ASTM D2923-95

Standard Test Method for Rigidity of Polyolefin Film and Sheeting

SCOPE
1.1 This test method describes two procedures for measuring the rigidity of polyolefin film and sheeting.  
1.2 Procedure A prescribes a procedure using high-voltage static eliminators and the use of TFE-fluorocarbon -coated plates to overcome the spurious effects of static electricity and friction.  
1.3 Procedure B prescribes the use of a fine powder on uncoated plates to achieve a similar effect.  
Note 1—Although the two procedures are designed to achieve similar effect, they may not achieve the same results.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.5  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. /p>
Note 2—There is no similar or equivalent ISO standard.

General Information

• Status: Historical
• Publication Date: 09-Aug-2001
• ICS: 83.140.10 - Films and sheets
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.19 - Film, Sheeting, and Molded Products

Relations

• Replaced By: ASTM D2923-01 - Standard Test Method for Rigidity of Polyolefin Film and Sheeting
• Effective Date: 10-Aug-2001
• Referred By: ASTM D8065/D8065M-16 - Standard Classification System and Basis for Specification for Specifying Plastic Films
• Effective Date: 10-Aug-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 2923 – 95 An American National Standard
Standard Test Method for
Rigidity of Polyolefin Film and Sheeting
This standard is issued under the fixed designation D 2923; 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.
1. Scope horizontal platform upon which the sample rests. An indicating
microammeter, wired to the strain gage, is calibrated in grams
1.1 This test method describes two procedures for measur-
of load sensed by the strain gage. The rigidity is read directly
ing the rigidity of polyolefin film and sheeting.
from the meter and expressed as grams per centimetre of
1.2 Procedure A prescribes a procedure using high-voltage
sample width.
static eliminators and the use of TFE-fluorocarbon -coated
plates to overcome the spurious effects of static electricity and
5. Significance and Use
friction.
5.1 The rigidity of polyolefin web can affect its machinabil-
1.3 Procedure B prescribes the use of a fine powder on
ity, particularly on those packaging machines where a cut
uncoated plates to achieve a similar effect.
portion of a web is required to remain flat momentarily without
NOTE 1—Although the two procedures are designed to achieve similar
being supported on all sides.
effect, they may not achieve the same results.
5.2 Rigidity is not a simple property since it depends on two
1.4 The values stated in SI units are to be regarded as the
other properties of the sample: the thickness (gage), and the
standard. The values given in parentheses are for information
stiffness which is an inherent property of the material of which
only.
the film or sheet is made. The combined effect of these two
1.5 This standard does not purport to address all of the
factors is the rigidity that influences performance on converting
safety concerns, if any, associated with its use. It is the
machines.
responsibility of the user of this standard to establish appro-
6. Interferences
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. 6.1 Static electricity has considerable influence on the
measured rigidity. It contributes to poor precision and accu-
NOTE 2—There is no similar or equivalent ISO standard.
racy, frequently giving results biased toward the high side.
2. Referenced Documents 6.2 To a lesser extent, precision and accuracy is adversely
affected by frictional properties of the sample, particularly
2.1 ASTM Standards:
when the coefficient of friction is close to 1.
D 618 Practice for Conditioning Plastics and Electrical
3 6.3 The interference caused by the level of static electricity
Insulating Materials for Testing
and friction of the specimen is overcome in Procedure A by
D 1898 Practice for Sampling of Plastics
electrically destaticizing the sample and using TFE-
3. Terminology fluorocarbon-coated plates and in Procedure B by dusting the
platform with a fine powder at the start of the test.
3.1 Definitions:
3.1.1 rigidity—that combination of thickness and inherent
7. Apparatus
stiffness of a polyolefin film or sheet which resists flexure.
7.1 Procedure A:
4. Summary of Test Method 7.1.1 Handle-O-Meter, or equivalent, with TFE-
fluorocarbon-coated plates complete with calibrating and aug-
4.1 The resistance to flexure of the sample is measured by a
menting weights.
strain gage affixed to the end of a beam, the opposite end of
7.1.2 Cutting Board or Template suitable for preparing 203
which flexes the sample by forcing it into a groove or slot in a
by 203-mm (8.0 by 8.0-in.) specimens.
7.1.3 High-Voltage Static Eliminator— and Generator.
This test method is under the jurisdiction of ASTM Committee D-20 on Plastics
7.2 Procedure B:
and is the direct responsibility of Subcommittee D20.19 on Film and Sheeting.
7.2.1 Handle-O-Meter, or equivalent, complete with cali-
Current edition approved Oct. 10, 1995. Published December 1995. Originally
brating and augmenting weights.
published as D 2923 – 70. Last previous edition D 2923 – 94.
This edition includes the addition of Note 2 and Section 15, and a correction to
the equation in 12.1.
2 4
This test method is based on the use of Teflont, a registered trademark of E. I. The Handle-O-Meter and auxiliary equipment is available from Thwing-Albert
duPont de Nemours & Co. Instrument Co., Philadelphia, PA.
3 5
Annual Book of ASTM Standards, Vol 08.01. Simco Shockless Bars are suitable for this test method.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 2923
7.2.2 Cutting Board or Template suitable for preparing 203 11.1.7 Upon completion of the cycle, rotate the specimen
by 203-mm (8.0 by 8.0-in.) specimens. 90° and repeat 11.1.1 through 11.1.6 for measurement in the
7.2.3 Fine-Particle Silica, starch, or equivalent, having an transverse direction.
approximate nominal particle size of 50 μm or less.
11.1.8 Turn the specimen over so that the opposite side of
the film is being forced into the opening and repeat 11.1.1
8. Sampling
through 11.1.7.
8.1 The material shall be sampled in accordance with
11.1.9 Repeat 11.1.1 through 11.1.8 for the remaining speci-
Practice D 1898.
mens.
11.2 Method B:
9. Test Specimens
11.2.1 Place a light “dust” layer of powder on the Handle-
9.1 Using a cutting board or template, cut a minimum of
O-Meter platform.
three 203 by 203-mm (8.0 by 8.0-in.) test specimens with the
11.2.2 Follow 11.1.3 to 11.1.9.
edges parallel to the machine and transverse directions of the
film. Mark the specimens in the machine direction and trans-
12. Calculation
verse direction.
12.1 Calculate the average Handle-O-Meter rigidity in the
9.2 The specimens shall be conditioned in accordance with
machine direction and transverse direction for each side as
Procedure A of Practice D 618.
follows:
10. Calibration
R 5 r/n / W or R 5 r/n /W (1)
~ ! ~ !
MD TD
10.1 Calibrate the Handle-O-Meter in accordance with the
where:
instructions described in Appendix X1.
R = average machine direction rigidity for Side 1,
10.2 Calibrate other equipment in accordance with the MD1
g/cm,
manufacturer’s instructions.
R = average TD rigidity for Side 1, g/cm,
TD1
11. Procedure r = sum of meter readings for specimens tested, g,
n = number of specimens tested, and
11.1 Method A:
W = specimen width along the slot, cm.
11.1.1 Turn on the static eliminator.
12.1.1 If the R (or R ) for Side 1 is equal to R (or
11.1.2 Just before placing a test specimen on the instrument, MD TD MD
R ) for Side 2, the average of the two may be taken as the
TD
slowly draw the specimen several times over the bar of the
R (or R ) of the specimen. The two R ’s (or R ’s
...