ASTM D1316-93(1996)

Standard Test Method for Fineness of Grind of Printing Inks By the NPIRI Grindometer

SCOPE
1.1 This test method describes the procedure for determining the fineness of grind of printing inks using a NPIRI grindometer. It evaluates the size of the largest particles in a finished dispersion but not average particle size or concentration of sizes.
1.2 This test method is applicable to any dispersion that is fine enough to fall within the 0-25 μm range of the specified grind gage. With a minor variation in procedure, it is applicable to both paste (nonvolatile) and liquid (volatile) inks.
Note 1—The 0-25 μm gage specified in this test method is similar in principle to the 0-100 μm Hegman gage described in Test Method D 1210. Sieve analysis for concentration of particles above 45 μm is covered in Test Method D 2067.
1.3 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.

General Information

• Status: Historical
• Publication Date: 14-Oct-1993
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.56 - Printing Inks

Relations

• Replaced By: ASTM D1316-93(2001) - Standard Test Method for Fineness of Grind of Printing Inks By the NPIRI Grindometer
• Effective Date: 15-Oct-1993
• Referred By: ASTM D1210-05(2022) - Standard Test Method for Fineness of Dispersion of Pigment-Vehicle Systems by Hegman-Type Gage
• Effective Date: 15-Oct-1993
• Referred By: ASTM D7188-05(2019) - Standard Terminology for Printing Inks, Materials, and Processes
• Effective Date: 15-Oct-1993
• Referred By: ASTM D6336-11(2021) - Standard Practice for Evaluation of Flushing Vehicles for Pigment Wetting Using a Vacuum Modified Sigma Blade Mixer
• Effective Date: 15-Oct-1993
• Referred By: ASTM D6846-02(2020) - Standard Practice for Preparing Prints of Paste Printing Inks with a Printing Gage
• Effective Date: 15-Oct-1993
• Referred By: ASTM D2067-97(2020) - Standard Test Method for Coarse Particles in Printing Ink Dispersions
• Effective Date: 15-Oct-1993

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NOTICE: This standard has either been superseded and replaced by a new version or discontinued.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 1316 – 93 (Reapproved 1996)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Fineness of Grind of Printing Inks By the NPIRI
Grindometer
This standard is issued under the fixed designation D 1316; 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 bottom of the path and is drawn along by the blade.
3.1.3 speckle—protuberance of particles above the surface
1.1 This test method describes the procedure for determin-
of a grind gage drawdown. Speckles occur at gage depths
ing the fineness of grind of printing inks using a NPIRI
greater than those at which scratches occur and are caused by
grindometer. It evaluates the size of the largest particles in a
oversize particles that are not hard enough or of the proper size
finished dispersion but not average particle size or concentra-
to produce scratches.
tion of sizes.
1.2 This test method is applicable to any dispersion that is
4. Summary of Test Method
fine enough to fall within the 0–25 μm range of the specified
4.1 This test method utilizes a grind gage having two
grind gage. With a minor variation in procedure, it is applicable
precision machined grooves each 1 in. (25.4 mm) wide and
to both paste (nonvolatile) and liquid (volatile) inks.
with a 0–1 mil (0–25 μm) taper. The test specimen is drawn
NOTE 1—The 0–25 μm gage specified in this test method is similar in
down the paths slowly if a nonvolatile (paste) ink, briskly if a
principle to the 0–100 μm Hegman gage described in Test Method D 1210.
volatile (liquid) ink. The drawdowns are examined for the scale
Sieve analysis for concentration of particles above 45 μm is covered in
readings at which four and ten scratches appear and at which a
Test Method D 2067.
preponderance of speckles disappear. The mean of readings
1.3 This standard does not purport to address all of the
from four paths constitutes a single determination.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 5. Significance and Use
priate safety and health practices and determine the applica-
5.1 Oversize particles in a printing ink may damage a
bility of regulatory limitations prior to use.
printing plate and adversely affect the appearance of printed
ink films. Fineness of grind measurements are useful for
2. Referenced Documents
deciding when to stop the dispersion process and for determin-
2.1 ASTM Standards:
ing if the test material meets specifications as agreed upon
D 1210 Test Method for Fineness of Dispersion of Pigment-
between the supplier and the customer.
Vehicle Systems
5.2 Speckle endpoints identify the size of the largest par-
D 2067 Test Method for Coarse Particles in Printing Ink
ticles in a finished printing ink. They provide a better measure
Dispersions
of overall dispersion quality than do scratch endpoints but,
E 691 Practice for Conducting an Interlaboratory Study to
while their single-operator precision is better, their between-
Determine the Precision of a Test Method
laboratory precision is far poorer.
5.3 Scratch endpoints indicate the size and relative number
3. Terminology
of the coarsest hard particles in a finished printing ink. They
3.1 Definitions of Terms Specific to This Standard:
provide a measure of grittiness; the higher the 4-scratch
3.1.1 fineness of grind—a measure of the size and preva-
endpoint, the grittier the ink; the smaller the difference between
lence of oversize particles in a printing ink dispersion.
the 4- and 10-scratch endpoints, the larger the number of gritty
3.1.2 scratch—a depression at least 10 mm in length in the
particles in this range. Scratch endpoints may, however, miss
surface of a grind gage drawdown. A scratch develops when a
gritty particles that ride in the bank ahead of the scraper; for
particle (or agglomerate) is trapped between the blade and the
this reason, they are not recommended for premixes or other
dispersions containing a preponderance of gritty particles.
This test method is under the jurisdiction of ASTM Committee D-1 on Paint
6. Apparatus
and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.56 on Printing Inks.
6.1 NPIRI Grindometer, consisting of a block of hardened
Current edition approved Oct. 15, 1993. Published December 1993. Originally
issued as D 1316 – 54. Last previous edition D 1316 – 92.
2 5
Annual Book of ASTM Standards, Vol 06.01. The NPIRI Grindometer, developed by the National Printing Ink Research
Annual Book of ASTM Standards, Vol 06.02. Institute, may be obtained from the Precision Gage and Tool Co., 375 Gargrave Rd.,
Annual Book of ASTM Standards, Vol 14.02. Dayton, OH 45449.
D 1316
5 6
steel 25.4 mm in thickness, 89 mm in width and 240 mm in scarring or nicking. Avoid tapping or scratching with other
length. The top surface of the block is precision machined so as metal. Use only soft metal-free cloths for cleanup.
to contain two paths, each 25.4 mm in width, 165 mm in 8.3 Normal Wear—Under steady usage over an extended
length, and tapered uniformly in depth lengthwise from 25.4 period of time, both scraper and block will wear but localized
μm (1 mil) to zero depth. Depth markings are inscribed on the scraper wear is much more rapid than block wear. Periodically
shoulders at each 2.5 μm (0.1 mil) change in taper. Scale check the blade as follows:
inscriptions and the relationship among various scales are 8.3.1 Method 1—Place a small quantity of an ink across one
given in Table 1. end of a flat glass plate and make a drawdown. A uniform
drawdown indicates that the particular scraper edge is in good
condition. A streak of ink or a heavier film of ink at the places
TABLE 1 Relation Among Grind Gage Scales
corresponding to the shoulders of the grindometer is evidence
NOTE 1—gu—NPIRI grindometer unit.
of blade damage or excessive wear. Repeat the drawdown with
B
NPIRI Micrometer the other edge of the blade.
Depth
Hegman
A C
Scale, Scale,
D
Scale 8.3.2 Method 2 (from Test Method D 1210)—Face one edge
mils μm
gu μm
of the scraper down across the bottom of the top surface of the
00 0 0 8
grindometer or other smooth level surface. Place a strong light
1 0.1 2.5
behind the scraper and examine the contact edge; any light
2 0.2 5 5
3 0.3 7.5
coming through shows that the blade edge has been damaged
4 0.4 10 10
and is not satisfactory for use. Wear and warpage can also be
5 0.5 12.5 7
detected by rocking the blade back and forth. Repeat the
6 0.6 15 15
7 0.7 17.5
procedure on the other edge of the blade.
8 0.8 20 20
8.4 Rusting—The grindometer is made of carbon steel and
9 0.9 22.5
10 1.0 25 25 6 is subject to rusting. Apply a coating of grease or other
rust-preventative and keep covered or encased when not in use.
15 1.5 38 50 5
20 2.0 50 4
NOTE 2—Caution: Do not use a gage
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