ASTM D2061-07 (R2021) pdf free download.Standard Test Methods for Strength Tests for Zippers.
1 .1 These test methods cover the determination of the strengths for zipper and zipper parts. All methods are not suitable for use with all kinds of zipper. The restrictions, if any, are indicated in the scope for each individual test method. The test methods appear as follows.
4.2.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative test should be performed to dctcrminc if there is a statistical bias between them, using competent statistical assistance. As a minimum, the test samples should be used that are as homogeneous as possible. that arc drawn from the material from which the disparate test results were obtained, and that are randomly assigned in equal numbers to each laboratory for testing. Other materials with established test values may be used for this purpose. The test results from the two 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 must be adjusted in consideration of the known bias.
4.3 The method(s) in the standard along with those in Test Methods D205 I, D2052, D2053, D2054, D2057, D2058, D2059/D2059M, D2060, and D2062 are a collection of proven test methods. They can be used as aids in the evaluation of zippers without the need for a thorough knowledge of zippers. The enumerated test methods do not provide for the evaluation of all zipper properties. Besides those properties measured by means of the enumerated test methods there are other properties that may be important for the satisfactory performance of a zipper. Test methods for measuring those properties have not been published either because no practical methods have yet been developed or because a valid evaluation of the information resulting from existing unpublished methods requires an intimate and thorough knowledge of zippers.
5. Sampling
5.1 Lot Sample—As a lot sample for acceptance testing. take at random the number of individual containers from each shipping carton as directed in an applicable material specification or other agreement between the purchaser and the supplier. Consider individual containers from each shipping carton to be the primary sampling units.
Note 1—An adequate specification or other agreement between the purchaser and supplier requires taking into account the variability between shipping cartons and between zippers in a container to provide a sampling plan with a meaningful producer’s risk, consumer’s risk, acceptable quality level, and limiting quality level.ASTM D2061 pdf download.