Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F35/00—Washing machines, apparatus, or methods not otherwise provided for
  • D06F35/005—Methods for washing, rinsing or spin-drying
  • D06F35/006—Methods for washing, rinsing or spin-drying for washing or rinsing only
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/39—Organic or inorganic per-compounds
  • C11D3/3942—Inorganic per-compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/48—Medical, disinfecting agents, disinfecting, antibacterial, germicidal or antimicrobial compositions
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06L—DRY-CLEANING, WASHING OR BLEACHING FIBRES, FILAMENTS, THREADS, YARNS, FABRICS, FEATHERS OR MADE-UP FIBROUS GOODS; BLEACHING LEATHER OR FURS
  • D06L4/00—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs
  • D06L4/10—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs using agents which develop oxygen
  • D06L4/12—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs using agents which develop oxygen combined with specific additives
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2202/00—Aspects relating to methods or apparatus for disinfecting or sterilising materials or objects
  • A61L2202/20—Targets to be treated
  • A61L2202/26—Textiles, e.g. towels, beds, cloths
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D2111/00—Cleaning compositions characterised by the objects to be cleaned; Cleaning compositions characterised by non-standard cleaning or washing processes
  • C11D2111/40—Specific cleaning or washing processes
  • C11D2111/44—Multi-step processes

Definitions

• ABSTRACT Method (A) for laundering fabrics comprising washing said fabrics in hot water at a medium water level in the presence of soap and a sequestering agent; flushing the fabric load; wash- 51 Mar. 21, 1972 ing the fabric at a low water level for about to about minutes at a temperature of about 175 to about 195 F.
• an oxygencontaining bleach which is hydrogen peroxide or a material which forms hydrogen peroxide or nascent oxygen in the presence of water for a time sufficient to obtain substantially uniform penetration of the oxygen-containing bleach into the fabric with the concentration of oxygen-containing bleach ranging from about 0.1 to about 0.2 percent by weight of the dry fabric; increasing the temperature of the fabric load to at least about F. in the presence of a strong alkali and soap or a detergent for about 10 to about 15 minutes; rinsing the fabric load; souring the fabric load in the presence of a watersoluble germicide at a concentration level sufficient to inhibit the growth of mildew in the laundered fabric, and extracting the water from the soured fabric load.
• a major segment of the commercial laundry industry involves suppliers who supply their own linens to users, such as doctors offices, beauty shops, industrial plants, hotels, restau rants, and the like.
• a linen supplier of this type furnishes a continuous source of clean linens to its customers, delivering clean linens on a regular basis, picking up soiled linens on a regular basis, and laundering the soiled linens in its own plant.
• heat resistant bacterial spores may be embedded within the interstices ofa laundered product, such as a continuous towel, and can survive the severe laundering conditions used by a commercial laundry.
• a laundered product such as a continuous towel
• Such tests showed that commercial linens having a hygenically clean surface, can and ofttimes do, contain a large number of heat resistant bacterial spores embedded within their interstices.
• Such embedded spores may, of course, pose a health hazard since the spores, given the right growth conditions, may become activated to produce bacteria. This result would be very harmful if the linens were employed in a hospital or doctors office. Also, in the case of linens used by many different people, such as continuous toweling, the release of bacteria from within the interstices of the towel could result in rapid spreading of the bacteria. If the bacteria were a disease-producing type, the net result would be a spreading ofthe bacteria in epidemic proportions.
• medium soil refers to items such as waitress dresses, towels for beauty shops, and, in some cases, napkins from restaurants.
• the weight of the soiling material in items of this type is greater than in items in the light soil category, above, and items in this category will also contain more stains than items in the light soil category.
• medium soil items in the light soil category may typically contain approximately five pounds of dry soil (2.0 percent) per 300-pound load.
• items which fall into the category of heavy soil not only contain stains but also contain appreciable amounts of loose soil which must be flushed or rinsed out of the washing machine in order to avoid gray work.
• Items in this category inelude, for example, aprons from butcher shops, towels from restaurants, and swipes that are used for clean-up purposes.
• the weight of the soiling material for items in this category will be approximately 30 pounds of dry soil (10.0 percent) for a BOO-pound load.
• items which fall in the category ofindustrial soil contain oily soil rather than fatty soil and include, for example, linens such as towels and coveralls from garages and industrial plants.
• the weight of the soiling material in this category is far greater than in any other-for example, approximately pounds of dry soil (30.0 percent) for a 300-pound load may be taken as typical.
• the first laundering step involved thoroughly wetting the load with water. in the event that the load was bloody, the temperature of the water was about F. and if the load was not bloody, the temperature of the water was about F. 1n laundering fabrics according to my method (A), I have found that it is undesirable to begin the laundry cycle with a water-wetting of the load as previously employed since this has been found to redistribute bacteria and bacterial spores contained within the fabric.
• the first step in the laundry operation is a mild washing step.
• Hot water i.e., about 160 F.
• soap at a concentration of about 0.02 percent by weight of the dry fabric and sequestering agent is present at a concentration in the order of about 0.01 percent to about 0.05 percent by dry weight of the fabric.
• sequestering agents include, for example, polyphosphates and Versene, which is the sodium salt of ethylene diamine tetraacetic acid.
• Open pocket washers as employed, contain one vertical partition mounted perpendicular to the axis of the washer and dividing it in two.
• the washer contains no horizontal or radial partitions and rotates at a constant speed of about 21 revolutions per minute.
• the degree of agitation obtained is determinated by the water level. As the water level is increased, the degree of agitation is decreased and as the water level is decreased, the agitation is increased.
• My laundering procedure is particularly suited for the washing of continuous towels.
• a continuous towel will, for example, have a length of about 50 yards and it is tied into a bundle for washing.
• the towel bundles are formed by folding the towel into 36-inch lengths to form a bundle having a length of about 36 inches and a height of about 6 inches. The bundle is then tied in two places and is washed in this manner.
• a bundled fabric such as continuous toweling, it is difficult to penetrate the interstices of the toweling at the center of the bundle during washing to kill any bacteria or bacterial spores contained therein.
• the initial waterwetting step previously employed also had the disadvantage of embedding bacterial spores within the interstices of the fabric being washed. This resulted from the force of the water striking against the fabric during agitation.
• the dirt and bacteria are loosened and placed in suspension within the wash water such that they are removed from the fabrics and are not embedded therein.
• the quantity of soap e.g., sodium stearate or detergents, including anionic and nonionic detergents, which is present during the first step is at a concentration of about 0.02 percent by dry weight of the fabric being laundered.
• the amount of soap employed can, of course, be varied depending upon the salt content of the water. If the water is deionized, the soap content can be reduced proportionately.
• the load is drained and is then flushed one or more times by introducing hot water, e.g., about 160 F., into the machine to a high level, i.e., a water level of about 12 inches.
• a high level i.e., a water level of about 12 inches.
• the load is subjected to mild agitation for about 3 minutes.
• the speed of rotation of the washer is maintained constant and the degree of agitation determined by the water level.
• the load is drained and, if desired, can be subjected to a second flush cycle in the same manner as described.
• the laundry is then subjected to a washing cycle for a period of about to about 15 minutes.
• the wash water is maintained at a temperature of about 175 to about 195 F. at a low water level, such as about three inches.
• a strong alkali such as caustic soda, is present at a concentration from about 0.2 to about 0.5 percent by weight of the dry weight of the fabric and soap or detergent is present at a concentration of about 0.1 to about 0.3 percent by weight of the dry weight of the fabric.
• a portion, such as about percent of the soap or detergent may be replaced with a sequestering agent, as defined previously.
• the linens being laundered are colored, a small quantity of dye, such as about one-quarter to about one-half ounce per one hundred pounds dry weight of fabric, is added for restorative purposes.
• the various dyes which may be employed are well known to the industry; For example, in washing blue fabrics, the dye known as Direct Copper Blue manufactured by Ciba Company, may be used, and in the case of red toweling, Congo Red may be used. With yellow towels, a yellow dye such as Ciba RLSW may be used, and for green toweling, the dye sold as Ciba Direct Green CBM may be used.
• the quantity of dye as set forth above, is used for restorative purposes to maintain the color of the fabric.
• the load is subjected to several flushing steps. Generally, the load is flushed twice; however, if a great deal of dirt is present, the load may be flushed three times.
• hot water at a temperature of about 160 F. is added to the machine to a water level of about 12 inches and the load is subjected to mild agitation for a period of about 3 minutes and thereafter drained.
• the load may be subjected to additional flushing treatments in the same manner, as desired.
• an oxygen containing bleach which is hydrogen peroxide or a material which forms hydrogen peroxide or nascent oxygen in the presence of water.
• the bleach is present at a concentration level ranging from about 0.1 to about 0.2 percent by weight of the dry fabric weight.
• oxygen-containing bleach includes liquid hydrogen peroxide, solid sodium peroxide, or equivalent water soluble noncolor forming salts, such as sodium perborate.
• a peroxide is added in the form of an aqueous solution such as, for example, a 35 percent aqueous solution of hydrogen peroxide. In admixture with the peroxide is hot water, e.g., about 160 F., at a medium level of about 6 to 8 inches.
• Soap such as sodium stearate, or other anionic or nonionic detergent, is present at a level ranging from about 0.01 to about 0.02 percent by weight of the dry fabric load. As discussed previously, the quantity of soap employed can be reduced considerably if the water is softened and preferably deionized. No strong alkali, e.g., caustic soda, or sequestering agent is added to the bleach cycle.
• the load After addition of the hot water and other ingredients to the washing machine, the load is heated, in the event that the water is not already at this temperature, to a temperature of at least about 175 F. The load is then maintained at this temperature for about 6 to about 10 minutes with agitation.
• the load is subjected to a number of rinses.
• the number of rinse cycles is not critical to my process, 1 generally find it advantageous to use three rinse cycles following the bleaching treatment.
• water is introduced into the machine in an amount sufficient to provide a high water level, e.g., about 12 inches, and thereafter the load is subjected to mild agitation at the high water level for a period of about 3 minutes and then drained. 1n the course of the rinse cycles, the temperature of the load is gradually reduced to about F.
• the water for the first rinse cycle could be at a temperature of about 150 F.
• the water employed for the second rinse cycle could be at a temperature of about F.
• the water employed for the third rinse cycle could be at a temperature of about 105 F.
• the load is then subjected to a souring treatment.
• the souring treatment is used to provide the fabric with a pH of about 5.4, which is that of the human skin.
• a souring step can be used to provide a higher pH of the fabric such as about 6.0.
• a typical souring agent is ammonium silicofluoride.
• the concentration of souring agent may range from about 0.02 percent to about 0.05 percent by weight of the dry fabric load and can be varied depending upon the pH of the city water which is used.
• a water-soluble germicide at a concentration level sufficient to inhibit the growth of mildew in the laundered fabric.
• the concentration of germicide can, of course, be varied, depending upon its potency.
• the concentration 'level of germicide may range from about 0.004 to about 0.008 percent by weight of the dry fabric load.
• Typical germicides include water soluble organometallics, such as phenyl mercuric acetate, which is a standard germicide.
• the load is subjected to agitation at a medium water level (about 6 to 8 inches) for a period of about 5 minutes.
• a medium water level about 6 to 8 inches
• the water is then extracted from the load, either centrifugally or by pressure, and the fabric may then be ironed.
• my novel laundry process provides fabrics which are not only clean, i.e., free from dirt, but also essentially free from bacteria and bacterial spores before exposure to air. Although many methods are known for laundering fabrics and many methods are known for sterilization, to my knowledge there is no satisfactory process available which can provide fabrics which are both clean and essentially free from bacteria and bacterial spores without excessive fabric damage. As described, my laundry process may be used for cleaning linens containing light soil, medium soil, heavy soil, or industrial soil. It should be understood, of course, that the detergency level and the number of rinse cycles may be increased or decreased depending upon the soil level in the fabric.
• Method A as previously disclosed in copending application Ser. No. 802,670, which is now abandoned comprises eight steps which are as follows:
• Method (B) which is particularly suitable for killing heat resistant spores as found in fabrics from slaughter houses, a slightly different procedure is used than in Method (A). To illustrate the difference between my Method (B) and my Method (A), the following steps are employed in Method (B):
• an oxygen-containing bleach which is hydrogen peroxide or a material which forms hydrogen peroxide or nascent oxygen in the presence of water, for a time sufficient to obtain substantially uniform penetration of the oxygen-containing bleach into the fabric, the concentration of oxygen-containing bleach ranging from about 0.1 to about 0.2 percent by weight of the dry fabric weight;
• Method (A) the fabric load is first washed in the presence of a strong alkali in step (3) and thereafter in step (5) the fabric load is treated with an oxygencontaining bleach at a temperature of at least about 175 F.
• Method (B) the oxygen-containing bleach is brought into contact with the fabric load in step (3) to obtain substantially uniform penetration of the oxygen-containing bleach into the fabric load. It is only then in step (4) that a strong alkali is added and the temperature of the fabric load is increased to a temperature of about 175 to about 195 F.
• Method (B) The steps required for Method (B) are more complex in that they require the addition of two different laundry supplies to the same wash load, i.e., first the addition of the oxygencontaining bleach material in step (3) and later the addition of a strong alkali in step (4).
• the steps of Method (A) do not require the addition of two laundry supplies to the same wash load and thus this method provides an easier procedure for use in a commercial laundry. For this reason, Method (A) is preferred for laundering fabrics which do not require the conditions of Method (B) to kill heat-resistant bacterial spores embedded within the fabric.
• agitation of the fabric load at a low water level i.e., about 3 to 5 inches of water, for a period of about 3 to 5 minutes is generally sufficient to obtain substantially uniform penetration of the oxygen-containing bleach material into the fabric load.
• the speed of rotation of the washer as defined previously, is relatively constant at about 21 revolutions per minute. If desired, of course, the speed of rotation of the washer may be varied, as, for example, from about 18 to about 26 revolutions per minute.
• the precise conditions employed in steps 3 and 4 of my improved process may, of course, be varied in accord with the type and size of the laundry equipment and the quantity of fabric overload.
• Steps 1, 2, 5,6 and 7 of Method (B) are the same as steps 1, 2, 6, 7 and 8, respectively, of Method (A), as described in detail previously.
• dry fabric weight is used. This term refers to the weight of the soiled fabrics in an as is condition when received by the laundry. Thus, the term includes the weight of soil in the fabric, the weight of the fabric itself and the weight of any moisture in the fabric due to atmospheric humidity, i.e., from a few percent ranging up to as high as possibly 10 percent on a very humid day.
• flushing and rinsing are in terchangeable since the conditions used for flushing" are essentially the same as those used for rinsing. The only difto remove a particular laundry supply from the load, e.g., in
• step (4) of Method (B) alkali is added in an amount sufficient to give a pH of about 1 1.7 to about 12.1 in the presence of sodium perborate or about 12.1 to about 13 in the presence of a peroxide.
• step (3) of Method (A) the strong alkali is present in an amount sufficient to give a pH of about 11.7 to about 12.1 in the presence of sodium perborate or about 12.1 to about 13 in the presence of a peroxide.
• step (4) of Method (B) is quite similar to step (3) of Method (A). If a dye is added for color restorative purposes in Method (B), it may be and preferably is added in step (3) before addition of the strong alkali in step (4). Also, however, it can be added with or after addition of the strong alkali in step (4).
• An optional step which may be incorporated into either my Method (A) or Method (B) involves the use ofa hypochlorite bleach.
• This step may be employed in order to facilitate stain removal.
• the oxygen-containing bleach material will neutralize the hypochlorite bleach, it is necessary that the fabric load be flushed or rinsed a sufficient number of times after treatment with the oxygen-containing bleach material so as to reduce the content of the oxygen-containing bleach material to a level where it does not interfere unduly with the hypochlorite bleach.
• a hypochlorite bleach step may be termed step (6a) and would follow step (6) in which the fabric load is rinsed to reduce the content of oxygen-containing bleach material to a satisfactory level.
• the hypochlorite is present in an amount sufficient to remove stains and may vary in concentration, for example, from about 50 to about 1,000 parts per million, depending upon the soil level or stains which are to be removed.
• a medium water level is employed in the washer with a water temperature of about 145 F.
• the fabric load is agitated during the hypochlorite bleach step for a time ranging from about 5 to about 7 minutes.
• hypochlorite bleach material there may be employed a water-soluble hypochlorite salt or a material which yields a water-soluble hypochlorite on dissociation in situ.
• suitable materials are sodium hypochlorite, lithium hypochlorite, dichlorodimethyl hydantoin, and chlorinated metallic salts of isocyanuric acid, e.g., the sodium or potassium salts.
• soap may also be present during'the hypochlorite bleach step.
• the fabric load may be rinsed several times before the souring step (7).
• the rinsing may be termed step (6b), as applied to my Method (A).
• the duration of a single rinse cycle is approximately 3 minutes.
• the temperature of the fabric load may be gradually reduced to about 1 10 Fv before being subjected to the souring treatment (step7).
• a hypochlorite bleach step would be step (5a) and the rinsing would be step (5b).
• steps (5a) and (5b) would be carried out in the same manner as described for steps (6a) and (6b) ofMethod (A).
• Detectors Nos. 4, 5, 6, 7 and 8, as described in my prior patent,' were employed to monitor the temperature and time, alkali level, and the degree of agitation or mechanical action used in the overall laundry cycle.
• Detectors Nos. 4-8 may be employed in my present processes for monitoring the time, temperature, degree of alkalinity, and mechanical action used by the laundry operator. Since my present processes require the use of an oxygen-containing bleach which is hydrogen peroxide or a material which forms hydrogen peroxide or nascent oxygen on contact with water in the bleaching step, detectors 1, 2 and 3 of my patent are not required for the present processes. If, however, an optional hypochlorite bleach step is employed in either of my processes, detectors 1, 2 and 3 of my patent are employed to monitor the efficiency of the hypochlorite bleaching step.
• I employ a series of detectors, each of which has a different sensitivity to peroxide and undergoes a color change at a particular peroxide level. At the present time I employ five such detectors, and each detector meets the following specifications:
• Each of the five detectors which 1 now employ to detect varying levels of peroxide employs a paper that is impregnated with chromic chloride and may include also small quantities of titanium oxide as a brightener.
• the chromic chloride and titanium oxide may be held to the surface of the paper by a conventional resinous binder.
• the binder may comprise a carrier resin dissolved in a fast evaporating solvent.
• the resins which may be used are ethyl cellulose, either alone or in admixture with polyethylene, modified alkyd resins or zein.
• Various solvents which may be used with ethyl cellulose as the resin include methylene dichloride, benzene, toluene, ethyl alcohol, methyl alcohol, aromatic hydrocarbons and chlorinated hydrocarbons.
• a mixture of chromic chloride and titanium oxide may be mixed with a boiled, i.e., oxidized, linseed oil mixed with a petroleum thinner.
• the paper may be immersed in the linseed oil mixture and then air dried at an elevated temperature to remove the thinner.
• the chromium chloride in its anhydrous form is purple in color and, on exposure to steam or moisture, it picks up six molecules of water but is still putple in color.
• the impregnated paper can be prepared so that it will have a greenish-gray color which matches plate 27D-l in Maerz and Paul Dictionary of Color, published by McGraw-Hill Book Company, Inc. in 1950. This is a standard reference work on color.
• the best method for preparing a suitable indicator paper for use in my detectors is to allow the purple colored (Plate 4lF-5, Maerz and Paul) paper defined above to age at room temperature and atmospheric moisture. On aging the paper becomes greenish-gray (Plate 27D-l, Maerz and Paul). During aging, the pH of the pigment changes to become more alkaline.
• the pH produced by adding 25 grams of the shredded purple paper to ml. of distilled water is in the range of 5.0 to 6.0.
• the pH resulting from adding 25 grams of the shredded paper to 100 ml. of distilled water is 8.0 to 9.0.
• the weight ratio of chromic chloride to titanium dioxide in the pigment may be about 9 to l.
• the impregnated paper is allowedto age at room temperature for six months or more and undergoes a color change from purple to gray and finally to greenish gray. It is the aged paper having a greenish-gray coloration which I employ in my detectors for sensing peroxide efficiency in my processes.
• the most sensitive detector (A) contains an aged impregnated paper having a ratio of about I to 9 of titanium oxide to chromium chloride.
• the pigment also contains sodium carbonate in an amount sufficient to raise the pH produced by adding the paper to water in the manner defined above to a level of about 9.5.
• the paper is then stapled to a single strand of l6-ply cotton twine which is held against the back of the paper by -mil nylon film.
• the three items are then enclosed in a packet formed of a single layer of 2-mil Nylon Autoclavable film with the cotton twine extending through a side of the heat-sealed portion of the packet.
• the Nylon Autoclavable film is a Rilsan Nylon 1 l film, which is a vegetable derivative of l l-amino undecanoic acid polymer (Nylon 11) made from castor oil and used in pure form without the addition of plasticizers or fillers.
• the film may be purchased from Vail Medical Products, 923 Cole Avenue, Los Angeles, Calif. 90038.
• the next most sensitive detector comprises a paper impregnated with anhydrous chromium chloride and titanium oxide, as described previously, which is then aged in a normal manner to a greenish-gray coloration.
• the aged detector is then sealed in a packet formed of a single layer of 2-mil Nylon Autoclavable film.
• the 2-mil film, after scaling, is then punctured with a /zto 2-millimeter needle (preferably about I millimeter) which enters the film adjacent the back of the indicator and passes through the paper and the film on the other side ofthe paper.
• This detector is denoted (B).
• the next most sensitive detector is denoted (D) and is the same as detector (C), except that only two strands of rayon cord are employed which extend through the heat sealed portion ofthe two mil film packet.
• the least sensitive detector (E) employs the same aged indicator paper as described above. with respect to detectors (B) through (D) and the detector is completely encased in a heat sealed packet of lmil Nylon Autoclavable film which is identical chemically to the 2-mil film.
• a color change is denoted in detector (A) from greyish-green to brownish tan every time an item is laundered in accord with my process, even at the lowest permissible peroxide concentration.
• detector (B) a brownish tan coloration near the punctured portion indicates that the peroxide level is sufficient to produce a bacterial kill that is more rapid than that provided by a color change in detector (A).
• the peroxide level employed is sufficient to cause a color change in detector (C) to brownish tan, the entire inked area in detector (B) changes to a brownish tan coloration.
• a color change in detector (C) to brownish tan is definite evidence that the peroxide bleaching intensity is sufficiently high to not only kill bacteria and bacterial spores but to main tain a low count for an indefinite period of time.
• the color change here to brownish tan is gradual.
• a color change in detector (E) to brownish tan indicates a very high peroxide level which produces a very high bacterial killing intensity.
• a color change in detector (E) to brownish tan would only be desirable in, for example, a first laundering of fabrics according to my process, the fabrics having a very high level of embedded bacteria and bacterial spores. This high peroxide level would be sufficient to kill all the embedded bacteria in one washing. However, the damage which would result to fabrics from using this peroxide intensity would be so excessive that a laundry facility could not afford to use this peroxide level on a day-to-day basis.
• continuous white toweling as bleach step represents a trade-off between the desirability of described previously, was laundered by three different methods.
• the origin of the toweling is denoted a Slaughter House" or Normal," the term normal” referring to toweling which was not soiled by use in a slaughter house.
• the Conventional Process" columns indicate a typical kill of bacteria and bacterial spores in laundering a particular slaughter house towel by using a conventional heavy soil formula of the general type shown in Table VII of my U. S. Pat. 3,094,373.
• the kills of bacteria and bacterial spores for particular toweling laundered by Method (A) are shown in the Table. In these runs the optional hypochlorite bleach step was not employed. Lastly, the kills obtained using Method (B) using the optional hypochlorite bleach step with lithium hypochlorite are shown in the Table.
• the total counts shown for both the soiled and washed towels include the total bacterial count and the total spore count. By subtracting the total spore count from the total count, one obtains the total bacterial count. All of the counts reported in the table were obtained by mascerating one square inch of the toweling, which is equal to approximately 0.] grams of toweling.
• the Nylon Autoclavable film transmits small molecules such as water or peroxide and is substantially impervious to larger molecules such as soap, detergent or brightener.
• the thickness of the film is related to the permeability of the film, the 2-mil film being less permeable than the one mil film.
• a means to conduct moisture to the interior ofthe packet as, for example, the wicking or small hole described with regard to detectors A, B, C and D previously, it is not necessary for the material forming the packet to be capable of transmitting moisture. In this instance, the wicking, or hole, etc., transmits the moisture.
• the function of the packet is to protect the pigment on the indicator paper and to prevent its removal by the washing steps preceding the bleaching step.
• the packet is formed from one mil Nylon Autoclavable film, as defined above, or an equivalent material, the film can serve a dual function in protecting against removal of the pigment from the indicator paper while, at the same time, transmitting moisture and the peroxide to the indicator paper.
• detectors In using my detectors in the laundering of items, such as continuous toweling, which are folded and tied prior to being placed in the washer, it is frequently desirable to place the detectors at various positions within a towel bundle.
• detectors may be placed in the outer third of the bundle, in the middle third of the bundle, and in the inner third of the bundle.
• an optional hypochlorite bleach step as defined previously, in either of my methods (A) or (B), may result in some damage to the fabrics being laundered.
• the tensile test fabric is supplied in rolls which are approximately 18 inches wide. The roll is cut at 10 inch intervals to provide a number of test pieces which measure ten inches by approximately 18 inches. The individual test pieces are then numbered in consecutive order as they appear on the test roll.
• the first piece cut from the roll would be numbered 1, the next piece would be numbered 2, etc.
• the test pieces are used in groups of 4, for example, test pieces I, 2, 3 and 4 in one group, 5, 6, 7 and 8 in another group, etc.
• pieces 1 and 4 are control pieces while pieces 2 and 3 are wash pieces.
• Each of the pieces, 1 through 4 is then cut into 10 strips with the direction of cutting being parallel to the direction of the warp yarns in the tensile test material.
• the smaller strips, 1 through 10, of the first test piece 1 are each tested on a tensile test machine and the average of the tests is determined to be the tensile strength for piece 1.
• the 10 individual strips in piece 4 are also tested in the tensile test machine to determine the average tensile strength for piece 4.
• the average of pieces I and 4 is then assumed to be the average tensile strength for the two intermediate pieces 2 and 3.
• Pieces 2 and 3 are also cut into 10 equal strips along the direction of the warp of the yarns and these individual strips are used to determine fabric damage in the wash cycle. Certain of the strips go through the entire washing cycle. After going through the entire washing cycle, they are dried and subjected to tensile testing to determine the extent to which their tensile strength has been reduced from that of the control. Other of the tensile test strips are placed into the washing machine immediately prior to the hypochlorite bleach step. These strips are also subjected to tensile testing to determine the extent to which their tensile strength has been reduced by the hypochlorite bleach step. By comparing the reduction in tensile strength caused by the hypochlorite bleach step with the reduction of tensile strength caused by the overall process, the precise effect of the hypochlorite bleach step can be determined in terms of fabric damage.
• the procedure In order to determine whether the treatment of the fabric load is uniform, the procedure generally is to take all ten of the individual strips from an individual test piece, for example, piece 2, and to place all of the strips in the washing machine. As in the case of my detectors, the strips may be placed at various positions within the fabric load. To illustrate, if the fabric load is composed of bundles of continuous toweling, some of the strips would be placed in the outer third of a bundle, some in the middle third, and some in the inner third of the bundle. By running the strips through the entire laundry cycle, it can be determined whether the treatment of the fabric load is uniform. For example, if certain of the strips are L3 only slightly reduced in tensile strength and other are reduced greatly in tensile strength, this is an indication of nonuniform treatment of the fabric load.
• all of the strips cut from piece 3 may be placed in various positions within a clean towel bundle or other piece of laundry which is added to the washer immediately prior to the hypochlorite bleach step.
• a slub or other imperfection is found in a particular piece cut from the tensile test cloth, that entire piece is discarded. If that particular piece is a control piece, e.g., either piece l or 4 of the first four pieces, the entire group of four pieces is discarded. 1f the imperfection is found in one of the intermediate wash pieces, pieces 2 or 3 of the first 4 pieces, only that particular piece is discarded. The other intermediate piece, 2 and 3, which contains no imperfections is used in the wash cycle and its tensile strength is taken as the average of the two control pieces 1 and 4.
• the tensile test cloth which 1 use is made from bleached 38/2 sewing thread yarn, of extra long staple cotton made by Coats & Clark, lnc. This thread is then sent to Prodesco, Inc. for weaving into a plain weave cloth having 54 ends per inch and 49 picks per inch. One-inch wide strips running along the direction of the warp yarns are delineated on the cloth by black dyed yarn so that the one-inch wide strips cut from the individual test pieces can be ravel stripped. l found this particular material to be very useful in determining fabric damage since the material is extremely uniform in its tensile strength.
• the laundry operator can determine whether additional stain removal by use of an optional hypochlorite bleach step is justified in terms of the fabric damage which may also result. If the fabric damage is too severe, the laundry operator may well decide not to use the optional hypochlorite bleach step. On the other hand, if the fabric damage is minimal, the laundry operator may decide to use the bleach step in order to facilitate stain removal.
• a method for laundering fabrics to produce fabrics which are clean and substantially free from bacteria and bacterial spores comprising:
• bleaching the fabric load in hot water at a medium water level with an oxygen-containing bleach which is hydrogen peroxide or a material which forms hydrogen peroxide or nascent oxygen in situ said oxygen containing bleach being present at a concentration of about 0.1 to about 0.2 percent by weight of the dried fabric weight and the bleaching being carried out at a temperature of at least about 175 F. for about 6 to about 10 minutes;
• a method for laundering fabrics to produce fabrics which are clean and substantially free from bacteria and bacterial spores comprising:
• washing said fabrics in hot water having a temperature of about F., said water containing soap and a sequestering agent, said sequestering agent being present at a concentration in the order of about 0.01 to about 0.05 percent by dry weight of the fabric load, and said washing step being carried out at a medium water level for a period in the order of about 3 to 5 minutes with mild agitation;
• a method for laundering fabrics to produce fabrics which are clean and substantially free from bacteria and bacterial spores comprising:
• step (4) ofthe process is carried out in the presence of caustic soda.
• step (4) The method of claim 17 wherein the strong alkali employed in step (4) is present at a concentration of about 0.2 to about 0.5 percent by weight of the dry weight of the fabric load.
• a method for laundering fabrics to produce fabrics which are clean and substantially free from bacteria and bacterial spores comprising:
• washing said fabrics in hot water at a temperature of about F.. said water containing soap and a sequestering agent, said sequestering agent being present at a concentration in the order of about 0.01 to about 0.05 percent by dry weight of the fabric load, and said washing step being carried out in a medium water level for a period in the order of about 3 to 5 minutes with mild agitation;
• souring the fabric load by introducing water at a temperature of about 100 F. to a medium water level.
• the souring agent being present in the range ofabout 0.005 percent to about 0.02 percent by weight of the dry fabric load and said water containing a water-soluble germicide at a concentration level sufficient to inhibit the growth of mildew in the laundered fabric.

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• 1969
  • 1969-12-12 US US884694A patent/US3650667A/en not_active Expired - Lifetime
• 1970
  • 1970-02-23 CA CA075628A patent/CA924454A/en not_active Expired
  • 1970-02-23 GB GB877470A patent/GB1307691A/en not_active Expired
  • 1970-02-23 SE SE02268/70A patent/SE366342B/xx unknown
  • 1970-02-25 BE BE746522D patent/BE746522A/fr unknown
  • 1970-02-25 CH CH826271A patent/CH529874A/fr not_active IP Right Cessation
  • 1970-02-25 NL NL7002670A patent/NL7002670A/xx unknown
  • 1970-02-25 CH CH272370A patent/CH523370A/fr not_active IP Right Cessation
  • 1970-02-25 DE DE19702008877 patent/DE2008877A1/de active Pending
  • 1970-02-26 FR FR707006972A patent/FR2032430B1/fr not_active Expired

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