1、WORLDWIDEENGINEERINGSTANDARDSTest Procedure GMW14776Test Method for Determining the Bursting Strength of Cardboard,Fiberboard and Similar Rigid Materials Copyright 2013 General Motors Company All Rights ReservedJune 2013 Page 1 of 41 ScopeNote: Nothing in this standard supercedes applicable laws and
2、 regulations.Note: In the event of conflict between the English and domestic language, the English language shall takeprecedence.1.1 Purpose. This standard shall be used to determine the strength properties of cardboard, fiber board, andsimilar rigid materials by measuring, under specified condition
3、s, the pressure necessary to rupture a test pieceof the material.1.2 Foreword. The test is carried out using hydraulic pressure applied to a rubber diaphragm over which thetest piece is tightly clamped, until the test piece ruptures.1.3 Applicability. Not applicable.2 ReferencesNote: Only the latest
4、 approved standards are applicable unless otherwise specified.2.1 External Standards/Specifications.None2.2 GM Standards/Specifications.GMW32213 Resources3.1 Facilities.3.1.1 Calibration. The test facilities and equipment shall be in good working order and shall have a validcalibration label.3.1.2 A
5、lternatives. Alternative test facilities and equipment may also be used. However, all measuringvariables as specified in this standard shall be determined correctly with respect to their physical definition.3.1.3 Apparatus for conditioning to GMW3221.3.2 Equipment.3.2.1 Burst Strength Tester (Mullen
6、 Tester) such equipment available at .3.2.1.1 Pressure shall be transmitted hydraulically and it shall be uniformly increased. The circular free testarea of the test piece shall be (780 5) mm2 corresponding to a diameter of (31.5 0.05) mm. The hydraulicpressure on the rubber diaphragm shall be trans
7、mitted by technically pure air free glycerin.3.2.2 The tester shall consist of a metal base plate covered by a thin rubber diaphragm over which the testpiece can be placed, and securely clamped by a metal ring. The internal diameter of the ring shall be(31.5 + 0.05) mm.Note: A schematic representati
8、on of the test head is shown in Figure 1.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14776 Copyright 2013 General Motors Company All
9、Rights ReservedJune 2013 Page 2 of 43.2.3 The clamping device shall consist of two annular steel rings, the contacting surfaces of which are spirallygrooved and parallel such that, when clamped onto the test piece, the clamping pressure is uniform andsufficient to prevent slippage of the test piece
10、during test. The inner diameter of the clamping rings shall be(31.5 0.1) mm and the outer diameter shall be 96.0 mm minimum. The lower inside edge of the upperclamping rings shall be rounded with a radius of 0.5 mm. The lower clamping ring shall be (6 2) mm thick andits lower inside edge shall be ro
11、unded with a radius of (6.0 0.5) mm to prevent damage to the diaphragmduring testing. The clamping pressure shall be adjustable (either manually or automatically) to give theapproximate pressures shown in Table 1.Figure 1: Test HeadTable 1: Clamping PressureBursting strengthin MPaClamping pressure i
12、n MPaSolid board or corrugated cardboard Paper or similar thin materials 1.5 0.4 0.71.5 to 2.0 0.6 0.72.0 to 2.5 0.8 0.7 2.5 1.0 0.73.2.4 Pressure gauges capable of measuring the applied pressure to an accuracy of 0.02 MPa shall be fitted.The capacity of the machine shall be such that the bursting s
13、trength shall be between 5 % and 90 % of themaximum scale deflection.3.2.5 The replaceable rubber diaphragm shall be made of high quality rubber such that even after repeatedstress a permanent set is minimal. The diaphragm shall be replaced when the pressure to achieve an archingheight of (10.0 0.1)
14、 mm above the base pressure plate face, falls outside the range (0.16 to 0.21) MPa.3.3 Cutting dies or shears for preparation of the test pieces.3.3 Test Vehicle/Test Piece.3.3.1 The complete component shall be used as test piece or, from the available material, test pieces| 110 mm x 220 mm shall be
15、 taken from various areas of the component.3.3.2 Test pieces shall, wherever possible, be taken in the longitudinal direction or parallel to an outer edge.3.3.3 With this size test piece it is possible to perform two tests, one face up and one face down.3.4 Test Time. Not applicable.Copyright Genera
16、l Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14776 Copyright 2013 General Motors Company All Rights ReservedJune 2013 Page 3 of 43.5 Test Required Inf
17、ormation. Not applicable.3.6 Personnel/Skills. Not applicable.4 Procedure4.1 Preparation. For initial sample approval arbitration purposes and routine quality control at least five testpieces, or complete components shall be tested, both face up and face down, i.e. 10 separate determinationsin all.4
18、.2 Conditions.4.2.1 Environmental Conditions.4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Suchrequirements shall be specified on component drawings, test certificates, reports, etc.4.3 Instructions.4.3.1 The test shall be performed immediately
19、 after conditioning in accordance with GMW3221 Code D.4.3.2 The test piece shall be symmetrically placed on the membrane of the testing device and clamped withthe metal ring such that it cannot move during test except by distension, and the clamping pressure complieswith the requirements of Table 1.
20、4.3.3 Any distortion of the test piece shall be avoided.4.3.4 The pressure of the diaphragm shall be increased at a uniform rate such that the test piece ruptureswithin 30 s, and the burst pressure recorded.4.3.5 The intake valve shall be closed immediately.4.3.6 Should any test piece rupture at the
21、 clamping ring or “double bursting occur the test shall be disregardedand repeated using an additional test piece.5 Data5.1 Calculations. Not applicable.5.2 Interpretation of Results. Not applicable.5.3 Test Documentation. For tests to this standard, the bursting strength shall be recorded as the me
22、asuredindividual value or as the arithmetical mean value in MPa rounded to the nearest 0.02 MPa.6 SafetyThis standard may involve hazardous materials, operations, and equipment. This standard does not propose toaddress all the safety problems associated with its use. It is the responsibility of the
23、user of this standard toestablish appropriate safety and health practices and determine the applicability of regulatory limitations priorto use.7 Notes7.1 Glossary.Bursting Strength: Bursting strength is defined as the maximum pressure necessary to rupture test pieceunder the conditions of this test
24、.7.2 Acronyms, Abbreviations, and Symbols. Not applicable.8 Coding SystemThis standard shall be referenced in other documents, drawings, etc., as follows:Test to GMW14776 (2.20 MPa)Where the actual requirement replaces the information in the parenthesis.Copyright General Motors Company Provided by I
25、HS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14776 Copyright 2013 General Motors Company All Rights ReservedJune 2013 Page 4 of 49 Release and RevisionsThis standard was originated
26、 in November 2005. It was first approved by Global Textile SSLT inDecember 2006. It was first published in July 2007.Issue Publication Date Description (Organization)1 JUL 2007 Initial publication.2 JUN 2013 5 year refresh update (Textile GSSLT)Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
