US3853463A

US3853463A - Bleachability test for colored fabrics

Info

Publication number: US3853463A
Application number: US00266049A
Authority: US
Inventors: P Woodward
Original assignee: Clorox Co
Current assignee: Clorox Co
Priority date: 1972-06-26
Filing date: 1972-06-26
Publication date: 1974-12-10
Anticipated expiration: 1991-12-10

Abstract

A method for rapidly and simply determining the susceptibility of a fabric to color change in a wash solution including bleach, comprising the steps of preparing a test solution having an available chlorine concentration of within the approximate range of 4,000 to 10,000 parts per million (ppm), saturating a small area of the fabric with the solution, drying the fabric, and comparing the dried fabric with a similar untreated fabric to determine if there has been a color change.

Description

OTHER PUBLICATIONS National Institute of Dry Cleaning, Practical Operating Tips, Bulletin P-8, Oct. I953.

United States Patent [191 [11] Woodward Dec. 10, 1974 BLEACHABILITY TEST FOR COLORED National Institute of Dry Cleaning, Practical Operat- FABRICS ing Tips, Bulletin P-23, April i957.

[75] Inventor: Eats;- K. Woodward, San Rafael, Primary Examiner Joseph Scovmnek Assistant Examiner-Barry I. Hollander [73] Assignee: The Clorox Company, Oakland, Attorney, Agent, or Firm-Phillips, Moore,

Calif- Weissenberger, Lempio & Strabala 22 F1 d: 26 1972 1 1e June 57 ABSTRACT [21] Appl' 266049 A method for rapidly and simply determining the susceptibility of a fabric to color change in a wash solu- 52 US. Cl. 8/137, 23/230 R, 8/108 tipn including bleach, comprising the steps of p p 51 1 3 H 0 3 0 0 1 3 1 01 33 3 ing a test solution having an available chlorine con- 58] Field of Search 23/230 R; 8/19, 101, 108, centration of within the approximate range of 4,000 to 8/137 10,000 parts per million (ppm), saturating a small area of the fabric with the solution, drying the fabric, [56] Ref Ci d and comparing the dried fabric with a similar untreated fabric to determine if there has been a color change.

6 Claims, 1 Drawing Figure 3 80 Q LLI n: 0.

g 88 s 8 Q 0 N we 8 AVAILABLE CHLORINE p. p. m.

1 BLEACHABILITY TEST FOR COLORED FABRICS The present invention relates to a method for predicting or determining if a fabric will remain substantially colorfast in a wash solution including bleach. Bleach has long been used in wash solutions in combination with detergents for maximum stain removal, soil removal and disinfection, particularly in the laundering of white fabrics. The same advantages may be achieved in the laundering of colored fabrics by using bleach. With the fiber and dye combinations presently available for various types of colored fabrics, it has been found that most of them may now also be subject to wash solutions including bleach without experiencing a color change.

Certain fabrics, however, still remain susceptible to color change when immersed in a wash solution including bleach. Most fabrics or garments are not marked to indicate whether or not they will remain colorfast if bleach is used in the wash solution. Accordingly, it has heretofore been necessary to conduct relatively laborious and time consuming individual tests on garments and fabrics to determine if they will remain colorfast after being washed one or more times with bleach. For example, one test has been to merely duplicate the wash conditions on a limited portion of the fabric. In this test, the fabric must remain in the test solution for a substantial period of time. Tests of this type are both awkward and unreliable since it isnot possible to duplicate wash cycle conditions to which the fabric may be subjected.

In overcoming this problem, the present invention has been found to provide a simple and reliable method of predicting or determining whether a fabric will re main colorfast upon being subjected to oxidation conditions in wash solutions including a bleach. The invention is based upon the unexpected discovery that susceptibility of the fabric to color change may be predicted by subjecting it for a short period of time to a solution having a substantially increased available chlorine concentration within a selected range.

In a typical wash solution, including both detergent and a hypochlorite, the available chlorine concentration may be in the range of up to approximately 200 ppm. By the present invention, it has been found'that the color fastness of a fabric subjected to such a wash solution may be accurately predicted by subjecting a small area of the fabric to a test solution having an available chlorine content within the approximate range of 4,000 to 10,000 ppm. In other words, the color fastness of fabrics may be rapidly and accurately determined prior to subjecting them to a wash solution including bleach by spot testing the fabric with a test solution having an available chlorine concentration very much greater than the normal available chlorine concentration in the wash solution. A wide variety of fabrics was tested with solutions having widely varying concentrations of'available chlorine with the abovenoted range being particularly and unexpectedly effective for predicting the color fastness of various fabrics.

The most common type of color change which may occur under these conditions, of course, is the simple fading of colors where the dyes are unduly affected by the bleach. However, other types of undesirable color change may also be predicted by the present invention. For example, while most of the modern parmanent press fabrics can be safely subjected to solutions including bleach, certain of them have resin finishes which may tend to yellow under such condition. The present test method has also been found effective for use in determining the tendency of such fabrics to yellow.

The method of detennining the accuracy of the present test in predicting color fastness of various fabrics is discussed in greater detail below. In general, test solutions of different available chlorine concentrations were applied to different portions of the fabrics. Similar fabrics were then subjected to one or more wash cycles including bleach, these fabrics then being correlated for color fastness with the similar spot tested fabrics. It was thus discovered that, through the use of a test solution having an available chlorine concentration within selected limits, the color fastness of the various fabrics could be predicted with a high degree of accuracy.

The accompanying drawing graphically illustrates the effectiveness of the present invention in predicting color fastness of fabrics. In the drawing, the percent predictability of color change is plotted versus the concentration of available chlorine in a test solution applied to the fabric. Referring to the drawing, it may be noted that the percent predictability or the effectiveness of the present method is particularly high when the concentration of available chlorine is maintained within the selected limits taught by the present invention.

In determining the accuracy of the present method, a variety of fabrics and many different classes of dyestuff were tested. Forexample, the evaluated fabrics included both natural and man-made fibers, as well as fiber blends. Specific fibers included in the tests were cotton, linen, rayon, cellulose acetate (secondary), cellulose triacetate,.polyester, nylon, acrylic, modacrylic and polypropylene. Various dyestuffs included in the test were direct, disperse, vat, sulfur, azoic, acid, acid premetalized and cationic (basic) dyes. As is commonly known within the art, certain of these dyes are specifically adapted for usewith certain of the fabrics listed above. For purposes of the present invention, the fibers and dyestuffs listed above are intended only to illustrate that the present invention has been found to be effective for a large cross section of fibers and associated dyes presently available.

Tests to determine the predictability of the present method were carried out on different fabric and dye combinations. Each of the sample fabrics was cut into at least two portions. One portion of each fabric was subjected to a typical wash solution including both detergent and bleach. Washing of these fabrics was carried out in an automatic washing machine having an operating cycle of: fill, agitate (wash), drain, spin, fill, rinse, drain and spin. The wash water used in these tests was approximately 1 15F, which is believed to most accurately correlate with typical temperatures employed within such machines. However, it is noted that home laundries may commonly employ water having a temperature of up to F or a substantially lower temperature, for example in cold water washing and the tests described herein for the present invention are believed to be representative. The wash solution to which the various fabrics were subjected was prepared by adding one-fifth cup of a typical commercial grade detergent (such as sodium dodecylbenzene sulfonate) and one cup of a bleach (such as an aqueous solution of approximately 5.25 percent sodium hypochlorite) to approximately 16 gallons of water.

The other portion of each fiber sample was treated in different locations with drops of test solution having varying concentrations of available chlorine. The test solutions were prepared by adding suitable quantities of the above noted hypochlorite bleach (commercially available for example, under the trade name Clorox) to the water. A concentration of approximately 10,000 ppm available chlorine may be obtained by mixing one part of the above noted commercial liquid bleach with approximately four parts of water. It is necessary to assure that each drop penetrates the fabric. On certain water repellent fabrics, the drop of test solution may tend to bead up, but it was found that the test solution could be readily induced to penetrate the fabric in each instance, for example, by working the solution into the fabric with a glass or polyethylene rod. The test solution was applied to the fabric at room temperature, generally within the range of 60-90F, and allowed to stand for approximately 1 minute.

The spots on the fabric treated with the test solution I were then blotted dry with paper towels and compared with the other fabric samples for color change. The determination of color difference between the similar types of fabric could be carried out by various mechanical means or standard test methods, such as the well known Gray Scale for example. However, since it was anticipated that the test would normally be conducted where such test apparatus was not available, the color comparison was made by visually examining the fabrics to determine if a color difference could be observed. As shown on the graph, it was found that spot testing the various fabrics with a test solution having an available chlorine'concentration of about 5,000 ppm correctly indicated color fastness for 98 out of the 105 different fabrics tested, equivalent to a 93.3 percent predictability. With a test solution having an available chlorine concentration of 10,000 ppm, 97 of the 105 fabrics were correctly predicted for a predictability percentage of 92.4 percent. By comparison, when the test solution had an available chlorine concentration of 20,000 ppm, color fastness for only 85 of the 105 fabric samples was correctly indicated for a predictability percentage of 81.0 percent. The present predictability similarly dropped off at a very rapid rate when the concentration of available chlorine was substantially below 4,000 ppm. Accordingly. color fastness of various fabrics may best be indicated by applying a test solution having an available chlorine concentration within the approximate range of 4,000 to 10,000 ppm in the manner described above.

What is claimed is:

1. In a method of washing colored fabrics by subjecting them to oxidation conditions in an aqueous wash solution including detergent and bleach, the wash solution having an available chlorine concentration of up to approximately 200 ppm and a temperature of up to approximately F, the steps comprising:

preparing a test solution having an available chlorine concentration of above 4000 and below 10,000

pp treating a small area of the fabric with the test solution, by saturating the small area of the fabric with the test solution, then drying the fabric,

comparing the treated fabric when substantially dry with similar untreated fabric for color differences, and excluding only those fabrics exhibiting said color difference from said wash solution and subjecting the remaining fabrics to said wash solution in a subsequent washing step.

2. The method of claim 1 wherein the test solution comprises a hypochlorite.

3. The method of claim 1 wherein the test solution comprises sodium hypochlorite.

4. The method of claim 1 wherein the step of treating the fabric comprises saturating the fabric with the test solution for approximately 1 minute and then blotting the saturated fabric so that it is substantially dry prior to the comparison step.

5. The method of claim 4 wherein the test solution comprises a hypochlorite.

6. The method of claim 1 wherein the step of treating the fabric comprises saturating the fabric with a small portion of the test solution at a temperature of approximately 60-90F for approximately 1 minute and then substantially drying the saturated fabric prior to comparing it with untreated fabric for color change.

Claims

1. IN A METHOD FOR WASHING COLORED FABRICS BY SUBJECTING THEM TO OXIDATION CONDITIONS IN AN AQUEOUS WASH SOLUTION INCLUDING DETERGENT AND BLEACH, THE WASH SOLUTION HAVING AN AVAILABLE CHLORINE CONCENTRATION OF UP TO APPROXIMATELY 200 PPM AND A TEMPERATURE OF UP TO APPROXIMATELY 150*F, THE STEPS COMPRISING: PREPARING A TEST SOLUTION HAVING AN AVAILABLE CHLORINE CONCENTRATION OF ABOVE 4000 AND BELOW 10,000 PPM TREATING A SMALL AREA OF THE FABRIC WITH THE TEST SOLUTION, BY SATURATING THE SMALL AREA OF THE FABRIC WITH THE TEST SOLUTION, THEN DRYING THE FABRIC, COMPARING THE TREATED FABRIC WHEN SUBSTANTIALLY DRY WITH SIMILAR UNTREATED FABRICS EXHIBITING SAID COLOR DIFFERENCE ING ONLY THOSE FABRICS EXHIBITING SAID COLOR DIFFERENCE FROM SAIID WASH SOLUTION AND SUBJECTING THE REMAINING FABRICS TO SAID WASH SOLUTON IN A SUBSEQUENT WASHING STEP.

2. The method of claim 1 wherein the test solution comprises a hypochlorite.

5. The method of claim 4 wherein the test solution comprises a hypochlorite.

6. The method of claim 1 wherein the step of treating the fabric comprises saturating the fabric with a small portion of the test solution at a temperature of approximately 60*-90*F for approximately 1 minute and then substantially drying the saturated fabric prior to comparing it with untreated fabric for color change.