ASTM D1316-93(2001)

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
• ICS: 87.080 - Inks. Printing inks
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.56 - Printing Inks

Relations

• Replaces: ASTM D1316-93(1996) - Standard Test Method for Fineness of Grind of Printing Inks By the NPIRI Grindometer
• Effective Date: 15-Oct-1993
• Replaced By: ASTM D1316-06 - Standard Test Method for Fineness of Grind of Printing Inks By the NPIRI Grindometer
• Effective Date: 01-Mar-2006
• 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 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
• 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 D7188-05(2019) - Standard Terminology for Printing Inks, Materials, and Processes
• Effective Date: 15-Oct-1993

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D1316–93(Reapproved2001)
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 3.1.2 scratch—a depression at least 10 mm in length in the
surface of a grind gage drawdown. A scratch develops when a
1.1 This test method describes the procedure for determin-
particle (or agglomerate) is trapped between the blade and the
ing the fineness of grind of printing inks using a NPIRI
bottom of the path and is drawn along by the blade.
grindometer. It evaluates the size of the largest particles in a
3.1.3 speckle—protuberance of particles above the surface
finished dispersion but not average particle size or concentra-
of a grind gage drawdown. Speckles occur at gage depths
tion of sizes.
greater than those at which scratches occur and are caused by
1.2 This test method is applicable to any dispersion that is
oversize particles that are not hard enough or of the proper size
fine enough to fall within the 0–25 µm range of the specified
to produce scratches.
grindgage.Withaminorvariationinprocedure,itisapplicable
to both paste (nonvolatile) and liquid (volatile) inks.
4. Summary of Test Method
NOTE 1—The 0–25 µm gage specified in this test method is similar in
4.1 This test method utilizes a grind gage having two
principletothe0–100µmHegmangagedescribedinTestMethodD 1210.
precision machined grooves each 1 in. (25.4 mm) wide and
Sieve analysis for concentration of particles above 45 µm is covered in
with a 0–1 mil (0–25 µm) taper. The test specimen is drawn
Test Method D 2067.
down the paths slowly if a nonvolatile (paste) ink, briskly if a
1.3 This standard does not purport to address all of the
volatile(liquid)ink.Thedrawdownsareexaminedforthescale
safety concerns, if any, associated with its use. It is the
readings at which four and ten scratches appear and at which a
responsibility of the user of this standard to establish appro-
preponderance of speckles disappear. The mean of readings
priate safety and health practices and determine the applica-
from four paths constitutes a single determination.
bility of regulatory limitations prior to use.
5. Significance and Use
2. Referenced Documents
5.1 Oversize particles in a printing ink may damage a
2.1 ASTM Standards:
printing plate and adversely affect the appearance of printed
D 1210 TestMethodforFinenessofDispersionofPigment-
ink films. Fineness of grind measurements are useful for
Vehicle Systems by Hegman-Type Gage
deciding when to stop the dispersion process and for determin-
D 2067 Test Method for Coarse Particles in Printing Ink
ing if the test material meets specifications as agreed upon
Dispersions
between the supplier and the customer.
E 691 Practice for Conducting an Interlaboratory Study to
5.2 Speckle endpoints identify the size of the largest par-
Determine the Precision of a Test Method
ticles in a finished printing ink. They provide a better measure
of overall dispersion quality than do scratch endpoints but,
3. Terminology
while their single-operator precision is better, their between-
3.1 Definitions of Terms Specific to This Standard:
laboratory precision is far poorer.
3.1.1 fineness of grind—a measure of the size and preva-
5.3 Scratch endpoints indicate the size and relative number
lence of oversize particles in a printing ink dispersion.
of the coarsest hard particles in a finished printing ink. They
provide a measure of grittiness; the higher the 4-scratch
1 endpoint,thegrittiertheink;thesmallerthedifferencebetween
This test method is under the jurisdiction of ASTM Committee D01 on Paint
the 4- and 10-scratch endpoints, the larger the number of gritty
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.56 on Printing Inks.
particles in this range. Scratch endpoints may, however, miss
Current edition approved Oct. 15, 1993. Published December 1993. Originally
gritty particles that ride in the bank ahead of the scraper; for
issued as D 1316 – 54. Last previous edition D 1316 – 92.
2 this reason, they are not recommended for premixes or other
Annual Book of ASTM Standards, Vol 06.01.
Annual Book of ASTM Standards, Vol 06.02. dispersions containing a preponderance of gritty particles.
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D1316
6. Apparatus 8.2 Misuse—The grindometer is a precision instrument and
must be treated as such. Do not let any hard materials contact
6.1 NPIRI Grindometer, consisting of a block of hardened
5 6 the gage surface or scraper in any manner that might result in
steel 25.4 mm in thickness, 89 mm in width and 240 mm in
scarring or nicking. Avoid tapping or scratching with other
length.Thetopsurfaceoftheblockisprecisionmachinedsoas
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
TABLE 1 Relation Among Grind Gage Scales
condition.Astreak of ink or a heavier film of ink at the places
NOTE 1—gu—NPIRI grindometer unit.
corresponding to the shoulders of the grindometer is evidence
B
NPIRI Micrometer
Depth
of blade damage or excessive wear. Repeat the drawdown with
Hegman
A C
Scale, Scale,
D
Scale
the other edge of the blade.
mils µm
gu µm
8.3.2 Method 2(fromTestMethodD 1210)—Faceoneedge
00 0 0 8
of the scraper down across the bottom of the top surface of the
1 0.1 2.5
20.2 5 5
grindometer or other smooth level surface. Place a strong light
3 0.3 7.5
behind the scraper and examine the contact edge; any light
4 0.4 10 10
5 0.5 12.5 7 coming through shows that the blade edge has been damaged
6 0.6 15 15
and is not satisfactory for use. Wear and warpage can also be
7 0.7 17.5
detected by rocking the blade back and forth. Repeat the
8 0.8 20 20
procedure on the other edge of the blade.
9 0.9 22.5
10 1.0 25 25 6
8.4 Rusting—The grindometer is made of carbon steel and
15 1.5 38 50 5
is subject to rusting. Apply a coating of grease or other
20 2.0 50 4
rust-preventative and keep covered or encased when not in use.
25 2.5 63 75 3
30 3.0 75 2
NOTE 2—Caution: Do not use a gage or blade that exhibits damage or
35 3.5 88 100 1
wear (see 8.2-8.4). Replace or return to the manufacturer for recondition-
40 4.0
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