ASTM D203-33 Methods of Testing Tolerances for Cotton Yarns (Withdrawn 1936)

Trang 1 STANDARD SPECIFICATIONS FOR TOLERANCES AND TEST METHODS FOR ELECTRICAL COTION YARNS1 A.S.T.M.. Designation: D 203-33 These spccifirotions nrc issm:d under Lhe fixed designation D

STANDARD SPECIFICATIONS

FOR TOLERANCES AND TEST METHODS FOR ELECTRICAL

COTION YARNS1 A.S.T.M Designation: D 203-33 These spccifirotions nrc issm:d under Lhe fixed designation D 203; the final number indicates the year of original adoption ns stMdard or, in the cnse of revi si on, the year of last revision

Issunn AS 'l'I!NTATIVI·:, 1924; AuOI'TRU IN AMIHIIJIW FOI(M, 1925; RRVISBD, 1933 Scope

1 These specifications cover the tolerances and methods of

testing for electrical cotton yams, both single and multiple wound

TOLERANCRS

Strength

2 The avemge tensile strength of each case or bale of yam, either single or plied, as dctennincd hy test slmll be not less than the sped tied strength

Size or Yarn Number

3 The average size of each case or bale of yarn, in the singles, either c 1.rdcd or combed, as determined by test slmll not be more

than 3 per cent over or under the spcdticd size

Kmmf1le.-No 36 canlcd yaru specified; tolerance wou!J nllmv 34.92 lo 37.08

Twist

4 D-ircclion of 1'wist.-The direction of twist shall be as defined

in the Tentative :Oellnitions and Terms Relating to Textile :Materials (A.S.T.M Designation: D 123 - 33 T) of the American Society for Testing Materials, as follows:

Twist, Di,·cctio~t 11].-In the case of yarn or cord: the yam or cord has right-hand or regular twist if when it is held vertically the spirals

or twists are seen to incline upward in a right·h<~nd direction and has left-hand or reverse twist when the spirals or twists are seen to incline upward in a left-hand direction

NoTE.-Attention is rolled to the fact that this definition of twist is opposite

to that used in sewing thrend manufacture

'Under tho stAndi\Cdi•.ation proco<lur" or the Society, these opeci6oation1 ft!O un<.lor the ju risdk· tioll <>f tho A.S.'l' M CommiLtt~ 0.1 1 on Te~tilo MRtedals

(1171)

1172 SPECIFICATIONS FOR ELECTRICAL CoTTON YARNS

Twist of Plied Yarns

5 The average twist of each case or bale 0£ yarn, either single

or plied, as determined by test shall not be more than 5 per cent over

or under the specified twist

Example.-Twist specified is 20 twists per inch; tolerance 19 to 21

METHODS OF TESTING STRENGTH

Testing Machine

6 All skeins shall be broken on an automatic power yarn tester

of inclination balance type of 150 and 300-lb capacities The lower capacity should be used until the swing of the pendulum exceeds an angle of 45 deg from the vertical When yarns break above this mark, the higher capacity of testing machine should be used

Spools

7 The spools used in holding skeins during testing shall not be less than 1 in in diameter, and not less than 1 in in width The upper

or head end spool should be fastened solidly, and the lower spool

be allowed to revolve

Speed

8 The speed of pulling jaw shall be 12 in per minute

Reels

9 Any yarn reel having a 1~-yd perimeter may be used in pre-paring the skeins For yarn wound on cones, where the yarn is drawn from the top, a speed of 100 to 300 r.p.m of reel shall be used For yarn wound on parallel tubes, the yarn shall be drawn from the side, and a speed of 20 to 30 r.p.m of reel shall be used On reels that have only one pigtail guide and for yarns on cops or cones, either single

NUMBER OF ENDS IN

SINGLE STRAND

TABLE I,

LENGTH TO REEL

FOR TEST, YO,

2 60

3 45

4 and 5 ' 30

6 and 7 21

8 and above 15

end or multiple wound, the tension shall be applied by making one full wrap around the guide For yarns on parallel tubes, either single end

or multiple wound, there shall be no wraps around the guide On reels using two or more guides, the yarn, either single end or multiple wound, shall pass straight through the guides onto the reel, the angles

of the guides supplying the necessary tension Judgment must be

A.S.T.M DESIGNATION: D 203-33 1173

used in regard to the amount of tension required on yarns having little

or a large amount of twist

Number of Tests

10 Three tests from each of four cops, cones or tubes of yarn from every case shall be made, and the average of these twelve tests shall be the average of the case

Two skein test methods are given, A, Preferred Method and B, Alternate Method The Alternate Method can be used where routine testing is done on

a large scale The Preferred Method should always be used in case of dispute

A Preferred Method

Strength, Single End Yarn

11 For single end yarn a standard skein (120 yd.) shall be broken after conditioning in an atmosphere of 65 per cent relative humidity, and 70° F (21 ° C.)

Strength, Multiple Wound Yarns

12 For multiple wound yarn, a skein shall be prepared in accord-ance with Table I, and shall be broken after conditioning in an atmos-phere of 65 per cent relative humidity, and 70° F (21 ° C.) The table provides for skeins of approximately 120 yd of single yarn or

80 loops No skeins shall be less than 10 loops or 15 yd of multiple strand

Conditioning

13 Cops, cones and tubes selected for test shall be conditioned for at least 12 hours Yarn removed for testing after conditioning shall not penetrate into a tube a distance of more than !-in on a radial line Skeins shall be conditioned for at least 3 hours

B Alternate Method

Strength, Single

14 Skeins of either single end or multiple wound yarn prepared

as outlined in Method A shall be broken under natural humidity conditions at the time of test The results thus obtained shall be reduced to a common basis of standard moisture regain equal to

7 per cent of the bone-dry weight

Moisture Regain DetermiD.ation

15 To determine moisture regain present in samples, the several skeins shall be weighed collectively, immediately after testing, under natural moisture conditions which obtain at the time of test The skeins shall then be p)aced in the basket of an oven at a temperature

of 105 to 110° C (221 to 230° F.) and dried to constant weight The moisture regain is then computed as the percentage of the dry weight

117 4 SPECIFICATIONS FOR ELECTRICAL COTTON YARNS

Correction to Standard Regain

16 The following formula shall then be applied, based on the assumption that the standard moisture regain of cotton yarns is 7 per cent of the dry weight, that the actual percentage regain is between the limits of 3 and 7 per cent of the dry weight, and that for 1 per cent

of moisture regain there is an increase of 6 per cent in the tensile strength of the yarn:

(Tensile strength from machine read-Tensile strength corrected to ing) X 142

standard moisture regain = 100 + (6 X actual percentage regain)

Example.-With a skein of yarn broken under natural conditions showing

a tensile strength of 120 lb as read from the machine dial and which by weighing before and after drying the skein was found to contain a moist\lre regain equal

to 5 per cent of the bone-dry weight, the tensile strength corrected to a common basis of 7 per cent moisture regain would be:

Corrected tenstle strength = ) = 131lb

(b) Moisture regain tests shall be made periodically during the hours of testing as the natural humidity conditions are found to vary

C Strength Correction to Size

Strength Correction to Size

17 The average tensile strength shall be corrected to the specified size as determined in accordance with Sections 18 and 19 by the fol-lowing formula:

Actual average size Corrected tensile strength = Actual average strength X

Specified s1ze

Yarn Number, Preferred Method

18 All skeins used in the Preferred Method of testing for strength shall be sized immediately after being broken

Yarn Number, Alternate Method

19 All skeins used in the Alternate Method of testing for strength shall be sized under natural humidity conditions at the time

of test The moisture regain shall then be determined as outlined in Section 15 and the results corrected to a common basis of standard moisture regain equal to 7 per cent of the bone-dry weight by means

Size corrected to standard Size X (100 +actual percentage of regain)

Balance

20 The balance to be used shall be accurate to 0.25 per cent of the standard size of the yarn When the balance does not indicate

A.S.T.M DESIGNATION: D 203-33 1175

the size directly, the yarn number or size may be calculated from the formula:

Length in yards of Yarn number or size = single yarn 7000 (grains in I lb.)

Weight in grains X 840 (yards of No I

cot-ton yam per pound)

Number of Tests

21 The average size of the,12 skeins used in the strength test shall

be the average size of case or bale

Twist

22 (a) Single Twist.-The single yarn twist shall be determined

on any standard single yarn twist tester employing the principle of first taking the twist out of a given length of yarn and then retwisting

in the opposite direction until the same amount of twist is put back, dividing the results by twice the distance between grips to get the twists per inch The minimum distance between jaws shall be 5 in., but a 10-in distance is preferable In making this test it is essential that check tests be made before proceeding with regular tests in order

to determine the proper tension to be placed on the yarn so as not

to cause slippage of the fibers and other variations

(b) Ply Twist.-The ply twist in yarns of two or more ply shall

be determined on any standard twist counter with jaws set 10 in apart The strands shall be clamped in jaws under a definite tension

by attaching weights The tension to be used shall be determined from the formula:

!56 (Constant) Tension, in grams = "

-Equivalent singles size

Example.-The weight for 80/2 ply would be as follows

1:~ = 3.9 g (approximately) NoTE.-The constant of 156 represents a tension (basis yarn No 1) which should be placed on yarn or cord to hold it sufficiently taut and still not remove any

Number of Twist Tests

23 (a) Single Yarns.-Three twisftests on each of ten packages

of single yarn from each case or bale shall be made, and the average

of these 30 tests shall be the average twist of the case or bale

(b) Plied Yarns.-Three twist tests on each of four packages of plied yarn from each case or bale shall be made, and the average of these 12 tests shall be the average twist of the case or bale