ASTM D3811/D3811M-21a PDF

SIGNIFICANCE AND USE 5.1 This procedure simulates hand and machine unwinding of tape at low rates. The force required for unwinding at low rates is a function of rate. At some rate (expected to be different for each construction type and manufacturer) there occurs an inversion of the response. The rate for this test method does not allow for comparisons of different tapes that will be unwound at high rates. 5.2 This procedure can be used to indicate satisfaction where a specification for unwind; either maximum, minimum, or mean; is established and when the responses referred to in 5.1 are taken into consideration. SCOPE 1.1 This test method covers one procedure for determining the force required to unwind a roll of pressure-sensitive tape. 1.2 The values stated in either SI or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system must be used independently, without combining values in any way. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.