, indentations, watermarks, suspicious points, etc. 6.2 Cover the three packaging material samples that have been cleaned and pretreated as specified in 5.2.5 on the middle of the three metal test pieces. Select the part in contact with the metal based on the actual usage. For aluminum-plastic cloth composite materials, the plastic surface should be in contact with the metal; for vapor phase anti-rust paper, the side coated with vapor phase corrosion inhibitor should be in contact with the metal. On each piece of packaging material sample Press a clean, non-corrosive 75mm×25mm glass slide in the middle, and then press a 75mm×25mm×25mm rectangular steel block for fixing. The direction of the glass slide and the steel block is perpendicular to the long direction of the metal test piece. Then use a marker to draw lines on the metal test piece along the pressure surface of the packaging material sample, the glass slide and the metal test piece to distinguish the pressure contact surface, the non-pressure contact surface and other blank surfaces under the glass slide, see Figure 1 and Figure 2 for details. Packaging material sample
Metal test piece
Figure 1 Test piece and sample contact method
Rectangular steel block
Glass slide
Packaging material sample
Metal test piece
Figure 2 Schematic diagram of combination
6.3 Put the above combination Three groups of test pieces were placed in a desiccator with a diameter of about 320 mm. After preheating at (49 ± 1) °C for half an hour, they were taken out and immediately placed in a desiccator with 300 mL of glycerol aqueous solution with a density of 1.17800.0004 g/mL preheated at (49 ± 1) °C at the bottom. A small amount of vacuum sealing ointment was applied to the ground joints, and the lid was covered. The lid was fixed at three places with medical tape, and then placed in a drying oven at (49 ± 1 °C. The relative humidity in the desiccator was (65 ± 3)%. 6.4 After 20 hours for steel test pieces and 72 hours for aluminum test pieces, the sample and the test piece surface were separated, and the corrosion of the test piece surface was immediately checked. It was recorded whether the part covered by the sample and the part not covered on the test piece surface were corroded. At the same time, the degree and distribution of corrosion should be stated.
7 Result evaluation
7.1 Test piece rating
The corrosion degree of the pressure surface of the test piece after the test shall be rated according to the following provisions: 368
7.1.1 Steel test piece
Grade 0: Bright as before;
GB/T 16266—1996
Grade 1: No more than 3 rust spots with a diameter less than 1mm or the total rust area is less than 2.4mm, Grade 2: Slight rust. There are more than 3 and no more than 10 rust spots with a diameter less than 1mm, Grade 3: Moderate rust. There are more than 10 rust spots or the rust area does not exceed 50%; Grade 4: Severe rust. The rust area exceeds 50%. 7.1.2 Aluminum test piece
Grade 0: Bright as before:
Grade 1: Lost luster;
Grade 2: Slight rust. Visible white spots appear on the surface of the sample; Level 3: Moderate rust. Obvious corrosion products or rust area does not exceed 50%; Level 4: Severe rust. Obvious corrosion or rust area exceeds 50%. 7.2 Evaluation of test results
7.2.1 The test results are evaluated by three test pieces of the same metal. When the grade difference of the three test pieces does not exceed one level, two test pieces of the same grade are used for grading; when the grades of the three test pieces differ by one level, the intermediate value is used for grading; if the above conditions are not met, no grading can be performed.
7.2.2 Corrosion is allowed on the non-pressure surface.
7.2.3 Corrosion is not allowed on the blank space, otherwise the test should be repeated. 8 Test report
The test report should include the following contents:
a The number of this standard;
b Detailed description of the test pieces and specimens used in the test, including type, size, quantity, state, etc., pretreatment conditions;
Test environment conditions;
e Test parameters;
Test results;
Differences from this standard during the test:
Test date, signature of the tester, and seal of the test unit. h
Additional notes:
This standard was proposed by China National Packaging Corporation. This standard is under the jurisdiction of the National Technical Committee for Packaging Standardization. This standard was drafted by the 621st Research Institute of China Aviation Industry Corporation, Shenyang Anti-Rust Packaging Material Company, China Light Industry Association Papermaking Research Institute, and National Packaging Product Quality Supervision and Testing Center (Jinan). The main drafters of this standard are Luo Xiangji, Zhou Jiayan, Zhang Shaoling, and Ding Guozhen. This standard refers to the method 3005 "Contact Corrosion Test Method for Soft, Hard or Granular Solid Materials" in the US Federal Standard FED-STD-101 "Test Procedures for Packaging Equipment".
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.