ASTM D3376-18

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it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3376 − 14 D3376 − 18
Standard Test Methods of
Sampling and Testing Pulps to be Used in the Manufacture
of Electrical Insulation
This standard is issued under the fixed designation D3376; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 These test methods cover the sampling and testing of cellulosic pulps for use in the manufacture of electrical insulating
papers and boards or in the direct application of pulp fibers as insulation to electrical conductors.
NOTE 1—The Consider the significance of any one pulp property test method, as set forth herein, should be considered with discretion depending on
the product made from the pulp.
1.2 Sections on Reagents, Sampling, and Report are integral parts of each of the individual test methods that follow.
1.3 Each test method is described as being a measure of either a bulk property of the pulp or a property of a handsheet formed
from the pulp.
1.3.1 Bulk characteristics determinable by these procedures appear in the following sections:
ASTM TAPPI
Method Method
Procedure Sections Reference Reference
Aqueous Extract Conductivity 8 and 9 D202 .
Aqueous Extract pH 10 and 11 D202 .
Aqueous Extractable 12 and 13 D202 .
Acidity-Alkalinity
Analysis of Ash for Cations by 70 – 78 D1193 and D2576 .
Atomic Absorption Spectro-
photometry
Ash Content 79 – 82 D202 T 413
Dirt in Pulp 40 and 41 . T 213
Fiber Analysis 23 and 24 D202 and D1030 .
Fiber Length of Pulp 42 and 43 . T 232, T 233
Freeness (Canadian Standard 53 and 54 . T 227
Freeness)
Kappa Number/Permanganate 27 and 28 . T 236, UM 251
Number (Substances
Oxidizable by Permanga-
nate)
Laboratory Processing of Pulp 51 and 52 . T 200
(Beater Method)
Moisture in Pulp 31 – 33 . T 210
Neutral Aqueous Extractable 16 – 22 D202, D1126, and .
Hardness in Pulp D2576
Pentosan Content of Pulp 29 and 30 . T 223
Resistance of Pulp to 44 – 50 . T 239, UM 252
Disintegration (Standard
RPG)
Shive Count 34 – 39 . .
Solvent-Soluble Matter in Pulp 25 and 26 D202 .
Tensile Properties 65 – 69 D202 .
Water-Extractable Chlorides 14 and 15 D202 .
ASTM TAPPI
Method Method
Procedure Sections Reference Reference
Aqueous Extract Conductivity 8 & 9 D202 . . .
These test methods are under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and are the direct responsibility of Subcommittee
D09.01 on Electrical Insulating Products.
Current edition approved Nov. 1, 2014Nov. 1, 2018. Published November 2014November 2018. Originally approved in 1975. Last previous edition approved in 20092014
as D3376 – 88 (2009).D3376 – 14. DOI: 10.1520/D3376–14.10.1520/D3376-18.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3376 − 18
ASTM TAPPI
Method Method
Procedure Sections Reference Reference
Aqueous Extract pH 10 & 11 D202 . . .
Aqueous Extractable Acidity- 12 & 13 D202 . . .
Alkalinity
Analysis of Ash for Cations by 70 – 78 D1193 & . . .
Atomic Absorption Spectrophotometry D2576
Ash Content 79 – 82 D202 T 413
Dirt in Pulp 40 & 41 . . . T 213
Fiber Analysis 23 & 24 D202 & D1030 . . .
Fiber Length of Pulp 42 & 43 . . . T 232, T 233
Freeness (Canadian Standard 53 & 54 . . . T 227
Freeness)
Kappa Number/Permanganate 27 & 28 . . . T 236, UM 251
Number (Substances Oxidizable
by Permanganate)
Laboratory Processing of Pulp 51 & 52 . . . T 200
(Beater Method)
Moisture in Pulp 31 – 33 . . . T 210
Neutral Aqueous Extractable Hard- 16 – 22 D202, D1126, . . .
ness in Pulp & D2576
Pentosan Content of Pulp 29 & 30 . . . T 223
Resistance of Pulp to Disintegration 44 – 50 . . . T 239, UM 252
(Standard RPG)
Shive Count 34 – 39 . . . . . .
Solvent-Soluble Matter in Pulp 25 & 26 D202 . . .
Tensile Properties 65 – 69 D202 . . .
Water-Extractable Chlorides 14 & 15 D202 . . .
1.3.2 Handsheet characteristics determinable by these procedures appear in the following sections:
ASTM TAPPI
Method Method
Procedure Section Reference Reference
Air Resistance (Porosity) 57 and 58 D202 T 205
Apparent Density 63 and 64 D202 T 205
Bursting Strength 59 and 60 D202 and D774/ T 205
D774M
Folding Endurance (M.I.T.) 51 and 52 D202 and D2176 T 205
Forming Handsheets for 55 and 56 . T 205
Physical Tests of Pulp
Tensile Strength 65 and 66 D202 and D828 T 205
ASTM TAPPI
Method Method
Procedure Sections Reference Reference
Air Resistance (Porosity) 57 & 58 D202 T 205
Apparent Density 63 & 64 D202 T 205
Bursting Strength 59 & 60 D202 & D774/ T 205
D774M
Folding Endurance (M.I.T.) 51 & 52 D202 & D2176 T 205
Forming Handsheets for Physical 55 & 56 . . . T 205
Tests of Pulp
Tensile Strength 65 & 66 D202 & D828 T 205
NOTE 2—Methods for Ash, Silica, selected cations from Ash, Heat Stability, α, β, and γ Cellulose, Viscosity, Total Chlorine, Tear, and Dissipation Factor
and Relative Permittivity, will be considered for addition as methods are developed.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
D3376 − 18
2. Referenced Documents
2.1 ASTM Standards:
D202 Test Methods for Sampling and Testing Untreated Paper Used for Electrical Insulation
D774/D774M Test Method for Bursting Strength of Paper (Withdrawn 2010)
D828 Test Method for Tensile Properties of Paper and Paperboard Using Constant-Rate-of-Elongation Apparatus
D1030 Test Method for Fiber Analysis of Paper and Paperboard
D1126 Test Method for Hardness in Water
D1193 Specification for Reagent Water
D1711 Terminology Relating to Electrical Insulation
D2176 Test Method for Folding Endurance of Paper and Plastics Film by the M.I.T. Tester
D2576 Method of Test for Metals in Water and Waste Water by Atomic Absorption Spectrophotometry (Withdrawn 1979)
D3376 Test Methods of Sampling and Testing Pulps to be Used in the Manufacture of Electrical Insulation
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
2.2 TAPPI Standards:
T 200 Laboratory Processing of Pulp (Beater Method)
T 205 Forming Handsheets for Physical Tests of Pulp
T 210 Weighing, Sampling, and Testing Pulp for Moisture
T 213 Dirt in Pulp
T 221 Drainage Time of Pulp
T 223 Pentosans in Wood and Pulp
T 227 Freeness of Pulp
T 232 Fiber Length of Pulp by Projection
T 233 Fiber Length of Pulp by Classification
T 236 Kappa Number of Pulp
T 413 Ash in Paper and Paperboard
T 445 Identification of Specks and Spots in Paper
T 1002 Drainage Time for Insulating Board
UM 203 Freeness of Pulp (William Tester)
UM 251 Permanganate Number of Pulp
UM 252 Resistance of Pulp and Paper Stock to Disintegration
3. Terminology
3.1 Definitions—For definitions of terms used in these test methods and associated with electrical and electronic insulating
materials use Terminology D1711.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 aqueous extractable hardness, n—the amount of calcium and magnesium present in pulp and which may be is extracted
by hot neutral water under prescribed conditions.
3.2.2 hardness, n—a characteristic of water that represents the total concentration of calcium and magnesium in the water,
expressed as parts per million (ppm) CaCO .
3.2.3 pulp, n—a fibrous material that is made by chemical or mechanical treatment, or both, of wood, cotton, hemp, or other
cellulosic fiber to achieve substantially separate fibers that are suitable for a sheet-forming process.
NOTE 3—Electrical insulation made from pulp may be are papers or boards used for capacitors, transformer coils, creped papers, and so forth. It may
also be pulp Pulp is also applied directly onto electrical conductors.
3.2.4 resistance to disintegration, n—the amount of work (expressed as revolutions per gram of pulp) required under standard
conditions to bring a sample of pulp to a state of complete dispersion of single fibers.
3.2.5 shive, n—a particle in pulp or paper that is a bundle of cellulosic fibers bonded together in a parallel arrangement.
NOTE 4—Dark single fibers are not to be counted as shives. Count only bundles of fibers regardless of color.
3.2.6 shive count, n—the quantitative expression of the concentration of shives in a quantity of pulp or paper.
3.2.6.1 Discussion—
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Available from Technical Association of the Pulp and Paper Industry (TAPPI), 15 Technology Parkway South, Norcross, GA 30092, http://www.tappi.org.
D3376 − 18
For this method the shive count is restricted to the number of shives that exceed 1.5 mm in length that are present after a specified
processing of the pulp to form handsheets for evaluation.
4. Summary of Test Methods
4.1 These test methods describe the specific procedures for testing the properties of pulp, both in its original bulk form and after
it has been formed into a handsheet in the testing laboratory.
5. Reagents
5.1 Purity of Reagents—Use reagent grade chemicals in all tests. Unless otherwise indicated, it is intended that all reagents shall
conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such
specifications are available. It is acceptable to use other grades, provided it is first ascertained that the reagent is of sufficiently
high purity to permit its use without lessening the accuracy of the determination.
5.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean water conforming to
Specification D1193, Type III.
6. Sampling
6.1 Terminology regarding sampling and evaluation terminology shall conform to those in the sampling sections of Test
Methods D202.
6.2 Obtain the sample of pulp from the lot to be evaluated in a manner that will maximize the probability that a representative
sample is collected. Where practicable, use one of the sampling plans shown in Test Methods D202. Protect the material sample
from contamination during handling and transporting to a laboratory for testing. The instructions for preparation of specimens are
given in the sections pertaining to the individual property tests. Take the sample for moisture content in accordance with TAPPI
T 210.
6.3 Condition samples in a container suitable for preventing moisture variation over the period of testing. When test specimens
are drawn, determine the moisture content of the material to allow correction of weights to moisture-free equivalent weight.
7. Report
7.1 At the completion of any or all of the following tests, report the test results (as defined in 6.1) of the pulp properties with
identifying units as follows:
7.1.1 Identification of the pulp sampled and tested by lot number, type, grade, and so forth,
7.1.2 Dates of testing,
7.1.3 Location of the testing laboratory and the person responsible for the testing,
7.1.4 Remarks indicating method or procedures used and the deviation, if any, from the standard test procedures,
7.1.5 Indication of the variance in test measurements (as defined in 6.1) such as high, low, standard deviation, and so forth, and
7.1.6 Any information particular to the cited procedure.
7.2 Report the test results (as defined in 6.1) as calculated or observed values rounded to the nearest unit in the last right-hand
place of figures used in the material specification to express the limiting value. (See the rounding method of Practice E29.)
AQUEOUS EXTRACT CONDUCTIVITY
8. Significance and Use
8.1 The conductivity of the water extract of electrical grade pulp results from electrolytic impurities in the pulp potentially
present as ionizable acids, bases, salts, or a combination of these. The presence of electrolytic impurities in electrical insulation
is undesirable as they tend to lower insulation resistance and have corrosion-producing tendencies under conditions of applied
potential. When comparing test data, note that the extract conductivity of pulps, especially those of high purity, changes with time
after manufacturing in some instances. This test is useful for routine acceptance testing, the comparison of different pulps, and
research work.
9. Procedure
9.1 Follow Test Methods D202 except use a specimen weight equivalent to 1 g of moisture-free pulp.
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by
the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville, MD.
For more detailed information see Paper and Paperboard—Characteristics,Nomenclature, and Significance of Tests, ASTM STP 60 B, Am. Soc. Testing Mats., 1963, pp.
59–61.
D3376 − 18
AQUEOUS EXTRACT pH
10. Significance and Use
10.1 The extract pH determination measures the degree to which a pulp alters the hydrogen-hydroxyl equilibrium of pure water.
The test gives a measure of the active acidity or alkalinity of the pulp extract. It is possible that the presence of active acidic or
alkaline contaminants in a pulp will result in their being incorporated into the electrical insulation made from the pulp, and canwill
lead to a deterioration of the insulation in service. This test is useful for routine acceptance testing, the comparison of different
pulps, and research work.
11. Procedure
11.1 Follow Test Methods D202, except use a specimen weight equivalent to 1 g of moisture-free pulp.
AQUEOUS EXTRACTABLE ACIDITY-ALKALINITY
12. Significance and Use
12.1 The extract acidity-alkalinity determination for a pulp measures the quantity of extracted ionizable material, which alters
the hydrogen-hydroxyl equilibrium of pure water. It is possible that the presence of active acidic or alkaline contaminants in a pulp
will result in their being incorporated into the electrical insulation made from the pulp, and this canwill lead to a deterioration of
the insulation in service. This test is useful for routine acceptance testing, the comparison of different pulps, and research.
13. Procedure
13.1 Follow Test Methods D202, except use a specimen weight equivalent to 1 g of moisture-free pulp.
WATER-EXTRACTABLE CHLORIDES
14. Significance and Use
14.1 It is possible that the occurrence of significant amounts of chloride ion in a pulp will lead to the incorporation of the ion
in the electrical insulation made from the pulp. It is possible that the presence of chloride ions will adversely affect the electrical
properties and service life of the insulation. This test is useful for routine acceptance testing, the comparison of different pulps,
and research testing.
15. Procedure
15.1 Follow Test Methods D202, except use a specimen weight equivalent to 4 g of moisture-free pulp. For pulps with higher
levels of chloride (greater than 30 ppm), 10 min of masceration as in the above method for aqueous extract conductivity is an
acceptable way to hasten the extraction, followed by 1 h refluxing as in Test Methods D202. When the chloride content is less than
30 ppm, masceration is not permitted. The appropriate extraction time must be determined to give complete extraction of the
chloride for each pulp type. Times greater than 1 h will be necessary in some instances.
NEUTRAL AQUEOUS EXTRACTABLE HARDNESS PULP
16. Significance and Use
16.1 Cellulose pulps contain varying amounts of aqueous extractable hardness as supplied to the purchaser. It is possible that
the dissolved hardness from the pulp will accumulate in process water used in wet-forming methods and will interfere with the
action of process additives and affect product quality adversely.
16.2 Method A is the preferred method and shall be used for reference purposes.
METHOD A
17. Procedure
17.1 Extraction:
17.1.1 Prepare extracts of the pulp specimens in accordance with the Test Methods D202 method for aqueous extract
conductivity, except:
17.1.2 Use a specimen weight equivalent to 2.0 g of moisture-free pulp. Determine the moisture content of the pulp sample on
a separate specimen taken at the same time as the test specimen.
17.1.3 The extraction volume shall be 200 mL.
17.1.4 Run a blank determination concurrently with the test specimen determination.
17.1.5 Following extraction and filtration, collect the clear filtrate and adjust the volume to exactly 200 mL.
17.2 Determine the calcium and magnesium concentration of the extract in accordance with Test Method D2576.
D3376 − 18
18. Calculation
18.1 Calculate the hardness of the extracts as follows:
Hardness, ppm 5 100 2.497 P 2 P 14.117 P 2 P (1)
@ #
~ 1 a! ~ 2 b!
where:
P = ppm calcium in the pulp extract,
P = ppm calcium in the blank,
a
P = ppm magnesium in the pulp extract, and
P = ppm magnesium in the blank.
b
METHOD B
19. Procedure
19.1 Follow the procedure of Method A for the preparation of the extract.
19.2 Take two 100-mL aliquots of the extract and titrate for total hardness, following the “low total hardness” procedure of the
nonreferee volumetric method of Test Method D1126.
20. Calculation
20.1 Calculate the hardness of the specimen extract as follows:
Hardness, ppm 5 500 V 1V 2 V 2 V (2)
~ !
1 2 a b
where:
V = standard EDTA solution for titration of first aliquot of extract, mL,
V = standard EDTA solution for titration of second aliquot of extract, mL
V = standard EDTA solution for titration of second aliquot of extract, mL,
V = standard EDTA solution for titration of first blank aliquot, mL, and
a
V = standard EDTA solution for titration of second blank aliquot, mL.
b
21. Report
21.1 Report the results as neutral aqueous extractable hardness, ppm, expressed as calcium carbonate according to the
appropriate method of Test Methods D3376.
22. Precision and Bias
22.1 The precision of this test has not been determined. No statement can be made about the bias of this test since standard
material is not available.
FIBER ANALYSIS
23. Significance and Use
23.1 The fiber composition of a pulp (fiber source and pulping treatment) strongly affects the ultimate product characteristics.
Fiber analysis is useful both as a specification and as a control test, and is acceptable in referee testing or research.
NOTE 5—For accurate results the analyst shouldmust have considerable training and experience. The analyst should It is recommended the analyst make
frequent use of standard fiber sources of known composition, or of authentic fiber samples, and be thoroughly familiar with different fibers and their
behavior when treated with the various stains.
24. Procedure
24.1 Follow Test Methods D202 and D1030 using a specimen weight of 0.2 g of pulp drawn from a composite sample of pulp,
equivalent to 30 g of moisture-free pulp disintegrated in 2 L of water, as in Test Method D1030 and the section on fiber analysis
in Test Methods D202.
SOLVENT-SOLUBLE MATTER IN PULP
25. Significance and Use
25.1 Since pulping processes usually remove most water-soluble and volatile compounds that are also soluble in organic
solvents, consider the solvent extractives in pulp to consist primarily of resin and fatty acids, their esters, waxes, and unsaponifiable
substances. No single organic solvent is capable of removing all these substances, and different solvents remove different
combinations. The mixture of one part (by volume) of 95 % ethanol and two parts of benzene appears to provide the most complete
removal of all solvent-extractable substances in pulp.
D3376 − 18
25.2 Solvent-extractable materials, if present in sufficient quantity in electrical insulation, will lower the quality of the insulation
or have a deleterious effect on the liquid compounds used in contact with insulation in various types of apparatus. Ethanol-soluble
materials in capacitor paper have been found to increase the conductivity of chlorinated organic compounds, which are used as
impregnants in capacitors. A combination of ether and alcohol-benzene extractives is reported to represent the quantity of pitch
in wood pulp. Pitch in pulp will, in some instances, cause operating problems in the paper mill, such as the plugging of felts, wires,
and so forth.
25.3 This method, with solvent or solvents specified, is acceptable for routine acceptance testing, comparing different pulps, and
research tests.
26. Procedure
26.1 Test for solvent-soluble matter in accordance with Test Methods D202.
KAPPA NUMBER/PERMANGANATE NUMBER
(SUBSTANCES OXIDIZABLE BY PERMANGANATE)
27. Significance and Use
27.1 The permanganate consumption of a pulp is a measure of its lignin content and is acceptable as a measure of lot-to-lot
uniformity. For a given species of wood or other fibers, the permanganate consumption is a measure of the degree of cooking to
which the fiber has been subjected, and can relate relates to the ease of refining of the pulp produced from the cooked fiber. This
test is useful for control purposes, specifications, and the comparison of different pulps.
28. Procedure
28.1 Kappa Number—Follow TAPPI T 236.
28.2 Permanganate Number—Follow TAPPI UM 251.
PENTOSAN CONTENT OF PULP
29. Significance and Use
29.1 The pentosan content of a pulp strongly affects the dissipation factor-temperature relationship of electrical insulation made
from it. It is also a potential indicator of lot-to-lot uniformity and is one of several factors related to the bonding power of a pulp,
and the amount of energy required to refine the pulp.
30. Procedure
30.1 Follow TAPPI T 223.
MOISTURE IN PULP
31. Significance and Use
31.1 Pulp is purchased on the basis of moisture content. In addition, the moisture content is acceptable for consistency control.
It is possible that the moisture content will affect the energy of repulping and the biological degradation of the pulp. This test is
useful for control purposes and specifications.
32. Procedure
32.1 Follow TAPPI T 210.
33. Report
33.1 This method gives the percentage moisture content of the pulp. Report percent water and percent moisture-free fiber (equal
to 100 minus percent water).
SHIVE COUNT
34. Significance and Use
34.1 Several grades of electrical insulating paper are most effectively manufactured using pulps having a low shive count.
Shives in wood pulp to be used for direct application to electrical conductors can beis potentially detrimental to the insulating
characteristics and strength of the insulating wall. This test is useful for control purposes, specifications, and the comparison of
different pulps.
D3376 − 18
35. Apparatus
35.1 Disintegrator, Sheet Machine, Press, Blotters, and so forth, in accordance with TAPPI T 205.
35.2 Steel Rule, graduated in 0.5 mm.
35.3
...