ANSI T 811 OM-2011 Edgewise compressive strength of corrugated fiberboard (short column test).pdf

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1、T 811 om-11 OFFICIAL STANDARD 1970 REVISED 1979 OFFICIAL TEST METHOD 1983 REVISED 1988 REVISED 1995 REVISED 2002 REVISED 2007 REVISED 2011 2011 TAPPI The information and data contained in this document were prepared by a technical committee of the Association. The committee and the Association assum

2、e no liability or responsibility in connection with the use of such information or data, including but not limited to any liability under patent, copyright, or trade secret laws. The user is responsible for determining that this document is the most recent edition published. Approved by the Standard

3、 Specific Interest Group for this Test Method TAPPI CAUTION: This Test Method may include safety precautions which are believed to be appropriate at the time of publication of the method. The intent of these is to alert the user of the method to safety issues related to such use. The user is respons

4、ible for determining that the safety precautions are complete and are appropriate to their use of the method, and for ensuring that suitable safety practices have not changed since publication of the method. This method may require the use, disposal, or both, of chemicals which may present serious h

5、ealth hazards to humans. Procedures for the handling of such substances are set forth on Material Safety Data Sheets which must be developed by all manufacturers and importers of potentially hazardous chemicals and maintained by all distributors of potentially hazardous chemicals. Prior to the use o

6、f this method, the user must determine whether any of the chemicals to be used or disposed of are potentially hazardous and, if so, must follow strictly the procedures specified by both the manufacturer, as well as local, state, and federal authorities for safe use and disposal of these chemicals. E

7、dgewise compressive strength of corrugated fiberboard (short column test) 1. Scope 1.1 This method describes procedures for determining the edgewise compressive strength (ECT), perpendicular to the axis of the flutes, of a short column of single-, double-, or triple-wall corrugated fiberboard (1). 1

8、.2 The method includes procedures for cutting the test specimen, specimen support (waxed edges), and two procedures for applying the compressive force (constant strain rate, or constant load rate). Studies have shown that any combination of these procedures will yield the same test results with the

9、stated precision (Section 9). 2. Significance 2.1 Research has shown that the edgewise compressive strength of specimens with flutes vertical, in combination with the flexural stiffness of the combined board and box dimensions, relates to the top-to-bottom compressive strength of vertically fluted c

10、orrugated fiberboard shipping containers (2,3). 2.2 This method may also be used for comparing the edgewise compressive strength of different lots of similar combined boards or for comparing different material combinations (4,5). 3. Apparatus 3.1 Compression testing machine1meeting the requirements

11、of either 3.1.1 or 3.1.2, and 3.1.3, 3.1.4, and 3.1.5. 1Names of suppliers of testing equipment and materials for this method may be found on the Test Equipment Suppliers list, available as part of the CD or printed set of Standards, or on the TAPPI website general Standards page. T 811 om-11 Edgewi

12、se compressive strength of corrugated / 2 fiberboard (short column test) 3.1.1 Rigid Support Compression Tester. Two platens, one rigidly supported and the other driven. Each platen shall have a working area of approximately 100 cm2(16 in.2). The platens must not have more than 0.050 mm (0.002 in.)

13、lateral relative movement, and the rigidly supported platen not more than 0.150 mm (0.006 in.) movement, perpendicular to the surface, within a load range of 0 to 2224 N (0-500 lbf). Within the specimen contact area, each platen shall be flat within 0.0025 mm (0.0001 in.) of the mean platen surface,

14、 and the platens shall remain parallel to each other within 1 part in 2000 throughout the test (6). 3.1.1.1 Within a range of platen separations necessary to cause compressive failure of the test specimen, and within a load range of 0 to 2224 N (0-500 lbf), the speed of the driven platen shall be co

15、ntrollable at 12.5 0.25 mm (0.5 0.01 in.) per minute. (For convenience, the test machine should be capable of rapid return and automatic, settable positioning). 3.1.2 Flexible Beam Compression Tester. Two platens, one flexible beam supported and the other driven. Each platen shall have a working are

16、a of approximately 100 cm2(16 in.2). Within the specimen contact area, each platen shall be flat within 0.0025 mm (0.0001 in.) of the mean platen surface, and the platens shall remain parallel to each other within 1 part in 2000 throughout the test. The platens must not have more than 0.050 mm (0.00

17、2 in.) lateral relative movement. 3.1.2.1 Within a range of platen separations necessary to cause compressive failure of the test specimen, and within a load range of 0 to 2224 N (0-500 lbf), the speed of the driven platen shall be controlled so that the rate of force increase (without considering s

18、pecimen deformation) is 111 22 N/s (25 5 lbf/s) (6). 3.1.3 The driven platen shall be moveable to achieve an initial platen separation of at least 60 mm (2.36 in.). 3.1.4 The tester shall have a capacity of at least 2224 N (500 lbf). 3.1.5 The tester shall have a means for measuring and indicating t

19、he maximum load sustained by the test specimen with an accuracy of 0.5% or better between a measured load of 440 N (100 lb) and the equipments maximum load. Below this measured load, the accuracy shall be 2.2 N (0.5 lbf), or better. 3.2 A means such as a saw or other device for cutting specimens hav

20、ing clean, parallel and perpendicular edges, within the tolerances specified in 6.2 and 6.3. Opposite edges shall be parallel to each other and perpendicular to adjacent edges (7, 8). 3.2.1 Knife cutter, single knife device with guides or, preferably, a twin-knife motorized or pneumatically driven d

21、evice to cut the test specimens according to the specifications in Section 6. The knives must be sharp and of the single-bevel type and arranged in the device so that the unbevelled side is toward the test piece and at 90 to the specimens surface. 3.2.2 Saw, circular, equipped with a sharp, no-set (

22、hollow ground or taper ground is desirable) saw blade. The saw blade shall be 90 to the table supporting the specimen. 3.3 A means for supporting the specimen at the initiation of the test so that the applied force is parallel to the flutes. 3.3.1 Metal guide blocks (Fig. 1) to be used with the waxe

23、d edge specimens (7.5). Two are required to align the specimen vertically in the testing machine. Fig. 1. Metal guide block. 3 / Edgewise compressive strength of corrugated T 811 om-11 fiberboard (short column test) 4. Sampling Obtain samples in accordance with TAPPI T 400 “Sampling and Accepting a

24、Single Lot of Paper, Paperboard, Containerboard, or Related Product.” 5. Conditioning Precondition and condition the sample in accordance with TAPPI T 402 “Standard Conditioning and Testing Atmospheres for Paper, Board, Pulp Handsheets, and Related Products.” Condition waxed-edge specimens an additi

25、onal minimum of 2 hours after waxing and before testing (9) 6. Test specimens 6.1 From each test unit accurately cut at least 10 specimens with the motorized knife or circular saw or other method that will cut clean, parallel, and perpendicular edges. 6.1.1 Sample away from scorelines, joints, and c

26、losures. Specimens should be representative of the materials being tested. For example, if roughly 25% of a box is printed, roughly 25% of the samples should be collected from the printed areas. Specimens should not be taken from obviously damaged areas and/or areas not representative of the contain

27、er as a whole. 6.2 Cut the specimens to a width of 50.8 0.8 mm (2.00 0.03 in.) so that the loading (width) edges are parallel to each other and perpendicular to the axis of the flutes (Fig. 2). Fig. 2. Edgewise test specimen for B-flute. 6.3 Cut the specimens to a height of 31.8 1.6 mm (1.25 0.06 in

28、.) for B-flute, 38.1 1.6 mm (1.50 0.06 in.) for C-flute, and 50.8 1.6mm (2.00 0.06 in.) for A-flute and typical double- and triple-wall board (1,6). These heights meet the Euler criteria for pure compression failure in a short column for their respective structures (8). For some thin double-wall boa

29、rd (e.g., EB double-wall), and for other flute structures (e.g., E flute), different heights may be required to achieve a pure compression failure in the test specimens. NOTE 1: In some U.S. Federal and Military Specifications and Standards for corrugated board, the short column crush test is requir

30、ed. The procedure is technically identical to that described here in Sections 4-6 except for specimen size. The height for all flute constructions, single-, double-, and triple-wall, is 31.8 1.6 mm (1.25 0.06 in.). When testing against these specifications, this height is to be used and should be me

31、ntioned explicitly in the report. NOTE 2: In some testing protocols (e.g., compliance with National Motor Freight Classification item 222), alternate numbers of specimens may be required for testing. The test procedure is technically identical to that described here in Sections 4-7. NOTE 3: Other pr

32、ocedures are sometimes used which require different specimen dimensions, specimen geometry (10), or specimen support techniques. These may include, but are not limited to: TAPPI T 839 “Edgewise Compressive Strength of Corrugated T 811 om-11 Edgewise compressive strength of corrugated / 4 fiberboard

33、(short column test) Fiberboard using the Clamp Method (Short Column Test)” (11), TAPPI T 841 “Edgewise Compressive Strength of Corrugated Fiberboard using the Morris Method (Short Column Test)”, TAPPI T 838 “Edge Crush Test Using Neckdown” (12), and FEFCO test Method No. 8 “Edgewise Crush Resistance

34、 of Corrugated Fiberboard.” The FEFCO method requires testing specimens cut to 100 mm (3.94 in.) wide and 25 mm (0.98 in.) high without any additional specimen support such as waxed edges, or mechanical support beyond the initial vertical alignment. The procedures described in Notes 1, 2, and 3 will

35、 not necessarily yield the same results as this test method. (13, 14) 6.4 Prepare test specimens with waxed edge reinforcement as follows: Dip each loading edge in molten paraffin at 69-74C (156-165F) approximate melting point, 52C (125F), to a depth of 6 mm (1/4 in.) and hold there until the absorb

36、ed paraffin, as determined visually, begins to migrate above the 6 mm (1/4 in.) dipped zone. Normally, a 3 second dip in molten paraffin is satisfactory. If excessively rapid migration is encountered, reduce the temperature of the molten paraffin. Immediately after dipping, momentarily blot the load

37、ing edges of the specimen on paper toweling preheated on a hot plate maintained at 77-82C (171-180F). NOTE 4: The following alternative procedure for impregnating the loading edges of specimens with paraffin wax is permissible. Place the edge on a paraffin wax saturated pad, such as paper toweling,

38、heated on a hot plate maintained at 77-82C (171-180F) until the paraffin wax impregnates the specimen to the desired 6 mm (1/4 in.) depth. Generally, this method is slower than the dipping method and therefore permits better control of the depth of paraffin wax penetration for specimens in which par

39、affin wax migration is rapid. NOTE 5: When reinforcing the loading edges of waxed or curtain coated boards, take care that the heat of the reinforcing paraffin wax does not adversely affect the integrity of the boards structure in the area of the edge wax impregnation. Evidence of proper treatment w

40、ill be that in performing the test, failure occurs away from the reinforced area. 7. Procedure 7.1 Perform all tests in the conditioning atmosphere. 7.2 The rate of platen movement required for a flexible beam compression machine has been determined to be 111 22 N/s (25 5 lbf/s). Record the platen m

41、ovement rate actually used. On most machines this rate of platen movement will be 13-51 mm (0.5-2.0 in.) per minute depending on the load range at the beam. 7.3 Set the rate of platen movement for each rigid support compression machine to 12.5 0.25 mm (0.5 0.01 in.) per minute. 7.4 Measure the width

42、 (nominally 50.8-mm (2-in.) dimension of each specimen to the nearest 1 mm (1/32 in.). 7.5 Center the specimen on the platen. Place a guide block on each side of the specimen centrally located relative to it so that the flutes are held perpendicular to the platen. Place the blocks largest faces face

43、 up, with the offset ends adjacent and in contact with the specimen above the paraffin areas. 7.5.1 Apply a compressive force to the specimen. Verify the platen movement rate described in 7.2 or 7.3. When the force on the specimen is between 22 and 67 N (5 and 15 lbf), remove both guide blocks and,

44、without altering the platen movement rate, continue to apply force until the specimen fails. A valid test is when one or both liners have buckled in the unwaxed center portion of the specimen. If neither liner shows a buckling failure in the unwaxed area of the specimen, or if failure occurs in the

45、waxed portion of the sample, declare the test invalid. 7.6 Record the maximum load in newtons (pounds-force), the specimen width, and whether or not the specimen exhibited a valid failure. 8. Report 8.1 For each test unit, report: 8.1.1 Average maximum load per unit width for valid tests calculated

46、from average maximum load and specimen width in kilonewtons per meter (pounds-force per in.). 8.1.2 Standard deviation among valid determinations in kilonewtons per meter (pounds-force per in.). 8.1.3 Number of valid test determinations. 8.1.4 A description of material tested. 8.1.5 A statement that

47、 the test was conducted in compliance with this test method and a description of any deviations. 5 / Edgewise compressive strength of corrugated T 811 om-11 fiberboard (short column test) 9. Precision 9.1 Repeatability (within a laboratory) = 4%. 9.2 Reproducibility (between laboratories) = 19%. Rep

48、eatability and reproducibility are estimates of the maximum difference (at 95% confidence) that should be expected when comparing test results for materials similar to those described below under similar test conditions. These estimates may not be valid for different materials and testing conditions

49、. 9.3 The estimates of repeatability and reproducibility listed above are based on data from the CTS Containerboard Interlaboratory Program using testing conducted in 2005 and 2006. The data included 17 rounds of testing on 5 different samples of “C” flute corrugated board in either 42-26-42 or 35-26-35 board combinations. The precision estimates are based on 10 determinations per test result and 1 test result per lab for each of the 17 rounds of testing. Only laboratories that reported using rigid-platen type instruments an