The FrazierTM Schiefer Abrasion Testing Instrument - Overview

 

Unifrom Abrasion Tester with 1,2,3,6,7

 

Abrasion Tester w/ Accessories 1, 2, 3, 6, and 7 for testing tension suspended specimens, such as woven and knitted fabrics and thin flexible materials.

 

THE Frazier Schiefer Abrasion Testing Machine abrades a plane area of a specimen uniformly from every azimuthal direction. It is based upon a new kinematics principle worked out mathematically by Dr. Herbert F. Schiefer, well known physicist at the National Bureau of Standards, to obtain uniformity of wear, excluding any preferential direction (see schematic diagram below). The advantages and applications of this machine to research and testing are many, for the machine realizes perfectly determined constant testing conditions and will therefore lead to comparable results.

 

Abrasion Uniform Wear Diagram

Uniform Wear Diagram

 

Results obtained at the National Institute of Standards and Technology (NIST) (formerly The National Bureau of Standards) and in Industry have demonstrated conclusively that this machine produces amazingly uniform abrasion (see photograph below) as predicted by the mathematical theory of Dr. Schiefer.

Abrasion Uniform Wear Samples

Uniform Wear Samples

Applications

The Schiefer Abrasion Testing Machine has been found to have many applications in research and testing. It offers a new approach for measuring the resistance to abrasion, one of the most important factors that affect serviceability, of many organic and inorganic products, such as textiles, rubber, plastics, paper, leather, linoleum, ceramics, mastic tile, concrete, stone, wood, paints, and metals. The effects of chemical treatments on the resistance to abrasion of these materials can likewise be determined. Fabric series, which varied systematically in construction, fiber blend, and finishing treatment have been successfully evaluated for resistance to abrasion. Similarly, the efficacy of different detergents and washing methods have been successfully evaluated by using this machine to uniformly soil a given area of a fabric with a known amount of synthetic soil. The effect of the amount of plasticizer in plastics on the resistance to abrasion was measured quantitatively. The machine has been used successfully to grind disks of plastics plane and parallel to a precise predetermined thickness for high precision measurements of dielectric constant and power factor.

 

Abrasion Tester without Accessories

Abrasion Tester without accessories

     For maximum utility this machine has been provided with many interchangeable accessories. Different abradants can be used. The spring steel blade abradant has been found to remain remarkably constant. In over 8 million rotations it was found that the change in this abradant was less than 2 percent per million rotations. Clamps for holding specimens of different products are available. The specimen and specimen holders are readily removable and replaceable to permit quantitative measurements of the amount of abrasion at stated intervals during a test.  The rate of abrasion from beginning to termination of a test and a numerical abrasive index can be obtained from these measurements. The size of the specimen to be tested, the tension on the specimen, and the pressure between the specimen and abradant can be varied. A ball-bearing counterbalancing yoke has been provided so that tests can be made at extremely small loads. A sensitive micro-switch has been provided to AUTOMATICALLY stop the machine when a tension suspended specimen has been abraded to a destructive endpoint. Some of the interchangeable accessories are illustrated and described in the following pages. The basic Frazier Schiefer Abrasion Testing Machine, without accessories, is shown directly above. The photograph at the top of this document illustrates the basic machine equipped with the accessories 1, 2, 3, 6, and 7, for testing tension suspended specimens, such as woven and knitted fabrics and thin flexible materials.

 

Abrasion Tester with 1,3,7,14,15

 

Abrasion Tester w/ Accessories 1, 3, 7, 14, and 15 for testing stiff specimens, such as carpets, rugs, and thick felts.

 

The photograph shown directly above illustrates the basic machine equipped with the accessories 1, 3, 7, 14, and 15, for testing stiff specimens, such as carpets, rugs, and thick felts. The change in the thickness of the specimen is continuously indicated on the dial during the test. Three special abradants are shown below.

 

Abrasion Accessory #16 Abrasion Accessory #17 Abrasion Accessory #18Accessory #16, #17, and #18

 

Accessories

 

Abrasion Accessory #2 to #7     Abrasion Accessory #8 to #15

Accessories # 2 to #15

 

1. Basic Schiefer Abrasion Testing Machine, including motor, cam for lifting abradant, cam for lifting specimen clamp assembly, resettable counter, ball-bearing counterbalancing yoke and counterweight, and sensitive micro-switch to automatically stop the machine when a tension suspended specimen has been abraded to a destructive endpoint.

2.  Clamp for woven fabrics, including constant tensioning base and mounting template.

3.  Spring steel blade abradant.

4.  Clamp for abradants such as cloth, emery-paper, sandpaper, etc.

5.  Leather abradant for matting and crushing tests of pile fabrics, carpets, and rugs.

6.  Plastics presser feet; 1/2, 1, 1-1/4, 1-1/2, and 2 inches in diameter.

7.  Set of abradant weights; one 1-lb., two 2-lb., and one 5-lb.

8.  Clamp for solid cylinders, such as plastics; 1/4, 1/2, 3/4, and 1 inch in diameter.

9.  Tensioning base for use with clamps 10, 11, and 12 and tension weights 13.

10. Special fabric clamp for use with base 9 for testing over-edge seams, etc.

11. Light weight clamp for woven and knitted fabrics (Must be used with base 9).

12. Light weight clamp for heel and toe of socks and for wet abrasion tests of knitted and woven fabrics (Must be used with base 9).

13. Two 2-1/2 lb. tensioning weights for use with base 9.

14. Clamp for carpets, rugs, and thick felts.

15. Thickness indicator for specimens of carpets, rugs, and thick felts., etc.

16. Cross-cut spring steel blade abradant for plastics.

17. Cross-cut tungsten tool steel abradant for coated fabrics.

18.  Carboloy rod abradant for rubber.

19.  Jig for mounting carpet, rug, and thick felt specimens.

20.  Clamps for testing yarns, threads and cords.

21.  Adapter to permit the use of the abradants on the specimen shaft and presser feet on the abradant shaft.

22.  Clamp for holding block of wood specimen, sponge, etc.

23.  Clamp for holding cellulose sponge yarns, fabric edges, etc.

24.  Very light weight clamp for rubber. Change in weight of specimen can be accurately measured.

25.  Light weight clamp for furs, etc. Change in weight of specimen can be accurately measured.

26.  Clamp and jig for abrading 2-inch diameter plastics disk plane and parallel to a known thickness for very precise dielectric measurements.

27.  Clamp for enamel felt base floor coverings for detergency tests.

28. Plastic nylon brush, to fit in adapter 29, for detergency tests of enamel floor coverings.

29. Adapter for nylon abradant.

30. Clamp for frosted glass distributor of synthetic soil on fabric for detergency tests.

31. Clamp for holding fabric specimen to be uniformly soiled for detergency tests.

32. Capacitor as described in NBS Research Paper RP 1988, exclusive of capacitance bridge.

Arrangement is for detergency tests of printed felt base floor covering, using accessories 1, 7, 27, 28, and 29.

 

Arrangement for testing knitted fabrics, using accessories 1, 3, 6, 7, 9, and 11.

Arrangement for testing heels and toes of socks, using accessories 1, 3, 6, 7, 9, 12, and 13.

Arrangement for testing over-edge seams in lingerie, using accessories 1, 4, 6, 7, 9, and 10.  

Arrangement for testing yarns, sewing thread and cords, using accessories 1, 3, 7, and 20.

Arrangement for testing furs, pile fabrics, etc., using accessories 1, 3, 7, 15, and 25.  

Arrangement for testing tension suspended specimens, using accessories 1, 2, 3, 6, and 7 and showing the micro-switch which automatically stops the machine at the destructive endpoint.

 

Testing Procedures for Woven Textiles

In mounting a circular specimen of a woven or knitted textile, the lower half of the clamp assembly, accessory 2, is placed over the template with a plastic hub projecting a given distance, which is adjustable, through the center of the clamp. The circular specimen is placed over the hub and the annular conical ring is placed on top of the specimen, so that the recess cut in the rim of the ring registers with a square pin of the lower half of the clamp. The upper half of the clamp is then screwed to the lower half, thereby clamping the specimen evenly and securely without distortion. When the clamp is lifted from the template, the specimen is in the prescribed relaxed state. The two fold reason for mounting the specimen in this relaxed state is to obtain even circumferential tension on the specimen and to provide enough material so that the portion of the specimen that is in contact with the plastic presser foot projects sufficiently above the clamp for the abrasion test The clamp is placed in the machine on the conical seat and locked in place by a slight rotation. The lower cam is rotated, thereby lowering the clamp assembly and applying an even tension on the specimen to stretch it uniformly over the plastic presser foot. The upper cam is then rotated, thereby lowering the abradant on the specimen and applying a known pressure. The counter is set at zero and the machine is started. After a pre-assigned number of rotations of abrasion the machine is stopped, the abradant is raised by rotating the upper cam and the specimen is examined visually. For quantitative measurement and closer inspection of the amount of abrasion the lower cam is rotated to raise the clamp assembly and to remove the tension from the specimen. The clamp and specimen are removed for inspection and quantitative measurement without removing or disturbing the specimen in the clamp. The clamp and specimen are then replaced in the machine as described above and the test is continued on the same area of the specimen until the next quantitative measurement of the amount of abrasion. If desired, the test may be continued to the destructive end-point, at which instant' the clamp assembly drops on the lower cam which actuates the sensitive micro-switch to AUTOMATICALLY stop the machine. The testing procedure for the other accessories is similar with minor obvious departures depending upon the type of material being tested and the quantitative measurement of the amount of abrasion.

In making a test the pressure of the abradant on the specimen can be varied by increments of one pound by placing abradant weights, accessory 7, on the hub specifically mounted on the top of the abradant shaft for this purpose. The rate of abrasion, which increases with the downward pressure of the abradant, can be made such that the material being tested is worn to destruction in an appropriate time interval. Presser feet, accessory 6, of diameters up to two inches are available. The rate of abrasion can be greatly changed by using presser feet of different diameter. A small foot is used for testing the heel and toe portion of socks and hosiery.

The applications of the Frazier Schiefer Abrasion Testing Machine are many and limited only by the ingenuity of the technicians and researchers of progressive concerns and research organizations interested in evaluating the wear resistance of organic and inorganic materials.

The Schiefer Abrasion Testing Machine has received world-wide acclaim because of its great versatility and adaptability and because it is the only abrasion testing machine which is based upon a sound, logical, and mathematically correct theory to produce UNIFORM abrasive action from every azimuthal direction in each rotation of abrasion for every point of the abraded area.

 

References:         Schiefer, Herbert F., "Solution of Problem of Producing Uniform Abrasion and Its Application to the Test­ing of Textiles." Jour. of Research of the National Bureau of Standards, Vol.39, pp. 1-10, July 1947, Research Paper RP1807; Textile Research Jour., Vol. 17, pp.360-368, July 1947. "Uniform Abrasion in the Testing of Textiles." National Bureau of Standards Technical News Bulletin, Vol. 31, pp.70-71, June 1947 "Scheuerapparat System Schiefer." Textile-Praxis, Vol. 3, pp.227-228, August 1948; "Capacitance Method of Measuring Wear." National Bureau of Stand­ards Technical News Bulletin, Vol.33, pp. 60-62, May 1949; Schiefer, Herbert F., Crean, Lawrence E., and Krasny, John F., "Improved Single-Unit Schiefer Abrasion Testing Machine." Jour. of Research of the National Bureau of Standards, Vol.42, pp.481-497, May 1949, Research Paper RP1988; Textile Research Jour., Vol. 19, pp. 259-69, May 1949; ASTM Bulletin No. 159, pp. 73-78, July 1949; Baker, Edward B., "Variable Temperature Dielectric Cell of Wide Frequency Range for Solids and Liquids." The Review of Scientific Instruments, Vol.20, pp.716-723, Oct. 1949; Gagliardi, D. D., and Nuessle, A. C., "Modification of Fiber and Fabric Properties by Wrinkleproofing and Stabilizing Agents." American Dyestuff Reporter, Vol.39, page P19, Jan.1950; Schiefer, Herbert F., and Krasny, John F., "Note on the Disintegration of Wool in Abrasion Tests." Textile Research Jour., Vol. 19, pp.802-9, Dec. 1949; Jour. Research NB 5, Vol.44, pp.9-14, Jan.1950, Research Paper RP2054; Sanders, H. L., and Lambert, J. M., "An Approach to a More Realistic Cotton Detergency Test." In Press.