1、WORLDWIDEENGINEERINGSTANDARDSTest Procedure GMW14777Test Method for Determining Moisture Content, Water Absorption andThickness Swell of Fiberboards, Chipboards, Cardboard,and Similar Rigid Materials Copyright 2013 General Motors Company All Rights ReservedJune 2013 Page 1 of 41 ScopeNote: Nothing i
2、n this standard supercedes applicable laws and 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 for the determination of moisture content, water absorption, andthickness swell of f
3、iberboards, chipboards, cardboards and similar materials.1.2 Foreword. Not applicable.1.3 Applicability. Not applicable.2 ReferencesNote: Only the latest approved standards are applicable unless otherwise specified.2.1 External Standards/Specifications.ISO 50842.2 GM Standards/Specifications.GMW3221
4、3 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 Alternatives. Alternative test facilities and equipment may also be used. However, all measuringvariables as specified in this standard shall be
5、 determined correctly with respect to their physical definition.3.1.3 Apparatus for conditioning to the appropriate requirements as described in GMW3221 Code A, unlessotherwise specified in the relevant material specification.3.1.4 Apparatus for determining thickness to ISO 5084.3.1.5 Mechanical Con
6、vection Oven capable of maintaining the required temperature from the materialspecification to a tolerance of 3C.3.2 Equipment.3.2.1 Suitable punching devices, saws etc. for preparation of test pieces.3.2.2 Suitable vessel for soaking the test pieces.3.2.3 Glass or stainless steel rods for supportin
7、g test pieces.3.2.4 Suitable sinkers such as lead, or other suitable dense metal, sinkers shown in Figure 1.3.2.5 Balance accurate to 1 mg.3.2.6 Desiccator.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted
8、without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14777 Copyright 2013 General Motors Company All Rights ReservedJune 2013 Page 2 of 4Figure 1: Suitable Sinkers3.3 Test Vehicle/Test Piece. From the material to be tested, square test pieces of (100 1) mm side lengthshall be taken fro
9、m various points, if possible equally distributed over the whole area. The test pieces shall betaken parallel to an outer edge where possible. For initial sample approval and arbitration purposes at least5 test pieces, and for routine quality control at least 3 test pieces shall be tested.3.4 Test T
10、ime. Not applicable.3.5 Test Required Information. Not applicable.3.6 Personnel/Skills. Not applicable.4 Procedure4.1 Preparation. The test shall be carried out immediately after cutting test pieces and without conditioning, inthe as received condition (i.e., no special preconditioning).4.2 Conditio
11、ns.4.2.1 Environmental Conditions. See paragraph 4.3.4.2.2 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 Determination of the Moisture C
12、ontent.4.3.1.1 The test pieces shall be weighed to the nearest 1 mg. If immediate weighing is not possible, the testpieces shall be protected against any change of the moisture content (e.g., by storing in airtight containers,polyethylene bags, wrapping in aluminum foil) prior to weighing.4.3.1.2 Af
13、ter weighing, the test pieces shall be dried for 24 h at (+105 3) C in the oven.4.3.1.3 After removal from the oven, the test pieces shall be cooled in the desiccator for 1 h 5 minutes at(+23 5) C and subsequently be weighed to the nearest 1 mg.4.3.2 Determination of Water Absorption and Thickness S
14、well.4.3.2.1 The tests shall be performed immediately after conditioning in accordance with GMW3221 Code A. Thetest pieces shall be weighed to the nearest 1 mg.4.3.2.2 For testing the thickness swell, the thickness shall be measured in accordance with ISO 5084 at5 different points. These 5 measuring
15、 points shall be: 1 in the center, the other 4 on each diagonal, and| 35 mm from each corner.4.3.2.3 The test pieces shall then be immersed in de-ionized water at (+23 5) C for the specified testingperiod.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot f
16、or ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14777 Copyright 2013 General Motors Company All Rights ReservedJune 2013 Page 3 of 44.3.2.4 The test pieces shall be stored without edge protection in such a manner that the upper face
17、 liesapproximately 25 mm below the water level. For this purpose, the test pieces shall be placed on suitablesupports, length 30 mm, height 6 mm, e.g., on wires of non corrosive material, glass rods or glass beads inthe test vessel, in such a manner that line contact with the support and free access
18、 of water is achieved. Thetest pieces shall be weighted (e.g., by sinkers according to paragraph 3.2.4) to eliminate buoyancy problems.4.3.2.5 After the prescribed test period, the test pieces shall be removed from the water and placed on edge orsuspended for (10 0.5) minutes so that the water can d
19、rain. Any remaining surface water shall be removedby dabbing with filter paper - without shaking the test piece.4.3.2.6 The test pieces shall then be immediately weighed to the nearest 1 mg.4.3.2.7 The thickness shall then be remeasured, in accordance with ISO 5084, at the 5 measuring points.4.3.3 S
20、ummary of Test Periods. Code shall be called out as a suffix to the specification for Water Absorptionand Thickness Swell. See Table 1.Table 1: Suffix Codes for Test Periods.Coding Test PeriodA (30 1) minutesB (60 2) minutesC 2 h 2 minutesD 4 h 5 minutesE 8 h 5 minutesF 16 h 10 minutesG 24 h 10 minu
21、tesH to special data5 Data5.1 Calculations. Not applicable.5.2 Interpretation of Results.5.2.1 Moisture Content. The moisture content shall be calculated as follows:%100m mmuddu Where:u = moisture content in %mu = mass of the wet test piece in gmd = mass of the dry test piece in g5.2.2 Water Absorpt
22、ion. The water absorption shall be calculated as follows:%100m mmwnnwg Where:wg = water absorption in %mw = mass of the test piece after immersion in water in gmn = mass of the test piece after conditioning in g5.2.3 Thickness Swell. The thickness swell shall be calculated as follows: the arithmetic
23、 average of themeasured 5 thickness values after conditioning and after immersion in water shall be calculated. These valuesshall then be taken as the mean thickness of the test pieces.%100 nnwaaaqCopyright General Motors Company Provided by IHS under license with General Motors CompanyNot for Resal
24、eNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14777 Copyright 2013 General Motors Company All Rights ReservedJune 2013 Page 4 of 4Where:q = thickness swell in %aw = mean thickness of test piece after water immersion in mman = mean thickne
25、ss of test piece after conditioning in mm5.3 Test Documentation. With reference to this Test Procedure, the properties determined in these tests shallbe indicated as the arithmetical average in % rounded to the nearest 0.1 %.6 SafetyThis standard may involve hazardous materials, operations, and equi
26、pment. This standard does not propose toaddress all the safety problems associated with its use. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and determine the applicability of regulatory limitations priorto use.7 Notes7.1 Glossary.Moistur
27、e Content: The moisture content gives an indication of the hygroscopic nature of the material undertest. It is a measure of the amount of water absorbed by the material from the atmosphere, and is expressedas weight percentage relative to the dried test material.Thickness Swell: The thickness swell
28、gives an indication of the swelling propensity of the material under test.It is a measure of the increase in thickness caused by water absorption after total immersion, and is expressedas a percentage relative to the thickness of the conditioned test material.Water Absorption: The water absorption g
29、ives an indication of the propensity of the material under test toabsorb water by total immersion, and is expressed as weight percentage relative to the conditioned testmaterial.7.2 Acronyms, Abbreviations, and Symbols. Not applicable.8 Coding SystemThis standard shall be referenced in other documen
30、ts, drawings, etc., as follows:Test to GMW14777x Moisture Content to GMW14777 - (3 to 6) % by mass. Where the actual requirement replaces the examplein parenthesis.x Water Absorption to GMW14777- (G) - (30 % max) by mass. Where the actual requirements replace theexample Test Period and weight percen
31、t in parenthesis.x Thickness Swell to GMW14777- (G) (20 % max). Where the actual requirements replace the exampleTest Period and thickness percent in parenthesis.9 Release and RevisionsThis standard was originated in November 2005. It was first approved by Global Textile SSLT inDecember 2006. It was
32、 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-,-,-
