ASTM D2061 – Standard Test Methods for Strength Tests for Zippers
Significance and Use
4.1 The usefulness of a zipper in service can be evaluated by these tests. No one test determines the suitability of a zipper for a specific end use. Since the tests are inter-related more than one may be needed for a complete evaluation.
4.2 These methods are considered satisfactory for acceptance testing of commercial shipments because the methods have been used extensively in the trade for this purpose, and because estimates of current between-laboratory precision are acceptable in most cases.
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 determine 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 are 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 D2051, 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no practical methods have yet been developed or because a valid evaluation of the information resulting from existing unpublished methods requires an intimate and thorough knowledge of zippers.
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:
|Holding Strengths of Separable Units||25 – 32|
|Holding Strength of Slider Lock||92 – 100|
|Holding Strength of Stops||17 – 24|
|Resistance to Angular Pull-Off of Slider Pull||82 – 91|
|Resistance to Cushioned Compression of Sliders||33 – 42|
|Resistance to Pull-Off of Slider Pull||72 – 81|
|Resistance to Twist of Pull and Slider||52 – 61|
|Slider Deflection and Recovery||43 – 51|
|Strength of Chains and Elements||9 – 16|
|Torsional Resistance of Slider Pull for Removal of Components||62 – 71|
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.