ASTM D4604-95

1.1 These test methods cover procedures for the operation of several instruments measuring various properties of cotton fibers; specifically micronaire, color, trash content, length, length uniformity, strength, and fiber elongation. These instruments are connected through a computer communications network and collectively are known as the Motion Control HVI Fiber Information System (See Fig. 1). These methods are applicable to loose cotton fibers taken from raw or partially processed cotton or some types of cotton wastes.

1.1.1 The micronaire reading of loose cotton fibers is determined by measuring the resistance of a "plug" of cotton fibers to air flow under prescribed conditions.

1.1.2 The measurement of length and length uniformity is made by an air flow measuring instrument outputting a voltage directly proportional to the amount of fiber in the prepared specimen at a given distance from the base of the prepared test beard, which is held in a clamp.

1.1.3 The measurements of tensile strength or breaking tenacity and elongation are made by an instrument in which the fibers are clamped between jaws with 1/8-in. (3.2-mm) spacing. A strain-gage device is used to measure breaking force, and a displacement measuring device is used to determine the fiber elongation at breaking load.

1.1.4 The measurement of the color of raw cotton is done by means of a cotton color meter of the Nickerson-Hunter type. It can be used to measure color of any type of raw cotton.

1.1.5 The measurement of the surface trash content of raw cotton is accomplished through optical analysis of the sample by a computer governing the scanning action of the sample through a video camera.

1.2 These test methods may exhibit shifts in the levels of the instrument outputs depending on the stage of processing at which the cotton fiber exists for testing.

1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are for information only; the conversion may be approximate.

1.4 This standard contains the following sections:

Sections Scope 1 Referenced Documents 2 Terminology 3 Sampling 4 Conditioning 5 Micronaire Method 6-11 Length and Length Uniformity Method 12-20 Strength and Elongation Determination Method 21-29 Color and Trash Determination Method 30-34 Calculations 35 Report 36 Precision and Bias 37-39 Keywords 40

1.5 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. Specific precautionary statements are given in Note 6 and Section 17.