ASTM D3776/D3776M-20 pdf free download.Standard Test Methods for Mass Per Unit Area (Weight) of Fabric.
9. Option C — Small Swatch of Fabric
9.1 Significance and Use.
9.1.1 This procedure is applicable whcn a small swatch of fabric is sent to the laboratory to be used as the sample. The results are considered to be applicable to the sample only and not necessarily to the lot from which the sample was taken.
9.1.2 Measurements by this option do not include selvages and should be reported as such, unless a selvage allowance is sped lied.
9.1.3 Option C is not recommended for acceptance testing of commercial shipments since Option A is regularly used for that purpose.
9.2 Sainpling—Option C is used only when limited fabric is available and should not he used for acceptance sampling. Prepare such specimens from available swatches.
9.3 Preparaiioi of Specimens—Prepare a conditioned spec i - men having an area of at least 100 cm2 (15.5 in.2) or a number of smaller die cut specimens taken from different locations in the sample and having a total area of at least 100 cm2 (15.5 in.2) Do not take these specimens closer than one tenth of the fabric width to a selvage or cut edge. If insufficient fabric is available to meet these criteria, note that fact in the report.
9.4 Proc edure:
9.4.1 Determine the area of the specimen(s) used. For die-cut specimens, the area of the die is normally given. For square or rectangular specimens. use Eq 13.
10. Option D—Narrow Fabrics
1 0. 1 Sign ificance and Use:
10.1.1 This procedure is intended for use with narrow fabrics as so designated by the trade. These fabrics are usually 300 mm (12 in.) in width or less. The procedure and calculations are the same as for Option B, except longer specimens are used.
10.1.2 Option D is not recommended for acceptance testing of commercial shipments since Option A is regularly used for that purpose.
1 0.2 Sampling:
10.2.1 Lot Sample—As a lot sample. take at random the number of rolls of fabric as directed in an applicable material specification or other agreement between the purchaser and the supplier. Consider the rolls of fabric to he the primary sampling units.
1 0.2.2 Lihoratorv Sample—From each roll in the lot sample. cut a conditioned laboratory sample 1 rn ± 3 mm (36.0 ± 0.10 in.) long perpendicular to the selvages. Take a minimum of three such laboratory samples from different places. distributed as evenly as practicable along the length of the roll. In this procedure. a complete laboratory sample is used as a specimen.ASTM D3776/D3776M pdf download.