纸箱爆裂强度标准 tappi 810

SUGGESTED METHOD – 1966OFFICIAL TEST METHOD – 1980

REVISED – 1985REVISED – 1992REVISED – 1998© 1998 TAPPI

The information and data contained in this document were preparedby a technical committee of the Association. The committee and theAssociation assume no liability or responsibility in connection with theuse of such information or data, including but not limited to anyliability or responsibility under patent, copyright, or trade secret laws.The user is responsible for determining that this document is the mostrecent edition published.

Bursting strength of corrugated and solid fiberboard

1.

Scope

This method describes the procedure for measuring the bursting strength of single wall and double wall corrugatedand solid fiberboard. It is not designed to be used for the bursting strength of paper (TAPPI T 403 \"Bursting Strengthof Paper\"), paperboard and linerboard (TAPPI T 807 \"Bursting Strength of Paperboard and Linerboard\"), or triple wallcorrugated board.2.

Significance

The bursting strength of combined board is primarily an indication of the character of the materials used inmanufacturing a fiberboard box and has value in this respect. Bursting strength of combined board is an optionalrequirement of the various carrier regulations for shipping containers. The bursting strength of the componentpaperboard is an important control test in the paperboard mill since the conformity of the finished container is generallycontrolled by the bursting strength of the paperboard. Triple-wall corrugated board cannot be tested suitably by thebursting method. Testing of double-wall board is of questionable accuracy since it is rarely possible to get sufficientlysimultaneous bursts of the multiple facings. The test is simple and rapid to execute, but it must be recognized that it issubject to serious errors if instrument, diaphragm, and gages are not properly maintained or if improper procedures areused (1, 2, 3).3.

Apparatus

3.1Bursting tester1, consisting of the following:3.1.1Means for clamping the test specimen between two annular, plane surfaces having fine concentric toolmarks to minimize slippage. The upper clamping platen (clamping ring) has a minimum diameter of 95.3 mm (3.75 in.),a minimum thickness of 9.53 mm (0.375 in.), and a circular opening of 31.50 ± 0.03 mm (1.240 ± 0.001 in.) diameter.The lower edge of the opening (side in contact with the board) has a 0. mm (0.025 in.) radius. The lower clampingsurface (diaphragm plate) has a thickness of 5.56 ± 0.08 mm (0.219 ± 0.003 in.) with an opening 31.50 ± 0.03 mm (1.240± 0.001 in.) in diameter and an overall diameter at least as large as the upper clamping plate.. The upper edge of theopening (in contact with the board) has a 0.41 mm ± 0.1 mm (0.016 ± 0.004 in.) radius and the lower edge of the opening(in contact with the rubber diaphragm) has a radius of 3.1 ± 0.1 mm (0.122 ± 0.004 in.) to prevent cutting the rubberwhen pressure is applied. The upper clamping ring is connected to the clamping mechanism through a swivel joint to

Names of suppliers of testing equipment and materials for this method may be found on the Test Equipment Suppliers list in the bound

set of TAPPI Test Methods, or may be available from the TAPPI Technical Operations Department.

1

Approved by the Fiberboard Shipping Container Testing Committee of the Corrugated Containers Division

TAPPI

T 810 om-98Bursting strength of corrugated and solid fiberboard / 2facilitate an even clamping pressure. The openings in the two clamping plates are required to be concentric to within0.13 mm (0.0051 in.) and their clamping faces flat and parallel (see T 807 Appendix A.1.1).

3.1.2A molded (disk-shaped) diaphragm requiring a pressure of not less than 160 kPa nor more than 210 kPa(not less than 23 psi nor more than 30 psi) to distend it to a height of 9.53 mm (0.375 in.) above the diaphragm plate (seeT 807, Appendix A.1.2.)

3.1.3Means of forcing liquid into the pressure chamber below the diaphragm at a steady rate of 170 ± 16mL/min (0.045 ± 0.004 gal/min). This pressure shall be generated by a motor-driven piston forcing a liquid (glycerin)into the pressure chamber of the apparatus (see T 807, Appendix A.1.3).

3.1.4A Bourdon pressure gage of the maximum reading or the lazy hand type. The scale should have a radiusof 47.6 mm (1.875 in.) with graduations extending over a minimum arc of 270° indicating bursting pressure in kPa orpsi, with an accuracy of 0.5% of full scale, and have sufficient capacity so that all readings can be maintained in themiddle half of the scale. In its operating position, have the gage inclined between horizontal and not over 30° from thehorizontal. When more than one gage is mounted on a single apparatus, only the gage on which the measurement is beingmade is open to the hydraulic system so as not to reduce the rate of distention of the sample.

3.1.5As an alternate to 3.1.4, a pressure transducer with suitable signal processing circuitry to display themaximum bursting pressure may be used provided it gives comparable results.

3.1.6Electronic instruments are now available that automate and speed up the testing procedure. Theseinstruments must maintain the critical elements of 3.1.1 through 3.1.3.

NOTE 1:

Care should be taken when comparing results between bourdon tube and electronic measuring systems. Differences in test resultscan arise due to differences in system expansibility and speed of data acquisition.

3.1.7 4.

Vernier caliper with micrometer gage to measure penetration of the upper clamping platen into the board.

Calibration4.14.2

Calibrate apparatus as per Instrument Manufacturers specifications.

Appendix A.1 of TAPPI T 807 describes a calibration procedure for one manufacturers apparatus.

5.Sampling and test specimens

5.1Solid fiberboard5.1.1From each test unit obtained in accordance with TAPPI T 400 \"Sampling and Accepting a Single Lotof Paper, Paperboard, Containerboard, or Related Product,\" prepare five specimens at least 305 × 305 mm (12 × 12 in.).If the dimensions of each sheet of the test unit are too small, then use specimens no less than 102 mm (4 in.) wide andof sufficient length or number to permit a total of 20 bursts.

5.2Corrugated board5.2.1From each test unit obtained in accordance with T 400, prepare five specimens at least 305 × 305 mm(12 × 12 in.). If size does not permit this, take specimens no less than 152 mm (6 in.) wide and of sufficient length ornumber to permit a total of 20 bursts.6.

Conditioning

Condition all specimens prior to testing and conduct tests in an atmosphere in accordance with TAPPI

T 402 \"Standard Conditioning and Testing Atmospheres for Paper, Board, Pulp Handsheets, and Related Products.\"7.

Procedure

7.1Solid fiberboard7.1.1Insert the specimen between the clamping ring and diaphragm plate, then apply a clamping pressure of690 kPa (100 psi) either manually, pneumatically, or hydraulically and verify the pressure applied to the specimen. Thespecimen must not slip during the test.

7.1.2Apply the bursting pressure by forcing the piston forward until the diaphragm ruptures the specimen.Record the maximum pressure registered.

7.1.3Allot a minimum area of 102 x 102 mm (4 × 4 in.) for each burst to prevent the clamping areas fromoverlapping. Make an equal number of bursts from each side of the specimen. Arrange that no more than one burst from

3 / Bursting strength of corrugated and solid fiberboardT 810 om-98each side of the specimen falls in the same line of machine formation. Make no test on areas containing wrinkles,creases, or other obvious imperfections. Make a minimum of 6 bursts on each 305 × 305 mm (12 × 12 in.) specimenand a maximum of 10 bursts to determine the average bursting strength of the material tested.

7.2Corrugated board7.2.1Insert the specimen between the clamping ring and the diaphragm plate. Apply a clamping pressure sothat the top compression ring moves into the board to a depth as follows: \"A\" flute 2.08 ± 0.05 mm (0.082 ± 0.002 in.);\"B\" flute 0.81 ± 0.05 mm (0.032 ± 0.002 in.); \"C\" flute 1.62 ± 0.05 mm (0.062 ± 0.002 in.) and for Double Wall 3.05± 0.07 mm (0.12 ± 0.003 in.). The specimen must not slip during the test. Apply the bursting pressure by forcing thepiston forward until the diaphragm ruptures the specimen. Record the maximum pressure registered.

NOTE 2:

On some testers equipped with a clamping wheel this corresponds to: \"A\" flute 3/4 turn; \"B\" flute 1/4 turn; \"C\" flute ½ turn anddouble wall 1 turn. Due to the surface and frictional characteristics of the board, the penetration depth to prevent slippage couldvary by +1/4 of a turn. If the tester is equipped with a hand wheel, pneumatic or hydraulic loading system adjust clamping pressureso that the sample will just slip between the clamping rings, measure the distance between the yoke and top clamping ring (see Fig.1), and adjust the pressure to get the specified penetration depth. There should be no slipping during the test, if slippage does occurincrease the penetration depth.

7.2.2On corrugated board a minimum area of 152 × 152 mm (6 × 6 in.) is required for each burst. Amaximum of four bursts, two from each direction, is therefore made on each 930 cm2 (1 ft2) specimen. A margin of atleast 25 mm (1 in.) is left between the periphery of the clamping ring and the edge of the specimen. Locate the burstsso that not more than one burst from each direction is made in line with the same corrugation. Make a minimum of 20bursts.

NOTE 3:

On testers with adjustable clamp pressure (pneumatic or hydraulic) the following alternative clamp procedure can be used.Determine the clamping force required to collapse the flutes of the test material. Reduce the clamp pressure by 35 kPa (5 psi) torun the burst tests.

Occasionally a \"double pop\" may occur on some corrugated materials. These results should be included in the report and labeledas double pops.

NOTE 4:

8.Report

For each test unit report the average of the test determinations in kilopascals (or in lb/in.2 equivalent to kPa/6.)to three significant figures.

NOTE 5:

For purposes of determining compliance with the optional carrier classification requirements, Uniform Freight Classification Rule41 and National Motor Freight Classification Item 222 specify a minimum bursting test rather than an average of the testdeterminations. These rules state, in effect, that only one burst (out of the six prescribed) is permitted to fall below the minimumtest required. Board failing to pass the foregoing will be accepted if, in a retest consisting of 24 bursts, not over 4 bursts fall belowthe minimum test required.

9.Precision

9.1Repeatability (within a laboratory) = 5.7%9.2Reproducibility (between laboratories) = 13.5%9.3The above values were obtained using test results, each an average of 20 determinations among 12laboratories on 6 different corrugated combinations. The interlaboratory study was conducted in accordance with TAPPIT 1200 \"Interlaboratory Evaluation of Test Methods Used with Paper and Board Products\" by the Fibre Box AssociationTechnical Committee, 1971-2.10.

Keywords

Corrugated boards, Fiber boards, Burst strength.