ASTM D4120-01

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 4120 – 01
Standard Test Method for
1
Fiber Cohesion in Roving, Sliver, and Top in Dynamic Tests
This standard is issued under the fixed designation D 4120; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This test method describes the measurement of fiber 3.1 Definitions:
cohesion as the dynamic cohesive force required to maintain 3.1.1 cohesive force, n—in a textile strand, the force re-
drafting in rovings, slivers or tops when they are subjected to quired to overcome fiber cohesion as the strand is being
stress induced by passing between pairs of drafting rolls of reduced in linear density.
different surface speeds. The cohesive force is converted to 3.1.1.1 Discussion—In dynamic tests, cohesive force is the
cohesive tenacity based on the linear density of the material. force required to maintain drafting in a roving, sliver, or top. In
static tests, cohesive force is measured while a test specimen is
NOTE 1—For static tests refer to Test Method D 2612.
held in fixed position between two slowly separating clamps.
1.2 This standard does not purport to address all of the
3.1.2 fiber cohesion, n—in textiles, the resistance to sepa-
safety concerns, if any, associated with its use. It is the
ration of fibers in contact with one another.
responsibility of the user of this standard to establish appro-
3.1.2.1 Discussion—This resistance is due to the combined
priate safety and health practices and determine the applica-
effects of the surface characteristic, length, crimp, finish, and
bility of regulatory limitations prior to use.
linear density of the fibers. Cohesion should not be confused
with adhesion or sticking together as in a glutinous substance.
2. Referenced Documents
3.1.3 roving, n—a loose assemblage of fibers drawn or
2
2.1 ASTM Standards:
rubbed into a single strand, with very little twist. In spun yarn
D 123 Terminology Relating to Textiles
systems, the product of the stage, or stages, just prior to
D 519 Test Method for Length of Fiber in Wool Top
spinning.
D 1440 Test Method for Length and Length Distribution of
3.1.4 sliver, n—a continuous strand of loosely assembled
Cotton Fibers (Array Method)
fibers that is approximately uniform in cross-sectional area and
D 1447 Test Method for Length and Length Uniformity of
without twist.
Cotton Fibers by Fibrograph Measurement
3.1.5 tenacity, n—in a tensile test, the force exerted on the
D 1575 Test Method for Fiber Length of Wool in Scoured
specimenbasedonthelineardensityoftheunstrainedmaterial.
Wool and in Card Sliver
3.1.6 top, n—(1) worsted process —a sliver in which the
D 1776 Practice for Conditioning and Testing Textiles
fibers have been parallelized, and usually combed; (2) manu-
D 2258 Practice for Sampling Yarn for Testing
factured fibers or tow to top process—a sliver obtained by
D 2612 TestMethodforFiberCohesioninSliverandTopin
drafting, along with breaking or cutting a multifilament tow.
Static Tests
3.1.7 For definitions of terms related to force and deforma-
D 3333 Practice for Sampling Manufactured Staple Fibers,
tion in textiles refer to Terminology D 4848. For definitions of
Sliver, or Tow for Testing
other textile terms used in this test method refer to Terminol-
D 4848 Terminology of Force, Deformation and Related
ogy D 123.
Properties
4. Summary of Test Method
4.1 This test method provides an indication of the ability of
1
This test method is under the jurisdiction ofASTM Committee D13 onTextiles
fibers to hold together by measuring the force required to slide
and is the direct responsibility of Subcommittee D13.58 on Yarn and Fiber Test
Methods. fibers in a direction parallel to their length. Specific lengths of
Current edition approved Sept. 10, 2001. Published December 2001. Originally
roving, sliver, or top are drafted between two pairs of rollers,
published as D 4120 – 82. Last previous edition D 4120 – 95.
with each pair moving at a different peripheral speed.The draft
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
forces are recorded. Test specimens are then weighed and the
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on linear density calculated. Drafting tenacity, calculated as the
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
D4120–01
3
draft resisting force per unit linear density, is considered to be 6.2 Tensio
...