ASTM D5591-22

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Designation: D5591 − 04 (Reapproved 2016) D5591 − 22
Standard Test Method for
Thermal Shrinkage Force of Yarn and Cord With a Thermal
Shrinkage Force Tester
This standard is issued under the fixed designation D5591; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers preparation and procedures to measure the thermal shrinkage force of yarns and cords in air.
1.2 This test method is applicable to measurement of the thermal shrinkage force of yarns and cords whose shrinkage force at 180
6 2°C2 °C (355 6 4°F)4 °F) in air does not exceed 20 N (4 lbf). This test method is applicable to nylon, polyester, and aramid
yarns and cords within the applicable range of thermal shrinkage force, as well as to comparable yarns and cords from other
polymers.
1.2.1 Test specimens may be taken from yarn or cord packages, or retrieved from fabrics.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.after
SI units are provided for information only and are not considered standard.
1.4 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. Specific hazards statements are given in Section 8.
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.
2. Referenced Documents
2.1 ASTM Standards:
D123 Terminology Relating to Textiles
D885D885/D885M Test Methods for Tire Cords, Tire Cord Fabrics, and Industrial Filament Yarns Made from Manufactured
Organic-Base Fibers
D2258D2258/D2258M Practice for Sampling Yarn for Testing
D6477 Terminology Relating to Tire Cord, Bead Wire, Hose Reinforcing Wire, and Fabrics (Withdrawn 2022)
This test method is under the jurisdiction of ASTM Committee D13 on Textiles and is the direct responsibility of Subcommittee D13.19 on Industrial Fibers and Metallic
Reinforcements.
Current edition approved July 1, 2016June 1, 2022. Published August 2016July 2022. Originally approved in 1995. Last previous edition approved in 20112016 as
D5591 – 04 (2011).(2016). DOI: 10.1520/D5591-04R16.10.1520/D5591-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 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 the ASTM website.
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D5591 − 22
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms relating to tire cord, bead wire, hose wire, and tire cord fabrics, refer to Terminology D6477.
3.1.1.1 The following terms are relevant to this standard: adhesive-treated tire cord, cord,cord; cord; greige cord,cord; greige tire
cord,cord; pneumatic tire,tire; retraction, in yarns and cords,cords; standard atmosphere for testing textiles,textiles; thermal
shrinkage force,force; thermal shrinkage force tester, and tester; tire.
3.2 For definitions of other terms related to textiles, refer to Terminology D123.
3.2.1 The following terms are relevant to this standard: thermal shrinkage force; thermal shrinkage force tester; yarn.
4. Summary of Test Method
4.1 A specified length of yarn or cord is conditioned in a relaxed state, mounted with a pretension of 5 6 1mN/tex 6 1 mN
mN/tex (0.05 6 0.01 ⁄tex (0.05 gf/den 6 0.01 gf/den), then exposed to dry heat at a temperature of 180180 °C 6 2°C (3552 °C
(355 °F 6 4°F) for 120 6 5 s.4 °F) for 120 s 6 5 s.
4.2 The shrinkage force induced in the specimen is read from the tester.
5. Significance and Use
5.1 This test method may be used for the acceptance testing of commercial shipments of yarns and cords.
5.1.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests
should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum,
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 for that material must be adjusted in consideration of the known bias.
5.2 Experience shows that yarns or cords on would packages, usually being under tension, exhibit a contraction in length (and a
resulting increase in linear density) when removed from the package and allowed to relax over a period of time at room
temperature. Consequently, it they are tested without being allowed to relax, they will register higher thermal shrinkage force
values as the relaxation shrinkage will be incorrectly included as the thermal shrinkage force.
5.2.1 Retractive forces vary widely by polymer type, being almost nil within aramids and significant within most nylons. For
example, the exposure of untensioned skeins of nylon yarn or cord to 95 to 100 % relative humidity at room temperature for two
days and reconditioning under standard laboratory conditions will cause most of the length change that is possible at room
temperature to occur within a sample. This reduction in length is accompanied by some lowering of thermal shrinkage force.
5.3 The thermal shrinkage force of nylon, polyester, and aramid fiber is related to the polymer of origin and its manipulation in
processing. Thermal shrinkage force measurement can be used to control product uniformity.
5.4 The level of thermal shrinkage force is critical in the user’s subsequent operations, such as the drum-set (original length of
cord) required to build a tire of a particular size.
5.5 The thermal shrinkage force is critical to the final shape and size of fiber-reinforced articles. For example, thermal shrinkage
force affects the final size of V-belts and their ability to maintain tension during their operation.
5.6 This test method is in agreement with the nominal procedures of Test Methods D885D885/D885M for the determination of
thermal shrinkage force in yarns and cords.
D5591 − 22
5.6.1 Shrinkage force is measured while the specimen is within an oven at a specified temperature and after a specified length of
time.
6. Interferences
6.1 If the chamber in which the specimen is heated is open on three sides, air drafts can effectively shorten the length of specimen
experiencing the prescribed temperature environment. The results obtained without a shield are generally lower than those obtained
with a shield.
6.2 The accurate control of temperature at any prescribed setting is of utmost importance. Differences between the set point
temperature and the temperature experienced by the specimen are a major cause of the bias of test results. The temperature that
the specimen experiences may be checked by attaching a small calibrated thermocouple to a piece of cord and suspending it in
the specimen position such that the tip of the thermocouple is in the center of the oven cavity. The thermocouple must not touch
the oven walls. Either correct any set point/sample temperature bias or determine the proper set point to give the specified specimen
temperature. An intralaboratory comparison is the preferred method to determine whether a bias exists.
6.3 The differences in the amount of pre-relaxation of yarns can cause differences in thermal shrinkage force, as noted in 5.2.1.
6.4 Shrinkage force is a combination of pretension force and the force that is developed in the specimen as a result of the specimen
being heated.
6.5 Shrinkage force can be affected by the pretension, the length of specimen exposure, improper location of the specimen within
the oven, and oven-surface contact of any part of the specimen. Specimens that are spun, textured, or crimped (such as those
removed from a fabric) may allow filaments to come into contact with interior surfaces of the thermal shrinkage force oven. Such
physical contact will cause inaccurate readings of the thermal shrinkage force.
7. Apparatus
7.1 Thermal Shrinkage Oven, consisting of a specimen heating cavity capable of heating up to 250°C (480°F),250 °C (480 °F),
a means of accurately controlling the temperature of the cavity 6 2°C (4°F), 62 °C (4 °F), and a means for measuring and
displaying the shrinkage force up to 0.1 N (0.02 lbf).
7.2 Stopwatch or Time, capable of reading to 6 1.0 61.0 s.
7.3 Clip-On Tensioning Masses.
7.4 Draft Shield for Shrinkage Oven, if the oven does not have one provided.
8. Hazards
8.1 Do not touch the oven while it is in operation because it can reach temperatures up to 200°C (390°F).200 °C (390 °F).
8.2 Do not leave the oven unattended if a specimen is installed.
9. Sampling
9.1 Lot Sample—As a lot sample for acceptance testing, randomly select the number of shipping containers directed in an
applicable material specification or other agreement between the purchaser and the supplier. In the absence of such an agreement
or material specification
...