This standard is issued under the fixed designation D ; the number 1 This test method is under the jurisdiction of ASTM Committee D on Textiles. Jan 1, Buy ASTM D R TEST METHOD FOR TEARING STRENGTH OF FABRICS BY FALLING-PENDULUM (ELMENDORF-TYPE). The ASTM D Elmendorf based tear test is the most popular test for measuring the tearing strength of most fabrics. The Elmendorf test testing machine uses.
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ASTM D seam str A number in parentheses indicates the year of last reapproval. This standard has been approved for use by agencies of the Department of Defense. The fabrics may be untreated, heavily sized, coated, resin-treated, or otherwise treated. Instructions are provided for testing specimens satm, or without, wetting. It is not suited for the course direction of warp knit fabrics or either direction of most other knitted fabrics.
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. Summary of Test Method 4. The resistance to tearing is in dd1424 factored into the scale reading of the instrument and is computed from this reading and the pendulum capacity. Comparative tests as directed in 5. The last approved version of this historical standard is referenced on www.
Current edition approved Jan. Originally approved in Discontinued January and reinstated as D — Last previous edition approved in as D —07a. Statistical assistance is recommended for the investigation of bias.
As a minimum, the two parties should take a group of test specimens that are as homogeneous as possible and that are from a lot of fabric of the type in question. The test specimens should then be randomly assigned in equal numbers d14224 each laboratory for testing. The average results from the two laboratories should be compared using appropriate statistical analysis and an acceptable probability level chosen by the two parties before the testing began.
If a bias astmm found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results with consideration to the known bias.
ASTM D Tearing Strength of Fabrics by Falling-Pendulum (Elmendorf-Type) Apparatus_百度文库
See Test Methods D and D The distance between the axis and the top edges of the clamping jaws is 0. The clamping surface in each jaw is at least 25 mm 1. Preferably the clamps may be air actuated, but manual clamping is permitted. Typical full scale ranges are shown in Table A3. Either die provides the basic rectangular test specimen 6 2 mm 4 6 0. The critical dimension of the test specimen is the distance These dies can be made to order by most die manufacturers.
Sampling and Test Specimens 7. Consider the rolls or pieces of fabric to be the primary sampling units. In the absence of such an agreement, take the number of fabric rolls or pieces speci?
NOTE 2—An adequate speci? Apparatus is commercially available. For rolls of fabric, take a sample that will exclude fabric from the outer wrap of the roll or the inner wrap around the core of the roll of fabric.
Take the specimens to be used for the measurement of the cross-machine with the longer dimension parallel to the cross-machine direction. Use the cutting die described in 6. When specimens are to be tested wet, cut from areas adjacent to the dry test specimens. Label to maintain specimen identity. This precaution is most important when testing bowed fabrics. Ensure specimens are free of folds, creases, or wrinkles. Avoid getting oil, water, grease, etc.
NOTE 3—The reading obtained is directly proportional to the length of the material torn, therefore, it is essential that the specimen be prepared to the exact size speci?
For most fabrics this time period will be about 1 h. For fabrics not readily wet out with water, such as those treated with waterrepellent, or water resistant materials, add a 0. Close the clamps, securing the specimen with approximately the same tension on both clamps.
The specimen should lie free with its upper area directed toward the pendulum to ensure a shearing action. Preparation of Apparatus and Calibration 8. Ensure the clamps are spaced as directed in A1. Using care zstm without touching the sensor, vacuum away any loose?
ASTM D Tearing Strength of Fabrics by Falling-Pendulum Type (Elmendorf) Apparatus
D — 09 Ensure that the balance of the fabric remaining to be torn is 43 6 0. Perform the test within 2 min after removal of the specimen from the water. Otherwise, discard the specimen and replace with another one. Catch the pendulum just after the threshold of its backward swing and return to its locked starting position. When equipped, be careful not to disturb the position of the pointer.
Record the scale reading required to completely tear the test specimen. In the absence of other criteria, such as in a material speci? Note when puckering occurs during the test. Otherwise, aatm some test instruments manual calculation of the average is required. Ft 5 Rs 3 2 where: Record values as read from the direct reading scale to the nearest mN gf. In any event, it is recommended that computer-processed data be veri?
Describe the fabric or product sampled and the method of sampling used. NOTE 6—Some instruments may require different calculations than percentage of scale. Precision and Bias The square roots of the components of variance are being reported c1424 express the variability in the appropriate units of measure rather than as the squares of those units of measure.
Larger differences are likely x1424 occur under all e1424 circumstances. Two operators astmm each laboratory each tested eight specimens of each fabric using Test Method D Four of the eight specimens were tested on one day and four specimens were tested on a second day. Analysis of the data c1424 conducted using the Practice D and Practice D The components of variance for Elmendorf tear strength expressed as standard deviations were calculated to be the values listed in Table 3.
The three woven fabric types were: Analysis of the data was conducted using Practice D and Practice D There were sufficient differences related to the fabric type and structure to warrant listing the components of variance and the critical differences separately.
Consequently no multi-fabric comparisons were made. NOTE 7—The tabulated values of the critical differences should be considered to be a general statement, particularly with respect to betweenlaboratory precision. Before a meaningful statement can be made about two speci? Within this limitation, Test Method D has no known bias. Ensure that there is no perceptible movement of the tester base or bench during the swing of the pendulum.
ASTM D1424 Tearing Strength of Fabrics by Falling-Pendulum Type (Elmendorf) Apparatus
Movement of the instrument during the swinging of the pendulum is a signi? Verify this by holding down the pendulum stop and allowing the pendulum to swing free. When the pendulum ashm to rest, the positioning line at the center of the pendulum should be directly above the edge of the pendulum stop. Align, if necessary, by turning the leveling thumb screw at the left end of the astk base.
Visually check the alignment of the clamps. Loosen the shoulder head screw on top of the pendulum support. With both clamps in the open position, gently pull the pendulum out until the jaw e1424 gage will?
Gently push the pendulum in until the jaw spacer gage has just enough clearance to slide out the top of the clamps.
With the jaw spacer in place, tighten the shoulder head screw on the pendulum support. Remove the jaw spacer gage. If the knife is dull it will d144 a V-notch near the top of the cut and push the material outward.
When the knife is determined to be dull, sharpen it with a rough stone, alternately, continuing specimen knife cuts, until no V-notch is observed. Replace the knife blade if necessary. If the knife cannot be positioned centrally, replace one or any combination of: Place the gage in the stationary specimen clamp in the usual manner for testing fabric.
Ensure the gage is positioned with the wide dimension upwards and the projection extending over the edge of the stationary clamp far enough such that the knife can be adjusted 6 to the bottom edge of the gage. Adjust the knife position such that the highest point of the blade just touches the bottom edge of the gage and then secure it in place. Replace the knife when it no longer can be adjusted to the gage, or optionally.
Apply a small amount of graphite from an ordinary lead pencil to the cutting knife or the edge of the d4124 used for cutting the slit so that when the cut is made some of the graphite transfers to the paper; this serves to contrast the cut from the uncut portion of the paper and facilitates the measurement.
Make this measurement either with a precision steel rule graduated in 0.