### APPENDIX C. DEVELOPMENT OF A STANDARDIZED ENERGY TEST CLOTH Report: Development of a Standardized Energy Test Cloth Report for Masuring

Remaining Moisture Content in a Residential Clothes Washer Appendix A: Test Data Appendix B: Summary of Extractor Based Test Data Appendix C: Procedure for Using RMC Correction Factors in Clothes Washer Efficiency Tests

## Development of a Standardized Energy Test Clothfor 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 02 140-2390

### Table of Contents

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### 1 Introduction 1-1 1.1 Background 1-1 1.2 Energy Test Cloth 1-2 1.3 Moisture Absorption and Retention in an Energy Test Cloth 1-3 1.4 Summary and Approach 1-3 2. Extractor-Based R]\'IC Testing 2-1 2.1 Purpose of Test Program 2-1 2.2 Laboratory and Procedure 2-1 2.2.1 Laboratoiy Equipment 2-2 2.2.2 Procedure 2-2 2.2.3 Shakedown Tests 2-3 2.3 Test Cloth Sources 2-3 2.4 Test Matrix 2-4 2.5 Test Results: RMC versus cfg for Different Test Lots 2-6 2.5.1 Comparison of Cloth Lots 2-6 2.5.2 Evaluation ofAlliance Cloth 2-8 2.6 Test Results: Influence of Other Test Variables on RMC 2-9 2.6.1 Effect of Spin Time on RMC 2-9 2.6.2 Effect of Load Size on RMC 2-10 2.6.3 Effect of Soak Water Temperature on RMC 2-11 2.6.4 Effect of Soak Time on RMC 2-13 2.6.5 Effect of Cloth Lfe on RMC 2-13 2.6.6 Effect of Pre-Conditioning on RMC 2-16 3. Results of Washer Based RMC Tests Conducted by Intertek Testing

Services (ITS) 3-1 3.1 Cloth Characteristics and Relation to RMC 3-1 3.2 Discussion of Cloth Characterization Variables 3-1 4. Cloth Characteristics and Relation toRMC 4-1 4.1 Discussion of Cloth Characterization Variables 4-1 4.2 Results of Cloth Characterization Tests 4-2 4.3 Comparison of Cloth Characterization Test Results with RMC Test

Results 4-7 5. RMC Correction Factor 5-1 5.1 Procedure to Calculate Correction Factor 5-2 5.1.1 Standard RMC versus cfg Curve 5-3 5.1.2 Establish RMC versus cfg Values for New Test Cloth 5-3

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### 5.1.3 Least Squares Fit 5-3 5.1.4 Apply to Clothes Washer Test Results 5-4 5.2 Test Data Confirming Correction Procedure 5-5 6. Approach to Obtaining and Verifying Consistent Test Cloth 6-1 6.1 Outline of Proposed Specification 

### 6-1 6.2 Verification 6-2 6.3 Standard Language 6-2

### Listof Figures

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### Figure 2.1 RMC vs. g for TI and CG Cloth 2-7 Figure 2.2 RIvIC vs. g for all TI loads 2-7 Figure 2.3 RMC for Alliance Cloth before and after Treatment for Removal

of Stain-Resistance Fluoropolymer Surface Finish 2-9 Figure 2.4 RMC vs. Spin Time for 100 and 300g 2-10 Figure2.5 RMC vs. Load Size at 100 and 300 g's 2-11 Figure 2.6 RMC vs. g for Warm and Cold Soak for Load T12 2-12 Figure 2.7 RMC vs. g for Warm and cold Soak for Load T13 2-12 Figure 2.8 RMC vs. Soak Time in Minutes for Warm and Cold Soak at 115 g. 2-13 Figure 2.9 RMC vs. Number of Wash/dry cycles 2-14 Figure 2.10 Bone Dry Weight vs. Number of "Washes" 2-15 Figure 2.11 Shrinkage of Energy Cloth Used in Cloth Life Tests 2-16 Figure5-1 RMC Correction to Determine the RMC that would have been

Measured with "Standard" Test Cloth 5-2 Figure 5-2 Linear Correction Curve for TI Lot 4, with Individual Extractor

RMCDataPoints 5-5 Figure5-3 Linear Correction Curve for TI Lot5, with Individual Extractor

RMC Data Points 5-5

### List of Tables

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### Table 2.1 Equipment used in Extractor Based RMC Tests 2-2 Table 2.2 Summary of Test Lot Status 2-4 Table 2.3 Extractor Based RMC Test Program 2-5 Table 2-4 RMC Values for Different Pre-Conditioning Machine Type 2-16 Table 3.1 ITS Washer Based RMC Results 3-1 Table 4.1 Cloth Characterization Variables 4-2 Table 4.2 Cloth Characterization: Fabric Weight, Thread Count, Yam Number

and Fiber Content 4-4 Table 4.3 Cloth Characterization: Water Retention, Drop Absorbency, Finish,

Repellency and Vertical Wicking Rate 4-5 Table 4.4 Summary of Results from Independent Laboratories 4-6 Table5-1 Standard RMC vs. g Values and Corresponding New Cloth RMC

Values for Linear Least Squares Fit 5-4 Table5-2 Correction Coefficients 5-5 Table 5-3 Lot 4 Verification of Correction Factor in Clothes Washer 5-7 Table5-4 Lot5Verification of Correction Factor in Clothes Washer 5-8 Table2.6.5 Matrix of Extractor RMC Test Conditions 6-5 Table 2.6.6.1 Standard RMC values (RMCstandard) 

### 6-7

iv

### 1 Introduction

This report summarizes the result to-date of the investigation, "remaining moisture content" (RMC) 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 two 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 volume 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 cycle in removing 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 efficiency 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 (10 CFR 430 Subpart B, Appendix J and Ji). Revisions to Appendix J are currently in effect, however, Appendix Ji will not go into effect until proposed efficiency standards into effect. A modified energy factor (MEF) is defined in Appendix Ji, 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 new efficiency standard in terms of the MEF is ongoing. In the Appendix J 1 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 RIVIC test results under the new Appendix Ji 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 Intertek Testing Services (ITS), the RMC values that were obtained in one machine with two different lots of energy test cloths differed by over 11 percentage points (67.9 percent versus 56.0 percent). When these two lots of energy test cloth were run through a second machine, a similar difference in RN/IC occurred. 1-1

### The effect of RMC on MEF can be substantial, particularly for washers which are more efficient

with respect to electrical consumption and use of hot water. The following scenario illustrates: For a high efficiency horizontal axis washer, an 18% increase in RMC (54.5%-64.5%)will result in a 13% decrease in MEF(1.52-1.33). For a lower efficiency washer, a 17% increase in RMC (57.7%- 67.7%) will result in only a 6% decrease in MEF (.82-.77). 1.2 Energy Test Cloth A wide variety of articles and fabrics are machine washed by consumers, including: Cotton knit goods, denim, towels Cotton/polyester blends in shirts, sheets, tablecloths Various synthetics in a wide variety 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: • A50/50cotton/polyester to represent a rough average of the typical mix of cotton, cotton/polyester 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 be5.75oz. per sq. yd. (195.0gm. 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 henirned to 22 in. by 34 in. (55.9cm. 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. by3O.5 cm.)andarehemmedto 10 in. by 10 in. (25.4cm. by25.4 cm.) before washing. Both energy test cloths and stuffers cloths 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) 1-2

### 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. 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 several factors: Surface wetting, which is a function of relative humidity Water retained between the warp and fill Water retained between the fibers Water retained in the lumen, or center of the cotton fiber Water ionically 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: • Identifying the variables in the construction of50/50 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 variables and reporting them in a publicly available document 1-3

### 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: • 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 following report.

1-4

### 2. Extractor basedRMCTesting

Tounderstand the effects of operating variables and cloth specifications, it is necessary to conduct laboratory 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 typical 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 laboratory tests (as explained in Section 4.). Determine whether differences in RMC vs. g in the extractor test correlate with differences in RMC in a particular clothes washer as obtained by Intertek Testing Services (ITS). 2. 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 volume 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. 2-12.2.1 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 was initially utilized. Table 2.1 Equipment used in Extractor Based RMC Tests

IILM 

# J SII( fllCAi1ON 

# J S[PPLIF1 I>1iriuosE 

# J Washing Machines (2) Typical, 3 speed, 14 Local supplier For initially preparing cloth for extractor. cycle, 2.9ft3 Two machines of identical construction. (Maytag Model #

_________________ LAT97O6AAE)

____________ Clothes Diyer 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, 11.5in. Engineered requirements. depth, with variable Products

______________________ speed drive Extractor 20 lb. capacity, 17 in. Smart-Sox, Inc. This is a smaller extractor, purchased diameter, 10.5 in. because of its immediate availability. It



### ______________________ depth

________________ was used for initial testing. Power Inverter MagneTek, 3 hp, 3 Blanchard Required to operate the smaller extractor at phase, 220 volts Electric, Inc. variable speed.

______________________ Water Heater 40 gallon capacity In-house Required for 135F wash water. Scales 26 lb. +1- .00022 In-house Required for weighing cloth.

____________________ lb.480 lb. +1- .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 washers. 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 

### 1. 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. 2. Clothes washers are preconditioned per Appendix Ji: Section 2.9 (Ji :2.9) 3. Inlet hot and cold water temperatures are recorded. Hot water is maintained at 135F +1- 5F. 2-2

### 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 5. Each load is made bone-dry per Ji :1.3. RMC Test Procedure Each extractor-based RMC test is conducted using the following procedure: 1. Record the bone-dry weight. 2. Soak in a cylindrical vessel 16" in diameter containing approximately 10 gallons of water. Soak temperature is either cold (60F ±.5F) or warm (100F ±5F) and time is variable. 3. Remove the load and place carefully in the extractor without wringing the cloth. 4. Run the extractor at the prescribed g and time. 5. Remove the load and record the weight.6. Compute %RMC as follows: % RMC= [(Weight after extraction - bone-dry weight) / bonedry weight] * 100 7. Bone-dry the load and repeat steps 1-7 as prescribed in test plan. 2.2.3 Shakedown Tests We conducted shakedown tests to verify the above procedures and to establish parameters for our initial tests. The load size was4.5lbs., 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. (TI) and Cotton Goods Manufacturing Company, Inc. (CG). To date, five lots (orders) have been received from TI and two lots from CG. In addition, cloth was distributed as follows: A portion was sent to Intertek Testing Services Inc. (ITS) for washer-based RMC tests.(see Section 3) 2-3

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

characteristics (see Section 4). A small portion of TI lot 3, and a larger portion of TI lot 5was sent to each washer manufacturer for in-house laboratory testing. In addition, we 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 below, 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. Table 2.2 Summary of Test Lot Status Lo md Load deoIiIintion

__________________________

# J Tci. Loads cr Lot 

# ] RI( ct IFS 1 cssing j haatcrstLcs Tes a LaL Maiiu1ac1iirer TI Lot 1, (ADL 1) 2 C C C N TI Lot 2, (ADL 2) 1 C C C N TI Lot 3, (ADL 3) 1 C C C C TI Lot 4, (ADL 4) 1 C N C N TI Lot 5, (ADL 5) 1 C P C C CGLotl 2 C C C N CGLot2 1 C N N N Alliance Initial 1 C C C N Alliance Treated 1 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 were intended to evaluate the differences in RIvIC vs. spin g with respect to test lots. We also tested the Alliance load with and without a fluorochemical finish. In the remaining tests, we evaluated the effect of variables (in addition to g) on RMC results. These variables included: Spin time Load size Soak water temperature prior to spin Soak time prior to spin Cloth life (cumulative wash cycles, shrinkage)
2-4

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

Table 2.3 Extractor Based RMCTest Program ( kUt 1.D.

________________

# [ S)H-I 

# j 

# {Spu. Timi',



### rniu Soak 

# j TemP. 

# ] SoI 1 iiin.



## mum. I..od

size. lb. Piir' of ie TIl, CG1, 100 10 Warm 20 4.7 Evaluate RMC vs. g for Lots CG2 300 from different Suppliers

___________ 500

_____________ __________ _____________ TIl, T12, 50 15 Warm 20 _________ 8.4 _________________________

Evaluate RMC vs. g for Lots T13 100 from the same Supplier

200 300 500

___________ 800

_____________ __________ _____________ _________ Alliance 100 10 Warm 20 4.7 _________________________ Effect of Finish Removal on Initial and 300 RMC Treated 500

_____________ __________

100, 2 Warm _____________ 20 _________

8.4 _________________________

Effect of Spin time on RMC 4 TIl,T12 300 6 10 15 20

___________ ________ 25 T12 100, 15 __________ "Wash"* _____________

"Wash"* _________

3 _________________________

Effect of Load Size on RMC 4.7 300

____________ _________ ____________ 8.4 T12, T13 50 15 Warm, 20 8.4 ________________________ Effect of Soak Temperature 100 Cold on RMC 200 300 500

____________ 800

______________ ___________ TIl 115 10 Warm, ______________ 10 _________

4.7 ___________________________

Effect of Soak Time on 20 RMC Cold 60

120

__________ _______ ____________ _________ 16 hr. T12, T14, T15 100 15 "Wash"* "Wash"* ________ 8.4 _______________________

Effect of Cloth Life on RMC (50 "washes" with RMC determined after every fifth "wash") T13, T14, 50 4 Warm, 20 8.4 Obtain data for generation of T15 200 15 Cold correction curves

___________ 350

_____________ __________ * A "wash" consists of an agitation. sninning lightly and _____________ _________ a second agitation with no d _________________________ etergent and warm water in a washer

2-5

### 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 two suppliers, TI and CG, as well as evaluation of the Alliance cloth that was suspected to have a fluorochemical finish. Below, we first compare the TI and CG lots, discuss differences between lots, and finally address the Alliance lot. 2.5.1 Comparison of Cloth LotsComparison of TI and CG lots is shown on Figure 2.1. These data (taken in the smaller, SmartSox extractor) are with a spin time of 10 mm., warm soak temperature, 20-mm. soak time and a 4.7 lb. load. As expected, there is a clear decrease of moisture content with higher g. Typical vertical axis washing machines produce spin g's in the range of 120 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 TI loads was 2% RMC, while the CG to TI difference is 11%. The two cloths had a different "feel", the CG cloth feeling much smoother than the TI cloth. In Section 4, we present laboratory results indicating that TI 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 TI cloth came from different manufacturers. The TI cloth was purchased from Riegel Mills, which produces finished product (cloth) from raw 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 explained by examining cloth specifications. Water absorption and retention may change with 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.

2-670% 65% 60% 55% 50% 45% 40% 35% 30% 25% 20% Load Size: 4.7 lbs.

Soak Time: 20 Mm. Soak Temp: Warm Spin Time: 10 Mm. -'-TIlA -CG1A -*-Tll B -*-CGIB

0 100 200 300 400 500 9 Factor 

### Figure 2.1 RMC vs. g for TI and CG Cloth
60.0% 55.0%

Soak Temp: Warm 20.0% 600

---ADL I ADL 2 -*-ADL 3 - ADL4 •i-AOL 5

0 100 200 300 400 500 600 700 800 900 g 

### Figure 2.2 RMC vs. g for all TI loads2-7

### Also of interest is the difference between lots supplied by the same manufacturer. Figure 2.2

shows data for five TI lots (ADL1-5). These data (taken in the Bock extractor) are all with a spin time of 15 minutes, warm soak temperature, 20-minute soak time and an 8.4 lb. load. For the first three lots tested ADL1, ADL2, ADL3, there is a maximum data spread of about 2 percent. Subsequent lots 4 and5varied significantly as shown. 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 TI and obtained inconsistent results in their in-house tests, i.e., RMC was lower than expected. It was suspected that a fluorochemical finish that would repel moisture was present on this material. This was verified by laboratory tests performed by Minnesota Mining and Manufacturing Company (3M). We tested this cloth as received and also after a finish removal process. A procedure recommended by the United States Department of Agriculture (USDA) Laboratory (Southern Regional Research Center) for removal of finish was p8rformed. 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 212 °F. The results are shown in Figure 2.3. These data are with a spin time of 10 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 fluorochemical finish was not removed by the process or that the fluorochemical 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.

2-80



### Figure2.3 RMCfor 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 level. Several other operating variables also influence the RMC level reached after a spin cycle: • 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 variables on RMC levels; it is further of general interest to have this information publicly available. 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 2-9 o 100 200 300 400 500 600 g Factor

### process for that g force. Figure 2.4 plots RMC vs. spin time for two different lots at 100 and 300 g.

These data represent TIl and T12 loads with warm soak temperature, 20-minute soak time, and an 8.4 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 with effectiveness that varies with g, apparently resulting in somewhat longer equilibrium times as more moisture is removed.

-

55%
50%
45%
40% C) 35%
30%
25%
20% -*-Tl Lot 1 (300 g) --TI Lot 2 (300g)

- --A-TI Lot 1(1009) K TI Lot2 (1009)

Load Size: 8.4 lbs. Soak Time: 20 Mm Soak Temp: Warm 0 5 10 15 20 25 30 Spin Time (mm) 

### Figure 2.4 RMCvs. Spin Time for 100 and 300g. 2.6.2 Effect of Load Size onRMC RMC vs. load size is plotted in Figure2.5at 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 sizes 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 2.5shows 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 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. 2-1055% 50% 45%
40% C.) 35% 30% 25% 20% 152.9% "9.4% .46.6%

0355% e335% 31.5%
TI 1967 (Lot 2) Spin Time: 15 Mm. 0 1 2 3 4 5 6 7 8 9 10 Load Size (lb.) 

### Figure2.5 RMC vs. Load Size at 100 and 300 g's 2.6.3 Effect of Soak Water Temperature on RMC TheRMC is generally higher when the rinse water temperature is lower. Figures 2.6 and 2.7 show RMC vs. g for T12 and T13 loads respectively at warm (100°F) and cold (60°F) soak temperatures. The spin time was 20 minutes, soak time was 20 minutes and the load was 8.4 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).

2-115 5 4 4 0 3 3 2 20% 0 100 200 300 400 500 600 g Factor 

### Figure 2.6 RMC vs. g for Warm and Cold Soak for Load T12 55% 5 4 4 0 3 3 2 20% 0 100 200 300 400 500 600 700 g Factor 

### Figure 2.7 RMC vs. g for Warm and Cold Soak for Load T13 2-12 700 800 900

800 900

### 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 explained earlier, for our extractor based RMC tests, we soak the cloth in a cylindrical tub containing 10 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 TI cloth, 115 g, 10-mm. 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.

70%
60%
50%
40% C, 30%
20%
10%
0% L S Soad Size: pin Time pinSpee 4.7 lbs : 10 Mn d: 115g.. DTl 1 Warm* Tl 1 Cold*

-

# '

Ii

# _-F I I,

___=

# _I _4_
10 20 60 120 16 Hours Soak Time 

### Figure 2.8 RMCvs. Soak Time in Minutes for Warm and Cold Soak at 115 g. 2.6.5 Effect of Cloth Life onRMC 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" cycle 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 spinlrinse. The presoak is optional and we considered the spin/rinse taken care of in the RMC test. We "washed" the load 5 times, then performed an RMC test and repeated this process 10 times, ultimately completing 50 "washes". Results for RMC change with "washes" and the change in bone dry cloth weight with "washes" are 2-13

### shown in Figures 2.9 and 2.10, respectively. The data are for TI cloth, at 100 g, with 15-mm. spin

time, and an 8.4 lb. load. The cloth weight is reduced approximately 2% in 50 "washes" because of the continual removal of material in the washing process. The RMC increases on the order of 1% in 50 "washes". The rate of weight loss from the fabric and the rate of RMC increase were linear over the entire 50 wash cycles. Neither showed any sign of increasing toward the end of the 50 wash cycles. The conclusion is that the cloth appears to hold slightly 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 cycles.

60% 58% 56% 54% 52% 35 50% 48% 46% 44% 42% 40% D

Lot4 - - a a Lot5 .

Load Size: 8.4 lbs. Spin Time: 15 Mm. Spin Speed: bOg 0 10 20 30 40 50 60 # Washes 

### Figure 2.9 RMCvs. Number of Wash/dry cycles

2-143950
3900
3850 a) 3800
3750
3700
3650 0 5 10 15 20 25 30 35 40 45 50 55 60 65 Wash # 

### Figure 2.10 Bone Dry Weight vs. Number of "Washes"
Aspart ofthe 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 testcloth dimensions established the baseline. Measurements were recorded after each of the five preconditioning washes and then after every ten wash 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 5was nearly consistent at 1%. 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.

2-158.0% 7.0% 6.0% 5.0% 0C • 4.0% Ci, 3.0% 2.0% 1.0% 0.0% 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 # Washes Lot 4 lLot 5



### Figure 2.11 Shrinkage of Energy Cloth Used in Cloth Life Tests 2.6.6 Effect of Pre-Conditioning onR1\'IC Thepre-conditioning procedure was verified using both a vertical and horizontal axis washing machine to determineifthe machine type used in pre-conditioning impacts the RMC results. TI Lot 4 and Lot5were each pre-conditioned following the procedure described in section 6.3, subsection 2.6.3. Each load was then mn in the extractor to compare RMC values. The extractor tests were performed, as previously, with a 20 minute warm soak, 15 minute spin, at 100 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: RMCValues for Different Pre-Conditioning Machine Type R1abirw 1pe 

# J Io 4

- 

# ] Vertical 53.3% 50.1% 52.1% 51.0% Horizontal 53.1% 50.9% 52.3% 50.3% 53.0% 50.5%

2-16

### 3. Results of Washer Based RMC Tests Conducted by Intertek Testing (ITS)

Since ITS is an independent laboratory that routinely does washer based RMC testing for the industry, it was decided to send cloth to them from the same lots we used in our extractor-based RMC tests for evaluation. This would allow a comparison of washer-based RMC to extractor-based RMC. The results of ITS washer based RMC tests are given in Table 3.1. The ITS tests are done on two washers, listed as Amana and Whirlpool. The loads that originated the study are listed as Alliance (origin TI) and ITS (origin CG). Our (ADL) cloth came from lots used in our RMC tests discussed above. The lots were purchased at different times from the supplier listed. The dramatic difference between the Alliance and ITS loads is also evident in the ADL data, suggesting that the discrepancies in RMC between TI and CG cloth is independent of lot. There is about 5%maximum difference in the TI 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 intrend. Numerical values cannot be compared because of the differences in test methods, i.e., washerbased vs. extractor-based. Table 3.1 ITS Washer-BasedRMCResults

Mliaitce kflL. Til MW II. AIDL 113 ET AIL CCI Amana 56.0% 55.21% 52.28% 53.09% 67.9% 66.09% Whirlpool 53.7% 54.65% 51.56% 49.58% 64.9% 63.84% 

### 3.1 Cloth Characteristics and Relation to RMC The construction of a textile fabric and its constituent yams 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. 3.2 Discussion of Cloth Characterization Variables A listing of cloth characterization variables, their descriptions, suspected relation to RMC, specification in current (proposed) regulation and appropriate test for evaluation is given in Table 4.1. Note that only fabric construction, thread count, fiber content, fabric weight and finish are currently specified in the proposed regulation.

3-1

### 4. Cloth Characteristics and Relation to RMC

Theconstruction 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 A listing of cloth characterization variables, their descriptions, suspected relation to RMC, specification in current (proposed) regulation and appropriate test for evaluation is given in Table 4.1. Note that only fabric construction, thread count, fiber content, fabric weight and finish are currently specified in the proposed regulation.

4-1

### Table 4.1 Cloth Characterization Variables

roper1 

### Deserpioii Rehtliuii jCuFrenl Fl ioi• 

### Suspected to 

### Siwcii&atiou

## IEvaIt1aioL1

___________ 

### _________________________ RMC 

# i I 'abric Veave of cloth. Either momie Jnknown 

# __________ vlomie 

# ____________

[dentified Construction granite)- irregularly woven (granite) visually

vith rough surface or plain weave

___________ 

### veave-regularly woven. farn Type ither open-end or ring spun Jnknown Jnspecified Identified

___________ 

### (open end common today) visually [hread Count '.Tumber of yams that run ______________ 

### Higher thread ___________



### 65/57 .STM D3775: engthwise (warp or count implies Jhread Counts nds)/number of yams that nore cotton, er Inch

_____________ 

### nterlace(fill or picks) iigher RMC

____________ 

### iber Content % blend by weight of fiber type vlore cotton fiber 50/50 cotton! ATCC 20A-with



### n yam implies higher olyester noisture: Fiber 

### RIVIC omposition Tarn Number inear density of yarn, mass/length Thicker thread implies 'Tot specified ,.STM D 1059: ore cotton , higher Standard Test IMC 4ethod for Yam 1umber abric Weight )ry weight per unit area (oz. per sq. yd. or leavier weight implies 5.75 oz. Per sq. .STM D 3776:

ms. per sq. m.) aore cotton, more d. Veight MC inish ould cover a variety of finishes applied ny finish would lower 'ure finished tATCC TM 94:

o the cloth (related to final uses or IMC leached inishes in Textiles: acilitating manufacturing process) dentification Vater Retention mount of water retained in a centrifuge Vater retention 'Tot specified STM D 2402:

est increases RJvIC Vater Retention by mbibition bsorbency mount of time for a drop of water to bsorbency increases 'Tot specified ATCC TM 79:

bsorb MC thsorbencyof leached Textiles Tertical Wicking 'ime for water to travel a fixed distance up aster wicking implies 'Tot specified [ertical Wicking Late he cloth. Tested in the warp and fill Ligher RMC tate

irections Lepellency to Oil f a surface is wetted by oil or water. lepellency lowers 'Tot specified ATCC TM 118: nd Water dentifies fluorochemical and other MC )il Repellency

inishes

4-2

### 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 are 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 weave on both CGand TI samples to be "crepe weave" (not momie), CG to be "ring-spun" yarn, and TI to be "openend" spun yarn.

4-3

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

Content 

# LF bric nipI Ii) lci L;iI' FIjcid. Cii pit 

# Iai ii Ntunbrr ' liur (o ii fiiiIrce 

# j Warp lu! WarI, ii 

# ji iUon 04 N]v% 

# j 'extile 'Alliance" CTS .86 5.0 0.0 9.58 50.2 nnovators ntertek .90 7.20 1.00 _______ -

- 9.8 19.5

_____________ 5.2 7.00 2.00 ______

- 0.2 19.8 JSDA 58! 1.00 7.00 ______ 16.90 16.20 1.9 18.1

____________ 584

_______ Tartest 5.90 6.20 _______ 1.00 ______

- _______ 0.53 _______

19.47

_____________ ____________ .98 6.70 1.00 ______

______ - 0.24 19.76 DLLotl (TI!) /artest 5.60 4.80 5.00 16.20 15.5 1.2! 18.79

______________ _____________ ;.64 4.00 5.30 16.40 16.10 0.7 19.3 iDLLot2 (TI2) ntertek .3 0 4 16.0 16.0 2.6 7.4

_______________ Tartest .23 0.5 3.5 16.3 15.8 8.5 1.5 DL Lot 3 (T13) CTS .3 2 3 16.3 15.8 18.5 1.5

ntertek .3 1 3 15.9 15.9 1.5 L8.5

______________ Tartest .33 1.7 4.0 15.8 15.5 0.09 9.9! WL Lot 4 (T14) CTS .87 3 3 14.6 14.7 0.5 .9.5

ntertek .9 5.6 3.6 15.! 14.3 1.6 .8.4

______________ Iartest .62 4.3 530 16.7 15.! 1.76 .8.24 DLLot5 (T15) CTS .5 3 2 15.4 14.5 0.7 9.3

ntertek .89 6.0 540 15.2 15.2 i2.0 .8.0

___________ ______________ Tartest 44 3.3 53.0 15.3 15.0 il.76 .8.24 otton Goods TS CTS .73 0.00 51.00

______ 5.1 4.9 ntertek .90 0.60 54.00 - 7.2 2.8

____________ .80 0.40 52.40 ______

______ - 8 2.0 JSDA .67 3.00 /1.00 18.10 - 17.50 7.8 2.2

______________ .75 Tartest .88 ________ 9.70 ________ 53.00 _______ ________ 8.32 ________

1.68

______________ _____________ .88 1.00 54.30 _______ .8.32 1.68

Tartest .20 7.30 6.00 ______ 18.00 18.10 4.27 .5.73

__________ _____________ ____________ .24 7.00 5.50 1730 lQ 4.02 5.98

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

Vertical Wicking Rate trre coHrce i thplt ID Ls ii aer I!L1Iii(1II )iôp

.U)S()1LIIIV, Fjpjiji Repk.ILy, I )5OI), :SiI Vi?r ital

%%ICIdNI, see. (ii Clii

____________ ______________ ___________ ____________ _______________ Vtt'r warn rextile 'Alliance" ISDA 15.5 388 _______________________________

________________________ (58 99 nnovators

________ 15.2 153

_____________________ ______ - Iartest

_________ ___________ ________________________ _____ ) - )

_____ ____ ____ _____ ) - - \.DL Lot 1 TIl) Iartest 191 .8 __________ 'ossible lubricant or urfactant ___ ) 185 .8 'ossible lubricant or surfactant ) \DL Lot 2 ntertek 8.0 T12) Iartest 196.6 .9 'olyvinyl Acetate ) ) 0 0 DL Lot 3 \CTS 13.75 .1

________________________ ) ) T13) ntertek

_________ '.4

________________________ - -

___________ Jartest 226.68 .6 one _______ ) ) - -

0 WL Lot 4 CTS

________ :1

_______________________ ) ) T14) ntertek

________ .6

_____________________ --

___________ Jartest

________ 1.9

_______________________ ______ ) - ) - DLLotS CTS

________ :1

_______________________ -- T15) ntertek

________ 1.2

_______________________ ______ ) )

________ __________ /artest

________ 1.4 ) ) - otton TS

________ ________ __________ _____________________ - joods

_____ ______ _______________________ ______

______________ ____ - JSDA 18.4 :1

_______________________ 15 12

________ 17.2 :1

______________________ ______ - Tartest

_________ ___________ _________________________ ______ ) )

_____ ____ ____ _____ ) ) - Gl Jartest 92 .4 ___________ Vax, Silicone/polyester ligomer, Possible lubricant r surfactant ) ) 87 ).5 ossible lubricant or urfactant ) ) Table 4.4 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 extractor-based RMC tests, not the "Alliance" and ITS data.

4-5

### Table 4.4 Summary of Results from Independent Laboratories Prortv, Diffeieice 1)jfficiici Itweeii 1.)iftruos (oicIuiii aTI reIiioit tn jL5, saifl ippIiip JH^IweeII C( tnd R1 C Iahotoric. (II onI) T Fabric Construction Vartest reported TI and CG cloth to be crepe weave (not momie) More data needed Yarn Type Vartest reported CG to be ring-spun and TI to be open-end yarn More data needed Thread Count 2% 4% 4% -11% between Significant difference TI and CG, but not between CG and TI. may be overlapping TI lot connected to RMC difference Fiber Content 4% 4% 6-12% No discernable differences between lots and laboratories. Differences between CG and TI may be connected to RMC Yarn Number 2% 2% 12% No discernable differences between lots and laboratories. Differences between CG and TI may be connected to RMC Fabric Weight Small 5% 2% 5%between lots

______________________ ______________ __________________ ________________ may be significant Finish Not enough data Some reported Same finish on Finishes reported, but no both connection to RIvIC Water Retention Data here difficult to analyze because of differences in test More information needed methods/results Absorbency Large Large Not reported More information needed Vertical Wicking Rate Not enough data Not enough data Not reported More information needed Repellency Data indicates all samples studied absorb oil and water No differences noted

4-6

### 4.3 Comparison of Cloth Characterization Test Results with R1'1CTest Results

Table 4.3 indicates some differences in cloth characteristics that may be linked to RMC results. However, there are no clear connections. There is reasonable uniformity in characteristics between TI lots reported here and these differences are within 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.

4-7

### 5. R1\'IC 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 absorptionlretention characteristics as measured by a standard RMC test is tenuous at best. The difficulty of relating specifiable characteristics - fiber content, weight, etc. to RMC 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 TI lots 1, 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 Permalux50/50Momie Weave (the cloth used for TI 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 yarns from purchased fiber and weaves and finishes the cloth material, so they have complete control over the process. However, as discussed in the preceding sections, the extractor based RMC-g curves of subsequent lots of the Riegel cloth (TI lots 4 and 5)were5to 8 percentage points higher than the corresponding RMC-g curves for TI lots 1,2, and 3. To account for lot-to-lot variation, 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 RMC vs. g values for cold and warm (60°F and 100°F) water and 4 minute and 15 minute spin times. The RMC values of TI 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 RIVIC that would have been expected with standard cloth. Figure 5-1 illustrates the basic concept.

5-1Standard Test Cloth Basis Standard RMC for Clothes

Correction Curve RMCfor 

# H Standard Clothes A New Lot of Extractor RMC Washer X with Test Cloth V5•g New Test Cloth 

### Figure 5-1 RMC Correction to Determine the RMC that would have been Measured with "Standard" Test Cloth As described below, 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 curve for a new lot of test cloth and the test data, to date, that shows that this procedure will yield 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 RMCCOI.rected=

### A +

### B*RM'measured 

### Where: • RMCconected 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 Jl RtvIC test • RMCmeasured is the RMC measured by the J 1 test procedure for clothes washer X with a lot of non-standard test cloth for which a linear correction curve has been created. 5-2

### 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 The procedure has four basic steps. 1. Establish the standard RMC vs. g values for cold and warm water and 4 minute and 15 minute spin time. 2. For a new lot of test cloth, measure the RMC vs. g values for cold and warm water and 4 minute and 15 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 StandardRMC vs. gCurve 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 215 extractor. For this test procedure it was decided that the Bock Model 215 extractor would be the "standard". 5.1.2 EstablishRMCvs. g Values for New Test Cloth Using the standard Bock Model 215 extractor measure the RMC at the specified combinations of spin time, water temperature and spin g in Table5-1. Each of the RMC measurements should be done three times, with the average used to determine the correction curve. 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 quantify the uncertainty of the linear least squares fit a root mean square error analysis is performed. The root mean square value of:

5-3

## 12 1=1 Should be less than 2-percent. 

## (RMCstandardRMq \2xs)hhi'2 orr_i) 10 The Root Mean Square (RMS) is a standard statistical quantity generated in least-squares regression analysis. 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 RMC % from any corresponding RMC % value observed with new cloth. Underlying theory and computational details are given in most applied statistics texts. Table 5-1: StandardRMCvs. g Values and Corresponding New Cloth RMC Values for Linear Least Squares Fit Sjiii Tinic Wii.r Ttmperauiie Sph g' RIC leaiirtd iii ihr Standaid Etraclnr Staudard (loili 

# ] Nes Cloth 4 mm. Cold 50 59.0%

___________________ 200 43.1% 350 35.8% _________________

____________________ Warm 50 55.7%

___________________ 200 40.4% 350 33.1% ___________________

___________________ 15 mm. Cold 50 52.8%

___________________ 200 37.9% 350 30.6% ___________________

___________________ 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 which the Ji test 5-4

### procedure is applicable. The RMC measured with the new test cloth is corrected to the standard test

cloth RIvIC, 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 TI lots 4 and 5 were used to generate the linear correction curves to TI lot 3. The resulting coefficients for the linear correction equation RMCStd A + B*RJVIC measured are summarized in Table 5-2. 

### Table5-2: Correction Coefficients

Tet(2Iolh Li A B TI 4 -0.038 0.967 T15 -0.0319 0.9975 

### The linear correction curve and the individual extractor RMC data points for lots 4 and 5are plotted in Figures5-2and5-3,respectively. The individual data points are the average 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.

Correction Curve for Lot 4 65.00% - 60.00% - 55.00% 50.00% - a 45.00% - 40.00% - 35.00% - 30.00% - 25.00% - 30.0 0% - 0.9676 - 0.038

35,00% 40,00% 45.00% 50.00% 55.00% 60.00% 65.00% Lot 4 RMC (1⁄4) 

### Figure 5-2: Linear Correction Curve for TI Lot 4 5-5Correction Curve for Lot 5 65.00% - 60.00% -- 55.00% - 50.00% - 0 45.00% - 40.00% 35.00% - 30.00% - 25.00% - 30. 0 0% 0.9975x-0.0319

35.00% 40.00% 45.00% 50.00% 55.00% 60.00% 65.00% Lot 5 RMC (%) 

### Figure 5-3: Linear Correction Curve for TI Lot 5 The results of the extractor-based correction curve tests are shown in table 5-3 and5-4. The tables show the standard (Lot 3) measured value, the Lot 4 (or5)measured value, and the corrected value. All measured values are shown, however, the average of the three test values at each condition are used for the least squares curve fit.

5-6