General-purpose flat pallets for through transit of goods-Test methods
Some standard content:
GB/T4996-1996
This standard is a revision of GB4996-85 "Test methods for wooden intermodal flat pallets" based on ISO8611:1991 "Intermodal general-purpose flat pallets - Test methods", and is equivalent to the international standard in terms of technical content. During the revision, those contents in GB4996-85 that have been proven to be suitable for my country's situation in practice and do not hinder international use were retained. The various rules specified in this standard involve the test methods for intermodal general-purpose flat pallets. These regulations are used to ensure the unification of the test methods for intermodal general-purpose flat pallets of different materials, and regardless of their specific contents, they should meet the same requirements as much as possible. Under the general title of "Intermodal general-purpose flat pallets", the following three standards are included: GB/T2934 "Main dimensions and tolerances of intermodal general-purpose flat pallets" GB/T4995 "Performance requirements for intermodal general-purpose flat pallets" GB/T4996 "Test methods for intermodal general-purpose flat pallets" This standard will replace GB4996-85 from the date of entry into force. This standard was proposed by the Ministry of Transport of the People's Republic of China. This standard is under the jurisdiction of the Standardization and Metrology Research Institute of the Ministry of Communications. The drafting unit of this standard is the Standardization and Metrology Research Institute of the Ministry of Communications. Dalian Port Authority and Shanghai Port Design and Research Institute participated in the drafting. The main drafters of this standard are Xiong Caiqi, Gao Qizhai and Bao Yaoyou. This standard is revised for the first time.
This standard is entrusted to the Standardization and Metrology Research Institute of the Ministry of Communications for interpretation. 26
GB/T4996--1996
ISO Foreword
ISO (International Organization for Standardization) is a worldwide federation of national standards bodies. The work of drafting international standards is usually carried out by ISO technical committees. Each member body has the right to send representatives to participate in the technical committees of the topics it is concerned with. All governmental or non-governmental international organizations, as long as they have liaison relations with ISO, can also participate in this work. ISO and IEC (International Electrotechnical Commission) work closely together in all aspects of electrotechnical standardization.
The draft international standards adopted by the technical committees must be approved by the member bodies before they are officially recognized as international standards by the ISO Council. According to ISO regulations, any draft international standard must be approved by 75% of its members before it can be formally accepted as an international standard. International Standard ISO8611 was drafted by ISO/TC51\Pallets for Handling Piece Goods "Technical Committee. This second edition replaces the first edition (ISO8611:1988) and adds the wing pallet test (8.3). 27
1 Scope
National Standard of the People's Republic of China
Test methods for general-purpose flat pallets for through transit of goods
General-purpose flat pallets for through transit of goods--Test methods
This standard specifies the test methods for general-purpose flat pallets for through transit made of wood, plastic, steel and other materials. This standard applies to general-purpose flat pallets for road, rail, water and air transport. 2 Referenced Standards
GB/T 4996--1996
eqv IS0 8611: 1991
Replaces GB4996--85
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 will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB3716-83 Pallet Terminology
GB4857.11-92 Packaging and Transport Package Horizontal Impact Test Method 3 Definitions
This standard adopts the following definitions.
All definitions listed in GB3716 apply to this standard. 4 Measurement and inspection of test pallets
4.1 The pallets to be tested should be inspected to ensure that their materials, structures and dimensions meet the specified technical requirements. 4.2 Measure and record the mass of each pallet, and at the same time measure the moisture content of each component. 5 Number of pallets to be tested and test procedure
Select three or more pallets of the same type to be tested. The pallet shall be tested and the entire procedure of each test shall be carried out in the strict order specified in this standard. Wing pallets shall be subjected to all eight tests listed in Chapters 8 and 9. Other pallets shall not be subjected to test 8.3, but only the other seven tests.
The entire procedure of each test shall be carried out on the same pallet. 6 Pretreatment
6.1 Select the pretreatment environmental conditions according to the pallet material and the environmental conditions that may be encountered during the circulation process. 6.2 Pretreatment environmental conditions
The pretreatment environmental conditions are shown in Table 1, and the requirements are as follows: a) The moisture content of wooden pallets shall not be less than 18%. If it is lower than this value, the test can continue, but the moisture content of the main components shall be recorded every 24 hours until the end of the test project; b) Plastic pallets shall be pretreated at least one pallet according to environmental condition A and the other pallet according to environmental condition B; Approved by the State Administration of Technical Supervision on December 4, 1996 28
Implementation on August 1, 1997
GB/T 4996---1996
c) For paper-based and wood-based pallets, at least one shall be pretreated to environmental conditions C or D. Note: Composite pallets composed of two or more materials, such as structures with porous plastic supported glued wood decking, have higher pretreatment requirements. Table 1 Pretreatment environmental conditions
Pretreatment environmental conditions
No pretreatment required (see 6.2a)
-25±3
No pretreatment required
1) Includes any pallet containing adhesive or bonded with adhesive. Relative humidity
Pallet materials
Unprocessed (sawn stock only) wood with metal fasteners
Paper-based and processed wood (e.g. plywood, particleboard)
All metal
6.3 If the preconditioning room meets the requirements but the entire test room cannot maintain the required working conditions, the test should be started within 1 hour after the pallet is removed from the preconditioning room. When using environmental conditions A and B, the test should be started immediately after the pallet is removed from the preconditioning room. After each individual test is completed, the pallet required to be in environmental condition A or B is immediately returned to the preconditioning room for at least 1 hour. 6.4 For pallets with wood or wood as the base material, the moisture content of the selected pallet components should be recorded at the beginning of the entire test procedure. 7 Accuracy of test equipment
7.1 The various test equipment described in Chapters 8 and 9 shall meet the following requirements: a) In the design of the test equipment, the tolerance of all dimensions shall be ±2%; b) The resolution/accuracy of the test measuring equipment shall be better than ±0.5mm; c) The positioning accuracy of each component including the test load shall be ±2mm; d) The positioning accuracy of the center of gravity of the test load related to Chapter 8 shall be ±20mm; e) The total mass of the test load used shall be within ±3% of the predetermined value. 7.2 Under the maximum test load, the deflection of any component of the test bench shall not be greater than 2mm. 7.3 The structure of the inclined plane test equipment shall comply with the provisions of GB4857.11. 8 Static test
For the static tests listed in 8.1 to 8.4, the applied test load shall in any case include the weight of the load plate and the load head.
8.1 Stacking test
The purpose of this test is to determine the compressive strength of the pallet or pallet corner pad to the local vertical load. 8.1.1 Deformation measurement
Carry out the test according to the method specified in 8.1.2, and record the change in the height difference of the top deck relative to the ground (or test frame) at point A as shown in Figure 1 at the following times.
a) Under quasi-load (see 8.1.2);
b) At the beginning and end of the full load stage; c) When unloading, under quasi-load conditions, every 5 minutes until there is no change in several consecutive readings (the maximum time is limited to 1 hour). Take the average value of the measurements at points A1 and A2 (see Figure 1) as the deflection at point A. When repeating this test at the diagonally opposite corner, the same measurement should be made at point B (see 8.1.2). 8.1.2 Test procedure
GB/T 4996--1996
Place the pallet in its normal position on a smooth, hard, rigid horizontal surface. Place a rigid loading head with a size of 200mm×200mm×25mm on top of an outer pad (as shown in Figure 1a); or place it on top of one end of the longitudinal beam of a longitudinal beam pallet (as shown in Figure 1b).
Gradually increase a uniformly distributed test load from 0 to 0.25R at a uniform speed. R is the total design mass of the pallet. 0.25R will be used as the quasi-load for subsequent deflection measurements. Apply a full load of 1.1R to each pad within 1 to 5 minutes. If the loading block is used as the test load, it should be loaded symmetrically, depending on the material of the pallet (see Table 2), and the full load should be kept stable for a period of time. After the specified time, reduce the test load to the quasi-load (see 8.1.1c). Obtain the deflection measurement value equivalent to point A (see 8.1.1). Repeat the above steps at point B (see Figure 1) and obtain another set of deflection measurement values equivalent to point B (see 8.1.1). Note: It is also possible to perform this test by applying full load to several corners at the same time (i.e., 2.2R on two corners or 4.4R on four corners). 8.2 Bending Test
The purpose of this test is to determine the stiffness and bending strength of the entire pallet. Load block
Loading plate
Load block and loading head are placed on the outer pads and aligned centrally
Loading plate (or testing machine table)
a) Loading head is placed above the outer pads
(deflections measured at points A, and A2)
Loading plate
Loading plate
Loading head
Loading head is level with the edge of the pallet
b) Loading head is placed above one end of the longitudinal beam (deflections measured at points A: and A2)
Figure Stacking test
Table 2 Loading duration for static load test
Pallet materials
Non-processed (only sawn-off materials) with metal fasteners Wood Plastics
Paper-based and processed wood Materials (such as plywood, particle board) All metal
Composite pallets with plastic
Pallets glued with adhesive
Test time, h
8.2.1 Deflection measurement
Carry out the test according to the method specified in 8.2.2. Record the deflections at points A and B as shown in Figure 2 at the following times and measure the relative height difference between the upper (or lower) surface of the top or bottom paving and the ground (or test frame): a) under quasi-load (see 8.2.2);
b) at the beginning and end of the full load stage; c) when unloading, under quasi-load conditions, every 5 minutes until there is no change in several consecutive readings (the maximum time is limited to 1 hour). All dimensions are in mm
Load block
Loading plate
Loading head
Test load
Figure 2 Bend test using square support and loading head (see also Figure 3) Measure the distance h between the two decks directly below the loading head. Repeat the above steps along the second horizontal axis of the pallet and make the same measurements at points C and D and between the two decks (see 8.2.2). 8.2.2 Test procedure
Place the pallet with the deck facing up on the square (or semicircular) support, with the inner edge (or center line) of the support 75 mm from the outer edge of the pallet (see Figure 2). The loading head should be placed at 0.251, and when measuring, l1 is the distance between the inner edge of the square support of the pallet or the center line of the semicircular support (see Figure 2).
The loading head and support should be flush with the pallet or extend beyond the pallet. The edge should be made into an arc with a radius of 2 mm as shown in Figure 3. Increase the test load from 0 to 0.1R at a uniform rate, and use this as the quasi-load for subsequent deflection measurements. Use 1 to 5 minutes to increase to the full load of 1.25R. If a loading block is used as the test load, the load should be symmetrical. Depending on the material of the pallet (see Table 2), keep the full load stable for a period of time.
After the specified time, reduce the test load to the quasi-load (see 8.2.1c). Obtain the deflection measurements at points A and B (see 8.2.1). Repeat the above steps along the second horizontal axis of the pallet (i.e., test along the length and width of the pallet), placing the loading head at 0.2512, measured from the inner edge or center line of the pallet support, 12 is the distance between the inner edge of the square support or the center line of the semicircular support (see Figures 2 and 3). Obtain another set of deflection measurements at points C and D (see 8.2.1). 31
Contact line
8.3 Wing pallet test
GB/T4996—1996
Figure 3 Another type of pallet support/loading head
All dimensions are in mm
Decking
Contact line
The purpose of this test is to determine the stiffness and bending strength of the entire wing pallet when it is lifted by a balance beam. This test is carried out immediately after the bending test in 8.2.
8.3.1 Deflection measurement
Carry out the test in accordance with the method specified in 8.3.2, record the deflections at points A and B as shown in Figure 4 at the following times, and measure the relative height difference between the upper (or lower) surface of the top (or bottom) deck and the ground (or test frame): a) under quasi-load;
b) at the beginning and end of the full load stage; c) when unloading, under quasi-load conditions (see 8.3.2) every 5 minutes until there is no change in several consecutive readings (the maximum time is limited to 1 hour).
8.3.2 Test procedure
Place the top deck of the wing pallet with the top deck facing up on the supports placed under the wings of the top deck, so that the supports are in contact with the longitudinal beams/load bars or pads of the pallet. Each loading head should be placed at a distance from the inner edge of the support to the outer edge of the loading head equivalent to 0.2511 (see Figure 4). See 8.2.2 for loading heads and supports.
Note: This test simulates a rod lift, not a cable lift. 32
GB/T 4996
—1996
All dimensions are in mm
Load block
Loading plate
Loading head
Figure 4 Wing pallet (see also Figure 3)
》Test load
Increase the test load from 0 to 0.1R at a uniform speed, and use this as the quasi-load for deflection measurement. Use 1 to 5 minutes to increase to the full load of 1.25R. If the loading block is used as the test load, it should be loaded symmetrically, depending on the material of the pallet (see Table 2), and keep the full load stable for a period of time.
Reduced the test load to the quasi-load within the specified time (see 8.3.1c). Obtain the deflection values of points A and B (see 8.3.1). 8.4 Bottom deck test
The purpose of this test is to determine the rigidity and flexural strength of the bottom deck between two supporting points. 8.4.1 Deflection measurement
Carry out the test as specified in 8.4.2, recording the deflections at points A, B, C and D as shown in Figure 5 at the following times, and measuring the relative height difference between the upper or lower surface of the top deck and the ground (or test frame): a) under quasi-load (see 8.4.2);
b) at the beginning and end of the full load phase; c) when unloading, every 5 min until there is no change in several consecutive readings under quasi-load conditions (the maximum time is 1 h). Repeat the above steps on the second horizontal axis of the pallet and make the same measurements at points E, F, G and H as shown in Figure 5 (see 8.4.2).
8.4.2 Test Procedure
Place the top deck of the pallet face down on a smooth, hard, rigid horizontal surface and place two square or semicircular loading heads (as shown in Figure 5) with the centerline of the loading heads between the spacers or longitudinal beams (i.e., at 0.513, 0.51. and 0.515). The loading heads should extend beyond the edge of the bottom surface of the pallet or be flush with it and should be placed symmetrically on the left and right sides of the centerline of the pallet. Increase the test load from 0 to 0.1R at a uniform rate, which will be used as the quasi-load for subsequent deflection measurements. Take 1 to 5 minutes to increase to the full load of 1.15R. If loading blocks are used as test loads, they should be loaded symmetrically. Keep the full load stable for a period of time, depending on the material of the pallet (see Table 2).
Reduced the test load to the quasi-load (see 8.4.1) at the specified time. Obtain the measured deflection values at points A, B, C and D (see 8.4.1). For pallets other than the longitudinal beam pallet, repeat the above steps along the second horizontal axis of the pallet (i.e., test along the length and width of the pallet), placing the center line of the loading head in the middle of the pad (i.e., 0.514) (see Figure 5a). Obtain another set of deflection measurements at points E, F, G and H (see 8.4.1). 33
9 Impact test
GB/T4996--1996
The purpose of this test is to simulate the normal impact loads that are representatively transmitted to the pallet in direct transportation and to determine the pallet's ability to resist it.
9.1 Incline test
For all three inclined plane tests, the load is 0.075R. The test load includes a load box with a plane size of 600mm×800mm (see Figure 6) and a load inside the box. The position of the load box is determined according to the requirements of the following tests. The side length of the removable panel must be at least equal to the length of the pallet under test. The test load should not include the weight of the trolley. In the first two inclined plane tests (see 9.1.1 and 9.1.2), the trolley is raised 1000 mm on the inclined plane.3) The trolley only needs to rise 750mm away from the impact point before release. Each test is repeated three times. Loading head center line
Equal interval
Load block
Loading plate
Loading head
Test load
Bottom board (inverted pallet)
#) Three longitudinal beam plate pallet (two-way or partial four-way fork) or nine pad pallet (four-way fork) Load block
Test load
Loading plate
Loading head
Bottom board (inverted pallet)
0.51s0. 51s
Equal spacing
b) Pallet with four longitudinal beamsbzxZ.net
Figure 5 Test of bottom decking of inverted pallet
9.1.1 Shear test
GB/T4996—1996
Divided into grids, it helps to distribute the load evenlyUnit: mm
Removable panels on long sides
Figure 6 Load box for inclined plane test
The purpose of this test is to determine the shear strength between the top and bottom decking. 5
9.1.1.1 Measurement
The test is carried out in accordance with the method specified in 9.1.1.2 and the changes in deflection between points A and B and between points C and D are measured (see Figure 7). These data are recorded at several measuring points along the impact surface. Figure 7 Shear test
Measuring points
9.1.1.2 Test procedure
Fix a steel or high-density hardwood limit stop to the front of the rear stop. The stop has a nominal cross-section of 90 mm × 90 mm and a length at least equal to the long side of the pallet. When the trolley is in the lowest position, the upper edge of the stop should be 15 mm above the bottom surface of the pallet (top surface of the trolley) (see Figure 8).
Place the pallet on the trolley of the inclined plane test machine. When the front edge of the pallet touches the stop, there is a gap of 75 mm ± 25 mm between the trolley and the stop.
Center the load box on the pallet and increase the load to 0.075R with a ballast so that the center of the load is exactly on the axis of the downward movement along the track, but biased towards the top of the load box. Pull the trolley and the loaded pallet up the inclined plane to 1000 mm from the impact point and then release. Repeat the above steps two more times, repositioning the pallet, trolley and load before each impact, and then measure the data as specified in 9.1.1.1.
Carry out three more impact tests along the second horizontal axis of the pallet using the same procedure, and then obtain the specified measurement values. 35
Rear guard
GB/T4996—1996
All dimensions are in mm
Load box
a) Position before release
Load box
·Trolley
b) Impact position
Figure 8 Inclined shear test
9.1.2 Top deck edge impact test
The purpose of this test is to determine the resistance of the top front edge deck to spreading, and it is also applicable to the longitudinal beam deck. 9.1.2.1 Measurements
Carry out the test as specified in 9.1.2.2 and record the deformations z1, y1, yz and y3 (see Figure 9). The embedment depth and the combined damage at the point of impact shall also be recorded.
Figure 9 Impact test on the edge of the roof deck
9.1.2.2 Test procedure
Use the aforementioned inclined plane test apparatus and the buffer block shown in Figure 10. 36
Measuring points
GB/T4996
R12±2
Countersunk holes
R12±2
Figure 10 Buffer block for roof deck and angular impact test apparatusUnit: mm
Place the pallet together with the 0.075R load box on the trolley of the test apparatus. The center of the load is exactly on the axis of motion, but offset to the lower part of the load box.
Align the height of the buffer block and the pallet fork hole so that the edge board can hit the top surface of the blade somewhere between 100mm and 250mm from the handle surface (see Figure 11). Each impact point should fall within this range. Baffle
6°+0.8°
Buffer block
a) Position before release
Load box
Figure 11 Top deck edge impact test equipment
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