5.1 This test method for the determination of cohesion in sliver, roving, or top in dynamic tests may be used for the acceptance testing of commercial shipments but caution is advised since information on between-laboratory precision is lacking. Comparative tests as directed in 5.1.1 may be advisable.5.1.1 If there are differences or 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, test samples that are as homogeneous as possible, drawn from the material from which the disparate test results were obtained, and randomly assigned in equal numbers to each laboratory for testing. The test results from the two laboratories should be compare 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 known bias.5.2 The cohesive forces overcome in continuous drafting of slivers, rovings, or tops are affected by surface lubricants and such fiber properties as linear density, surface configuration, fiber length, fiber crimp, and fiber-frictional characteristics.5.2.1 The concept of drafting is one of the most important principles in the production of yarn from fibrous raw stock.5.2.2 The values of force to maintain drafting determined by this method are induced by mechanical means similar to those used in textile processing.5.2.3 The attenuation of textile fiber strands while in motion closely approximates actual textile processing conditions, and the relative values of force may be used to predict processing behaviors.5.3 Fiber cohesion is affected by the alignment of fiber in the textile strand and strand compaction in addition to the factors listed in 5.2. Although fibers are more nearly aligned in draw sliver than in card sliver, the draw sliver is more compact. Thus, for a given production run, the drafting forces are higher for draw sliver than for card sliver.5.4 In addition to the aforementioned effects on drafting forces, the direction of specimen movement through drafting rollers may give different drafting force. Fibers in slivers may have hooks of varying severity at one or both ends. Passage through drafting rollers results in higher drafting forces when the predominance of fiber hooks are oriented in the trailing mode of the strand.1.1 This test method describes the measurement of fiber cohesion as the dynamic cohesive force required to maintain drafting in rovings, slivers or tops when they are subjected to stress induced by passing between pairs of drafting rolls of different surface speeds. The cohesive force is converted to cohesive tenacity based on the linear density of the material.NOTE 1: For static tests refer to Test Method D2612.1.2 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.1.3 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.

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This specification covers asbestos roving have a specified minimum of mass % asbestos fiber, excluding the mass of other inorganic reinforcing strands which may be present. Asbestos roving covered here are classified into classes (Classes A, B, C, D, and E) according to structural component, grades (Commercial, Underwriters', A, AA, AAA, and AAAA) according to percentage of asbestos content by mass, and electrical insulation type (Types II, IV, and VI) according to magnetic rating. Specimens shall be sampled, prepared, tested, and conform accordingly to specified chemical composition (reinforcement and asbestos content), electromagnetic (electrical insulation), mechanical (tensile or breaking strength), and dimensional (roving number or linear density) property requirements.1.1 This specification covers asbestos roving having a minimum of 75 mass % asbestos fiber, excluding the mass of other inorganic reinforcing strands which may be present.1.2 The values stated in either SI units 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 shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.3 Warning—Breathing of asbestos dust is hazardous. Asbestos and asbestos products present demonstrated health risks for users and for those with whom they come into contact. In addition to other precautions, when working with asbestos-cement products, minimize the dust that results. For information on the safe use of chrysoltile asbestos, refer to “Safe Use of Chrysotile Asbestos: A Manual on Preventive and Control Measures.”21.4 The following safety hazards caveat pertains only to the test methods, Section 13, described in this specification: 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 and health practices and determine the applicability of regulatory limitations prior to use. For specific safety hazard warning, see 1.3.1.5 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.

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1.1 This specification covers standard plastic laminates, their testing, and minimum property requirements, for the qualification of materials used to manufacture structural, semi-structural, or electrical composites of fiberglass woven-roving and woven-yarn fabrics. It covers, in part, plastic laminates designed for printed-circuit boards, which are specified in MIL-P13949. It does not cover glass-reinforced plastic laminates for armor, which are specified in MIL-A-46166 and the companion MIL-A-46165 on input woven-roving glass fabric. Note 1-Companion ASTM specifications on the input woven-roving glass fabrics and woven-glass fabrics are included in Section 2. Note 2-This specification is one of a series to provide a replacement for ASTM Specification D 2150 and Military Specifications MIL-Y-1140 and MIL-C-19663. Note 3-This specification may replace Military Specification MIL-C-9084 upon further examination as to the utility of Specification D 4357 in military procurement. 1.2 The following precautionary caveat pertains only to the test method portion, Section 8, of the specification: 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 and health practices and determine the applicability of regulatory limitations prior to use. Note 4- There is no similar or equivalent ISO standard.

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