Technical manual section 03a

Standard Test Method for Basis Weight Grammage of Recombinant Battery Separator Mat .... This method summarizes sampling requirements for recombinant battery separator mat RBSM and outli

BCI Battery Technical Manual

FEB02

Current Revision: 2002-02

RECOMMENDED BATTERY MATERIALS SPECIFICATIONS VALVE REGULATED RECOMBINANT BATTERIES

TABLE OF CONTENTS

1 Organizations for Referenced Test Methods 2

2 Suppliers of Testing Equipment and Materials 3

3 Sampling Procedure for Recombinant Battery Separator Mat 7

4 Standard Test Method for Thickness of Recombinant Battery Separator Mat 9

5 Standard Test Method for Basis Weight (Grammage) of Recombinant Battery Separator Mat 14

6 Standard Test Method for Volume Porosity of Recombinant Battery Separator Mats 18

7 Test for Pore Size by the First Bubble Method Of Recombinant Battery Separator Mat 20

8 Test for Pore Size by the Liquid Porosimetry Method of Recombinant Battery Separator Mat 23

9 Test for Pore Size by the Mercury Intrusion Method of Recombinant Battery Separator Mat 28

10 Test Method for Surface Area of Recombinant Battery Separator Mat 31

11 Test Method for Determining Percent Moisture Content of Recombinant Battery Separator Mat 34

12 Test Method For Percent Ignition Weight Loss of Recombinant Battery Separator Mat 36

13 Test Method for Tensile Strength and Elongation of Recombinant Battery Separator Mat 39

14 Acid Wetting and Wicking of Recombinant Battery Separator Mat 45

15 Test Method for Determining the Compressibility of Recombinant Battery Separator Mat 46

16 Test for Determining Acid Weight Loss of Recombinant Battery Separator Mat (Reflux Method) 48

17 Extractable Metallic Impurities of Recombinant Battery Separator Mat 51

18 Extractable Chloride of Recombinant Battery Separator Mat 57

19 Test Method for Electrochemical Compatibility of Recombinant Battery Separator Mat 58

20 Total Organic Carbon For Recombinant Battery Separator Mat 71

21 Identification of Organic Impurities In Recombinant Battery Separator Mat 72

22 Electrical Resistance of Recombinant Battery Separator Mat 77

23 Conversion Factors for SI Units 78

1 ORGANIZATIONS FOR REFERENCED TEST METHODS

Referenced Test Method Procurement Addresses

1.1 American National Standard Institute, Inc (ANSI)

London W1A 2BS, England

Tel: 266933 BSI LON G

1.4 Technical Association of Pulp and Paper Industries (TAPPI)

2 SUPPLIERS OF TESTING EQUIPMENT AND MATERIALS

2.1 Summary

The following list of manufacturers and suppliers of testing materials, instruments and

machines is published by BCI solely for the convenience of its members BCI has made no investigation of its own with respect to the listed company compliance, however, and makes

no certification, representation or warranty, express or implied, with respect to such

compliance nor with respect to the quality of performance of such materials, instruments or machines Publication of this list or any reference to it in BCI Test Methods shall not be construed to be any such certification, representation or warranty Any purchaser or user of such material equipment or machinery desiring any certification or warranty with respect thereto must negotiate the same directly with the manufacturer or supplier from whom he makes such purchases

This equipment supplier listing is not intended to be inclusive, only a reference point, any manufacturer or supplier wishing to have his name included in this list should direct a request

2.4.3 Buck Scientific, Inc

58 Fort Point Street

2.4.6 Leeman Labs, Inc

2.4.11 Biomed Instruments, Inc

1020 S Raymond Ave., No B

2.5 Thickness (1) and Tensile (2)

2.5.1 Customer Scientific Instruments, Inc (1)

13 Wing Drive

Kearny, NJ 07927

Tel: 201-538-8500

3 SAMPLING PROCEDURE FOR RECOMBINANT BATTERY SEPARATOR MAT

3.1 Scope

3.1.1 This method summarizes sampling requirements for recombinant battery separator mat

(RBSM) and outlines the sample size needed for each BCI RBSM Test Method

3.1.2 Prior to purchase, there should be agreement between supplier and purchaser on details of

the sampling and acceptance procedure as well as on the required physical and chemical properties, dimensional tolerance, etc., and the test methods to be employed to determine frequency (and/or need) of testing

3.2.1 BCI’s RBSM Test Methods, BCIS-03a

3.2.2 TAPPI’s T 400 – Sampling and accepting a single lot of paper, paperboard, fiberboard, or

related product

3.2.3 ASTM’s – D585 – Sampling and accepting a single lot of paper, paperboard, fiberboard, or

related products

3.3 Terminology

3.3.1 LOT – a quantity of RBSM of a single grade, making (manufacture run), grammage, and

thickness about which it is desired to make a judgement (usually as to conformance to specification) by examining or testing a small fraction called the sample

3.3.2 SAMPLE – a specified number of test units selected according to a prescribed procedure to

represent a lot Each test method should be reviewed for any special procedures

3.3.3 TEST UNIT – an area of RBSM sufficient to obtain a single adequate set of test result for all

the properties to be measured

3.3.4 SPECIMEN – a test unit, or a portion of a test unit, upon which (for a specified property) a

single test determination is to be made

3.3.5 TEST DETERMINATION – the process of carrying out the series of operations specified in

the test method whereby one or more readings (observations) are made on a test specimen and the observations combined to obtain the value of a property of the test specimen, or the value obtained by the process

3.3.6 TEST RESULT – the value obtained for one test unit of the sample by carrying out the

complete protocol of the test method, the value being (as specified in the test method) either

a single test determination or specified combination of a number of determinations

3.3.7 ROLL – A coil of RBSM of continuous length

3.3.8 QUALIFICATION

3.3.8.1 RBSM test which are done for initial acceptance of vendor’s material

3.3.8.2 An agreement between user and supplier on subsequent testing frequency

3.4 Procedure

3.4.1 RBSM generally is a very delicate product Any rough handling or misuse of the test

specimen may result in test results, which are not representative of the material

3.4.2 RBSM may have specific aging characteristics These aging characteristics may have no

effect on the RBSM performance inside a battery but will result in different results of physical properties such as tensile and elongation This aging effect is believed to be accelerated by hot and humid conditions

3.4.3 If a lot number or roll identification system is needed then reference should be made to either

TAPPI’s T400 or ASTM’s D-585 for guidance

3.4.4 Table No 1 should be referenced for a summary of test specimens needed and the size of

each specimen

Table No 1

Test Method

Sample Size Needed

Frequency (Per Lot)

Comments

sampling

smaller pore size values

and may vary depending on whether the test specimen is taken from the wire of felt side of the RBSM

Tensile and

Elongation

25 x 150 mm

3 – strips

Qualification Tensile is extremely sensitive to handling

Sufficient sample should be obtained to cut strips without any damage

Notes: Remove the outer two wraps before sampling

4 STANDARD TEST METHOD FOR THICKNESS OF RECOMBINANT BATTERY

SEPARATOR MAT

4.1 Scope

4.1.1 This method covers the determination of the thickness of recombinant battery separator mat

(RBSM) which is used in a recombinant lead acid cell This method is to be used, except as otherwise required by materials specification

4.1.2 This method covers RBSM from 0.127 mm (0.005 in) to 3.048 mm (0.125 in)

4.1.3 This method covers measurement of RBSM using a pressure of 10 kPa (1.5 psi) and a 29

mm (1.14 in) presser foot

4.2.1 ASTM Standards

4.2.1.1 ASTM D-374 Standard Test Method for Thickness of Solid Electrical Insulation

4.2.1.2 ASTM D-645 Standard Test Method for Thickness of Paper and Paperboard ISO No 534 4.2.2 TAPPI Standards

T 411 Thickness (Caliper) of Paper and Paperboard

4.3 Significance

Thickness and its consistency is an important property of RBSM RBSM is used at various thicknesses and degrees of compression The thickness of RBSM allows for the proper selection of the mat for a given cell construction and the electrical characteristics desired 4.4 Description of Terms

4.4.1 RECOMBINANT BATTERY SEPARATOR MAT (RBSM) – Any material intended for use as a

separator between the cathode and anode plates in a VRLA battery

4.4.2 THICKNESS – The perpendicular distance between the two principal surfaces of a material,

as determined by the prescribed procedure

4.5 Apparatus

4.5.1 Method A – Manually-Operated Dead Weight Type Thickness Gauge

4.5.1.1 The gauge shall be a dead-weight type having a presser foot and a lower anvil parallel to

within 0.002 mm (0.0001 in) The presser foot shall move on an axis perpendicular to the anvil face

4.5.1.2 The diameter of the presser foot and anvil shall measure 29 mm (1.14 in) The presser foot

shall apply pressure of 10 ± 0.6 kPa (1.5 psi) on the specimen

4.5.1.3 If a dial gauge is used, the dial spindle shall be vertical The dial shall be at least 50 mm (2

in) in diameter and shall be continuously graduated to read directly to 0.002 mm (0.0001 in)

If necessary, it will be equipped with a revolution counter recording the number of complete revolutions of the large hand The dial indicator shall be essentially friction free

4.5.1.4 The indicator shall give readings repeatable to 0.001 mm (0.00004 in) at a zero setting or on

a steel gauge block

4.5.1.5 The frame of the indicator shall be of such rigidity that a load of 13 N applied on the dial

housing, out of contact with either the weight or the presser foot spindle, will produce a deflection of the frame not greater than the smallest division on the indicator

4.5.2 Method B – Motor-Operated Dead Weight Gauge:

4.5.2.1 Except as additionally defined in this Subsection, the instrument shall meet the requirements

of 4.5.1.1

4.5.2.2 The dead weight dial spindle shall be raised and lowered by a constant-speed motor through

a mechanical linkage such that the rate of descent (for a specified range of distance between the presser foot and the anvil) and the dwell time on the specimen are within the limits specified for the material being measured Downward force on the presser foot shall be only that of gravity on the weighted spindle with no addition from the lifting-lowering mechanism 4.6 Calibration

(General Considerations for Care, Use and Calibration of Thickness Measuring Apparatus) 4.6.1 Surfaces of Micrometer Apparatus

4.6.1.1 Cleaning Surfaces of Micrometers – Before and during instrument calibration and thickness

measurements, the micrometer surface shall be maintained in a clean condition Cleaning can be accomplished by pulling through a sheet of smooth paper

Warning

When using a motorized micrometer, caution should be exercised in pulling a sheet of RBSM through the anvil while in motion, since this may negatively effect the life of the instrument 4.6.1.2 Parallelism of Surfaces of Micrometers:

4.6.1.2.1 A hardened calibrated gauge or a calibrated tread measuring cylinder of suitable dimensions

to fit conveniently between the presser foot and the anvil of the thickness gauge shall be measured at several locations Note the maximum variations of readings

4.6.1.2.2 In calibrating the gauge, it is important that the gauge block or cylinder is inserted only under

the edge of the pressure foot

4.6.1.3 Flatness of Surfaces of Micrometers:

4.6.1.3.1 The anvil and spindle surfaces of the micrometer shall be flat to within 0.0013 mm (0.00005

in) The flatness may be determined by use of an optical flat

4.6.1.3.2 A flat surface forms straight, parallel, and equidistant fringes

4.6.1.3.3 A grooved surface forms straight parallel fringes at unequal intervals The estimated

maximum displacement of any line from its normal position, where all lines would be

equidistant, is a measure of deviation from flatness

4.6.1.3.4 A symmetrical concave or convex surface forms concentric circular fringes, and their number

is a measure of deviation from flatness

4.6.1.3.5 An unsymmetrical concave or convex surface forms a series of curved fringes, cutting the

periphery of the micrometer surface The number of fringes cut by a straight line connecting the terminals of any fringe is a measure of the deviation from flatness

4.6.2 Calibration of Micrometers (General Requirements)

4.6.2.1 All micrometers shall be calibrated in a standard laboratory atmosphere maintained at 50%

relative humidity and 23°C (73°F), or some other standard conditions as mutually agreed upon between the purchaser and seller To calibrate any thickness-measuring device, it is necessary to obtain standard gauge blocks or other metallic objects of known thickness The accuracy of these blocks shall be ±10% of the smallest scale division of the micrometer dial

or scale Thus, if an instrument’s smallest scale division is 0.002 mm (0.00001 in.), then the standard gauge block thickness shall be within ±0.0002mm (0.00001 in.) Calibration

procedures shall be performed at least twice every year, and only after the instrument has been checked and found to meet the requirements of these procedures

4.6.2.2 Manual Gauge

Force – The force applied to the presser foot spindle and the weight necessary to move the pointer upward from the zero position shall not exceed the product of the presser foot area and the maximum permissible force per unit area The force applied to the presser foot spindle and the weight necessary to just prevent movement of the pointer from a higher to a lower reading shall be greater than the product of the presser foot area and the minimum permissible force per unit area specified for the pressure exerted on the specimen

4.6.2.3 Accuracy of Scale Divisions

Set the instrument to zero reading, then measure the thickness of the standard gauge blocks – block thickness are known to be within 0.0002 mm (0.00001 in) Calibration data shall be collected from observations made on standard gauge blocks using detailed procedures specified for making measurements on a specimen The calibration data shall be utilized to construct a calibration curve, which shall be used to apply the indicated corrections to

observations made on specimens

4.6.2.4 Motor – Operated Gauge

The calibration of the motor-operated dead weight gauge shall be performed in the same manner as described for a manually operated gauge, except that the standard gauge blocks shall be measured using detailed procedures specified for making measurements on a specimen

4.7 Procedure

4.7.1 RBSM will give different thickness measurements based on parameters such as conditioning,

rate of loading, ultimate load, and foot/anvil dimensions Different conditions will result in different readings of thickness

4.7.2 Any thickness testing shall be performed within two days of receipt of a shipment Testing of

any material shall be done within 2 hours (maximum) from the removal of the samples from a sealed package

NOTE: It has been determined that if RBSM conditioned or exposed to a 70% relative humidity atmosphere, a loss of approximately 5-6 percent of its original thickness could be realized

4.7.3 Testing should be conducted in a controlled atmosphere (if possible) of 23°C (73°F) and 50%

RH See Subsection 4.6.2.1

4.7.4 Manual Gauge

4.7.4.1 Place the gauge on a clean, solid, level table, free of excess vibration Clean the contacting

surfaces of the presser foot and anvils Make the instrument’s zero adjustment Lift the presser foot and place the specimen under it Lower the foot onto the specimen at the

location outside the area to be measured Then raise the foot slightly, move the specimen to the measurement position, and reposition the presser foot to obtain a reading from 0.007 mm (0.0003 in.) to 0.01 mm (0.0004 in) higher than the preceding reading then drop the foot 4.7.4.2 For each succeeding measurement, raise the presser foot slightly, and move the specimen to

the next measurement position Again, position the presser foot to obtain a reading from 0.007 mm (.0003 in) to 0.01 mm (0.0004 in) higher than the preceding reading, and drop the foot

4.7.4.3 Do not make measurements with the presser foot less than 6 mm (0.23 in) from the edges of

the specimen

4.7.4.4 Recheck the instrument zero setting after measuring each specimen A change in the setting

is usually the result of contaminating particles being carried by the specimen to the contacting surfaces of the presser foot and anvil and necessitates the cleaning of the surfaces (as in 4.5.1.1)

4.7.5 Motor Gauge

4.7.5.1 Place the motor driven gauge on a clean, solid, level table, free to excess vibration Clean the

contacting surfaces of the presser foot and anvil as in 4.6.1.1, and make the instrument zero adjustment With the gauge running, position the specimen for the first measurement while the presser foot is near its maximum height Take the reading when the indicator pointer comes to a rest

4.7.5.2 For each succeeding measurement, shift the specimen when the pressure foot is near its

maximum height and repeat the above procedure at the next measurement position

Caution: Never attempt to move the RBSM while the presser foot is in contact with the anvil This will rip the RBSM and could damage the gauge

4.7.5.3 Do not make measurements with the presser foot less than 6 mm (0.23 in) from the edges of

the specimen

4.7.5.4 After measuring each specimen, readjust the instrument zero and clean the instrument as

necessary

4.7.6 Take at lest five readings, ten if feasible, spaced to represent the full width of the specimen

(at right angles to the machine orientation of the RBSM) Average the readings

4.8.3 Identification of the testing laboratory and responsible personnel

4.8.4 Model of gauge used

4.8.5 Number of specimens per sample and number of measurement per specimens

4.8.6 Conditioning procedures used (test ambient temperature and relative humidity) and,

4.8.7 Arithmetic mean, sample standard deviation and the range of all measurements

4.9 Precision and Bias

4.9.1 Precision

A round robin study on one material by three laboratories has indicated a within laboratory average coefficient of variation of 1.7 percent and a between laboratory reproducibility of 6.3 percent (Based on 20 separate measurements and each measurement counted as a result

An average reading of results will give a lower percent reproducibility)

4.9.2 Bias

No statement on bias can be made due to a lack of a standard reference material

4.9.3 Results will be effected by the relative humidity of the test conditions and prior handling of the

material, since most RBSM are delicate materials

4.9.4 Because of the high void volume of RBSM, slight changes in procedure, presser foot

diameter, and load will have large effects on the results of the thickness determinations

5 STANDARD TEST METHOD FOR GRAMMAGE (BASIS WEIGHT) OF RECOMBINANT

BATTERY SEPARATOR MAT

5.1 Scope

5.1.1 This test procedure covers the determination of the weight per unit area of recombinant

battery separator mat (RBSM) used in battery applications

5.1.2 The customary units used by the battery industry for this property are grams per square

meter (g/m2) Other units covered by this method are pounds per 3000 square feet (lb/3000

ft2) and pounds per 1000 square feet (lb/1000 ft2)

5.1.3 Weight per unit area is measured on a moisture-free sample and then corrected for the

moisture content of the test specimen

5.1.4 This method includes both the measure of a minimum size mat sample and the range of

weights, as determined on smaller portions of this sample

5.1.5 A rapid determination method is also included, which quickly provides approximate values

5.2.1 BCI Recombinant Mat Test Method BCIS-03-a 11, Test Method for Determining Percent

Moisture Content of Recombinant Battery Separator Material

5.2.2 ASTM D646 Grammage of Paper and Paperboard (Weight Per Unit Area)

5.2.3 TAPPI T-410 Grammage of Paper and Paperboard (Weight Per Unit Area)

5.2.4 British Standard BS 3432 Grammage

5.2.5 International Standards Organization ISO 536

5.3 Terminology

5.3.1 BASIS WEIGHT – The weight of RBSM material per unit of defined area

5.3.2 GRAMMAGE – The weight of a RBSM material expressed in grams per square meter 5.4 Significance and Use

5.4.1 The performance of a recombinant lead-acid battery is dependent upon the mass of mat

between the plates and the applied compression Therefore, basis weight must be controlled within reasonably close tolerances

5.4.2 Per pound, RBSM is one of the most expensive components used in a lead-acid battery

Since, in general, it is sold by weight but used by area, grammage (basis weight)

measurements are one of the criteria by which a shipment of mat is determined to be acceptable

5.5 Apparatus

5.5.1 Cutting Device, such as a “four square” cutter, or other device for ensuring parallelism of the

opposite edges, normally capable of repeatedly cutting out test specimens whose area, in at least 95 out of 100, falls with ±0.5% of a known area, as determined by this method in 5.6.1

5.5.2 Measuring Device capable of measuring the dimensions of the test specimen to an accuracy

of 0.2%

5.5.3 Electric Drying Oven (non-air recirculating), capable of maintaining a temperature of 150 ±

5°C (302°F ± 9°F)

5.5.4 Weighing Device, readable and accurate to within ±0.25% of applied load, and shielded from

air currents when used, Calibration as determined in 5.6.2

5.6 Calibration

5.6.1 Checking of Cutting Device

Frequently (5.6.3) check the area cut by using the measuring device (5.5.2) to measure 20 test specimens The cutting accuracy specified in 5.5.1 is attained when the standard

deviation of individual areas is less than 0.25% of the mean area

5.6.2 Checking of Weighing Device

5.6.2.1 Check the accuracy of the weighing device (5.6.3) by applying accurately measured masses

with both increasing and decreasing loads The sheet-weighing device must be accurate to

±0.25% of the applied load (5.5.4)

5.6.2.2 Before each use, frictional effects shall be sufficiently minimal and the zero reading shall be

sufficiently correct to obtain the required weighing accuracy (5.5.4)

5.6.3 Frequency of Checking

The frequency of checking in 5.6.1 and 5.6.2 should be based on experience A new device should be checked several times before being put into use Then, if in continual use, it should

be checked twice daily until stability is established, then weekly, monthly, or less frequently

as indicated by its stability, unless moved or unduly disturbed Because of wear, the cutting device may require more frequent checking than the weighing device

5.7 Sampling

5.7.1 RBSM is usually produced on papermaking equipment as large rolls of 50 inch or greater

width It is generally converted into narrow rolls, as low as 1 inch wide, for use by battery manufacturers Therefore, a minimum sample area rather than exact sample dimensions is specified

5.7.2 Each test specimen must be comprised of a minimum area of 1000 cm2 (approximately 150

in2)

5.7.3 A minimum of three specimens shall be sampled from each lot, unless the test is to be

performed on an entire slit roll

5.7.4 Following the completion of testing in 5.8.1.5, each specimen should be cut into 5 pieces of

approximately equal size for a determination of basis weight uniformity within a test

5.8.1.2 Measure and record the dimensions (centimeters or inches) of each specimen using the

measuring device (5.5.2)

5.8.1.3 Dry the specimens for 1 h at 150°C (302°F) in the electric drying oven (5.5.3) Remove the

specimens from the oven and allow them to cool in a desiccator for 15 minutes

5.8.1.4 Remove each specimen from the desiccator and quickly weigh it using the weighing device

(5.5.4) Record the weight in grams (or in kg if a full roll)

5.8.1.5 Return each specimen to the desiccator as soon as the weighing is complete

5.8.2 Method B – Basis Weight Uniformity

5.8.2.1 Remove a test specimen from the desiccator and cut it into five pieces of approximately equal

size using the cutting device (5.5.1)

5.8.2.2 Weigh each piece using the weighing device (5.5.4) and record the weight in grams

5.8.2.3 Repeat 5.8.2.1 and 5.8.2.2 until all specimens from 5.8.1.1 have been cut and weighed 5.8.2.4 Measure each small specimen with the measuring device (5.5.2) and record the dimensions

in centimeters (inches)

5.8.3 Method C – Rapid Determination

5.8.3.1 Cut and measure the test specimens as in 5.8.1.2 and 5.8.1.3

5.8.3.2 Weigh each test specimen using the weighing device (5.5.4) and record the weight in grams 5.8.3.3 This method is helpful for distinguishing between different grades of RBSM If accuracy

greater than 2% is needed, the specimen can be dried, cooled and reweighed as in 5.8.1.3 and 5.8.1.4

OBW - Oven-Dry Basis Weight (g/m2, lb/3000 ft2, lb/1000 ft2)

BW - Basis Weight (same units as OBW)

5.9.2 See Annex (5.12) for a table of unit conversions

5.9.3 Specimen Area: A = L x W

5.9.4 Oven-Dry basis Weight: OBW = WT/A

5.9.5 Basis Weight: BW = (OBW)/(1 – (M/100))

5.10 Report

5.10.1 Report the basis weight (grammage) average and range in g/m2 (lb/3000 ft2 or 1000 ft2) to

three significant figures for each test unit, along with the moisture content

5.10.2 Sample size other than 1000 cm2 (150 in2) should be reported

5.10.3 Results of basis weight (grammage) uniformity tests should be reported as averages and

Length & Width

6 STANDARD TEST METHOD FOR VOLUME POROSITY OF RECOMBINANT BATTERY

6.2.1.2 Method III Standard Test Method for Grammage (Basis Weight) of Recombinant Battery

Separator Material, BCIS-03a-5

6.3 Terminology

6.3.1 Volume Porosity – the ratio of the total void volume to the total apparent volume, expressed

as a percentage

6.3.2 Apparent Volume – the volume obtained by multiplying the sample area by the thickness

measured at a specified pressure

6.3.3 Void Volume – that portion of the apparent volume that is not occupied by the solids used to

make the separator It is usually determined by subtracting the volume of the solids from the apparent volume

6.3.4 Solid Volume – the volume that is calculated from the weights of the separator components

and their densities

6.3.5 Average Density of Solids = (dry weight of RBSM)/(Total solid volume based on a stated

thickness measurement technique)

(supplied by separator manufacturer in g/cc)

6.4 Significance and Use

The volume porosity of RBSM in the compressed state limits the maximum amount of acid between the plates

Conditioning shall be as specified in the BCI Standard Test Method II for Thickness of Recombinant Battery Separator Mats

6.8 Procedure

6.8.1 Obtain the average density of solids of the RBSM from the battery separator manufacturer 6.8.2 Measure the thickness and basis weight of the sample as described in the BCI test methods

BCIS-03a for RBSM

6.8.3 Calculate the volume porosity using the following formula:

For thickness measured in mm and grammage measured in g/m2

VP (%) = (100((TH x 25.4) – (BW/ADS)))/(TH x 25.4)

Where:

VP (%) = volume porosity expressed as a percentage

TH = sample thickness

BW = basis weight in grams per square meter

ADS = average density of solids

6.9 Reporting

If a report is required, it must include the pressure at which the thickness was measured 6.10 Bias

No statement of bias can be made because there is no standard reference material

6.11 Derivation of Volume Porosity Formula

Let:

TH = sample thickness

BW = grammage g/m2

ADS = average density of solids

By Definition: Volume Porosity = (Void Volume)/(Apparent Volume)

Assume Sample Area to be 1 Square Meter:

Apparent Volume (cc) = TH (mm) x 1 m2 x (10000 cm2/ m2) x (1 cm/10 mm)

= TH (mm) x 1000

Apparent Volume (cc) = TH (mil) x 1 m2 x 10000 cm2/m2 x 0.00254 cm/1 mil

= TH (mil) x 25.4

Solid Volume = Sample Weight = (Grammage)/ADS

Apparent Volume = 100((TH x 1000 – (BW/ADS))/(TH x 1000)

= 100((TH x 25.4) – (BW/ADS))/(TH x 25.4)

7 STANDARD TEST METHOD FOR PORE SIZE CHARACTERISTICS BY THE FIRST

BUBBLE METHOD OF RECOMBINANT BATTERY SEPARATOR MAT

7.2.2 BS 6410 British standard method of test for filter papers

7.3 Principle of Test Method

The bubble point test is based on the principle that a wetting liquid is held in separator pores

by capillary attraction and surface tension, and the minimum pressure required to force liquid from these pores is a function of pore diameter The pressure at which a steady stream of bubbles appears in this test is the bubble point pressure

7.4 Apparatus

7.4.1 Sample holder Figure 7.1

Figure 7.1 – Sample Holder

7.4.2 Test set-up Figure 7.2

Figure 7.2 – Test Setup

7.4.3 Pressure gauges

7.5 Reagents

7.5.1 Reagent grade or high purity liquid of known surface tension

7.5.1.1 Isopropyl alcohol

7.5.1.2 Petroleum distillate with surface tension of 30 dynes/cm at 25°C

7.5.1.3 Mineral oil with surface tension of 34.7 dynes/cm at 25°C

7.5.1.4 Porofil wetting liquid from Coulter Electronics, Inc

7.5.2 Clean compressed air

7.6 Procedure

7.6.1 Thoroughly wet the RBSM sample by immersing it in the liquid

7.6.2 Place the wet RBSM in the sample holder, close it, and fill the fluid reservoir with liquid 7.6.3 Apply gas pressure making sure to eliminate liquid back flow Slowly increase gas pressure 7.6.4 Record the lowest pressure when a steady stream of bubbles rises from center of liquid

7.8 Report

7.8.1 Record the minimum pressure for gas passage as indicated by continuous bubbles 7.8.2 Record the maximum pore size calculated, identification of RBSM tested and liquid used 7.9 Precision and Bias

The precision of this test method has not been determined

8 STANDARD TEST METHOD FOR PORE SIZE CHARACTERISTICS BY THE LIQUID

POROSIMETRY METHOD OF RECOMBINANT BATTERY SEPARATOR MAT

8.1 Scope

This procedure covers method of determining pore size distribution of Recombinant Battery Separator mat (RBSM) using liquid porosimetry

8.2 Applicable Documents

8.2.1 Coulter Porometer Instruction Manual

8.2.2 ASTM E-1294 pore size characteristics of membrane filters using automated liquid

porosimeter

8.2.3 ASTM F-316 pore size characteristics of membrane filters by bubble point and mean flow

pore test

8.2.4 BS 6410 British standard method of test for filter paper

8.2.5 PMI Capillary Flow Porometer Instruction Manual

8.3 Principle of Test Method

8.3.1 RBSM saturated with liquid will allow air to pass when air pressure exceeds the capillary

attraction of the liquid in the pores Smaller pores will exhibit similar behavior at higher pressures

8.3.2 The percentage of flow passing through the pores larger than or equal to the specified size

can be calculated from the pressure-pore size relationship by comparing the gas flow rates of both wet and dry RBSM at the same pressures

8.4 Apparatus

8.4.1 Coulter Porometer (Coulter Electronics, Inc., Hialeah, Florida) or equivalent

8.4.2 Sample holders Figure 8.1

8.4.3 Pressure gauges

8.4.4 Rotameters

8.4.5 Fluid trap

8.4.6 Test set up Figure 8.3, Figure 8.4

Figure 8.4 – Set-up for Two Holders

8.5 Reagents

8.5.1 Reagent grade or high purity liquid of known surface tension such as:

8.5.2 Porofil (Coulter Electronics, Inc.)

8.5.3 Isopropyl alcohol

8.5.4 Petroleum distillate with surface tension of 30 dynes/cm at 25°C

8.5.5 Mineral oil with surface tension of 34.7 dynes/cm at 25°C

8.5.6 Adequate liquid shown on Table 8.1

Table 8.1

Calculation of Maximum Pore Size from Bubble Point Pressure

(d = Cr/p)

Water 155/Bubble Point 30.0/Bubble Point 2.06 x 103/Bubble Point Petroleum distillate 64.6/Bubble Point 12.5/Bubble Point 8.58 x 104/Bubble Point Denatured Alcohol 47.75/Bubble Point 9.25/Bubble Point 6.38 x 104/Bubble Point Mineral oil 74.5/Bubble Point 14.4/Bubble Point 9.92 x 104/Bubble Point Freon TF™ 37.2/Bubble Point 7.2/Bubble Point 4.95 x 104/Bubble Point Example – A certain RBSM was observed to have a bubble point of 41.0 psi with petroleum distillate Size (µm) = 12.5/41.0 psi Therefore: maximum pore size = 0.305 µm

Note: This table was derived from ASTM F315-86

8.6 Procedure

8.6.1 Procedure for Coulter Porometer, PMI Porometer or equivalent

8.6.1.1 Follow porometer operating instructions to prepare the RBSM sample to introduce to the

instrument

8.6.1.2 Establish procedures for standard sampling to obtain repeatable results

8.6.2 Procedures for One Holder (Fig 8.3)

8.6.2.1 Place a dry RBSM sample disk in the sample holder

8.6.2.2 Close the holder and apply gas pressure in increments

8.6.2.3 Plot gas flow versus gas pressure over the intended range of use

8.6.2.4 Reduce gas pressure and remove the RBSM sample from the holder

8.6.2.5 Completely wet the RBSM in the liquid, replace the wet sample in the holder, checking to see

that a tight seal is made

8.6.2.6 Increase pressure gradually and record the pressure of the gas flow detected by the capillary

tube tip which is immersed in the test tube half filled with liquid

8.6.2.7 Change to rotameters and plot the fluid wet sample gas flow versus pressure on the same

coordinates as for the plot made in accordance with 8.6.2.3

8.6.3 Procedure for Two Holders Figure 8.4

8.6.3.1 Place a dry RBSM sample in the holder to be used exclusively for dry sample

8.6.3.2 Wet a RBSM sample of the same type and lot as the sample used in 8.6.3.1 in liquid medium

and place it in a holder to be used exclusively for wet sample

8.6.3.3 Apply gas pressure to the dry sample and plot gas flow versus gas pressure

8.6.3.4 Change the two position valve to apply gas pressure to the wet sample holder and record the

first gas flow as detected by the capillary tube as bubble point Switch to rotameters and plot fluid wet gas flow versus gas pressure

8.7 Calculations

8.7.1 Calculations of Mean Flow Pore Size

8.7.1.1 Record the minimum pressure for gas passage (bubble point pressure) Calculate the

maximum pore size from the equation and correlation data found in Table 8.1

8.7.1.2 Using the graph from 8.6.3.3 draw the line or curve corresponding to one half the dry gas flow

rate of the RBSM sample Find the intersection of this (one-half dry-flow) line and the wet flow

line or curve as shown in Figure 8.5 Determine the pressure coordinate of the intersection

and substitute into the pressure-pore size equation (See Table 8.1 for mineral oil)

Figure 8.5

8.7.2 Calculation of Pore Size Frequency

8.7.2.1 Select the limits of the pore size range being evaluated Substitute the limit individually into

the pore size versus pressure equation and obtain their respective pressures From the test graph determine the wet and dry flows at the pressure limits (pore size limits of the range) as

shown in Figure 8.6

Figure 8.6

8.7.2.2 Substitute the value found in the following equation:

Q = [(wet flowh/dry flowh) – (wet flowl/dry flow l)] x 100

Where:

l = lower pressure limit

h = higher pressure limit

8.7.2.3 Report Q as the percent of the sample flow passing through pores within the range specified

Example – Determine the percentage of the RBSM flow passing through a pore size range

from 0.8 to 0.2 µm of the RBSM described in Figure 8.6

Q = [(7 L/min / 21 L/min) – 2 L/min / 15 L/min)] x 100

= [0.333 – 0.167] x 100 = 16.6%

A 16.6 percent of the gas passing through the RBSM described in Figure 8.6 moves through pores between 0.8 and 0.2 µm

8.8 Precision and Bias

8.8.1 The precision of this test method has not been determined

8.8.2 Since the change in pore size per unit change in applied pressure is greatest at large pore

sizes and diminishes hyperbolically, repeatability and reproducibility increase accordingly with applied pressure

9 STANDARD TEST METHOD FOR PORE SIZE CHARACTERISTICS BY THE MERCURY

INTRUSION METHOD OF RECOMBINANT BATTERY SEPARATOR MAT

9.1 Scope

9.1.1 This procedure covers method of characterizing pore structure of recombinant battery

separator mat (RBSM) using mercury intrusion porosimetry

9.1.2 This test procedure may involve hazardous materials, operations, and equipment This

procedure does not purport to address all of the safety problems associated with its use It is the responsibility of the user of this test method to consult Material Safety Data Sheets (MSDS) of the materials involved with the test and to establish appropriate safety and health practices as well as determine the applicability of regulatory limitation prior to use

9.2.1 Instruction Manual, Micromeritics Mercury Intrusion Porosimeter

9.2.2 Instruction Manual, Quantachrome Mercury Porosimeter

9.2.3 Instruction Manual, Aminco Mercury Intrusion Porosimeter, Super Pressure Inc

9.2.4 Instruction Manual, PMI Automated Porosimeter, Porous Materials, Inc

9.2.4.1.1 ASTM D2873 The Method for Interior Porosity of PVC Resins by Mercury Intrusion

Porosimetry

9.3 Principle of Test Method

9.3.1 The method of mercury porosimetry is based on the principle that the external pressure

required to force a non-wetting liquid into a pore against the opposing force of the liquid surface tension depends on the pore size

9.3.2 Mercury is used as liquid medium since it does not wet most solids and its contact angle with

a variety of solids is in relatively narrow ranges

9.3.3 Assuming cylindrical pore geometry, the relationship between the applied pressure and the

pore diameter into which mercury will intrude is given by the Washburn equation:

d = 4 Γ cos Θ/ p

Where:

d = pore diameter

p = applied pressure

Γ = surface tension of mercury

COS Θ = contact angle between mercury and pore wall

The pressure required to force mercury into a pore is inversely proportional to the pore diameter

9.4 Significance and Use

9.4.1 Mercury porosimetry is a widely accepted technique of characterizing structure of porous

materials

9.4.2 The method of test is used to determine properties such as pore diameter, pore size

distribution, and pore volume

9.4.3 A pore size determined by mercury porosimetry should not be taken in a literal sense due to

some assumptions such as cylindrical pores, contact angle and surface tension of mercury imposed to calculate it Pore size is a relative term used to simplify discussion when making comparison between samples of certain material type

9.5 Precautions

9.5.1 Mercury is poisonous Prevent accumulation of mercury vapor in workspaces through

provision of proper exhaust system Avoid contact with skin and internal ingestion Use plastic or rubber gloves Clean up spills immediately with mercury clean-up kits Keep

containers of mercury closed at all times When cleaning mercury with mercury cleaning kit and nitric acid do so under well ventilated hood

9.5.2 Operation of mercury porosimeter requires high hydraulic pressure Even though all

porosimeters are equipped with built-in safety features, operator should observe strict safety precautions described in the operating manual

9.6 Apparatus

9.6.1 Micromeritics Mercury Porosimeter

e.g Pore Size 9320 Auto Pore II 9220

9.6.2 Quantachrome Mercury Porosimeter

e.g Autoscan – 33 or 60 Porosimeter

9.6.3 Aminco Mercury Porosimeter

e.g Model J5-7125D, 60K, 5-7107

9.6.4 PMI Automated Porosimeter

e.g Model No PMI 30K-A-1

9.7 Procedure

9.7.1 Follow the detailed procedure as described in the instruction manual provided with the

instrument

9.7.2 A sample weight between 0.040 to 0.060 gram weighed to an accuracy of 0.0001 g is

suggested for commonly available microfiber glass RBSM

9.8 Report

Report the following:

9.8.1 The instrument used

9.8.2 The weight of the specimen used

9.8.3 Median pore diameter in µm

9.8.4 Pore size distribution preferably in the form of a graph showing pore diameter in µm on X-axis

(log scale) and porosity in ml/g on Y-axis

9.9 Precision and Bias

The precision of this method has not been determined

10 STANDARD TEST METHOD FOR SURFACE AREA OF RECOMBINANT BATTERY

10.2.1 Adsorption, Surface Area and Porosity, 2 nd Ed By Greg and Sing, 1982

10.2.2 NIST Special publication 260 (Standard Reference Materials Catalog)

10.3 Terminology

10.3.1 SURFACE AREA – The total area of exposed surface of a finely divided solid, power, or

porous material Typically expressed in m2/g

10.3.2 WRM – Working Reference Material – a mat material similar to that being analyzed

Repeated testing of a WRM is useful for checking the daily performance of the instrument and the uncertainty (precision) of the procedure over long periods of time

10.3.3 BRUNAUER–EMMETT–TELLER (B.E.T.) – describes a model for multi-layer molecular

adsorption and its relationship to surface area based upon active sites on a sample

10.4 Significance and Use

The performance of a recombinant lead-acid battery is partially dependent on the surface area of the mat between the plates and must be controlled within reasonably close

tolerances

10.5 Apparatus

10.5.1 Surface area analyzer such as “Quantasorb Jr.”

10.5.2 Drying oven capable of reaching a temperature of 260°C (500°F)

10.5.3 Balance capable of weighing to 0.1 mg

10.6 Calibration

10.6.1 The balance should be cleaned and checked on a yearly basis It should be calibrated daily

using weights traceable to the National Institute of Standards of Technology (NIST)

10.6.2 Run a WRM with every batch of samples Results of the standard should be transferred to

the appropriate control chart NIST SRM’s are available and can be run occasionally to check accuracy at various levels

10.7 Sampling

10.7.1 Cut the RBSM into pieces 2 x 10 mm in size

10.7.2 Load samples into clean, dry, and previously weighed sample cells Sample weights should

be recorded on surface area data sheets or in laboratory notebooks

10.7.3 Place sample cells in oven, connect in series and run nitrogen through cells at a rate of one

bubble/sec Krypton can be used in place of nitrogen for most RBSM materials

If the RBSM is 100% inorganic, heat at 260°C (500°C) for 30 minutes and then overnight at 120°C (248°F) If the RBSM contains organics, then the material must be dried at lower temperature to avoid damage to the organics If the RBSM contains organics, dry the material

at 80°C (176°F) for a minimum of 24h

10.8 Procedure

10.8.1 Turn on the adsorbate and calibration gas toggle switches and then the instrument power Let

instrument warm up for 15 minutes before using

10.8.2 Turn off the oven and let the sample cool down Continue the nitrogen flow until the last

sample has been run

10.8.3 Transfer a sample cell from the oven to a cell holder assembly and place the assembly into

the instrument After a steady baseline is obtained, the sample is ready to analysis

10.8.4 Analyze the sample following the procedure for the appropriate instrument Single point

measurements are used routinely Multiple point measurements are not routinely used, but may be made for increased accuracy See Annex for a condensed operation procedure for a

“Quantasorb Jr.” instrument

10.8.5 After all samples have been run, turn off the instrument and then the gas flows Also turn off

the nitrogen in the drying oven

A cs = Cross Section Area of Adsorbate Molecule (for N2 = 16.2*10-10 m2)

T = Temperature of Calibration (Ambient) in degrees Kelvin

Po = Saturated Pressure of Adsorbate

R = Gas Constant = 82.1 cc atm/K Mole

Pa = Ambient Pressure, atm

A c = Area of Calibration

10.10 Report

Report the surface in m2/g

10.11 Precision and Bias

10.11.1 Precision

No statement may be made on the precision of this test method, since round robin testing among laboratories has not been conducted

10.11.2 Bias

No statement on bias may be made due to the lack of a standard reference material

10.12 Annex

10.12.1 Safety

10.12.1.1 Standard good laboratory practices should be employed, consistent with the applicable

Chemical Hygiene Plan

10.12.1.2 In addition, the analyst should be familiar with the Material Safety Data Sheets (MSDS) for

materials employed in the analysis

10.12.1.3 The analyst must be familiar with the rules governing the use of liquid nitrogen and

compressed gases

10.12.2 Condensed Operation Procedure

10.12.2.1 After a stable baseline has been obtained, select an attenuator setting that will give a signal

between 700 and 1200 counts This will usually be 8 or 16

10.12.2.2 Depress the “ADS” push button and set the signal meter to zero

10.12.2.3 Raise the liquid nitrogen bath so that the sample cell is immersed under the coolant

10.12.2.4 Observe the count rate during the adsorption step and make any adjustments in the

attenuator setting to obtain a count rate of 700 to 1200

10.12.2.5 When a stable baseline is gain obtained, depress the “DES” button and re-zero the signal

meter and integrator

10.12.2.6 Lower the Dewar flask and immerse the sample cell in a beaker of room temperature water

until the adsorbate flow meter float returns to its starting position

10.12.2.7 When the signal meter has returned to zero, record the integrator counts and re-zero

10.12.2.8 Using a gas-tight syringe, inject a sample of pure nitrogen into the gas =stream The counts

should be within 10-15% of the desorption counts At an attenuator setting of 32 (150 ma on the detector), 1 ml of N2 gas will give approximately 600 counts Total counts can be adjusted

by changing the volume of N2 injected

10.12.2.9 Record the total counts and volume injected

10.12.2.10 Turn the sample isolation valve to “Bypass”, remove the cell holder assembly and insert a

new sample in the holder Place holder into instrument, turn valve to “cell” and begin again at Step 1

10.12.2.11 Weigh the full sample cell Obtain the weight of the sample by subtracting the weight of the

empty cell Record the weight on the data sheet

11 STANDARD TEST METHOD FOR DETERMINING PERCENT MOISTURE CONTENT OF

RECOMBINANT BATTERY SEPARATOR MAT

11.2.2 International Standards Organization ISO 287

11.2.3 TAPPI T-412 Moisture in Paper and Paperboard

11.2.4 ASTM D-644 Test Method for Moisture Content of Paper a Paperboard by Oven Drying 11.3 Terminology

11.3.1 RECOMBINANT BATTERY SEPARATOR MAT (RBSM) – Any material intended for use as a

separator between the plates of opposite polarity in a valve regulated, lead-acid battery 11.3.2 % MOISTURE CONTENT – The percent weight of RBSM attributable to the pick-up of

moisture

11.3.3 MOISTURE FREE SPECIMEN – A dried and desiccated specimen of RBSM referred to as

dried RBSM in (11)

11.4 Significance and Use

Per pound, RBSM is one of the most expensive components, used in the lead acid battery Since it is sold by weight, the moisture content of the material is of major concern to the buyer

11.5 Apparatus

11.5.1 Laboratory balance with a sensitivity of 1 mg

11.5.2 Drying oven (non-air recirculation), capable of maintaining a temperature of 150°C ± 10°C

(302°F ± 18°F)

11.5.3 Laboratory timer, analog or digital, capable of measuring minutes and seconds

11.5.4 Clean suitable laboratory weighing dish capable of holding 10 ± 1 g of RBSM

11.5.5 Desiccator & Desiccant

11.6 Calibration

Checking of laboratory balance

11.6.1 Check the accuracy of the laboratory balance frequently by applying accurately measured

11.6.2 Before each use, frictional effects shall be sufficiently minimal and the zero reading shall be

sufficiently correct to obtain the required weighing accuracy (11.5.1)

11.7 Sampling

The outer two rounds from each roll of RBSM tested should be removed and discarded, to avoid sampling an area that might have become contaminated during shipping and handling before sampling

A minimum of three random specimens shall be sampled from each lot (11.8.1)

11.8 Procedure

11.8.1 Weigh out three 10 g ± 0.10 g specimens of RBSM into tared laboratory weighing dishes

using a laboratory balance accurate to the nearest mg

11.8.2 Place the specimens in the drying oven at 150°C ± 10°C for 30 minutes ± 3 minutes

11.8.3 After drying, place the specimens into the desiccator until cool

11.8.4 Reweigh the specimens to the nearest 1 mg

11.8.5 Repeat steps 11.8.2 through 11.8.4 until reproducible results are obtained, while periodically

checking the zero of the balance, between the specimen readings

11.9 Calculations

% Moisture = (Original RBSM weight – dried RBSM weight) x 100 / Original RBSM weight 11.10 Report

11.10.1 Percent moisture to the nearest 0.1%

11.10.2 Percent moisture should be reported as averages, range, and standard deviation

11.11 Precision and Bias

11.11.1 Precision

A round robin study on one material by six different laboratories indicated a

between-laboratory variance of 0.018%, and within-between-laboratory variance of 0.0009%

11.11.2 Bias

No statement on bias can be made due to a lack of a standard reference material

12 STANDARD TEST METHOD FOR PERCENT IGNITION WEIGHT LOSS OF

RECOMBINANT BATTERY SEPARATOR MAT

12.1 Scope

12.1.1 This test procedure covers the determination of the percent weight loss on ignition on a

moisture-free specimen of recombinant battery separator mat (RBSM)

12.1.2 This method covers all grades of RBSM used in various battery applications

12.2 Referenced Documents

12.2.1 TAPPI Standards

12.2.2 British Standards BS 3631 Ashin Paper and Paperboard Product

12.3 Terminology

12.3.1 RECOMBINANT BATTERY SEPARATOR MAT (RBSM) – any material intended for use as a

separator between the plates of opposite polarity in a valve regulated, lead acid battery 12.3.2 DRIED RBSM WEIGHT – Moisture free specimen weight, which is subtracted from the

original specimen weight to avoid moisture pick-up effect, when calculating the ignition weight loss of the RBSM

12.4 Significance and Use

This method will allow the determination of the percentage of combustible materials added to the RBSM

12.5 Apparatus

12.5.1 Laboratory balance with a sensitivity of 1 mg

12.5.2 Drying oven (non-air recirculating), capable of maintaining a temperature of 150°C ± 10°C

(302°F ± 18°F)

12.5.3 Muffle oven capable of maintaining a temperature of 540°C ± 10°C (1004°F ± 18°F)

12.5.4 Analog or digital laboratory timer capable of measuring minutes and seconds

12.5.5 Clean silica or platinum crucibles and lids

12.5.6 Heat resistance gloves and crucible tongs

12.5.7 Clean scissors or paper cutter (free from rust or other oxidation products of contaminants) 12.5.8 Desiccator and desiccant

12.6 Calibration

Checking of laboratory balance

12.6.1 Check the accuracy of the laboratory balance frequently by applying accurately measured

masses with both increasing and decreasing loads

12.6.2 Before each use, frictional effects shall be sufficiently minimal and the zero reading shall be

sufficiently correct to obtain the required weighing accuracy (12.5.1)

12.7 Sampling

The outer two rounds from each roll of RBSM tested should be removed and discarded to avoid sampling an area that might have become contaminated during shipping and handling before sampling

A minimum of three random specimens shall be sampled from each lot (12.8.1)

12.8 Procedure

12.8.1 Weigh out three 2.000 g ± 0.001 g specimens of RBSM using an analytical balance Place

each specimen into a clean pre-weighed silica or platinum crucible

12.8.2 Place the specimens in the drying oven, to dry for 30 minutes ± 3 minutes

12.8.3 After drying, place the specimens into a desiccator until cool

12.8.4 Reweigh the specimens to the nearest 1 mg

12.8.5 Repeat steps 12.8.3 through 12.8.4 until reproducible results are obtained

12.8.6 Pre-heat the muffle furnace to 540°C ± 10°C (1004°F ± 18°F)

CAUTION: Severe burns will occur if proper handling of crucibles is not observed

12.8.7 Using heat resistance gloves and tongs, place the crucibles and specimens into the muffle

furnace for 30 minutes ± 3 minutes Remove the crucibles and allow them to cool for a moment on top of a heat resistance surface After the crucibles are sufficiently cool, transfer the crucibles into a desiccator until cool

12.8.8 After the crucibles reach room temperature, reweigh the samples again to the nearest 1 mg

while periodically checking the zero of the balance between the specimen reading

12.10.1 Percent ignition weight loss to the nearest 0.1%

12.10.2 Results of percent ignition weight loss should be reported as averages, range, and standard

12.11.2 Bias

No statement on bias can be made due to a lack of a standard reference material

13 STANDARD TEST METHOD FOR TENSILE STRENGTH AND PERCENT ELONGATION

MEASUREMENTS ON RECOMBINANT BATTERY SEPARATOR MAT

13.1 Scope

13.1.1 This test method describes the use of a constant rate of elongation apparatus to determine

the force per unit width required to break a test piece (tensile strength) and the percentage of elongation at break (stretch); it may also be used to define the energy absorbed per unit area

of the test piece before breaking (tensile energy absorption)

13.1.2 This method is suitable for all types of recombinant battery separator mat (RBSM), either

binder-free or those using organic additives to increase strength, and which have tensile and elongation values within the limitations of the instruments used It may be used for

handsheets as well as samples taken from large production rolls

13.1.3 Tensile strength is commonly reported in pounds per inch or kilonewtons per meter; it may

also be expressed as grams per inch or pounds per square inch

13.2 Referenced Documents

13.2.1 TAPPI T494 Tensile Breaking Properties of Paper and Paperboard (using a

constant-rate-of-elongation apparatus)

13.2.2 ASTM Standards

13.2.2.1 ASTM D 76 Standard specification for Tensile Testing Machines for Textiles

13.2.2.2 ASTM D 828 Tensile Breaking Strength for Paper and Paperboard

13.2.2.3 ASTM D 1682 Standard Test Methods for Breaking Load and Elongation of Textile Fabrics

13.2.3 British Standard BS 6410 British Standard Methods of Test for Filter Papers; Section Three:

Test Methods for Mechanical Properties

13.2.4 ISO 1924 Paper and Board, Determination of Tensile Strength

13.2.5 Japanese Industrial Standard JIS C2202 Glass Mats for Lead Acid Storage Batteries

13.3 Terminology

13.3.1 Tensile Strength – the maximum tensile stress of a test sample prior to rupture during a

tensile test carried out under prescribed conditions It is reported as the force per unit width of the test specimen

13.3.2 Percent Elongation – is the maximum tensile strain developed in the test sample prior to

rupture during a tensile test carried out under prescribed conditions Percent elongation is expressed as a percentage representing the ratio of the increase in length of the test sample

to its original length multiplied by one hundred

13.3.3 Tensile Energy Absorption (TEA) (Optional) – the work done when a test sample is stressed

to rupture under tension during a pull test carried out under prescribed conditions as

measured by the integral of the tensile stress over the range of tensile strain from zero to the maximum value TEA is expressed as energy per unit area (test span x width) of the test specimen