ASTM D2165-94(2006)
(Test Method)Standard Test Method for pH of Aqueous Extracts of Wool and Similar Animal Fibers
Standard Test Method for pH of Aqueous Extracts of Wool and Similar Animal Fibers
SIGNIFICANCE AND USE
The pH values of the extracts give an indication of the acidity or alkalinity of the fiber and its water-soluble impurities. These values are useful in indicating previous processing and in anticipating subsequent performance. For particular purposes, the pH of an extract prepared by one method may be a more informative index than another and as a consequence four optional extraction procedures are included.
This test method is not recommended for acceptance testing because the between-laboratory precision is relatively poor. In some cases, the purchaser and the seller may have to test a commercial shipment of one or more specific materials by the best available method, even though the method has not been recommended for acceptance testing of commercial shipments. In such a case, if there is disagreement arising from differences in values reported by the purchaser and the seller when using this method for acceptance testing, the statistical bias, if any, between the laboratory of the purchaser and the laboratory of the seller should be determined, with each comparison being based on testing specimens randomly drawn from one sample of material of the type being evaluated.
SCOPE
1.1 This test method covers the determination of the pH of aqueous extracts from wool and similar animal fibers. It is applicable to fibers in any condition-raw wool, scoured wool, sliver, top, yarn, or fabric.
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 specific precautionary statements, see Section 11.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D2165–94 (Reapproved 2006)
Standard Test Method for
pH of Aqueous Extracts of Wool and Similar Animal Fibers
This standard is issued under the fixed designation D2165; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 3.1.3 For definitions of other textile terms used in this test
method, see Terminology D123.
1.1 This test method covers the determination of the pH of
aqueous extracts from wool and similar animal fibers. It is
4. Summary of Test Method
applicable to fibers in any condition—raw wool, scoured wool,
4.1 An extract is prepared using distilled water or 0.1 N
sliver, top, yarn, or fabric.
sodium chloride solution at the boil under reflux, or at room
1.2 This standard does not purport to address all of the
temperature with agitation. The pH of the extract is measured
safety concerns, if any, associated with its use. It is the
electrometrically with a glass electrode.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
5. Significance and Use
bility of regulatory limitations prior to use. For specific
5.1 The pH values of the extracts give an indication of the
precautionary statements, see Section 11.
acidity or alkalinity of the fiber and its water-soluble impuri-
2. Referenced Documents ties. These values are useful in indicating previous processing
2 and in anticipating subsequent performance. For particular
2.1 ASTM Standards:
purposes, the pH of an extract prepared by one method may be
D123 Terminology Relating to Textiles
a more informative index than another and as a consequence
D2525 Practice for Sampling Wool for Moisture
four optional extraction procedures are included.
E70 Test Method for pH of Aqueous Solutions With the
5.2 This test method is not recommended for acceptance
Glass Electrode
testing because the between-laboratory precision is relatively
3. Terminology poor. In some cases, the purchaser and the seller may have to
test a commercial shipment of one or more specific materials
3.1 Definitions:
by the best available method, even though the method has not
3.1.1 aqueous extract, n— in wool testing, the solution
been recommended for acceptance testing of commercial
obtained by digesting a material with water or with a sodium
shipments. In such a case, if there is disagreement arising from
chloride solution to dissolve soluble materials.
differences in values reported by the purchaser and the seller
3.1.2 pH, n—in common usage, a measure of acidity or
when using this method for acceptance testing, the statistical
alkalinity of a solution, on a logarithmic scale, with neutrality
bias, if any, between the laboratory of the purchaser and the
represented by a value of seven, with increasing acidity
laboratory of the seller should be determined, with each
represented by decreasingly smaller values, and with increas-
comparison being based on testing specimens randomly drawn
ing alkalinity represented by increasingly larger values.
from one sample of material of the type being evaluated.
3.1.2.1 Discussion—For a technical discussion of pH, in-
cluding such phenomena as the effect of temperature on pH,
6. Apparatus and Materials
see any recognized chemistry text. The pH of textiles is
6.1 All glassware coming in contact with the liquid shall be
generally determined on aqueous extracts of the textile being
of a chemical-resistant glass, in which the contacting surfaces
tested.
have been soaked for two days in 0.1 N hydrochloric acid and
then rinsed thoroughly with distilled water (see 7.1) until the
rinsings have a pH of 6.0 or higher.
This test method is under the jurisdiction ofASTM Committee D13 onTextiles
and is the direct responsibility of Subcommittee D13.13 on Wool and Felt.
NOTE 1—It is desirable but not mandatory that the glassware be
Current edition approved Aug. 15, 2006. Published October 2006. Originally
reserved for extraction tests only and be filled with distilled water during
approved in 1961. Last previous edition approved in 2000 as D2165 – 94(2000).
storage between tests.
DOI: 10.1520/D2165-94R06.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.2 Apparatus for Extraction at Room Temperature:
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. Borosilicate glass has been found satisfactory.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D2165–94 (2006)
TABLE 1 Values of Student’s t for One-Sided and Two-Sided
6.2.1 Erlenmeyer Flasks, 250-ml, wide-mouth, with
A
Limits and the 95% Probability
ground-glass stoppers.
One- Two- One- Two- One- Two-
6.2.2 Laboratory Shaker or Agitator, with apparatus for
df df df
Sided Sided Sided Sided Sided Sided
attaching the flasks, holding at least three flasks, to provide
1 6.314 12.706 11 1.796 2.201 22 1.717 2.074
agitation that will not raise the temperature more than 5.5°C in
2 2.920 4.303 12 1.782 2.179 24 1.711 2.064
2h.
3 2.353 3.182 13 1.771 2.160 26 1.706 2.056
6.3 Additional Equipment Needed for Extraction at The 4 2.132 2.776 14 1.761 2.145 28 1.701 2.048
5 2.015 2.571 15 1.753 2.131 30 1.697 2.042
Boil:
6 1.943 2.447 16 1.746 2.120 40 1.684 2.021
6.3.1 Erlenmeyer Flask, 500-mL, with ground-glass joint.
7 1.895 2.365 17 1.740 2.110 50 1.676 2.009
8 1.860 2.306 18 1.734 2.101 60 1.671 2.000
6.3.2 Air Condenser, Glass, reflux, to fit the flask.
9 1.833 2.262 19 1.729 2.093 120 1.658 1.980
6.3.3 Tube, to hold absorbent for acidic and basic gases.
10 1.812 2.228 20 1.725 2.086 1.645 1.960
6.3.4 Glass Stopper,forflask,equippedwithastopcockand
A
Values in this table were calculated using Hewlett Packard HP 67/97 Users’
thermometer with a range from 0 to 105°C.
Library Programs 03848D, “One-Sided and Two-Sided Critical Values of Student’s
6.4 pH Meter and Glass Electrode, conforming to the t” and 00350D, “Improved Normal and Inverse Distribution.” For values at other
than the 95 % probability level, see published tables of critical values of Student’s
requirements of Sections 5 and 6 of Test Method E70.
t in any standard statistical text (1), (2), (3), and (4).
7. Reagents
TABLE 2 Specimens Required Under Conditions of Unknown
7.1 Distilled Water, having a pH of between 6.2 and 7.0. If
Variability in User’s Laboratory, pH Units
not in that range of pH, redistillation is necessary.
Number of
A
Names of the Properties Basis
7.2 Sodium Chloride, Standard Solution (0.1 N), prepared
Specimens
from reagent grade sodium chloride (NaCl) and distilled water
Distilled water at 21°C 5 s = 0.154
having a pH of between 6.2 and 7.0.
Distilled water at boil 7 s = 0.196
0.1 N NaCl solution at 21°C 3 s = 0.126
7.3 Anhydrous Calcium Sulfate or Equivalent Absorbent for
0.1 N NaCl solution at boil 3 s = 0.126
Acid or Alkaline Gases.
A
The values of s in this table are somewhat larger than will usually be found in
practice (see 9.1.2).
8. Sampling and Specimen Preparation
8.1 Takealotsampleofrawwool,scouredwool,sliver,top,
yarn, or fabrics as specified in the sampling procedure in
using values of s which are listed in Table 2 and which are
Practice D2525.
somewhat larger values of s than are usually found in practice.
8.2 Select specimens at random from the unconditioned
When a reliable estimate of s for the user’s laboratory becomes
sample, each weighing 10 6 0.1 g. Cut the fibers of the
available, Eq 1 will usually require fewer specimens than are
specimen into lengths of about 5 mm and blend.
listed in Table 2.
9. Number of Specimens
10. Preparation of Extracts
9.1 Take a number of specimens per laboratory sampling
unit such that the user can expect at the 95 % probability level
10.1 Extraction with Boiling Water— Include an approxi-
that the test result for a laboratory sampling unit will be no
mately proportionate quantity of any fallout present in each
more than 0.5 percentage points above or below the true
specimen. Transfer each specimen to a separate flask. Cover
average for the laboratory sampling unit as follows:
the fibers with 200 mL of boiling water (see 7.1). Connect the
9.1.1 Reliable Estimate of s—When there is a reliable
reflux condenser, making certain that anhydrous calcium sul-
estimate of s based upon extensive past records in the user’s
fate absorbent is in the absorption tube. Shake, to complete
laboratory as directed in the test method, calculate the required
wettingofthefiber,andheatgentlytomaintainboiling.Agitate
number of specimens per laboratory sampling unit using Eq 1:
the solution every 10 min by shaking the apparatus.After 30 to
n 5 ~ts/E! (1) 35 min, remove the flask from the heat source, remove the
reflux condenser, and stopper the flasks as quickly as possible
where:
with a stopper containing a thermometer. Cool the flask and
n = number of specimens per laboratory sampling unit
contents in water maintained at 21 6 2°C, without removing
(rounded upward to a w
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.