1、FORD LABORATORY TEST METHOD BN 120-01 2001 O924 STIFFNESS OF FABRICS Revised Editorial - no technical change A. Cockman Application This procedure is used to determine the stiffness of textile fabrics. The stiffness is expressed as the bending modulus and is calculated from the dimensions of the spe
2、cimen and the degree to which it bends under its own weight. Apparatus Required Stiffness Tester Shirley Stiffness Tester Variable Angle Model: Source: Thwing-Albert Instrument Co. Pennsylvania Street one with the face side up and the other with the face side down as follows: (a) With the platform i
3、n a horizontal position, place the test specimen on it and in the grip. Adjust the specimen to the length (L) of overhang in centimetres to give a deflection of approximately 20 - 40 angular degrees. Page 2 of 6 Copynght02001, Ford Global Technologies, Inc FORD LABORATORY TEST METHOD BN 120-01 (b) D
4、epress the platform until the specimen hangs freely. (c) After 6 - 8 seconds, raise the platform so the upper edges of the reference lines are brought into line with the end of the specimen and read the deflection angle. Note: If the end of the test specimen twists, the reference lines are aligned w
5、ith its midpoint. (d) Repeat the test on the other side and on both sides of the opposite end of the test specimen. 2. Report the average of eight readings on the two warp specimens as the angle of deflection. Do the same for the fill specimen. 3. Calculate the bending modulus, using the formula in
6、para C. B. Fixed Angle Method 1. Place the instrument on a level table with the mirror towards the observer (a) The specimen is placed lengthwise on the platform with one end coincident with the front upper edge of the platform. (b) Place the slide, rubber surface down, on the specimen so that the z
7、ero of the scale is in line with the Datum Line D. (c) Push the slide forward, carrying the specimen with it, until by looking in the mirror it is seen that the end edge of the specimen is in line with the two scribed lines 1 and 2. Note: To do this it is necessary to adopt a viewing position so tha
8、t the reflections of lines 1 and 2 coincide. If the specimen twists the mid-point of the end, it is aligned with lines 1 and 2. (d) After 6 - 8 seconds, realign the end of the specimen with the scribed lines and read the bending length from the scale. (e) Repeat the test on the other side and on bot
9、h sides of the opposite end of the test specimen. 2. Since the scale is calibrated directly in bending length (C) in centimetres, the mean of the eight readings (two specimens) gives the bending length of the specimens. Page 3 of 6 Copynght02001, Ford Global Technologies, Inc FORD LABORATORY TEST ME
10、THOD BN 120-01 3. After obtaining the bending length of the specimens in both the warp and fill directions, the bending modulus can be calculated from the formula shown below. C. Calculations B = 73.13 (W) (Cj3 Kg/cm2 Where: W = weight of specimen in gm/m2. g = thickness of specimen in mils. C = ben
11、ding length in cm. Note: For the variable angle method calculate bending length as follows: C = L xf (A) cm Where: L = length of overhang in cm. A = angle of deflection in degrees. f(A) = see attached table Chemicals, materials, parts, and equipment referenced in this document must be used and handl
12、ed properly. Each party is responsible for determining proper use and handling in its facilities. Page 4 of 6 Copynght02001, Ford Global Technologies, Inc FORD LABORATORY TEST METHOD BN 120-01 STIFFNESS OF FABRICS Table of f(A) Angle A Dearees O 1 2 3 4 5 6 7 8 9 Function of A O 1.926 1.529 1.335 1.
13、213 1.125 1.059 1.004 0.960 0.923 10 ,889 ,861 ,835 ,811 ,791 ,771 ,754 ,737 ,722 ,707 20 ,694 ,681 ,669 ,657 ,646 ,635 ,625 ,615 ,606 ,597 30 ,588 ,579 ,571 ,563 ,555 ,547 ,539 ,532 ,525 ,517 40 .51 O ,503 ,497 ,490 ,483 ,476 ,469 ,463 ,456 ,449 50 ,443 ,436 ,430 ,424 ,418 ,412 Page 5 of 6 Copynght02001, Ford Global Technologies, Inc FORD LABORATORY TEST METHOD BN 120-01 STIFFNESS OF FABRICS - LINE 2 FIXED ANGLE SHIRLEY STIFFNESS TESTER Page 6 of 6 Copynght02001, Ford Global Technologies, Inc
