Development of a 

Standardized 

Energy Test Cloth 

for Measuring 

Remaining Moisture 

Content in a 

Residential Clothes 

Washer 

U.S. Department of Energy 

Buildings, Research and 

Standards 

May 2000 

Prepared by: 

Arthur D. Little, Inc. 

Acorn Park 

Cambridge, Massachusetts 

02140-2390 
Table of Contents (continued) 

1. 

I I 

I .2 

13 

14 

2. 

2. l 

l.l. j 

1 1 1 

l.l.3 

24 

2 5 

2.5. l 

l.5.2 

26 

2.6. j 

J.62 

J.6 3 

2.6-1 

::. 6. 5 

2.65.l 

3. 

4. 

41 

4.2 

Introduction ............................................................................................... 1-1 

Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................... 1-1 

Energy Test Cloth...... . ................................ 1-2 

Moisture Absorption and Retention in an Energy Test Cloth ..................... 1-3 

Summary and Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................... 1-3 

Extractor-Based RMC Testing .................................................................. 2-1 

Purpose of Test Program ........................................................................ 2-1 

Lahoratorv and Procedure ........................................................................ 2-1 

/,uhorotm:r 1~·q11ipme111 ............... ............................................................. 2-2 

l 1roced11re ..... .......................................................................................... 2-2 

Shakedown Jests ..................................................................................... 2-3 

Test Cloth Sources... . ......................................................... 2-3 

Test Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .................................. ." ... 2-4 

Test Results RMC versus cfg for Different Test Lots ................. 2-6 

( '0111pariso11 of ( 'loth l,o/s ....................................................................... 2-6 

I.1·(t/11ation ofA/liance Cloth ................................................................... 2-~ 

Test Results Influence of Other Test Variables on RMC ........................ 2-9 

l ."fI,. 1·c · J'· , DAA(' ) 111 : .f ( (/ 0 , ll)//I Jn](; ()JI IVVJ .•........•..••.••.....•..•..•....••..••.•..•.••••••••..••.•••.••. - - II 

Jjfect of IJ>od Size 011 Rl\1C .................................................................. 2-10 

/}feet of Soak Water frmperature 011 /?.MC. .......................................... 2-11 

/}feet <?(Soak lime 011 RM(' ................................................................. 2-13 

ljlect <!(Cloth J,[f'c: 011 Rlv!C .................................................................. 2-13 

/. -,:/", ' ffJ.' (, d' . . 7 jJAf(' ) 16 :ftUI <! IL- Oil lt/011111}.!. OJI VI-' ,. ...................................................... __ J 

Results of Washer Based RMC Tests Conducted by lntertek Testing 

Services (ITS) ........................................................................................ 3-1 

Cloth Characteristics and Relation to RMC ............................................. 4-1 

Discussion of Cloth Characterization Variables.. . .............................. 4-1 

Results of Cloth Characterization Tests .............. . . ................................ 4-2 

4J Comparison of Cloth Characterization Test Results with RMC Test 

Results..... . .................................................................................... 4-5 

5. RMC Correction Factor ............................................................................. 5-1 

:' I Procedure to Calculate Correction Factor . . . . ..................................... 5-2 

5. !. I S1u11dard RMC 1·ersu.\ cfK ( 'urve ............................................................. 5-3 

5. J.J Fstahlish RA·!C 1·ers11s ~'fk l"aluesfor New Jest Cloth .............................. 5-3 

5. 1.3 reus1 Squares ht .................................................................................... 5-3 

5. J.-1 App~1· to Clothes Washer Jest Results ..................................................... 5--1 

5 2 Test Data Confirming Correction Procedure .......................................... 5-4 

6. Approach to Obtaining and Verifying Consistent Test Cloth ................. 6-1 

6 I Outline of Proposed Specification ........................................................... 6-1 

6.2 Verification . ......... ... ... ... ....... ..... ............. . ....................... 6-1 

6J Standard Language...... .. .............................................................. 6-2 
List of Figures (continued) 

Figure 2 I RMC vs. g for Tl and CG Cloth ...... . . .. ········ .............................. 2-7 

Figure 2.3 

Figure 2.4 

Figure 2.5 

Figure 2.6 

Figure 2.7 

Figure 2.8 

Figure 2 9 

Figure 2 10 

Figure 2. I I 

Figure 5- I 

Figure 5-2 

Figure 5-3 

RMC for Alliance Cloth before and after Treatment for Removal 

of Stain-Resistance Fluoropolymer Surface Finish ............................ 2-9 

Rl\1C vs Spin Time for I 00 and 300g.... .. . . ............. 2-10 

Rl\1C vs. Load Size at 100 and 300 g's........ . ........................... 2-11 

Rl\1C vs. g for Warm and Cold Soak for Load TI2 ............................. 2-12 

Rl\1C vs. g for \Varm and cold Soak for Load TB ........................... 2-12 

Rl\1C vs. Soak Time in Minutes for Warm and Cold Soak at 115 g ...... 2-13 

R!\1C vs. Number of Wash/dry cycles ............................................. 2-14 

Bone Dry Weight vs. Number of "Washes.. . ........................... 2-15 

Shrinkage of Energy Cloth Used in Cloth Life Tests ........................ 2-16 

Rl\1C Correction to Determine the RMC that would have been 

Measured with ··standard" Test Cloth... .............. ........... . ..... 5-2 

Linear Correction Curve for Tl Lot 4, \vith Individual Extractor 

Rl\1C Data Points .. .. . .. . . . .. .. .. .. . ..................................... 5-5 

Linear Correction Curve for Tl lot 5, with Individual Extractor 

Rl\1C Data Points. . ........................................ 5-6 

ii 
List of Tables (continued) 

Table 2.1 

Table 2.2 

Table 2.3 

Table 2-4 

Table 3.1 

Table 4.1 

Table 4.2 

Table 4.3 

Table 4.4 

Table 5-1 

Table 5-2 

Equipment used in Extractor Based RMC Tests ................................. 2-2 

Summary of Test Lot Status....... . . . . . . . . . . . . . . . . . . . . ........... 2-4 

Extractor Based RMC Test Program .......................................... 2-5 

Rl\tC Values for Different Pre-Conditioning Machine Type ............. 2-16 

ITS Washer Based RMC Results ..................................... 3-1 

Cloth Characterization Variables ........ . ........ ······· .......... 4-2 

Cloth Characterization: Fabric Weight. Thread Count. Yarn Number 

and Fiber Content ............................................................................ 4-3 

Cloth Characterization: Water Retention, Drop Absorbency, Finish, 

Repellency and Vertical Wicking Rate .... . . ............................... 4-4 

Summar:-.· of Results from Independent Laboratories.... . ............. 4-5 

Standard RMC vs. g Values and Corresponding New Cloth RMC 

Values for Linear Least Squares Fit ..................... . . .... 5-4 

Correction Coefficients .... . ....................... . ........... 5-4 

Table 5-3 Lot 4 Verification of Correction Factor in Clothes Washer ................. 5-6 

Table 5-4 Lot 5 Verification of Correction Factor in Clothes \Vasher..... . .... 5-7 

Table 2 6. 5 l\fatrix of Extractor RMC Test Conditions ...... 6-3 

Table 2 6 61 Standard RMC values (RMC1;u1dar<l). . ....... .. . .. . ...... 6-5 

iii 
1. Introduction 

This report summarizes the result to-date of the investigation. ··remaining moisture 

content .. (Rl\1C) testing. fabric characterization, and correction procedure undertaken to 

define a standardized energy test cloth 

1.1 Background 

Under the National Appliance Energy Conservation Act (NAECA). energy efficiency 

standards and energy test procedures have been established for a wide range of consumer 

appliances. including clothes washers and clothes dryers. The energy test procedures for 

these t\VO laundry appliances originally were established in 1977 (clothes washers) and 

1981 (clothes dryers) ( 10 Code of Federal Regulations (CFR) 430. Subpart B, 

Appendices J and D. respectively). Both specify a 50/50 cotton/polyester blend "energy 

test cloth"' that is used as a simulated wash load for testing clothes washers and for testing 

clothes dryers 

The energy test procedure that is currently in effect for clothes washers measures the 

electric energy input to the washer and the energy content of the hot water consumed by 

the clothes washer. A clothes washer energy factor is defined in terms of the basket 

\ olume and the total electric and hot water energy use. The current efficiency standard is 

set in terms of this measurement of the energy factor. The effectiveness of the final spin 

c~·cle in remO\ ing moisture from the wash load (and thereby reducing the energy 

consumption of the clothes dryer) is not measured or considered. 

For a number of years, a rulemaking has been ongoing to revise both the test procedure 

and the efficiencv standard for clothes washers to take moisture removal effectiveness 

into account A revised test procedure was adopted in a Final Rule dated August 27, 

1997 (I 0 CFR 430 Subpart B. Appendix J and J 1 ). Revisions to Appendix J are currently 

in effect. however, Appendix J 1 will not go into effect until proposed efficiency 

standards into effect A modified energy factor (MEF) is defined in Appendix J 1, based 

on the electric energy input. the hot water energy, and the dryer energy. Dryer energy is 

based on the remaining moisture content of a test wash load. The process to establish the 

ne\\ efficiency standard in terms of the MEF is ongoing. 

ln the Appendix JI test procedure. ··remaining moisture content" (RMC) in a test load of 

the aforementioned energy test cloths is the measure of water removal effectiveness. 

Over the approximately 20 year period that the original clothes washer and clothes dryer 

test procedures have been used, no variations or inconsistency of washer or dryer test 

results had been attributed to variations in the test cloths A significant inconsistency in 

Rl\K test results under the new Appendix J 1 procedure was noted by Alliance Laundry 

Systems LLC and was brought to the Department of Energy's (DOE's or Department's) 

attention in a letter dated June 7. 1999. In the tests referred to in this letter, which were 

run at lntertd.; Testing Services (ITS), the RMC values that \Vere obtained in one machine 

with two different Jots of energy test cloths differed by over 11 percentage points (67 9 

1-
percent versus 56.0 percent). When these two lots of energy test cloth were run through a 

second machine. a similar difference in RMC occurred. 

The effect of RJ\1C on MEF can be substantiaL particularly for washers wfoch are more 

efficient with respect to electrical consumption and use of hot \\ater. The following 

scenario illustrates: For a high efficiency horizontal axis \vasher. an 18% increase in 

RMC (54 5%-64 5%) \viii result in a 13% decrease in MEF ( 1.52-1 33) For a lower 

efficiencv washer. a 17%) increase in Rl\1C (57 7%-67 7~/o) will result in onlv a 6% - - decrease in l\1EF (82- 77) 

1.2 Energy Test Cloth 

.-\ \\ ide variety· of articles and fabrics are machine washed by consumers. including: 

• Cotton knit goods. denim. towels 

• Cottonipoly·ester blends in shirts. sheets, tablecloths 

• \' arious svnthetics in a wide varietv of articles - -

It is clear that all of the above could not be evaluated in the revised procedures that 

include moisture content As mentioned above, to simplify RMC testing, the standardized 

cloth used successfully in previous energy tests was specified. A number of qualified 

vendors have been providing these test cloths to manufacturers and other test labs on an 

ongoing basis for many years. The specifications stated in the energy test procedure are: 

• A 50/50 cotton/polyester to represent a rough average of the typical mix of cotton, 

cotton1polyester blend, and synthetics. The cloth has a momie or granite weave and a 

pure bleached finish 

• The thread count shall be 61 x 54 (warp x fill) per inch 

• The fabric weight shall be 5.75 oz. per sq. yd. (195 0 gm per sq. m) 

Aside from the historical success with respect to previous procedures. there is no 

justification for these specifications. 

The energy cloths are 24 in. by 36 in. (61.0 cm by 91.4 cm.) and are hemmed to 22 in. by 

34 in (55 9 cm by 86.4 cm.) before washing. Energy stuffer cloths (smaller cloths used 

to even-out load size) are 12 in. by 12 in. (30.5 cm by 30.5 cm.) and are hemmed to 10 

in by I 0 in (25.4 cm. by 25.4 cm) before washing. Both energy test cloths and stuffers 

clot!is should shrink no more than 4% on the length and width after five washes. 

Cloth manufacturers typically produce yarn from fiber and subsequently weave and finish 

the cloth material Two suppliers. Textile Innovators Corp. (TI) and Cotton Goods Mfg. 

Co. Inc. (CG) purchase cloth materiaL prepare the energy cloth by sewing and hemming 

and provide it to washer manufacturers and testing laboratories. They have supplied 

energy test cloth that. over the years. has varied somewhat from the above standards. 

1-
There are additional cloth specifications that influence the moisture content. The yarn 

size is a parameter that is related to the yarn diameter. This. together with thread count, 

blend (fiber content) and weight define the porosity of the cloth Finish. referred to by 

descriptors such as .. pure bleached .. must be clearly identified. Any finish, particularly a 

water repellant finish (frequently specified for cloth used in other applications), must be 

avoided. 

1.3 Moisture Absorption and Retention in an Energy Test Cloth 

The amount of water absorbed and retained in an energy test cloth can be attributed to 

se\ era! factors 

• Surface \\ etting. which is a function of relative humidity 

• Water retained betv,een the warp and fill 

• Water retained between the fibers 

• Water retained in the lumen, or center of the cotton fiber 

• Water ionicallv bonded in the cotton fiber 

Polyester is hydrophobic, and essentially has no attraction for water. All of the factors 

listed. except ionic bonding, are effected by the mechanical removal process. Water that 

is ionically bonded can only be removed chemically or by heating. Since RMC tests are 

only mechanical. there is a limit to the moisture that is removed. 

1.4 Summary and Approach 

It is apparent that a standardized test cloth is required in order to provide consistent RMC 

test results. The work summarized herein is aimed at 

• Identif\'ing the variables in the construction of 50/50 polyester cloth and its 

constituent fiber and yarn that affect the moisture absorption and moisture retention 

characteristics of the cloth 

• Developing a process for obtaining and validating standard test cloth 

• Generating data that indicates the sensitivity of RMC values to different operating 

rnriables and reporting them in a publicly available document 

This report summarizes our efforts to date in addressing these issues Our approach 

includes the following tasks: 

• In-house laboratory testing using an extractor to obtain effects of operating variables 

on RMC for cloth from different suppliers and different lots from the same supplier 

• Analyze cloth samples using external testing laboratories 

• Use information from above to: 

1-
Document the effect of variables on RMC 

Propose a procedure to obtain and verify consistent test cloth 

Propose a revised definition of test cloth for regulations 

Details on progress are found in the follmving report. 

1-
2. Extractor based RMC Testing 

To understand the effects of operating variables and cloth specifications. it is necessary to 

conduct laboratorv tests to determine RMC To insure that test results would not be 

influenced or biased by any manufacturer's product (clothes washer). we used an 

extractor to remove moisture content. An extractor is a centrifuge - basically a rotating 

basket that has a controllable speed to produce a variety of centrifugal forces The speed 

was varied to impose different centripetal accelerations on the test load. These 

accelerations are reported in terms of gravitational acceleration (g) We also chose to 

soak the cloth in a tub at controlled temperature rather than use the agitated soak cycle 

provided by a t~vical washer. Otherwise, our RMC tests closely resembled those 

specified in the energy test procedure 

2.1 Purpose of Test Program 

The extractor-based RMC tests have two basic purposes: 

To evaluate the differences in spin g vs. RMC for available test cloths from different 

suppliers and different lots from the same supplier. Ultimately, relate these variations 

(or lack of variation) to differences in cloth specification that can be ascertained by 

laborator)· tests (as explained in Section 4.). Detem1ine whether differences in RMC 

's. gin the extractor test correlate with differences in RMC in a particular clothes 

washer as obtained by Intertek Testing Services (ITS). 

; To evaluate the impact of several basic variables on RMC results and the consistency/ 

repeatability of RMC results when identical cloth is run under identical conditions 

using an extractor. Variables to be studied are: 

• Effect of spin time on RMC 

• Effect of soak water temperature prior to spinning on RMC 

• Effect of length of soak time prior to spinning on RMC 

• Effect of load weight/basket \'Olume on RMC 

• Effect of test fabric life (cumulative wet - dry cycles) on RMC and shrinkage 

Quantitative data addressing each of these variables and repeatability under identical test 

conditions will be indicative of which variables need to be closely controlled in future 

testing and/or where bounds need to be established to ensure consistent results. 

2.2 Laboratory and Procedure 

This section discusses our extractor-based RMC testing laboratory and procedures. Also 

included is a description of shakedown tests used to verify testing procedures and 

establish initial test parameters 

2-
2.2.1 Laboratory Equipment 

Table 2.1 details major equipment used in our extractor-based RMC studies. As noted, 

our preferred extractor had a long delivery time, so a smaller unit with immediate 

availability \Vas initially utilized. 

Table 2.1 Equipment used in Extractor Based RMC Tests 

,·. tTE:M · · •· · Sf>ECtFlCA:TJON < •''• ............. 

,:,·.>SUPPLIER .· ... .· · . PURPOSE ... : .. • •: 

Washing Typical , 3 ~peed. 14 Local supplier For initially preparing cloth for extractor. 

Machines (2l cycle, 2.9 W Two machines of identical construction. 

(Maytag Model# 

LAT9706AAE) 

Clothes Dryer 90000 BTU/hr, gas Local Supplier A commercial size dryer to insure "bone 

fired dry" cloth. 

Extractor 35 lb. capacity, 20 in. Bock This extractor is sized to satisfy all test 

diameter. 11.5 in. Engineered requirements. 

depth, with variable Products 

speed drive 

Extractor 20 lb. capacity, 17 in. Smart-Sox, This is a smaller extractor, purchased 

diameter, 10.5 in. Inc. because of its immediate availability. It 

depth was used for initial testinq 

Power Inverter MagneTek, 3 hp, 3 Blanchard Required to operate the smaller extractor 

phase, 220 volts Electric. Inc. at variable speed 

Water Heater 40 gallon capacity In-house Required for 135F wash water 

Scales 26 lb. +/- 00022 lb. In-house Required for weighing cloth. 

480 lb. +/- .01 lb. 

2.2.2 Procedure 

Our procedure closely resembles those in the existing energy test procedure. We have a 

pretest procedure to both precondition the cloth and the clothes \vashers. Test loads are 

preconditioned once unless otherwise noted A series of extractor-based RMC tests is 

then performed on the test load at specified conditions. 

Pretest Procedure 

Test lots of cloth (energy test cloth and stuffer(s)) from different sources are divided 

into test loads Each cloth is marked with the test load number in indelible ink. 

' Clothes washers are preconditioned per Appendix J 1: Section 2.9 (JI :2.9) 

~ Inlet hot and cold water temperatures are recorded. Hot water is maintained at l 35F 

+i- SF. 

4. Each load is prewashed: 

2 complete cycles: warm prewash/ warm wash w/ AHAM detergent and 2 warm 

rinses and drying 

3 complete cycles: warm normal wash and warm rinse and drying 

:". Each load is made bone-dry per Jl: 1.3 

2-
RMC Test Procedure 

Each extractor-based RMC test is conducted using the following procedure: 

1. Record the bone-dry weight. 

Soak in a cylindrical vessel 16"' in diameter containing approximately 10 gallons of 

water. Soak temperature is either cold (60F ±_SF) or warm ( 1 OOF ±SF) and time is 

\ ariable. 

3. RemO\ e the load and place carefully in the extractor without wringing the cloth. 

4 Run the extractor at the prescribed g and time. 

:". Remove the load and record the v.·eight. 

6. Compute 0 oRMC as follows: % RMC= [(Weight after extraction - bone-dry weight) 

i bone-dry weight] * 100 

Bone-dry the load and repeat steps 1-7 as prescribed in test plan 

2.2.3 Shakedown Tests 

\Ve conducted shakedown tests to verif)1 the above procedures and to establish 

parameters for our initial tests. The load size was 4.5 lbs .. which represented a mid-sized 

load for a washer with the dimensions of our initial extractor. Other parameters included 

soak time and spin time. A soak time of 20 minutes and spin time of 10 minutes was 

selected for the initial tests. 

2.3 Test Cloth Sources 

Our test cloth is obtained primarily from Textile Innovators Corporation. (Tl) and Cotton 

Goods Manufacturing Company, Inc. (CG). To date. five lots (orders) have been received 

from Tl and t\\ o lots from CG. In addition. cloth was distributed as follows 

• A portion was sent to lntertek Testing Services Inc. (ITS) for washer-based RMC 

tests (see Section 3) 

• Samples from each lot were sent to independent laboratories for determination of 

cloth characteristics (see Section 4) 

• A small portion of Tl lot 3, and a larger portion of Tl lot 5 was sent to each washer 

manufacturer for in-house laboratory testing. 

In addition. \Ve performed extractor-based RMC tests on cloth received from Alliance 

Laundry Systems LLC. It was suspected that a fluorochemical finish was present on this 

material. Consequently. as detailed belmv, we tested this cloth both as received and also 

after a finish removal process was conducted. 

Table 2.2 summarizes the status of test lots. 

2-
Table 2.2 Summary of Test Lot Status 

:--I. .· •. !:,O}.;at .•..ffi~cla·ti~oadn· •. · •.·••.·••.••· .. ·•.•··.•• .. ••.·•.• .. •·.•••. + T~t··· .. 1 .•...· .a •. ·•.•r:.·.·• ·.·. s per RMC 'fesbf • ••••• ITS Testh1g •• CtiaracteriStk:s . M11ll:t1fa<:tμt~i;t • . iut:.. , j ... -. .. · ... · .. ···· · ...... ·. ·· · > le.$.ts ~f l;af)s .... ·.·.· · · Tili$ 

i Tl Lot 1. (AOL 1 .1 ! 2 C C C N 

r--fffot 2, (AOL 2; 1 1 C C C N 

: Tl Lot 3. (AOL 31 ·· I 1 C C C C 1-·--· . 

• Tl Lot 4. (AOL 41 _____ L 1 C N C N 0

1'1 Lot 5. (AOL 5} _____ L ___ 1_ _ C P C C 

• CG Lot 1 I 2 C C C N 

~ CG Lot 2 I 1 C N N N 

LAlliance Initial : C C C N 

• Alliance Treated I C C N N 

KEY TO TABLE: C =Complete, P =planned, N =not planned 

2.4 Test Matrix 

A test program was designed to carry out the objectives outlined in Section 2.1. 

As indicated in Table 2.3, the program was divided into a series of tests. The first two 

series of tests \\ere intended to evaluate the differences in RMC vs spin g with respect to 

test lots. We also tested the Alliance load with and v.ithout a tluorochemical finish. In 

the remaining tests, we evaluated the effect of variables (in addition tog) on RMC 

results These variables included 

• Spin time 

• Load size 

• Soak water temperature prior to spin 

• Soak time prior to spin 

• noth life (cumulative wash cycles, shrinkage) 

The Appendices include a list of all test results included in this report 

2-
Table 2.3 Extractor Based RMC Test Program 

r~· C1oft1 I.().·. i Sptf19> ~=. ····· =·•/> ~~'~·me, lo1b~ize;· / \ · >. I'"?>°:t:est \/ ~--~--~ < < -~-~+--"-'·=m=•n'-· •.-+.· --.....c.~~--'.f==~~~·.:...c·······=··· ·."""····..;....· -'---4~· ~··<~·•••··••·••·..,...>..,. .. ··~··~ .·<~. ·~······•••· ........... •·•••·••<·~····•••·•<'""-4 .·>••••······ 

. ... / 

. Tl 1 __ 100 _j 10 4. 7 Evaluate RMC vs. g for 

: CG1, CG2 300 i Lots from different Suppliers 

Warm 20 I 

I -50()1 e--- _, 50 I i Tl1 T12,Tl3 ___ 100! 15 Warm 20 

I 

I 

I 

I 

84 Evaluate RMC vs g for 

Lots from the same 

Supplier 200 I 

: L.-Alliance -----·---..; ' .-_.i_~-~-t---+-----------+-------+-----+--------------i -~ 10 Warm 20 4. 7 Effect of Finish 

I 

! Initial and 300 ' Removal on RMC 

I Treated 500 I r------------+ ---+-------+------+----,-----+-------+-c----.,..~,--------___, i Tl 1. Tl2 ' 100, 2 Warm 20 84 Effect of Spin time on 

300 4 RMC 

6 

10 

15 

20 

25 

r=r12 -foo.- 15 "Wash"• "Wash"• 3 Effect of Load Size on 

i ---- 30

0

vo j ---+-------+-------+------f--------------1 

iTl2, Tl3 ~ 15 

4.7 RMC --

84 

Warm, 20 84 Effect of Soak 

100 I Cold Temperature on 

200 I RMC 

300 ! --·50][j 

. __________ 8_00_-ll----+------+------+-----+--------------1 

Tl1 115 I 

i 

: Tl2, T14, Tl5 

I 

j T13. T14, TIS 

I 

I 

! 

i 

10 

I 

! 

100 15 

I 50 4 

' i r------+-----< 

200 15 

~------ ------< 

I 

I 350 

Warm, 10 

Cold 20 

"Wash"* 

Warm, 

Cold 

60 

120 

16 hr. 

"Wash"• 

20 

4.7 

84 

84 

Effect of Soak Time 

on RMC 

Effect of Cloth Life 

on RMC 

(50 "washes" with RMC 

determined after 

every fifth "wash") 

Obtain data for generation of 

correction curves 

L__----~----~------+-------+-----~----~--------------i 

~, A .. wash" consists of an agitation. spinning lightly and a second agitation with no 

detergent and warm water in a washer 

2-
2.5 Test Results: RMC vs. g for Different Test Lots 

This section discusses the differences in RMC vs. spin g with respect to different cloth 

suppliers. We report results for cloth from the t\vo suppliers. Tl and CG. as \veil as 

evaluation of the Alliance cloth that \Vas suspected to have a tluorochemical finish. 

Below. \Ve first compare the Tl and CG lots. discuss differences between lots, and finally 

address the Alliance lot 

2.5.1 Comparison of Cloth Lots 

Comparison of Tl and CG lots is shov..i1 on Figure 2.1. These data (taken in the smaller, 

Smart-Sox extractor) are with a spin time of 10 min .. \varm soak temperature, 20-min. 

soak time and a 4. 7 lb. load. As expected. there is a clear decrease of moisture content 

"ith higher g Typical vertical axis washing machines produce spin g·s in the range of 

I 20 g · s The asymptotic value at high g represents the maximum amount of moisture that 

can be mechanically removed from cloth. (see Section 1.3) The CG cloth clearly has 

higher RMC with decreasing differences at higher g values. At 100 g · s, the lot-to-lot 

variation of the Tl loads \vas 2% RMC, while the CG to Tl difference is 11 % The two 

cloths had a different "feel'". the CG cloth feeling much smoother than the Tl cloth. In 

Section 4, "'e present laboratory results indicating that Tl and CG cloth had some 

differences in characteristics. However. there is no clear connection between these 

differences and RMC Further investigation indicated that the CG cloth and Tl cloth 

came from different manufacturers. The Tl cloth was purchased from Riegel Mills, which 

produces finished product (cloth) from ra\\ material. The mill that produced the CG cloth 

is unknown. CG obtained their cloth from Artex, a distributor that purchases cloth from 

mills and resells it to users. Our conclusion is that in this case. differences in RMC could 

not be easily e-.:plained by examining cloth specifications. Water absorption and retention 

mav change \\ith manufacturers who are supplying material with similar characteristics. 

Identifying the mill of origin may help determine these differences. This may suggest that 

a single manufacturer of energy cloth may be desirable. 

2-
-~o,o ~-------------------------------~ 

---- --Tl11'. 

'--CG1A 

; --Tl1B 

~CG1B; 

;[' 

~ .:iS0:C 

0:: 

:5% 

Lead S1Z" 4 7 lbs 

S::.ak T ;:;1:::- 2C· f.11n 

:?'5°·o -Saa~ Temp vVarm · 

Spin frne 1 G Min 

]Q0,0 '--------------------------------------< 100 200 300 400 500 600 

g Factor 

Figure 2.1 RMC vs. g for Tl and CG Cloth 

Also of interest is the difference between lots supplied by the same manufacturer. Figure 

2 2 shows data for five TI lots ( ADLJ-5) These data (taken in the Bock extractor) are all 

with a spin time of 1 S minutes. warm soak temperature, 20-minute soak time and an 8.4 

lb. load. For the first three lots tested ADL 1. ADL2. ADL3. there is a maximum data 

spread of about 2 percent Subsequent lots 4 and 5 varied significantly as shown. 

2-
u 

:i 40 0°'" IX 

--ADL 1 

-111-ADL 2 

~ADL3 

~ADL4 

-+-ADL 5 

c· 1DO 200 300 400 500 600 700 800 900 

g 

Figure 2.2 RMC vs. g for all Tl loads 

2.5.2 Evaluation of Alliance Cloth 

As part of our test program, we were asked to perform RMC tests on cloth supplied by 

Alliance Laundry Systems LLC. They had purchased this cloth from Tl and obtained 

inconsistent results in their in-house tests, i.e, RMC was lower than expected. It was 

suspected that a tluorochemical finish that would repel moisture \vas present on this 

material This was verified by laboratory tests performed by Minnesota Mining and 

l\1anufacturing Company (3M). We tested this cloth as received and also after a finish 

remO\·al process. 

A procedure recommended by the United States Department of Agriculture (USDA) 

Laboratory (Southern Regional Research Center) for removal of finish was performed. 

The procedure called for a mixture of Triton X-100, Trisodium pyrophosphate, and 

Tide® to be mixed at a concentration of 1 gram/Liter, each. The test load was then 

soaked for one hour at 200 to 2 I 2 °F. The results are shown in Figure 2.3. These data are 

with a spin time of I 0 minutes, warm soak temperature, 20 minute soak time, and a 4. 7 

lb. load (taken in the smaller, Smart-Sox extractor). The results show that the RMC 

values were higher in the treated cloth, but not to the extent expected with finish removal. 

The conclusion is that the tluorochemical finish was not removed by the process or that 

the tluorochemical finish was not responsible for the differences in RMC. Since the 

removal process is used routinely by USDA, we suspect the latter conclusion is correct. 

2-
0 

::;: 

a: 

~,:::.% .-----------------------------------, 

~,Q% 

.?5% . ·Load Size 4 7 lbs - -

Soak T ane 20 Min 

Scak Tem;; \\'arm , 

Sr1nT1r.:i:o 10~.,1n 

·-+-1'.SG 

, --Stripped _ASG 

?D% ~--------------------------------! 

0 100 200 300 400 500 600 

g Factor 

Figure 2.3 RMC for Alliance Cloth before (ASG) and after Treatment for Removal of Stain-Resistance 

Fluorochemical Surface Finish (ASG Stripped) 

2.6 Test Results: Influence of other Test Variables on RMC 

The data in the previous section shows that the RMC is strongly influenced by spin g 

le\ el Several other operating variables also influence the RMC level reached after a spin 

cvcle. 

• Spin time 

• Load size 

• Soak water temperature prior to spin 

• Soak time prior to spin 

• Cloth life (cumulative wash cycles, shrinkage) 

The primary focus of the work reported herein has been to develop a test cloth 

specification, so that consistent RMC values are obtained with different lots of test cloth. 

In pursuit of this objective, it is of interest to understand the quantitative magnitude of the 

effect of these \'ariables on RMC levels: it is further of general interest to have this 

information publicly available_ 

2-
2.6.1 Effect of Spin Time on RMC 

For a fabric and load size, at a given spin g level, there appears to be an equilibrium RMC 

level that is reached after a comparatively long spin time. This is the limit of the 

mechanical removal process for that g force. Figure 24 plots RMC \ s. spin time for two 

different lots at I 00 and 300 g. These data represent TI l and TI2 loads \vith warm soak 

temperature. 20-minute soak time. and an 84 lb. load. The figure shows evidence of 

dependence of spin time on RMC The equilibrium time at 300g (about 20 minutes) 

appears to be somewhat longer than at 100 g (about 15 minutes) There is, of course. 

more moisture removed at higher g The process (see Section 1.3) involves several 

mechanisms\\ ith effecti\·eness that varies with g, apparently resulting in somewhat 

longer equilibrium times as more moisture is removed. 

-55°10 .--------------------------------. 

45% 

40% 

Load Size. 8.4 lbs 

.Soak Time: 20 Min 

Soak Temp Warm 

-+-Tl Lot 1 (300 g) 

-+-Tl Lot 2 (300 g) : 

.--Tl Lot 1 (100 g) 

-tt-TI Lot 2 _(100 g) 

2C· 0·o ,___ ____________________________ ___, 

10 15 20 25 30 

Spin Time (min) 

Figure 2.4 RMC vs. Spin Time for 100 and 300g. 

2.6.2 Effect of Load Size on RMC 

RMC vs. load size is plotted in Figure 2.5 at 100 and 300 g"s respectively. These data 

were taken in conjunction with our tests on cloth life (see Section 2.6.5 ). The three load 

size<; represent the minimum. average. and maximum load size recommended for the 

extractor drum volume. The normal soak process was replaced by a ·'wash" that 

consisted of an agitation. light spin and a second agitation No detergent and warm water 

was used. This was followed by the extractor-based spin. For these tests, the spin time 

was 15 minutes and the spin g was 100 and 300. Figure 2.5 shows the RMC decreases by 

several percentage points with increasing load at an amount that is independent of g 

force This is possibly due to the increased pressure on the outer cloths in the basket 

2-1 
caused by the increased radial depth of the load. It suggests that the load size and 

extractor dimensions (diameter. depth and perhaps basket porosity) be specified for RMC 

tests. 

~~5°10 ~---------------------------------, 

.?5% 

Tl 1967 I.Lot 2) 

Spin Time 15 Min. 

Ill 33 5% 

-- --

• 100g 

• 300g 

• 46 6% 

ID 31.5% 

:?00.'o ~----------------------------~ 

0 5 9 10 

Load Size (lb.I 

Figure 2.5 RMC vs. Load Size at 100 and 300 g's 

2.6.3 Effect of Soak Water Temperature on RMC 

The RMC is generally higher when the rinse water temperature is lov·ier. Figures 2.6 and 

2 7 show RMC vs. g for TI2 and TB loads respectively at warm (I 00°F) and cold (60°F) 

soak temperatures The spin time was 20 minutes. soak time was 20 minutes and the load 

was 84 lb Two figures are provided since the effect of temperature is difficult to discern 

when compounded with the data spread with load. Similar results were obtained with 

future lots 4 and 5. The cold water RMC values are as much as 8%. but generally 2-3% 

higher than the warm water RMC values. This is perhaps attributable to the temperature 

dependence of the surface tension and the absorptivity of water in cotton (both decrease 

with increasing temperature). 

2-1 
o!' 

(.) 

:: 

a: 

55% 

50% 

45% 

40% 

35% 

30% 

25% Loa j S12° ,3 4 lbs 

;Soak T 1r:v- 2·J Uin 

Spin T1mf- 15 r.1tn 

'--Tl2Cold 

-+-Tl2 Warm 

20% '--~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~--

0 

55% 

50% 

45% 

40% 

35% 

30% 

25% 

20% 

0 

100 200 300 400 500 600 700 

g Factor 

Figure 2.6 RMC vs. g for Warm and Cold Soak for Load Tl2 

.Load S12c a 4 lbsSoak Tw12 2G f.11n 

'SpinT1rn.: 15Uin 

100 200 300 400 500 600 700 

g Factor 

Figure 2.7 RMC vs. g for Warm and Cold Soak for Load Tl3 

800 900 

--Tl3Warm 

-4-Tl3 Cold 

800 900 

2-1 
2.6.4 Effect of Soak Time on RMC 

In actual RMC tests, a washer is used and the soak time also includes agitation As 

e:-;plained earlier. for our extractor based RMC tests, \\e soak the cloth in a cylindrical 

tub containing IO gallons of water. During our shakedown tests, we determined the effect 

of soak time on RMC. Figure 2 8 shows results for warm and cold soaks The data are for 

Tl cloth, 11 S g. I 0-min spin time and a 4. 7 lb. load. The data show no discernable trends 

in RMC vs soak times for cold soaks. There appears to be an increase in RMC with soak 

times of warm soaks for time greater than 1 hour. In order to resemble, to some extent, 

actual washer soak time and to maintain reasonable test times. we selected 20 minutes as 

soak time for our tests. 

-,=o,~, ------------------------------~ 

L :.ad Size 4 - !r,s 

Spin Time 1.:_,, '..1m 

Spin Speej ~ i:; g 

2G 60 

Soak Time 

I 

I 

1111

1

i!llllil!lll 

120 

:£'lTI 1 Warm· 

.ETI 1 Cold' 

16 Hours 

Figure 2.8 RMC vs. Soak Time in Minutes for Warm and Cold Soak at 115 g. 

2.6.5 Effect of Cloth Life on RMC 

To determine the effect of cloth life or cloth durability on RMC we repeatedly "washed" 

a load of cloth and periodically performed RMC tests (omitting soak time). Our "wash" 

c>·cle includes agitation. spinning lightly and a second agitation with warm water, all with 

no detergent. Other portions of a normal wash cycle are presoak and spin/rinse. The 

presoak is optional and we considered the spin/rinse taken care of in the RMC test. We 

--washed'' the load S times. then performed an RMC test and repeated this process I 0 

times, ultimately completing SO '·washes". Results for RMC change with ·'washes" and 

2-1 
the change in bone dry cloth weight with .. washes" are shown in Figures 2.9 and 2.10, 

respectively. The data are for TI cloth, at I 00 g, with IS-min. spin time, and an 8.4 lb. 

load. The cloth weight is reduced approximately 2% in SO '·washes'' because of the 

continual remc)\ al of material in the washing process. The RMC increases on the order 

of I 0/o in SO .. washes". The rate of weight loss from the fabric and the rate of RMC 

increase were linear over the entire SO wash cycles. Neither showed any sign of 

increasing toward the end of the SO wash cycles. The conclusion is that the cloth appears 

to hold slight!~· more moisture as it ages. This is possibly due to greater voids created in 

the cloth with age Note that the DOE test procedure allows test cloths to be used for up 

to 25 wash C\'cles. 

::/='~'C .-----------------------------------., 

'. ~t 4 • Ill 

'rt = 

•• 

;;< 

~ ~D% Q'. 

• 46% • 

''~ '1, ·Load Sizeo ii 4 lbs 

Spin Time, 1:'> l~1n 

Spin SpEc:J 1 DO g 

111111 

I •• 

... 

t • 

• 

Ill 

- ---- ".8 •• 

• 

• 

• 

•• • 

II 

• 

el gt? • 

• 

.. 

Ill 

Ill· .18. 

• 

•• 

_jC1S'~ ~------------------------------~ 

10 20 30 

#Washes 

40 

Figure 2.9 RMC vs. Number of Wash/dry cycles 

50 60 

2-1 
3950 

Lot 5 

Lot 4 .;-""'r*=====::===--?~-----w ~ 11~xio:-----...2f...- x x .. -.- .. ---X~-

5 380:! 

.. 

I: 

0 

m 

I 

Ala 

• ton-----

3650 L _______________________________ ~ 

10 15 2G 25 30 35 40 45 50 55 60 

Wash# 

Figure 2.10 Bone Dry Weight vs. Number of "Washes" 

As part of the fabric life testing the test cloth shrinkage was monitored. Linear 

dimensions were taken in three locations on both the horizontal and vertical axis of the 

test cloth. The unwashed test cloth dimensions established the baseline Measurements 

were recorded after each of the five pre-conditioning washes and then after every ten 

\\ash cycles The results are shown in Figure 2.11. The percent shrinkage increased 

steadily during the pre-conditioning process, reaching a plateau after ten wash cycles. 

The variation in percent shrinkage between lot 4 and lot 5 was nearly consistent at I%. 

There is no compelling evidence that the percent shrinkage has an impact on the moisture 

retention of the test cloth With the improved test cloth specification and more robust 

pre-conditioning procedure, it is suggested that the shrinkage requirement be removed 

from the test procedure. 

2-1 

65 
I 

! 

i 

SC·: 

II 

a 

• • 

• • 

• 

4 C.1 

3 G :, 

10 15 20 25 30 35 40 45 50 55 60 65 70 

#Washes 

Figure 2.11 Shrinkage of Energy Cloth Used in Cloth Life Tests 

2.6.5.1 Effect of Pre-Conditioning on RMC 

;•Lot 4 ~ 

:m Lot 5 

The pre-conditioning procedure was verified using both a vertical and horizontal axis 

washing machine to determine if the machine type used in pre-conditioning impacts the 

Rl\1C' results TI Lot 4 and Lot 5 were each pre-conditioned following the procedure 

described in section 6.3. subsection 2.6.3. Each load \Vas then run in the extractor to 

com;_Jare Rl\1C' values. The extractor tests were performed. as previously. with a 20 

minute warm soak. 15 minute spin. at I 00 g. The results. shown in Table 2-4, show 

nearly identical RMC results regardless of the pre-conditioning machine type used. 

Based on these results. specification of a pre-conditioning machine type is not necessary. 

Table 2-4: RMC Values for Different Pre-Conditioning Machine Type 

Machinet L.Ot5 

Vertical 53.3% 50.1% 

52 1% 51.0% 

53.1% 50.9% 

Horizontal 52 3% 50.3% 

L ___ 53.0% 50.5% 

2-1 
3. Results of Washer Based RMC Tests Conducted by lntertek Testing Services 

(ITS) 

Since ITS is an independent laboratory that routinely does washer based RMC testing for 

the industrv. it was decided to send cloth to them from the same lots \ve used in our 

extractor-based RMC tests for evaluation. This would allow a comparison of washerbased RMC to extractor-based RMC. The results of ITS washer based RMC tests are 

given in Table 31. The ITS tests are done on two washers, listed as Amana and 

Whirlpool The loads that originated the study are listed as Alliance (origin Tl) and ITS 

(origin CG). Our (ADL) cloth came from lots used in om RMC tests discussed above. 

The lots were purchased at different times from the supplier listed. The dramatic 

difference bet\\ een the Alliance and ITS loads is also evident in the ADL data, 

suggesting that the discrepancies in RMC between Tl and CG cloth is independent oflot. 

There is about :'% maximum difference in the Tl lots per machine and up to a 7 % 

difference between machines A comparison of values between those in the table and 

Figure 2.1, extractor-based results, indicates a similarity in trend. Numerical values 

cannot be compared because of the differences in test methods, i.e .. washer-based vs. 

extractor-based 

Table 3.1 ITS Washer-Based RMC Results 

I Wasb~r' •· .... • .... ·· .. · .. ... ....... · 'l'~tilt!J.lllf'l:O:V~tors < C~ffi>n Goods < .· •.... ·.·. 

r •. •·. < > .. ·· Amanc~ .• •. .•· Aot. Jl1 . . .. AC>t. [12 .· \ iAPL Tl$ /. l'f'Q • . ) APt: CQ1 

: Amana 56 0% 55.21% 52.28% 53.09% 67.9% 66 09% 

:_wF[r1poo-1 -153 7% 54.65% 51 56% 49.58% 64.9% 63.84% 

3-
4. Cloth Characteristics and Relation to RMC 

The construction of a textile fabric and its constituent yarns is characterized by a number 

of basic variables. For a particular fabric, cloth specifications could define the nominal 

value of these variables and the acceptable tolerance range. The material that follows is a 

discussion of these variables and the likely relationship of these variables to the moisture 

absorption and retention of the cloth. 

Following the discussion of the variables, the test results are summarized from several 

labs to characterize the test cloths that have been examined in this project. 

4.1 Discussion of Cloth Characterization Variables 

:\ listing of cloth characterization variables, their descriptions, suspected relation to 

RMC specification in current (proposed) regulation and appropriate test for evaluation is 

gi\'en in Table 4.1. Note that only fabric construction, thread count, fiber content, fabric 

\\eight and finish are currently specified in the proposed regulation. 

4-
Table 4.1 Cloth Characterization Variables 

~ PROPERTY ··. ··· DESCRIPTJOf{ / R.f.l.A'tJON ...... < < . CURRENT< / ttst~OR ·························· 

i· < \ .... •· · · •·· .... ·•·. · ..··.···• > > ~U~\1~1f P'to>/ >$PECIFJQATiQN ( ¢VAL-UATtQN ] L.~~~~~- -~-+......._-~'"--_...._---'",,,......__'+~...._......._.;~'--.---'"--+--~...-.U~~~=~~======="""! 

' Fabric Construction Weave of cloth. Either Unknown Momie (granite) Identified visually 

momie (granite)- weave 

irregularly woven with 

rough surface or plain 

weave-regularly 

woven. 

rvarn Type Either open-end or Unknown Unspecified Identified visually 

ring spun (open end 

common today) ----- ----+------~~--+------------+----------+---------~ 

Thread Count 

, ______ _ ; Fiber Content I 

f-Yarn Number 

f-Fabric Weight 

: F tnts_h ______ _ 

1-----------

i Water Retention 

i Absorbency 

vertical Wicking Rate 

I Repellency to Oil and 

! Water 

I 

! 

, 

i 

Number of yarns that 

run lengthwise (warp 

or ends)/number of 

yarns that interlace(fill 

or picks) 

% blend by weight of 

fiber type in yarn 

Linear density of yarn, 

mass/length 

Dry weight per unit 

area (oz. per sq. yd. 

or gms. per sq. m.) 

Could cover a variety 

of finishes applied to 

the cloth (related to 

final uses or 

facilitating 

manufacturing 

process) 

Amount of water 

retained in a 

centrifuQe test 

Amount of time for a 

drop of water to 

absorb 

Time for water to 

travel a fixed distance 

up the cloth. Tested in 

the warp and fill 

directions 

If a surface is wetted 

by oil or water. 

Identifies 

fluorochemical and 

other finishes 

Higher thread count 

implies more cotton, 

higher RMC 

More cotton fiber 

implies higher RMC 

Thicker thread implies 

more cotton , higher 

RMC 

Heavier weight 

implies more cotton, 

more RMC 

Any finish would lower 

RMC 

Water retention 

increases RMC 

Absorbency increases 

RMC 

Faster wicking implies 

higher RMC 

Repellency lowers 

RMC 

65/57 

50/50 cotton 

/polyester 

Not Specified 

5. 75 oz. Per sq. yd. 

Pure finished 

bleached 

Not Specified 

Not Specified 

Not Specified 

Not Specified 

ASTM D 3775 

Thread Counts per 

Inch 

AA TCC 20A-with 

moisture Fiber 

Composition 

ASTM D 1059 

Standard Test Method 

for Yarn Number 

ASTM D 3776 Weight 

AATCC TM 94 

Finishes in Textiles• 

Identification 

ASTM D 2402 Water 

Retention by 

lmbibit1on 

AATCC TM 79 

Absorbency of 

Bleached Textiles 

Vertical Wicking Rate 

AATCC TM 118 Oil 

Repellency 

'------------~--------~--------~---------'--------------' 

4.2 Results of Cloth Characterization Tests 

Tables 4.2 and 4.3 present results from the independent laboratories for the cloth 

characterization tests. As shown. there is an absence of data in some cases. Either the data 

was not requested or the laboratory was unable to perform the required tests. Also there 

4-
arc some discrepancies in the reporting and/or method of analysis (see results for water 

retention) Information on fabric construction and yarn type is particularly sparse. Vartest 

reported the \\eave on both CG and Tl samples to be ··crepe \\'eave·· (not momie). CG to 

be "ring-spun" \arn. and Tl to be "open-end" spun yarn. 

Table 4.2 Cloth Characterization: Fabric Weight, Thread Count, Yarn Number and Fiber Content 

Fabric Thread Count Yarn Number Fiber Content 

F a bric 

' : s 

l 

ource 

L_ __ 

Text 1le 

Inn avatars 

' 

Sample ID 

---·-

I 

I 

1 .. All1ance" I 

I 

I 

~ADL Lot 1 

I (Tl1) 

lADL Lot 2 

i (Tl2) 

r·~~L Lot 3 

(Tl3) 

~DL Lot 4 

! (Tl4) 

' r·- ·------· 

I AQL Lot 5 

~------

J (Tl5) ·---- -----

I 

i 

I 

I 

i 

ton i ITS 

ds I 

I 

i Cot 1 Goo I 

I 

L 

I CG 1 

___ _L_ ' i __ _ 

Test Lab Weight, 

oz. Per sq. Warp yd. 

ACTS 5.86 65.0 

5.90 67.20 

lntertek 

6.2 67.00 

5.81 61.00 USDA 5.84 -

Vartest 5.90 66.20 

5.98 66.70 

1 

Vartest 5.60 64.80 

5.64 64.00 

lntertek 5.3 60 

Vartest 5.23 60.5 

ACTS 5.3 62 

lntertek 5.3 61 

Vartest 5.33 61.7 

ACTS 5.87 63 

lntertek 5.9 65.6 

Va rt est 5.62 64.3 

ACTS 5.55 63 

lntertek 5.89 66.0 

Vartest 544 63.3 

ACTS 5.73 70.00 

5.90 70.60 lntertek 5.80 70.40 

USDA 5.67 63.00 

5.75 - 5.88 69.70 Vartest 5.88 71 00 

Va rt est 5.20 67.30 

5.24 67.00 

Warp Fill 

Fill Cotton Poly 

% % 

60.0 - - 49.58 50.2 

61 00 - - 49.8 49.5 

62.00 - 50.2 49.8 

67.00 16.90 16.20 51.9 48.1 

- - - - -

61 00 - - 50.53 49.47 

61.00 - - 50.24 49.76 

55.00 16.20 15.5 51.21 48.79 

55.30 16.40 16.10 50.7 49.3 

54 16.0 16.0 52.6 47.4 

53.5 16.3 16.0 

53 16.3 15.8 48.5 51.5 

53 15.9 15.9 51.5 48.5 

54.0 15.8 15.5 50 09 49.91 

53 14.6 14.7 50.5 49.5 

53.6 15.1 14.3 51.6 48.4 

53.0 16.7 15.1 51.76 48.24 

52 15.4 14.5 50.7 49.3 

54.0 15.2 15.2 52.0 48.0 

53.0 15.3 15.0 51.76 48.24 

61.00 - - 45.1 54.9 

64.00 - - 47.2 52.8 

62.40 - - 48. 52.0 

71.00 18.10 17.50 47.8 52.2 

- - - - - 63.00 - - 48.32 51.68 

64.30 - - 48.88 51.12 

56.00 18.00 18.10 54.27 45.73 

55.50 17.30 17.50 54.02 45.98 

4-
Table 4.3 Cloth Characterization: Water Retention, Drop Absorbency, Finish, Repellency and Vertical 

Wicking Rate 

--..-------·- ···---- - Water Repellency, Vertical 

Fabric 

Sourc Sample ID Test Lab Retention, Drop D =absorb, Wicking, sec. 

Absorbency, Finish 

e 

; Text1IE: 

In nova tors 

-

! Cotton 

Goods 

"Alliance" 

~;D~lot 1 

(Tl1 \ 

---

AOL Lot 2 

(Tl2\ 

ADL Lot 3 

(Tl3) 

--··-

AOL Lot 4 

(Tl4) 

~--

AOL Lot 5 

(TIS\ 

ITS 

f----. 

CG 1 

I 

% 

USDA 15.5 

15.2 

Vartest 

191 

Vartest 185 

lntertek 

Vartest 196.6 

ACTS 13.75 

lntertek 

Vartest 226.68 

ACTS 

lntertek 

Vartest 

ACTS 

lntertek 

Vartest 

USDA 18.4 

17.2 

Vartest 

292 

Va rt est 

287 

A= repel 

sec. Water Oil 

388 

153 

D D 

A D 

0.8 Possible lubricant D D 

or surfactant 

0.8 Possible lubricant D D 

or surfactant ---

8.0 

5.9 Polyvinyl Acetate D D 

7.1 D D 

6.4 

6.6 None D D 

< 1 D D 

2.6 

1. 9 D D 

< 1 

1.2 D D 

1.4 D D 

<1 

<1 

D D 

D D 

.4 Wax . D D 

Silicone/polyester 

oligomer, Possible 

lubricant or 

surfactant 

.5 Possible lubricant D D 

or surfactant 

Table 44 summarizes the differences found in the laboratory results and provides 

comments on conclusions and effect on RMC Here we discuss only the lots tested in our 

e:-;tractor-based RMC tests, not the "Alliance" and ITS data. 

4-

for 2 cm. 

Warp Fill 

68 399 

30 30 

30 30 

15 12 
Table 4.4 Summary of Results from Independent Laboratories 

i 

l----~ Fabric Construction 

'-Yarn Type 

f-Thread Count 

? · ~ttet~~ < ... · Differences \ ·.·_. ···· Qiff¢reriees < com:::tvsf:c>t'I ~~ .\···· Vartest 

1~;····.···· reported Tl and ~~· CG cloth to be .. 

crepe 

·: I~··•·····•· weave (not •>'~"'"'"tojg0j··· momie) 

More data needed 

Vartest reported CG to be ring-spun and Tl to be open-end More data needed 

yarn 

2% 4% 

4% 4% 

4% -11% 

between Tl and 

CG, but not 

overlapping Tl lot 

difference 

6-12% 

Significant difference 

between CG and Tl. may 

be connected to RMC 

No discernable 

differences between lots 

and laboratories. 

Differences between CG 

and Tl may be connected 

L__ __________ ----+---------+---------+---------+--to_R_M_C ______ ---< 

; Yarn Number 2% 2% 12% No discernable 

differences between lots 

and laboratories. 

Differences between CG 

and Tl may be connected 

to RMC 

Small 5% 2% 5% between lots 

l. ________ -----1-----------+---------+---------+--m_a_,1y_b_e_si_,,___Qn1_fi_ca_n_t __ ___, 

Finish Not enough data Some reported Same finish on 

both 

Finishes reported, but no 

connection to RMC 

:-~\later Retention Data here difficult to analyze because of differences in test More information needed 

1 methods/results 

r--;.:bsorbency Larqe Larqe Not reported More information needed 

~ Vert1 ca I Wic~_R_a_te __ --+_N_o_t_e_n_o_u_,,___Qh _d_a_ta_-+-_N_o_t _en_o_u~1q'--h_d_a_ta _ _._____N_o_t _re~~P_·o_rt_e_d __ +--M_o_re-,--in_fo_r_m_a_t_io_n_n_e_e_d_ed-----< 

' Repe1lency Data indicates all samples studied absorb oil and water No differences noted 

4.3 Comparison of Cloth Characterization Test Results with RMC Test Results 

Table 4.3 indicates some differences in cloth characteristics that may be linked to RMC 

results. Hmve\ er, there are no clear connections. There is reasonable uniformity in 

characteristics between Tl lots reported here and these differences are \vithin the same 

bounds as the differences in RMC results. This suggests that a "standard'' cloth should 

originate one manufacturer to limit the variability of characteristics. 

The tests available for finish can be extensive. However, two simple droplet tests for 

absorbency of water and oil can be used to detect the type of stain of water repellent 

finish that could be inadvertently applied during production of this fabric 

4-
5. RMC Correction Factor 

As discussed in the preceding sections, the relationship that can be discerned between 

measurable. specifiable properties of the cloth and the resulting moisture 

absorption 1retention characteristics as measured by a standard RMC test is tenuous at 

best. The difficulty of relating specifiable characteristics - fiber content. weight, etc. to 

Rl\'IC characteristics is compounded by the wide tolerances that apply to the nominal 

specifications of textile products. The textile industry requires wide tolerances to allow 

for the variability of cotton and synthetic fibers, as well as process control variability. 

Based on discussions with textile industry marketing and manufacturing managers, 

special manufacture to tighter specifications is probably not available: based on the 

laboratory testing to date. tight specifications alone will not necessarily lead to a 

comparably consistent RMC characteristic. 

Based on the highly consistent extractor based RMC-g curves for Tl lots L 2, and 3, it 

appeared that a viable approach to minimize the effects of cloth variation on RMC would 

be to consistently specify a single type of fabric that is produced frequently by one mill to 

a consistent set of specifications Riegel Permalux 50/50 Momie Weave (the cloth used 

for Tl lots 1. 2. and 3) appears to be a suitable choice. because this cloth is produced in 

high volume. has been produced to a consistent specification for many years and is likely 

to continue to be produced on this basis for the foreseeable future. Riegel produces the 

varns from purchased fiber and weaves and finishes the cloth material. so they have 

complete control O\'er the process. 

Howe\'er. as discussed in the preceding sections, the extractor based RMC -g curves of 

subsequent lots of the Riegel cloth (Tl lots 4 and 5) were 5 to 8 percentage points higher 

than the corresponding RMC-g curves for Tl lots 1, 2. and 3. To account for lot-to-lot 

\ ariation, Robert Van Buskirk of Lawrence Berkeley Laboratory (LBL) proposed a linear 

least squares fit based RMC correction (Appendix C) The basic approach is to define 

standard R1\1C vs g values for cold and warm ( 60°F and 100°F) water and 4 minute and 

I '.' minute spin times. The RMC values of Tl lot 3 have been adopted as this standard. 

For other lots of test cloth. RMC-g values are absorbed in the standard extractor. A linear 

least squares fit between the new cloth RMC and the "standard" cloth RMC yields a 

linear relation between the RMC obtained with the new cloth and the RMC that would 

have been expected with standard cloth. Figure 5-1 illustrates the basic concept. 

5-
i ANewL::-U Standard 

Extractor RMC 

\ Test Cloth_J I vs. g 

--T·- ~-~ 

RMC 

Correction 

Curve 

L---~~~~~~~~~~~~~~ 

1 Standard Test 

Cloth Basis 

RMC for Clothes 

Washer X 

~---- i 

RMC for 

Clothes 

Washer X with 

New Test Cloth 

Figure 5-1 RMC Correction to Determine the RMC that would have been Measured with "Standard" 

Test Cloth 

As described helow, test results to date indicate that this procedure produces results that 

are highly consistent. 

The material below summarizes the proposed method to determine the correction factor 

cun e for a ne\\ lot of test cloth and the test data, to date, that shows that this procedure 

will vield consistent RMC results for clothes washers. 

5.1 Procedure to Calculate Correction Factor 

The typical linear correction curve that is generated is shown in Figure 5-2. The simple 

algebraic equation is 

\\'here 

• RMC:,,nw1-:.i is the average RMC that would have been expected at each test condition 

for clothes washer X if "standard'' test cloth had been used for the J 1 RMC test 

• RMCi-·N11,·d is the RMC measured by the JI test procedure for clothes washer X with 

a lot of non-standard test cloth for which a linear correction curve has been created. 

• A and B are the coefficients (intercept and slope) that result in the least squares linear 

fit relating the RMC values measured in the standard extractor for a particular lot of 

non-standard test cloth and those that were measured with standard test cloth, at each 

water temperature. spin time, and g test point 

5-
The procedure has four basic steps. 

l Establish the standard RMC vs. g values for cold and warm water and 4 minute and 

IS minute spin time 

For a new lot of test cloth, measure the RMC vs. g values for cold and warm water 

and 4 minute and 1 S minute spin time. 

3 Linear least squares fit and root mean square (RMS) error check to generate the linear 

correction curve. 

4 Apply correction to JI measurements of RMC with clothes washer. 

5.1.1 Standard RMC vs. g Curve 

The standard RMC vs. g values are summarized in the ··standard cloth" column of Table 

5-1 They are the average of three measured RMC values at each spin time - water 

temperature - spin g test point with test cloths from TI lot 3. They were measured in a 

Bock Model 21 S extractor. For this test procedure it was decided that the Bock Model 

21 5 extractor would be the ''standard" 

5.1.2 Establish RMC vs. g Values for New Test Cloth 

Using the standard Bock Model 21 S extractor measure the RMC at the specified 

combinations of spin time. water temperature and spin gin Table 5-1. Each of the RMC 

measurements should be done three times, with the average used to determine the 

correction cu1Ye. 

5.1.3 Least Squares Fit and RMS Error Verification 

Using a spreadsheet or statistical calculator, calculate the linear least squares fit relating 

the pairs of "standard'' and "'new cloth" RMC values at each of the spin time - water 

temperature - spin g test points. 

To quantWv the uncertainty of the linear least squares fit a root mean square error analysis 

is performed The root mean square value of 

: L RMC standard_i - RMCcorr _ i J ,·' 12 ( \211/2 

!' i=1 10 

Should be less than 2-percent. 

5-
The Root ~dean Square (RMS) is a standard statistical quantity generated in least-squares 

regression analvsis. It is typically used to construct confidence interval estimates and to 

test hypotheses about the derived model. The RMS quantifies the amount of variation (or 

uncertainty) associated with estimating the standard Rl\1C % from any corresponding 

RMC 'Yo value observed with new cloth. Underlying theory and computational details are 

gi\ en in most applied statistics texts. 

Table 5-1: Standard RMC vs. g Values and Corresponding NE!W Cloth RMC Values for Linear Least 

Squares Fit 

r~·~~~~i~::L i Cold .... ·~t=··Tern~~j'~ ......... ··~··········~~1n••;·;··········· 50 ·········-=t~~:ii:!~•••the·~~=:·••~::CtiJ'•. 59 0% 

200 43.1% 

350 35.8% 

4 min Warm 50 55.7% 

200 40.4% 

350 33.1% 

~--------r-·c_o_l_d _______ f-c-50----+----5-2-...,.8-,-%,----+----------

200 37.9% 

350 30.6% 

15 min. : Warm 50 50.4% 

200 35.6% 

350 29 6% 

5.1.4 Apply to Clothes Washer Test Results 

Once the linear correction curve has been generated for a new lot of test cloth, energy test 

cloths and stuffers may be used to perform the JI RMC test on any clothes washer to 

\\hi ch the JI test procedure is applicable. The RMC measured with the nev.· test cloth is 

corrected to the standard test cloth RMC either graphically using a plot of the linear 

correction curve. or arithmetically, using the linear equation with the coefficients A and 

B that define the linear correction curve. 

5.2 Test Data Confirming Correction Procedure 

To evaluate the effectiveness of the correction procedure, results from extractor RMC-g 

tests for Tl lots 4 and 5 were used to generate the linear correction curves to TI lot 3. The 

resulting coefficients for the linear correction equation RMC1d =A+ B*RMCm.:asured are 

summarized in Table 5-2. 

Table 5-2: Correction Coefficients 

5-
! +t-~-------~=- -------~1~~-~---~-~-~_9 _____ _ 

I 0.967 

0.997) 

The linear correction curve and the individual extractor Rl\1C data points for lots 4 and 5 

are plotted in Figures S-2 and 5-3, respectively. The individual data points are the 

a\·erage of the 3 RMC values measured for each combination of water temperature, spin 

time. and spin g The detailed data is shown in tabular form in Appendix D. 

C orrect1on Curve for Lot 4 

----------

. 

-

u 

/ ~ 

;; 

L ____ ----------------~ 

Lo! A RMC \"',.I 

Figure 5-2: Linear Correction Curve for Tl Lot 4 

5-
C orrect1on Curve tor Lot S 

----------------·------

Lot!> RI.IC I· .. ; 

Figure 5-3: Linear Correction Curve for Tl Lot 5 

The results of the extractor-based correction curve tests are shown in table 5-3 and 5-4. 

The tables show the standard (Lot 3) measured value. 1 he Lot 4 (or 5) measured rnlue. 

and the corrected \'alue All measured values are shown. however. the average of the 

three test Yalues at each condition are used for the leas1t squares curve fit 

Table 5-3: Lot 4 Verification of Correction Factor in Clothes Washer 

.. ···•··•· <T~st Point·.•.\ ·.• / .• ..· l.;Qt:3.i'{MCJStan~~r- Lot~RMt··············· corr-ecte(f'RMC ' (Soak Temp .•. Time.;: a) ··• ·. ·· :::..:..::::--:::/::,:.: ... ; : .. :· ...... -····· :.· .. ·:··:_._ ..... _ .. _ ... <:: 

514% 56.2% 50.5% . 

Warm 15, 50 49.6% 57.2% 51.5% 

50.2% 57.2% 51.5% 

364% 42.2% 37.0% 

Warm. 15. 200 35.7% 42.6% 37.4% 

-- -------- -

34.9% 40.5% 35.4% 

29.1% 34.2% 29.3% 

. ------- - --- -

Warm. 15. 350 29.9% 34.2% 29.3% 

- - -- ---- - --

29.9% 34.1% 29.2% 

55.8% 61.5% 55.6% 

. --··--· ---- ----

Warm, 4, 50 55.8% 61.5% 55.6% 

-·--··-····---· -

55.5% 61 1% 55.3% 

41 1% 46.3% 41 0% 

Warm. 4. 200 40.6% 45.6% 40.3% 

39.6% 45.5% 40.2% 

5-
32.1% 37.5% 32.5% ·-

Warm 4. 350 33.6% 37 8% 32.8% 

--------· 

33.5% 38.5% 33.5% 

52.2% 58.8% 53.0% 

--- -- - ---

Cold 15. 50 53.3% 580% 52.3% -·····- --

53.1% 59.8% 54.0% 

38.0% 43.1% 37.9% 

42 20/o ··--------

Cold 15. 200 37.9% 37.0% 

43~4°/o --37.9% 38.2% 

30.2% 35.5% 30.6% ----··· -·-·· ·---

Cold. 15. 350 30.7% 35.4% 30 5% 

31.1% 35 4% 30.5% 

59.1% 64.6% 58.6% 

- -·--- --

Cold. 4, 50 58.9% 64.4% 58.4% 

58.9% 63.2% 57.3% 

43.5% 47 9% 42.5% 

- - ----- ---

Cold. 4. 200 43.0% 49.0% 43.6% ·- -- ---

42.8% 48.5% 43.1% 

35.3% 41.5% 36.3% 

Cold. 4. 350 ---- -· - -

36.0% 40.3% 35.2% --·-··- -- -· 

416% -·--·--------36.1% 35.9% 

Table 5-4: Lot 5 Verification of Correction Factor in Clothes Washer 

. i te$tPoint > .• ... · ..--~3-RM¢1$\a·oo·--'..-a ... -.-.'*'.•.·•.•·.-.••.:i.••.-.•.•. -.-.•.•.••.•.-.••.••.•.•.

1

.J ..•..•.... ·••.-i.i;)t58Mc · ¢9r~l~J~M<f-; <······ : -·(_$68k?t•fui:>a~--:TI;ne~::Qj _.- · 1: -::::·-:·;:-:::.::::};:.\:·:~>>~-:<>A:>:>>:·.:· ·.· · 

Warm. 15. 50 

Warm, 15. 200 

Warm, 15, 350 

Warm, 4. 50 

Warm. 4. 200 

Warm, 4. 350 

51.4% 

49.6% 

50.2% 

36.4% 

35.7% 

34.9% 

29.1% 

29.9% 

29.9% 

55.8% 

55.8% 

55.5% 

411% ·-·-. ----

40.6% 

39.6% 

32.1% 

33.6% 

33.5% 

54.8% 

55 4°k 

53.1% 

40.1% 

39.5% 

39.1% 

32.8% 

32.2% 

32.1% 

58.1% 

59 4o/o -

58.7% 

44.6% 

44~4o/o 

43.2% 

36.6% 

36.4% 

35.2% 

51.4% 

52.0% --- ----·---

49. 7% 

36.8% .. -- - ---- -

36.2% 

35.8% 

29.6% 

29.0% 

--- . -- ------------

28. 9% 

54.7% 

56.0% - ------------- --- ---

55. 3% 

41.3% 

41.1% 

39.9% 

33.4% -- ·- --- ·---- - - --- --- ----

33.2% 

320% 

5-
52.2% 56.4% 530% 

Cold, 15. 50 53.3% 55.4% 52 0% 

53.1% 55.8% 52.4% 

38 0% 41.7% 38.4% 

Cold. 15. 200 37.9% 400% 36.7% 

37.9% 42.4% 39.1% 

30.2% 35 1% 31.9% 

Cold 15. 350 30.7% 330% 29.8% 

31 1% 33.7% 30.5% 

59.1% 61.4% 58 0% 

Cold. 4. 50 58.9% 61.9% 58.5% 

58.9% 62.4% 590% 

43.5% 46.6% 43.3% 

-------·-- ·-

Cold. 4 200 43 0% 47.6% 44.3% 

42.8% 46.3% 43 0% 

35.3% 38.6% 35.3% 

-·-- --- . -

Cold, 4 350 360% 38.7% 35.4% 

36.1% 39 0% 35.7% 

R!\IC values \\ere determined for a horizontal axis washer and a vertical axis washer, 

following the JI RMC test procedure. with each of Tl lots 3 (the standard), 4 and 5 The 

R!\1C tests were run three times for each clothes washer/test cloth lot combination. 

Tables 5-5 and 5-6 summarize the RMC measured in each of the machines using test 

cloth from Tl lots 4 and 5. respectively In each table, these values are corrected to the Tl 

lot 3 standard and compared to the RMC values measured with test cloths from Tl lot 3. 

\\'ith one exception. the corrected RMC is less than I%. of the RMC measured with the 

standard (Tl lot 3) test cloth. 

Table 5-5: Verification of Lot 4 Correction Curve in Clothes Washer 

Machine Ty.Pe Lot 3 RMC Lot4 RMC ... · Corrected Lot 4 RMC =-Vertical-Axis Machine 55.4% 620% 56.1% 

560% 61.5% 55.7% 

56.1% 61.2% 55.3% ----

Horizontal-Axis Machine 47.1% 53.6% 48.1% 

49.3% 54.3% 48.7% 

48.6% 54.5% 48.8% 

Table 5-6: Verification of Lot 5 Correction Curve in Clothes Washer 

Machine.Jype Lot3 RMC •· .. < Lot5 RMC Corrected Lot 5 RMC · 

Vertical-Axis Machine 55.4% 59.4% 56.0% 

560% 59.6% 56.2% 

56.1% 60.0% 56.6% 

Horizontal-Axis Machine 47.1% 50.3% 47 0% 

49.3% 49.8% 46.5% 

48.6% 51.9% 48.5% 

5-
5-
6. Approach to obtaining and verifying consistent test cloth 

An approach to minimize the effects of cloth variation on RMC is to consistently specify 

a single type of fabric that is produced frequently by one mill to a consistent set of 

specifications Riegel Permalux 50/50 Momie Weave appears to be a suitable choice, 

because this cloth is produced in high volume, has been produced to a consistent 

specification for many years and is likely to continue to be produced on this basis for the 

foreseeable future Riegel produces the yarns from purchased fiber and weaves and 

finishes the cloth materiaL so they have complete control over the process. With the 

modest inconsistencies between lots that have been observed to date. a correction factor 

needs to be applied to obtain consistent clothes washer RMC test results. 

The previous section presented a linear least squares fit method to correct actual cloth to 

--standard" cloth. 

The material below summarizes the cloth specifications. the approach to consistency 

verification and the translation of these into draft language that could be inserted into the 

test standard (Appendix JI) 

6.1 Outline of Proposed Specification 

I) Specif}· one standard grade of cloth from one mill e.g., Riegel Permalux 50/50 

Momie \\"eave with pure bleached finish 

~) Change the energy test cloth specification in I 0 CFR 430 Subpart B Appendix JI to: 

• Duplicate the Riegel Mills specifications for the Permalux 50/50 

50. 50 cotton/polyester± 4% 

5 60 oz sq yd. ± 5% 

Warp and filling yarns 15! I ± 5% cotton ~ount. open end spun yarn 

Thread counts of 61 x 54 (warp x fill) ± 2% 

• Require AA TCC -118 with "D'' across the board result 

• Require AA TCC -79 with drop absorbing time on the order of I second 

• Require standard extractor based RMC vs. g standardization curves and RMC 

correction curve for each new lot of test cloth 

6.2 Verification 

I) AA TCC- l 18 Oil Repellency Test (DuPont or 3M version) of each new lot of test 

cloth (\vhen purchased from Riegel) to confirm absence of Scotchguard or other water 

6-
repellent finish (required scores of .. D'" across the board) 

2) AATCC-70 Drop Absorbency Test of each nevi lot oftest cloth (when purchased 

from Riegel) for further confirmation of the absence of Scotchguard or other water 

repellent finish (time to absorb one drop should be on the order of I second) 

3) Run 4 minute and I 5 minute standard RMC vs. g curves with 60°F and 100°F water 

temperature for each new lot of test cloth as the basis for calculating an RMC 

correction curve to correct RMC test results to "standard'' test cloth (average of TI lot 

3) 

6.3 Standard Language 

DOE Draft Language for Changes to JI Test Procedure to Specify The Energy Test Cloth 

and The RMC Correction to "Standard'" Test Cloth RMC 

Replace the current Section 2.6 in Appendix JI with the following: 

2 6 lest Clolf 1,. 

2 6 I Fner;:y Fest Cloth. The energy test cloth shall be made from energy test cloth 

materiaL as specified in 2.6.4, that is 24 inches by 36 inches (61.0 cm by 91.4 cm) and 

has been hemmed to 22 inches by 34 inches (55.9 cm by 86.4 cm) before washing. The 

energy test cloth shall not be used for more than 25 test runs (after preconditioning as 

specified in Section 2 6 3) 

l. 6 l ;.:111..'r,!.:r Slldf~r Cloth. The energy stuffer cloth shall be made from energy test 

cloth material. as specified in 2.6.4, and shall consist of pieces of material that are 12 

inches by 12 inches (30 5 cm by 30.5 cm) and have been hemmed to I 0 inches by I 0 

inches (254 cm by 254 cm) before washing. The energy stuffer cloth shall not be used 

for more than 2 5 test runs (after preconditioning as specified in Section 2 6 3) 

2 6.3 Preconditioning ol Jest Cloths. 

The nev,r test cloths, including energy test cloths and energy stuffer cloths, shall be preconditioned in a clothes washer in the following manner: 

2 6 3. I Perform 5 complete normal wash-rinse-spin cycles, the first two with AHAM 

Standard detergent 2A and the last three without detergent Place the test cloth in a 

clothes washer set at the maximum water level. Wash the load for ten minutes in soft 

\\ater ( 17 ppm hardness or less) using 6 0 grams per gallon of\vater of AHAM Standard 

detergent 2A The wash temperature is to be controlled to 135° .± 5° F (57.2° .±__2.8° C) 

and the rinse temperature is to be controlled to 60° ± 5° F ( 15.6° ± 2.8° C) Repeat the 

6-
c~·cle with detergent and then repeat the cycle three additional times \Vithout detergent, 

bone drying the load between cycles (total of five wash and rinse cycles). 

:. u. -I 1~·11erx_1 I est ( '/oth Material. 

The energy test cloths and energy stuffer cloths shall be made from fabric meeting the 

following specifications. 

:. 6 -I. 1 Xominal Fahric J)pe. Pure finished bleached cloth, made \vith a momie or 

granite wea,·e. \Vhich is nominally 50 percent cotton and 50 percent polyester. 

2 64.2 The fabric weight shall be 5.60 ounces per square yard ( 190 0 g/m2), ± 5%. 

2 6 4.3 The thread count shall be 61 x 54 per inch (warp x fill),± 2%. 

2. 6 4 .4 The \\ arp yarn and filling yarn shall each have fiber content of 50 percent ± 4 

percent cotton. with the balance being polyester, and be open end spun, 15/ I ± 5% cotton 

count blended varn. 

2 b 4 5 Water repellent finishes, such as fluoropolymer stain resistant finishes shall not 

he applied to the test cloth. The absence of such finishes shall be verified by: 

2 64.5 I AATCC-118 Oil Repellency Test (DuPont or 3M version) of each new lot of 

test cloth (\\hen purchased from the mill) to confirm the absence of Scotchguard or other 

\\ater repellent finish (required scores of ''D'' across the board) 

2 6 4 5 2 AA TCC-79 Drop Absorbency Test of each new lot of test cloth (when 

purchased from the mill) to confirm the absence of Scotchguard or other water repellent 

finish (time to absorb one drop should be on the order of 1 second) 

::: 6 4 6 The moisture absorption and retention shall be evaluated for each ne\v lot of 

test cloth by the Standard Extractor RMC Test specified in 2.6.5. 

26461 Repeat the Standard Extractor RMC Test 2.6 5 three times. 

2.6.4.6.2 An RMC correction curve shall be calculated as specified in Section 2.6.6. 

2 6 5 Standard 1'..~¥/ractor RAIC Jest Procedure The following procedure is used to 

evaluate the moisture absorption and retention characteristics of a lot of test cloth by 

measuring the RMC in a standard extractor at a specified set of conditions Table 2.6.5 is 

the matrix of test conditions. When this matrix is repeated 3 times, a total of 48 extractor 

Rl\1C test runs are required. For the purpose of the extractor RMC test, the test cloths 

may be used for up to 50 test runs (after preconditioning as specified in Section 2.6.3). 

Table 2.6.5 Matrix of Extractor RMC Test Conditions 

6-
: 6 5 I The standard extractor RMC tests shall be run in a Bock Model 215 extractor 

(ha\ing a basket diameter of 19.5 inch. length of 12. and \'olume of2.1 ft\ with a 

'ariable speed dri'e [Bock Engineered Products, P 0 Box 5127. Toledo. OH 43611] 

_

1 65.l ..... re,1 /,oad Test cloths shall be preconditioned in accordance with 2 6.3. The 

load size shall he 84 lbs .. consistent with Section 3.8.1. 

::. 6 5. 3 Procedure 

: 6 5.3.1 Record the actual 'bone-dry· weight of the test load (WI). 

2 6 5 3. 2 Soak the test load for 20 minutes in I 0 gal of soft ( < 17 ppm) water. The 

entire test load shall be submerged. The water temperature shall be I 00°F ± 5°F. 

2 6 5. 3. 3 Remove the test load and allow water to gravity drain off of the test cloths. 

Then manual!~· place the test cloths in the basket of the extractor, distributing them 

e' enly by eye Spin the load at a fixed speed corresponding to the intended centripetal 

acceleration le' el (measured in units of the acceleration of gravity. g) ± I g for the 

intended time period ± 5 seconds. 

2 6 5 3 A Record the weight of the test load immediately after completion of the 

extractor spin cvcle (WC) 

Calculate the RMC as (WC-Wl)/Wl 

2 653.6 The RMC of the test load shall be measured at four (4) g levels: 50 g. 200 g. 

3 50g. 500g. using two different spin times at each g level: 4 minutes and 15 minutes 

2 654 Repeat 2.6 5.3 using soft (<17 ppm) water at 60 F ± 5 F. 

::. 6. 6 ( 'alc11/01io11 (?l RA1C correctio11 rnn•e. 

2 6 6.1 Average the values of 3 test runs and fill in table 2.6.5 Perform a linear leastsquares fit to relate the standard RMC (RMC1and:ird) values (shown in table 2.6.6.1) to the 

'alues measured in 2.6 5 (RMC.1,,111): 

Where A and B are coefficients of the linear least squares fit. 

6-
( Snedecor. G \\' ad Cochran. W G. Statistical .\1ethod\. The Iowa University Press. 

:\mes. Iowa ( 1967). 6111 ed.) 

Table 2.6.6.1 Standard RMC values (RMCstandard) 

IS lll 111. sp111 

)Ii 'ill -I";, 55.'7'X• ~2.8{~~1 i )lJ ()'% --- -t· 21)(1 35.()>JI~) -lll.'1 1

Yt1 -'""l·lJt}'(, -13.1% 

L 3:'11_ 2 9. ()l~~) ,, IOI 3(1.6'~(, I 35.8°/,, .... - ----- ·"'·" "' 

2 b 6 2 Check accuracy of linear least squares fit using the following method: 

The root mean square value of 

12 ( Q\1/2 : L R~C s~§lndard_i - RMCcorr _ i I I 

. 10 

fee 1 ) 

shall be less than 2%. where a sum is taken over all of the different tests. where 

R\ I<·_,. : \,,_,: ., . is the RMC standard value measured for the i-th test. and Rl'v!C ·on- 1 is 

the corrected R!\1C value for the i-th cloth test. 

:3 6 - Applicol ion <?l RA1!C correct ion rnn•e. 

:2 6 7 I Using the coefficients. A and B calculated in Section 2.6.6. 1. 

2 6 7 2 Substitute RMC .. 11 values in calculations in Section 3.8. 

6-
6