ASTM D5793-18 pdf download.Standard Test Method for Binding Sites per Unit Length or Width of Pile Yarn Floor Coverings.
3. Terminology
3.1 For definitions terms relating to Pile Floor Coverings, D13.21, refer to Terminology D5684.
3.1.1 The following terms are relevant to this standard: back coating, backing, backing fabric, binding site, buried pile yarn, carpet, components, finished, finished pile yarn floor covering, floor covering, lengthwise direction, needles per unit width, pile, pile heights, pile yarn floor covering, pile yarn mass, pitch, stitches, stubble, textile floor covering, tuft, tufted fabric, widthwise direction.
3.2 For all other terminology related to textiles, refer to Terminology D123.
4. Summary of Test Method
4.1 The length of pile floor covering containing 40 binding sites is measured in either the lengthwise or widthwise direc- tion as required and the number of binding sites per unit length is calculated.
5. Significance and Use
5.1 This test method is useful in quality and cost control during manufacture. Both appearance and performance of pile yarn floor coverings can be affected by the number of binding sites per length and width.
5.2 This test method is considered satisfactory for accep- tance testing of commercial shipments because current esti- mates of between-laboratory precision are acceptable and the method is used extensively in the trade for acceptance testing. 5.2.1 If there are differences of practical significance be- tween reported test results for two laboratories (or more), comparative tests should be performed to determine if there is statistical bias between them using competent statistical assis- tance. As a minimum, use test samples for such comparative tests that are as homogeneous as possible, drawn form the same lot of material as the samples that resulted in the disparate results during initial testing, and that are randomly assigned in equal numbers to each laboratory for testing. The test results from the laboratories should be compared using a statistical test for unpaired data at a probability level chosen prior to the testing series. If a bias is found either its cause must be found and corrected, or future test results for that material must be adjusted in consideration of the know bias.
6. Apparatus
6.1 Shears or Clippers, capable of shearing close enough to the backing to leave a stubble of no more than 0.05 in. (1.3 mm). 6.2 Scale or Tape, metal, graduated in 0.05 in. (1 mm) and at least 10 % longer than the distance being measured.
6.3 Location Markers, two, such as straight pins.
7. Sampling Units and Test Specimens
7.1 Sampling Units:
7.1.1 Uncoated Floor Covering—The basic sampling unit of uncoated floor covering is a production roll.
7.1.2 Coated Floor Covering—The basic sampling unit of coated floor covering is a shipping roll. The number of shipping rolls obtained from each production roll ranges from one to over ten.
7.2 Take a lot sample as directed in Practice E122 when statistical knowledge of the product variability and test method precision is available, and decision has been made on the maximum deviation that can be tolerated between the estimate to be made from the sample and the result that would be obtained by measuring every sampling unit of the lot. Other- wise the number of sampling units in a lot sample and the use of the test results obtained from the individual test samples shall be in accordance with the manufacturer’s quality control program or with the specification agreed to by the purchaser and the supplier.
7.3 Atest sample shall consist ofa full width section offloor covering cut from one end of each roll in the lot sample and shall be at least 4 in. (100 mm) longer than the specimens required for the tests being conducted. Do not cut a test sample of coated floor covering from a seam end of a production roll.
7.4 Test Specimens:
7.4.1 The test specimens shall be large enough to include 44 binding sites in each direction.
7.4.2 This test method may be nondestructive since the measurements may be made on the test specimens without cutting the test specimens from the test sample. 7.4.3 A test specimen is a designated area of a test sample that may be marked on or cut from the test sample as directed in the test method. For test samples 120 in. (3000 mm) wide or wider, three test specimens are required, one at each edge no nearer to the edge than 5 % of the total floor covering width and one in the middle portion of the test sample. For test samples at least 60 in. (1500 mm) wide but less 120 in. (3000 mm), take two test specimens, one at each edge no nearer to the edge than 5 % of the total floor covering width. For test samples less than 60 in. wide (1500 mm), take one specimen, from the middle.ASTM D5793 pdf download.