ASTM D1894-00
(Test Method)Standard Test Method for Static and Kinetic Coefficients of Friction of Plastic Film and Sheeting
Standard Test Method for Static and Kinetic Coefficients of Friction of Plastic Film and Sheeting
SCOPE
1.1 This test method covers determination of the coefficients of starting and sliding friction of plastic film and sheeting when sliding over itself or other substances at specified test conditions. The procedure permits the use of a stationary sled with a moving plane, or a moving sled with a stationary plane. Both procedures yield the same coefficients of friction values for a given sample.
Note 1--For the frictional characteristics of plastic films partially wrapped around a cylinder, or capstan, see Test Method G143 under the jurisdiction of ASTM Subcommittee G02.50.
1.2 Test data obtained by this test method is relevant and appropriate for use in engineering design.
1.2.1 As an option to this test, coefficient of friction may be run at temperatures other than 23C by heating only the plane while the sled is at ambient temperature.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use. For a specific precautionary statement, see Note 7.
Note 2--This test method and ISO/DIS 8295-1994 are not technically equivalent.
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Designation: D 1894 – 00 An American National Standard
Standard Test Method for
Static and Kinetic Coefficients of Friction of Plastic Film and
Sheeting
This standard is issued under the fixed designation D 1894; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope * Determine the Precision of a Test Method
G 143 Test Method for Measurement of Web/Roller Fric-
1.1 This test method covers determination of the coefficients
tion Characteristics
of starting and sliding friction of plastic film and sheeting when
2.2 ISO/DIS Standard:
sliding over itself or other substances at specified test condi-
ISO/DIS 8295–1994
tions. The procedure permits the use of a stationary sled with
a moving plane, or a moving sled with a stationary plane. Both
3. Terminology
procedures yield the same coefficients of friction values for a
3.1 Definitions:
given sample.
3.1.1 friction, n—resistance to relative motion between two
NOTE 1—For the frictional characteristics of plastic films partially
bodies in contact.
wrapped around a cylinder, or capstan, see Test Method G 143 under the
3.1.1.1 coeffıcient of friction—the ratio of the force required
jurisdiction of ASTM Subcommittee G02.50.
to move one surface over another to the total force applied
1.2 Test data obtained by this test method is relevant and
normal to those surfaces.
appropriate for use in engineering design.
3.1.1.2 kinetic coeffıcient of friction—the ratio of the force
1.3 The values stated in SI units are to be regarded as the
required to move one surface over another to the total force
standard. The values given in parentheses are for information
applied normal to those surfaces, once that motion is in
only.
progress.
1.4 This standard does not purport to address all of the
3.1.1.3 static coeffıcient of friction—the ratio of the force
safety concerns, if any, associated with its use. It is the
required to move one surface over another to the total force
responsibility of the user of this standard to establish appro-
applied normal to those surfaces, at the instant motion starts.
priate safety and health practices and determine the applica-
D 996, D10
bility of regulatory limitations prior to use. For a specific
3.2 Definitions of Terms Specific to This Standard:
precautionary statement, see Note 6.
3.2.1 slip—in plastic films, lubricity of two surfaces sliding
in contact with each other.
NOTE 2—This test method and ISO/DIS 8295–1994 are not technically
equivalent.
4. Significance and Use
2. Referenced Documents
4.1 Measurements of frictional properties may be made on a
2.1 ASTM Standards: film or sheeting specimen when sliding over itself or over
another substance. The coefficients of friction are related to the
D 618 Practice for Conditioning Plastics and Electrical
Insulating Materials for Testing slip properties of plastic films that are of wide interest in
packaging applications. These methods yield empirical data for
D 883 Terminology Relating to Plastics
D 3574 Test Methods for Flexible Cellular Materials—Slab, control purposes in film production. Correlation of test results
with actual performance can usually be established.
Bonded, and Molded Urethane Foams
D 4000 Classification System for Specifying Plastic Mate- 4.2 Slip properties are generated by additives in some
plastic films, for example, polyethylene. These additives have
rials
E 691 Practice for Conducting an Interlaboratory Study to varying degrees of compatibility with the film matrix. Some of
them bloom, or exude to the surface, lubricating it and making
it more slippery. Because this blooming action may not always
This test method is under the jurisdiction of ASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.
Current edition approved July 10, 2000. Published October 2000. Originally Annual Book of ASTM Standards, Vol 14.02.
published as D 1894 – 61 T. Last previous edition D 1894 – 99. Annual Book of ASTM Standards, Vol 03.02.
2 6
Annual Book of ASTM Standards, Vol 08.01. Available from American National Standards Institute, 11 W. 42nd St., 13th
Annual Book of ASTM Standards, Vol 08.02. Floor, New York, NY 10036.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 1894
stick-slip behavior of the film.
be uniform on all areas of the film surface, values from these
tests may be limited in reproducibility. 9
5.2 Plane—A polished plastic, wood, or metal sheet, ap-
4.3 The frictional properties of plastic film and sheeting
proximately 150 by 300 by 1 mm (6 by 12 by 0.040 in.). A
may be dependent on the uniformity of the rate of motion
smooth, flat piece of glass may cover the upper surface of the
between the two surfaces. Care should be exercised to ensure
plane. This provides a smooth support for the specimen.
that the rate of motion of the equipment is as carefully
5.3 Scissors or Cutter, suitable for cutting specimens to the
controlled as possible.
desired dimensions.
4.4 Data obtained by these procedures may be extremely
5.4 Adhesive Tape, cellophane or pressure-sensitive.
sensitive to the age of the film or sheet and the condition of the
5.5 Adhesive Tape, double-faced.
surfaces. The blooming action of many slip additives is
5.6 Nylon Monofilament, having a 0.33 6 0.05-mm (0.013
time-dependent. For this reason, it is sometimes meaningless to
6 0.002-in.) diameter and capable of supporting a 3.6-kg (8-lb)
compare slip and friction properties of films or sheets produced
load.
at different times, unless it is desired to study this effect.
5.7 Beaded Chain, flexible metal cable, or equivalent,
4.5 Frictional and slip properties of plastic film and sheeting
having a spring rate no less than 600 lbs per inch of stretch per
are based on measurements of surface phenomena. Where
inch of length (40 lbs/in. (7000 N/m) for a 15-in. chain) in the
products have been made by different processes, or even on
range of 50 to 150 g of tension (such as beaded lampswitch pull
different machines by the same process, their surfaces may be
chain).
dependent on the equipment or its running conditions. Such
5.8 Low-Friction Pulleys—A phenolictype pulley mounted
factors must be weighed in evaluating data from these meth-
in hardened steel cone bearings on a metal fork. A ball-bearing
ods.
type pulley may also be used.
4.6 The measurement of the static coefficient of friction is
5.9 Force-Measuring Device, capable of measuring the
highly dependent on the rate of loading and on the amount of
frictional force to 65 % of its value. A spring gage (Note 3),
blocking occurring between the loaded sled and the platform
universal testing machine, or strain gage may be used.
due to variation in time before motion is initiated.
NOTE 4—The capacity of the spring gage (Fig. 1( a and b)) needed will
4.7 Care should be exercised to make certain that the speed
depend upon the range of values to be measured. For most plastic, a 500-g
of response of the recorder, either electronic or mechanical, is
capacity gage with 10-g or smaller subdivisions will be satisfactory. This
not exceeded.
spring will measure coefficients of friction up to and including 2.5.
4.8 For many materials, there may be a specification that
5.10 Supporting Base—A smooth wood or metal base
requires the use of this test method, but with some procedural
modifications that take precedence when adhering to the approximately 200 by 380 mm (8 by 15 in.) is necessary to
support the plane. The supporting base may be a simple
specification. Therefore, it is advisable to refer to that material
specification before using this test method. Table 1 of Classi- rectangular box. If a universal testing machine is used to pull
a moving plane, a supporting base of sufficient structural
fication System D 4000 lists the ASTM materials standards that
currently exist. strength and rigidity to maintain a firm position between the
moving crosshead and the force-measuring device will be
5. Apparatus
necessary.
5.1 Sled—A metal block 63.5 mm (2 ⁄2 in.) square by
5.11 Driving or Pulling Device for Sled or Plane—The
approximately 6 mm (0.25 in.) thick with a suitable eye screw
plane may be pulled by a driven pair of rubber-coated rolls not
fastened in one end. When a flexible film (see 6.2) is to be
less than 200 mm (8 in.) long, capable of maintaining a
attached, the block shall be wrapped with a sponge rubber 63.5
uniform surface speed 150 6 30 mm/min (0.5 6 0.1 ft/min)
1 1
mm (2 ⁄2in.) in width and 3.2 mm ( ⁄8in.) in thickness. The
(Fig. 1(b)), by the crosshead of a universal testing machine
foam shall be flexible, smooth-faced, and have a nominal
(Fig. 1(d)) (Note 6), or a worm drive driven with a synchronous
density of 0.25 g/cm when measured in accordance with the
motor (Fig. 1(e)). A constant-speed chain drive system has also
Density Test of Methods D 3574. The pressure required to
been found satisfactory (Fig. 1(a)). A power-operated source
compress the foam 25 % shall be 85 6 15 kPa (12.5 6 2.5 psi).
may be used for pulling the sled over the horizontally-mounted
The foam shall also have a high hysteresis when deformed.
specimen at a uniform speed of 150 6 30 mm/min (0.5 6 0.1
The rubber shall be wrapped snugly around the sled and held
ft/min). A universal testing machine equipped with a load cell
in place against the bottom and top of the sled with double-
in its upper crosshead and a constant rate-of-motion lower
faced masking tape. When a sheet (see 6.3) is to be attached,
crosshead has been found satisfactory (see Fig. 1(c)).
double-faced tape shall be used to attach the specimen. The
NOTE 5—Where the moving crosshead of a universal testing machine is
total weight of the (wrapped) sled and specimen shall be 200 6
used to pull the moving plane through a pulley system (Fig. 1(d)), the
5g.
strain gage load cell, or other load-sensing instrument in the testing
8 machine, acts as the force-measuring device.
NOTE 3—Round-robin testing has shown that the physical properties
of the backing can drastically affect both the coefficient of friction and
7 9
Sheet stock, available from Greene Rubber Co., 59 Broadway, North Haven, Acrylic or rigid poly(vinyl chloride) sheeting has been found satisfactory for
CT 06473, has been found satisfactory. this purpose.
8 10
Supporting data are available from ASTM Headquarters. Request RR: D20- Model L-500, available from Hunter Spring Co., Lansdale, PA, has been found
1065. satisfactory for this purpose.
D 1894
A. Sled H. Constant-speed drive rolls
B. Plane I. Nylon monofilament
C. Supporting base J. Low-friction pulley
D. Gage K. Worm screw
E. Spring gage L. Half nut
F. Constant-speed chain drive M. Hysteresis, synchronous motor
G. Constant-speed tensile tester crosshead
FIG. 1 Five Methods of Assembly of Apparatus for Determination of Coefficients of Friction of Plastic Film
either the machine or transverse direction of the sample, but it is more
6. Test Specimens
common practice to test the specimen as described in 6.1 with its long
6.1 The test specimen that is to be attached to the plane shall
dimension parallel to the machine direction.
be cut approximately 250 mm (10 in.) in the machine direction
NOTE 7—Caution: Extreme care must be taken in handling the speci-
and 130 mm (5 in.) in the transverse direction when such
mens. The test surface must be kept free of all dust, lint, finger prints, or
extrusion directions exist and are identifiable. any foreign matter that might change the surface characteristics of the
specimens.
6.2 A film specimen that is to be attached to the sled shall be
cut approximately 120 mm (4 ⁄2in.) square. Film is defined as
7. Preparation of Apparatus
sheeting having a nominal thickness of not greater than 0.254
7.1 Fig. 1 shows five ways in which the apparatus may be
mm as indicated in Terminology D 883.
assembled. The support bases for all apparatus assemblies shall
6.3 A sheeting specimen (greater than 0.254 mm nominal
be level.
thickness) or another substance that is to be attached to the sled
1 7.2 If the apparatus of Fig. 1(a)or(b) is used, calibrate the
shall be cut 63.5 mm (2 ⁄2 in.) square.
scale of the spring gage as follows:
6.4 Sheeting specimens shall be flat and free of warpage.
7.2.1 Mount the low-friction pulley in front of the spring
Edges of specimens shall be rounded smooth.
gage.
6.5 Five specimens shall be tested for each sample unless
7.2.2 Fasten one end of the nylon filament to the spring
otherwise specified.
gage, bring the filament over the pulley, and suspend a known
NOTE 6—Plastic films and sheeting may exhibit different frictional
weight on the lower end of the filament to act downward.
properties in their respective principal directions due to anisotropy or
extrusion effects. Specimens may be tested with their long dimension in NOTE 8—The reading on the scale shall correspond to the known
D 1894
weight within6 5 %. The weight used for this calibration shall be between movements in the machine direction of the specimens.
50 and 75 % of the scale range on the gage.
9.2 For film specimens, tape the edges of the 120-mm
7.3 The drive speed for the apparatus of Fig. 1(a and b) shall 1
(4 ⁄2-in.) square film specimen to the back of the sled, using
be adjusted to 150 6 30 mm/min (0.5 6 0.1 ft/min). This speed
adhesive tape and pulling the specimen tight to eliminate
may be checked by marking off a 150-mm (0.5-ft) section
wrinkles without stretching it. For sheet specimens, tape the
beside the plane and determining the time required for the 1
63.5-mm (2 ⁄2-in.) square sheet specimen or second substrate to
plane to travel 150 mm (0.5 ft).
the sled face with double faced tape. Keep the machine
7.4 If the apparatus of Fig. 1(c and d) employing a universal
direction of the specimen parallel to the length of the sled
testing machine is used, select the proper speed setting for a
(where such a direction exists and is identifiable).
crosshead motion of 150 6 30 mm/min (0.5 6 0.1 ft/min). A
9.3 Attach the specimen-covered sled through its eye screw
similar speed for the load-displacement recorder is desirable.
to the nylon filament. If a universal testing machine is used
However, the speed of the recorder can be adjusted to give the
(Fig. 1(c and d)), pass the filament through pulley(s) and
desired ac
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