Note:

DOE maintains an historical record of the standard extractor test data and final correction curve coefficients for each approved lot of energy test cloth. These can be accessed through DOE's web page for standards and test procedures for residential clothes washers at DOE's Building Technologies Office Appliance and Equipment Standards website.

1. Objective

This appendix includes the following: (1) Specifications for the energy test cloth to be used for testing clothes washers; (2) procedures for verifying that new lots of energy test cloth meet the defined material specifications; and (3) procedures for developing a set of correction coefficients that correlate the measured remaining moisture content (RMC) values of each new test cloth lot with a set of standard RMC values established as an historical reference point. These correction coefficients are applied to the RMC measurements performed during testing according to appendix J or appendix J2 to this subpart, ensuring that the final corrected RMC measurement for a clothes washer remains independent of the test cloth lot used for testing.

2. Definitions

AHAM means the Association of Home Appliance Manufacturers.

Bone-dry means a condition of a load of test cloth that has been dried in a dryer at maximum temperature for a minimum of 10 minutes, removed and weighed before cool down, and then dried again for 10 minute periods until the final weight change of the load is 1 percent or less.

Lot means a quantity of cloth that has been manufactured with the same batches of cotton and polyester during one continuous process.

Roll means a subset of a lot.

3. Energy Test Cloth Specifications

The energy test cloths and energy stuffer cloths must meet the following specifications:

3.1 The test cloth material should come from a roll of material with a width of approximately 63 inches and approximately 500 yards per roll. However, other sizes may be used if the test cloth material meets the specifications listed in sections 3.2 through 3.6 of this appendix.

3.2 Nominal fabric type. Pure finished bleached cloth made with a momie or granite weave, which is nominally 50 percent cotton and 50 percent polyester.

3.3 Fabric weight. 5.60 ± 0.25 ounces per square yard (190.0 ± 8.4 g/m2).

3.4 Thread count. 65 x 57 per inch (warp × fill), ±2 percent.

3.5 Fiber content of warp and filling yarn. 50 percent ±4 percent cotton, with the balance being polyester, open end spun, 15/1 ±5 percent cotton count blended yarn.

3.6 Water repellent finishes, such as fluoropolymer stain resistant finishes, must not be applied to the test cloth.

3.7. Test cloth dimensions.

3.7.1 Energy test cloth. The energy test cloth must be made from energy test cloth material, as specified in section 3.1 of this appendix, that is 24 ± 1/2 inches by 36 ± 1/2 inches (61.0 ± 1.3 cm by 91.4 ± 1.3 cm) and has been hemmed to 22 ± 1/2 inches by 34 ± 1/2 inches (55.9 ± 1.3 cm by 86.4 ± 1.3 cm) before washing.

3.7.2 Energy stuffer cloth. The energy stuffer cloth must be made from energy test cloth material, as specified in section 3.1 of this appendix, that is 12 ± 1/4 inches by 12 ± 1/4 inches (30.5 ± 0.6 cm by 30.5 ± 0.6 cm) and has been hemmed to 10 ± 1/4 inches by 10 ± 1/4 inches (25.4 ± 0.6 cm by 25.4 ± 0.6 cm) before washing.

3.8 The test cloth must be clean and must not be used for more than 60 test runs (after pre-conditioning as specified in section 5 of this appendix). All test cloth must be permanently marked identifying the lot number of the material. Mixed lots of material must not be used for testing a clothes washer according to appendix J or appendix J2 to this subpart.

4. Equipment Specifications

4.1 Extractor. Use a North Star Engineered Products Inc. (formerly Bock) Model 215 extractor (having a basket diameter of 20 inches, height of 11.5 inches, and volume of 2.09 ft 3), with a variable speed drive (North Star Engineered Products, P.O. Box 5127, Toledo, OH 43611) or an equivalent extractor with same basket design (i.e., diameter, height, volume, and hole configuration) and variable speed drive. Table 4.1 of this appendix shows the extractor spin speed, in revolutions per minute (RPM), that must be used to attain each required g-force level.

4.2 Bone-dryer. The dryer used for drying the cloth to bone-dry must heat the test cloth and energy stuffer cloths above 210 °F (99 °C).

5. Test Cloth Pre-Conditioning Instructions

Use the following instructions for performing pre-conditioning of new energy test cloths and energy stuffer cloths as specified throughout section 7 and section 8 of this appendix, and before any clothes washer testing using appendix J or appendix J2 to this subpart: Perform five complete wash-rinse-spin cycles, the first two with current AHAM Standard detergent Formula 3 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 water (17 ppm hardness or less) using 27.0 grams + 4.0 grams per pound of cloth load of AHAM Standard detergent Formula 3. The wash temperature is to be controlled to 135 °F ± 5 °F (57.2 °C ± 2.8 °C) and the rinse temperature is to be controlled to 60 °F ± 5 °F (15.6 °C ± 2.8 °C). Dry the load to bone-dry between each of the five wash-rinse-spin cycles. The maximum shrinkage after preconditioning must not be more than 5 percent of the length and width. Measure per AATCC Test Method 135-2010 (incorporated by reference; see § 430.3).

6. Extractor Run Instructions

Use the following instructions for performing each of the extractor runs specified throughout section 7 and section 8 of this appendix:

6.1 Test load size. Use a test load size of 8.4 lbs.

6.2 Measure the average RMC for each sample loads as follows:

6.2.1 Dry the test cloth until it is bone-dry according to the definition in section 2 of this appendix. Record the bone-dry weight of the test load (WI).

6.2.2 Prepare the test load for soak by grouping four test cloths into loose bundles. Create the bundles by hanging four cloths vertically from one corner and loosely wrapping the test cloth onto itself to form the bundle. Bundles should be wrapped loosely to ensure consistency of water extraction. Then place the bundles into the water to soak. Eight to nine bundles will be formed depending on the test load. The ninth bundle may not equal four cloths but can incorporate energy stuffer cloths to help offset the size difference.

6.2.3 Soak the test load for 20 minutes in 10 gallons of soft (<17 ppm) water. The entire test load must be submerged. Maintain a water temperature of 100 °F ± 5 °F (37.8 °C ± 2.8 °C) at all times between the start and end of the soak.

6.2.4 Remove the test load and allow each of the test cloth bundles to drain over the water bath for a maximum of 5 seconds.

6.2.5 Manually place the test cloth bundles in the basket of the extractor, distributing them evenly by eye. The draining and loading process must take no longer than 1 minute. Spin the load at a fixed speed corresponding to the intended centripetal acceleration level (measured in units of the acceleration of gravity, g) ± 1g for the intended time period ± 5 seconds. Begin the timer when the extractor meets the required spin speed for each test.

6.2.6 Record the weight of the test load immediately after the completion of the extractor spin cycle (WC).

6.2.7 Calculate the remaining moisture content of the test load as (WC-WI)/WI.

6.2.8 Draining the soak tub is not necessary if the water bath is corrected for water level and temperature before the next extraction.

6.2.9 Drying the test load in between extraction runs is not necessary. However, the bone-dry weight must be checked after every 12 extraction runs to make sure the bone-dry weight is within tolerance (8.4 ± 0.1 lbs). Following this, the test load must be soaked and extracted once before continuing with the remaining extraction runs. Perform this extraction at the same spin speed used for the extraction run prior to checking the bone-dry weight, for a time period of 4 minutes. Either warm or cold soak temperature may be used.

7. Test Cloth Material Verification Procedure

7.1 Material Properties Verification. The test cloth manufacturer must supply a certificate of conformance to ensure that the energy test cloth and stuffer cloth samples used for prequalification testing meet the specifications in section 3 of this appendix. The material properties of one energy test cloth from each of the first, middle, and last rolls must be evaluated as follows, prior to pre-conditioning:

7.1.1 Dimensions. Each hemmed energy test cloth must meet the size specifications in section 3.7.1 of this appendix. Each hemmed stuffer cloth must meet the size specifications in section 3.7.2 of this appendix.

7.1.2 Oil repellency. Perform AATCC Test Method 118-2007, Oil Repellency: Hydrocarbon Resistance Test, (incorporated by reference, see § 430.3), to confirm the absence of ScotchguardTM or other water-repellent finish. An Oil Repellency Grade of 0 (Fails Kaydol) is required.

7.1.3 Absorbency. Perform AATCC Test Method 79-2010, Absorbency of Textiles, (incorporated by reference, see § 430.3), to confirm the absence of ScotchguardTM or other water-repellent finish. The time to absorb one drop must be on the order of 1 second.

7.2 Uniformity Verification. The uniformity of each test cloth lot must be evaluated as follows.

7.2.1 Pre-conditioning. Pre-condition the energy test cloths and energy stuffer cloths used for uniformity verification, as specified in section 5 of this appendix.

7.2.2 Distribution of samples. Test loads must be comprised of cloth from three different rolls from the sample lot. Each roll from a lot must be marked in the run order that it was made. The three rolls are selected based on the run order such that the first, middle, and last rolls are used. As the rolls are cut into cloth, fabric must be selected from the beginning, middle, and end of the roll to create separate loads from each location, for a total of nine sample loads according to Table 7.2.2.

7.2.3 Measure the remaining moisture content of each of the nine sample test loads, as specified in section 6 of this appendix, using a centripetal acceleration of 350g (corresponding to 1111 ± 1 RPM) and a spin duration of 15 minutes ± 5 seconds.

7.2.4 Repeat section 7.2.3 of this appendix an additional two times and calculate the arithmetic average of the three RMC values to determine the average RMC value for each sample load. It is not necessary to dry the load to bone-dry the load before the second and third replications.

7.2.5 Calculate the coefficient of variation (CV) of the nine average RMC values from each sample load. The CV must be less than or equal to 1 percent for the test cloth lot to be considered acceptable and to perform the standard extractor RMC testing.

8. RMC Correction Curve Procedure

8.1 Pre-conditioning. Pre-condition the energy test cloths and energy stuffer cloths used for RMC correction curve measurements, as specified in section 5 of this appendix.

8.2 Distribution of samples. Test loads must be comprised of randomly selected cloth at the beginning, middle and end of a lot. Two test loads may be used, with each load used for half of the total number of required tests. Separate test loads must be used from the loads used for uniformity verification.

8.3 Measure the remaining moisture content of the test load, as specified in section 6 of this appendix at five g-force levels: 100 g, 200 g, 350 g, 500 g, and 650 g, using two different spin times at each g level: 4 minutes and 15 minutes. Table 4.1 of this appendix provides the corresponding spin speeds for each g-force level.

8.4 Repeat section 8.3 of this appendix using soft (<17 ppm) water at 60 °F ± 5 °F (15.6 °C ± 2.8 °C).

8.5 Repeat sections 8.3.3 and 8.3.4 of this appendix an additional two times, so that three replications at each extractor condition are performed. When this procedure is performed in its entirety, a total of 60 extractor RMC test runs are required.

8.6 Average the values of the 3 replications performed for each extractor condition specified in section 8.3 of this appendix.

8.7 Perform a linear least-squares fit to determine coefficients A and B such that the standard RMC values shown in Table 8.7 of this appendix (RMCstandard) are linearly related to the average RMC values calculated in section 8.6 of this appendix (RMCcloth):

RMCstandard ∼ A × RMCcloth + B where A and B are coefficients of the linear least-squares fit.

8.8 Perform an analysis of variance with replication test using two factors, spin speed and lot, to check the interaction of speed and lot. Use the values from section 8.6 of this appendix and Table 8.7 of this appendix in the calculation. The “P” value of the F-statistic for interaction between spin speed and lot in the variance analysis must be greater than or equal to 0.1. If the “P” value is less than 0.1, the test cloth is unacceptable. “P” is a theoretically based measure of interaction based on an analysis of variance.

9. Application of the RMC Correction Curve

9.1 Using the coefficients A and B calculated in section 8.7 of this appendix:

RMCcorr = A × RMC + B

9.2 Apply this RMC correction curve to measured RMC values in appendix J and appendix J2 to this subpart.

[87 span 33403, June 1, 2022, as amended at 87 span 78820, Dec. 23, 2022]