INTERNATIONAL iso STANDARD 3374 Second edition 1980-16-15. Textile glass mats — Determination of mass per unit area Verre textile — “grammage” Mals — Délermination de la masse surlacique ou Reference nuaber 10.3974 1850(E}Iso 2374:1990(E) Foreword {SO [the International Organization for Standardization) is a worl federation of national standards bodies (ISO member badies). The work of preparing International Standards is normally carried out ihrough |SO technical commitiees. Each member body interastad in a subject for which a technical commiltee has been established has the right fo be represented on that committee. Internationa! organizations, govern- ‘nnanial and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (VEC) on all matiers of electrotechnical standardization, Draft International Standards adopted by the technical committees are Circulated to the member bodies for voting. Publication ag an Inler- national Standard requires bodies casting 2 vole, npcoval by ot heact 75% of the membe International Standard ISO 3374 was prepared by Technical Commitice ISO/TC 81, Plastics, This second edition cancels and replaces the first edition (ISO 3374:1920), of which it constitutes a technical revision © 130 1060 Bil rights resecvac. Neo part of thie ication may be reproduced oF vtized in any form Permission in writing om te publigter ° Inereational Orgarizatien for Stancarazation Printed in SwitzerlandINTERNATICNAL STANDARD 180 2374:4990(e) Textile glass mats — Determination of mass per unit area 4 Scope This International Standard specifies a method for determining the mass per unit area of a glass mat (either chopped-sirand mat or continuous-sirand mal) 2 Normative references The following standards conisia provisions which, through reference in this text, constitute provisions Of this International Standard. At the time of pubil- calion, the editions indicated were vatid. Ail stan- dards are subject lo revision, and parties tc agreemenis based on this International Standard are encouraged lo investigate the possibilily of ap- plying {ke most recent editions of the standards in- dicated below. Members of EC and |SO maintain registers of currently valid International Standards 180 1886-1980, Textile glass — Method of sampling applicable to batches. ISO 2602:1980, Statistical interpretation of test re- suits — Estimation of the mean — Confidence interval. (GO 2244:1977, Textile glass products — Determi- pation af moisture content. 3. Definition For the purposes of this Internal foltewing deffnition applies jonal Standard, the ‘mass per unit area: The ratio of the mass of a piece of mat of specified dimensions | NOTE! This he birder mass includes both the giass strands and 4 Principle ‘The mass of a test specimen of known surface area is determined, and the mass per unit area caicu- laled. For products including more than 0,2 % moisture, this operation is preceded by a drying step in an over. 5 Apparatus 5.1 Polished metal template, ‘or preparing the test specimens. The preferred shape is 3 square with sides of 316 mm {Le 0,1 m2) with a tolerance of £imm Other shapes of test specimen may be used as long a5 their surface area is 0,1 m?, for example test specimens measuring 400 mm x 250 mm 5.2 Suitable trimming tool, for example knife. scis- sors or culling disc. 5.2 Specimen container. which provides optimum, air circulation around the specimen, made trom a heat-resistant material and such that there is no loss of the test product This may be a basket con- structed from stainless steel wire mesh. 5.4 Ventilated drying oven, with an air change rate of 20 to $0 fimes per hour, capable of maintaining a temperature of 105 °C + 2 °C. 5.5 Desiceator, containing a suilabie drying agent (for example’ Silica gel, calcium chloride, phosphorus pentoxide) 56 Balance, graduaied to 0.1 g 5.7. Stainiass steel tongs. for handling the specimen and specimen container.30 3374;1990{E} 6 Sampling and test specimens Sampling shal! be carried oul in accordance with 'SO 1826, As a rule. the number of specimens to be taken from each roll in the sample shall be five per metre of width for square (318 mim x 316 mm} specimens and seven per metre af width for reciangular (400 mm x 250 mm} specimens, Specimens shall be laken adjacently over the mat width, distributing them in Iwo or more rows, de- Pending on mat width, in order to obtain the ve. quired number of specimens. For this operation, fic Cul, from across the whole wigth of each roll in the sample, 2 strip al least 650mm wide for square (316 mm x 316 mm} specimens or 820 mm wide for rectangular (400 mm x 250 mm) specimens. Cut the ‘est specimens from this strip, using the tempiste 1) and the trimming too! (5.2) Rectangular specimens shall be cul so that their long side is parallel to Ine mat length. For untrimmed mats, fake the first specimen at 100 men from the untrimmed edge. Figure 1 and figure 2 provide models for cutting out square (316 mm x 318 mr} specimens and reclan- guiar (400 mm x 250 mm) specimens, respectively, Dimensions in mitimeires 21, | Figure 1 — Example of distribution of square (316 mm x 316 mm) specimens Dimersiane in mutmetres Figure 2 — Example of distribution of rectangular (400 mm x 250 mm} specimens Another way of measuring the mean area is by using a whale roll 96 the test spec: In this method, the mass of the roll is divided hy i's tolal area. In new of Ihe dilficuily involved in me: uring the leagth of a mat when i is wound in a roi this method is generatty used only when the mat is being produced {f, however, Ihe variability of mass Per unit area within tie roll is to be evaluated. the Rormal method {using 0,1 «n® specimens) will have lo be used 7 Procedure Weigh each specimen to the nearest 0.1 9 (11 In case of doubt regarding the moisture content of the mat, first determine the moisture content in ac- cordance with |SO 3344, if this moisture content ex- ceeds 0.2%, dry each specimen in 2 container (5.3) in a ventilated oven (5.4) for ih at 405 °C 42°C Remove the specimens from the rontainar and atlow them to cool in a desincatar (5.5) until ambient temperature is reached. Then weigh each dried specimen to the nearest 0.1 g 8 Expression of results 81 Mass per unit area of the specimen Calculate the mass per unit area p, of each test specimen, expressed in grams per Square metre. using the equation ra where m, is the mass, in grams, of the specimen. Ais the area. in square metees, of the specimen 8.2 Mass per unit area of the roll Express the mass per unil ares of each roll as the: arithmetic mean of the masses per unit ares ol the specimens taken from this roll hen sampling a balch of textile glass mats, the ‘oll represents the elementary unit and its mass per unit area is the value used in the stalislical evaluation of the results {see ISO 2602) NOTE 2 The mass per unit area obtained with specimens is nol comparable with the resull obtoi ing a wiele roll as the lest specimen (see clause paragraph) auto? I9.3. Mass per unit area of the batch area of a batch as the S805 per unil area of tha Express the mass per un arithmetic mean of lie es rolls taken from that baleh, Precision The precision of this test method is not known be- Cause inter-laboratory dala are not available. Thig method may not be suitable for use in soacifications OF in the event ef disputed results as long a5 these data are not available 10 Test report The test report shall include the following partic. ulars: 8) 4 reference to this international Standard b) a 180 2974:1999(2) all details necessary for the complote identiien- ‘ion of the mat tested {he dimensions of the test specimens nber of test specimens tested. the mass per unit area of each roll and, it ¢ Guested, the slandard deviation for the ‘spect mens from each toll; (he mean vaiue of the mass per unit area and the Standard deviation for all the specimens any details of procedure not provided in this Inlemational Standard and any incidents liable fo have influenced the results (indicate here i Preliminary drying of the specimens was neces. S2ny and, if $0, renort the measured percentage moisture’ content). } i i i } E i E