US3914107A - Cleansing by laundering and like processes - Google Patents

Abstract

This invention relates to a method of cleansing by laundering or like processes of a load of materials and/or articles made from polyester-cotton, synthetic fibres, blends of synthetic fibres and natural fibres which have been treated in such a way as to impart a non-iron or minimum iron finish thereto. The method is concerned with cleansing without detrimentally or seriously affecting such finishes. This is achieved by adopting a cleansing method which includes the step of continuously sensing conditions of the wash liquor during a cooling cycle of the process between the washing and rinsing cycles, and controlling the progress thereof by reference to said conditions to obtain a graded and stepped cooling pattern. The step essentially consists of continuously measuring the rate of cooling of the wash liquor and load and maintaining a predetermined rate of change, continuously monitoring the alkali and detergency values of the wash liquor and automatically introducing further alkali and/or detergent into the wash liquor in response to a reading below a predetermined value to maintain the alkali and detergent concentration above the predetermined value, and continuously determining the level of the wash liquor within the vessel and adjusting it upon the addition of cooling water, alkali and/or detergent to maintain it at a predetermined level, the temperature, alkali and detergency monitors being operable to a temperature below the thermal barrier of the material or articles being laundered.

Description

United States Patent 91 Ellis Oct. 21, 1975 1 CLEANSING BY LAUNDERING AND LIKE PROCESSES [76] Inventor: Christopher Ian Arthur Ellis, 30 Hill Road, Birkenhead, England [22] Filed: June 20, 1973 [21] Appl. No.: 371,892

[30] Foreign Application Priority Data I June 21, 1972 United Kingdom 28979/72 [52] US. Cl 8/158; 68/12 R; 68/13 R;

[51] Int. Cl D061 33/02; D06f 39/08 [58] Field of Search 8/158; 68/12 R, 13 R, 207

[56] References Cited UNITED STATES PATENTS 2,430,668 11/1947 Chamberlin 623/12 R 3,013,572 12/1961 Lahti et a1 623/13 R X 3,170,314 2/1965 Worst 8/158 X 3,550,170 12/1970 Davis 8/158 3,610,001 10/1971 Pellerin 68/12 R Primary Examiner-Harvey C. Hornsby Assistant ExaminerPhilip R Coe Attorney, Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson [57] ABSTRACT This invention relates to a method of cleansing by SOAP REJECT S/G- LATHER LOOP RATE OF CHANGE RINSE LOOP 5 PIN WASH WASH 1 2 LA MP DRIVERS S PUMP(CELL)ORIVERS COUNTER FT REGISTER 37 BIT DE CODE RS CON TROL (CELL FOUL D) laundering or like processes of a load of materials and- /or articles made from polyester-cotton, synthetic fibres, blends of synthetic fibres and natural fibres which have been treated in such a way as to impart a non-iron or minimum iron finish thereto. The method is concerned with cleansing without detrimentally or seriously affecting such finishes.

This is achieved by adopting a cleansing method which includes the step of continuously sensing conditions of the wash liquor during a cooling cycle of the process between the washing and rinsing cycles, and controlling the progress thereof by reference to said conditions to obtain a graded and stepped cooling pattern. The step essentially consists of continuously measuring the rate of cooling of the wash liquor and load and maintaining a predetermined rate of change, continuously monitoring the alkali and detergency values of the wash liquor and automatically introducing further alkali and/or detergent into the wash liquor in response to a reading below a predetermined value to maintain the alkali and detergent concentration above the predetermined value, and continuously determining the level of the wash liquor within the vessel and adjusting it upon the addition of cooling water, alkali and/or detergent to maintain it at a predetermined level, the temperature, alkali and detergency monitors being operable to a temperature below the thermal barrier of the material or articles being laundered.

9 Claims, 1 Drawing Figure START \iESET OM PA RA TOR FEEDBACK SIG.

P TIME IN TE RVA L DRIVERS RINSE QUALITY fixed CHINE C(WTACTS ALARM CLEANSING BY LAUNDERING AND LIKE PROCESSES The present invention relates to a method of cleansing by laundering and like processes articles and materials made from polyester-cotton, synthetic fibres, blends of synthetic fibres, and natural fibres which have been treated in such a way as to impart a non'iron or minimum iron finish.

During commercial laundering, articles to be cleansed are heated during the washing process in the presence of water, soap, detergents, alkali and other cleansing media. Subsequent to the washing period of the cleansing cycle, which is normally carried out at a temperature in excess of 8090C, a rinsing period is commenced which removes the chemical re-agents used in the washing period of the cleansing cycle. The rinsing period is normally carried out with cold water and the wash load is subject to a sudden and considerable drop in temperature.

The above process is unacceptable in the laundering of polyester cottons and the like since the articles or materials suffer from what is termed thermal shock. If such articles and materials were laundered by conventional means they would tend to set in a crumpled condition due to the sudden addition of cold water. This may distort the articles and materials and thus remove the advantages of a non-iron or minimum iron finish, imparted during manufacture, thus leading to the necessity for costly finishing in order to present the articles or materials to the customers in a satisfactory state.

The common method which is now in use for overcoming the above problems is to cool the load during the cleansing stage of the washing cycle by a series of additions of cold water allowing no more than a restricted temperature drop per stage. The machine is run for a considerable period at each of these stages in order to allow even temperature distribution throughout the load being processed. It can be seen that such a method is not only time consuming but also that cold spots will occur through the load being cooled, thus imparting local thermal shock" with consequent damage. Furthermore, due to the addition of cooling water being added to the washing machine, dilution of the washing liquor will take place thus allowing redeposition of the soiled matter held in suspension in the wash liquor as it falls below the required concentration to hold it in suspension. In consequence the soiling matter held in suspension will fall out of suspension and redeposit itself on the material or articles being cleansed thus imparting a dulling or greying affect.

This invention is directed to the treatment of materials and/or articles defined as being of polyester-cotton, synthetic fibres (often termed man-made fibres), blends of such fibres and natural fibres, as well as natural fibres which have been treated in such a way as to impart a non-iron or minimum-iron finish. Hereafter the words materials" and/or articles" will have that meaning.

According to the present invention a method of cleansing by laundering or like processes of a load of materials or articles as hereinbefore defined includes the step of continuously sensing conditions of the wash liquor during a cooling cycle of the process between the washing cycle and the rinsing cycle and controlling the progress thereof by reference to said conditions to obtain a graded and stepped cooling pattern, said step comprising continuously measuring the rate of cooling of the wash liquor and load and maintaining a predeterminedrate of change, continuously monitoring the alkali and detergency values of the wash liquor and automatically introducing further alkali and/or detergent into the wash liquor in response to a reading below a predetermined value to maintain the alkali and detergent concentration above the predetermined value, and

continuously determining the level of the wash liquor within the vessel and adjusting it upon the addition of cooling water, alkali and/or detergent to maintain it at a predetermined level, the temperature, alkali and detergency monitors being operable to a temperature below the thermal barrier of the material or articles being laundered.

The invention will now be described further by way of example.

A method of controlling the process of arriving at the end of the washing cycle prior to rinsing is substantially the same as that described and claimed in the Applicants prior British Patent Specification No. 927,846. On the completion of the washing cycle, the washing liquor suspends all the soiling matter which has been removed from the articles being laundered. It is essential therefore that the suspending power of the liquor is maintained or the soiling matter held in suspension in the wash liquor will be re-deposited on the articles being laundered as dilution of the wash liquor takes place when controlled additions of cold water are made during the cooling cycle. If the suspending power of the wash liquor is reduced a poor standard of processed work is obtained owing to redisposition of the soiling matter on the load. To prevent this, whilst cooling is taking place the alkali and detergency levels are continuously monitored. If either or both of these levels fall below a predetermined standard then further additions of alkali and detergent are made until the predetermined standard has again been reached.

The rate of cooling of the wash liquor and consequently also the load is continuously monitored and is held at a desired rate of change. During cooling, additions of water are automatically adjusted to maintain the preselected rate of change.

As further additions of alkali, detergent and water are added during the cooling cycle, there is an increase in the volume of the liquor within the washing vessel. When the level of the liquor rises beyond a preselected point of a level controller, an outlet valve or valves is opened until the level has been restored to the preselected point.

When the temperature of the was has fallen below the thermal barrier, a preselected outlet valve or valves is opened when the machine proceeds through its rinsing cycles in the normal manner.

It will be seen that during the cooling process as dilution takes place, comparatively clean liquor will be discharged through the outlet valve or valves. This liquor contains alkali, detergent and heat which can be stored and transferred to subsequent washing processes, particularly when a plurality of washing machines are in use.

Since the condition of the wash liquors during the washing and rinsing cycles is continuously monitored, its content is known to precise limits. By re-using some of these liquors which would normally pass into the main sewers, considerable savings in the materials water, and heat can be effected. The last rinse of a rinsing cycle, for example, is of substantially the same condition as that of the incoming water. If it were found that this liquor was suitable as a final rinse liquor then it must be of a similar standard as that of the incoming water. It would therefore be acceptable as a first rinse of a subsequent rinsing cycle.

Again, the first or second rinse of the washing cycle may carry substantial quantities of alkali ordetergent and by continuously monitoring these conditions the liquors can be diverted to a further storage tank and reused in the wash of a subsequent washing cycle.

Bleach addition can be controlled volumetrically on a timed basis or automaticallyby reference to a conductivity cell signal, or the rate of change of that signal.

In the final wash it is likely that only percent of the original soiling matter may be held in suspension, the previous 90 percent having been removed in a previous wash. This liquor may be reused in other washing processes with substantial savings in heat, alkali and detergent and the like.

A further aspect of the invention is that the waste liquors passing from the washing machine go directly into the sewers are of precisely known standards. These can readily be controlled in order to deal with standards laid down by the local authority.

The control of the entire cleansing cycle is conveniently programmed according to the nature of the materials and/or articles to be laundered and according to the degree of soiling thereof. A range of programme cards each giving a predetermined sequence of operations would be provided, and one typical control sequence would be as follows:

1. Cell Standordisaton A conductivity cell refers to incoming water condition and re-sets for preselected rinsing quality.

2. Drain Machine involves operation of main motor, opening of liquor outlet, and energisation of dip probe. 1

3. Interspin removes excess liquor and soiling from previous wash when looping back at step 6.

4. Fill involves main motor, opening of water inlet and operation of dip probe.

5. Heat and add selected supplies main motor in operation and introduction of steam, alkali, soap and temperature sensing together with introduction of optional step 6 if detergency parameters are not met; otherwise proceed to step 7.

6. Re-cycle (optional) revert to step 2 and proceed through steps 2 and 3 repeating steps 4 and 5.

7. Timed Wash as for step 5 but with optional sensors for bleach addition or with timed or volumetric bleach addition.

8. Subsequent Washes repeat steps 2, 3, 4, 5, 6 (optional) and 7.

9. Cooling Stage controlled reduction of temperature of liquor and load with cold water additions at such a rate as to maintain a pre-selected rate of change of temperature of liquor and load while continuously sensing and adjusting, as necessary, alkali and detergency values and adjusting the level of liquor within the vessel.

10. Drain repeat step 2.

l 1. Spin timed cycle of spin drying with outlet open and main motor running at increased speed.

Steps 12 to 15 are for a bleach sequence and are optional. If bleach sequence is not required they are omitted and step 11 is followed directly be step 16.

12. Fill (optional) repeat step 4.

13. Bleach (optional) with main motor operating bleach is added.

14. Drain (optional repeat step 2.

l5. Spin (optional) repeat step 11.

16. Fill Cold repeat step 4.

17. Rinse with main motor, rinsing water is introduced whilst rate of change of alkalinity is determined and the quality of the rinsing liquid is sensed by continuously comparing it with incoming water.

Steps 18 to 20 are for a starch sequence and are optional. If starch sequence is not required they are omitted and step 17 is followed directly by step 21, if an optional sour sequence is required, or step 23 if the sour sequence is not required.

18. Fill (optional) main motor running with temperature controlled inlet of steam whilst outlet is open and dip probe operating.

19. Heat (optional) as step 18 but with outlet closed and inlet controlled by dip probe.

20. Starch (optional) starch is introduced together with optional temperature and level control over a timed period.

Steps 21 and 22 are a sour sequence and are optional.

If sour sequence is not required they are omitted and step 17 or 20 is followed directly by step 23.

21. Fill (optionalc) as step 18.

22. Sour (optional) sour is introduced either .volumetrically for a timed period or by reference to a preselected standard controlled by a sensor.

23. Drain repeat step 2 24. Spin repeat step 11.

25. Spin as step ll but at further increased speed.

The single FIGURE of the accompanying sheet of drawings is a block diagram of an arrangement wherein the control sequences of a cleansing operation are governed by a solid state binary digital system. The arrangement is such that instructions, given by a programme card consisting of a 37 X 36 bit diode matrix board, are used to control the sequence of operations during the washing and rinse cycles of the process.

The programme card selects the following parameters:

. g. The selection of the number of washes.

h. The selection of bleach.

i. The selection of starch.

j. The selection of sour.

k. The length of time for high speed motor. 1. The selection of outlet valves.

m. The selection of inlet valves.

11. The selection of motor speeds.

Pre Sets 1. The rate of mixing measurement and control for temperature and alkalinity via the rate of change board.

2. The rejection of a wash cycle via the pulse generator/counter board.

3. The selection of the detergent level is via the pulse generator/counter board.

Each of the parameters is compared with preselected standards on the programme card or fixed standard on the pre sets. When all the parameters are satisfied, and only then, the shift register is pulsed on by the clock pulse generatorvia the sequence register control. If any of the measured parameters deviate from the preselected standards the shift register is held until the necessary adjustments have automatically been made and the preselected standards restored, at which time the shift register will be pulsed as previously described.

It will be appreciated that not all the sequences available are necessary in every wash programme and some may be omitted (or repeated) according to requirements of any particular load. The programme card is designed to select not only the number, of washes but also the parameters of each wash. The control of additional supplies is determined by the programme card. During the rinsing stage the rate of change board governs the length of each rinse and the number of rinses is governed by the selection of the quality of the final rinse via the programme board.

The number and content of the programme boards is a matter of customer choice, though whatever the selection the sequences of operations is controlled and governed by the selected parameters of each individual board.

The invention is specifically directed to the cooling cycle of a laundering process between the washing and rinsing cycles i.e. to item 9 in the exemplified control sequence given herein.

I claim:

1. A method of cleansing by laundering and like processes of a load of materials and articles made from polyester-cotton, synthetic fibres, blends of synthetic fibres, and natural fibres which have been treated to impart a finish thereto, including the step of continuously sensing conditions during a cooling cycle of said process between the washing cycle and the rinsing cycle and controlling the progress thereof by reference to said conditions to obtain a graded and stepped cooling pattern, said step comprising continuously measuring the rate of cooling of the wash liquor and load and maintaining a predetermined rate of change, continuously monitoring the alkali and detergency values of said wash liquor and automatically introducing further alkali and detergent into said wash liquor in response to a reading below a predetermined value thereby to maintain the alkali and detergent concentration above said predetermined value, and continuously determining the level of said wash liquor within said vessel and adjusting it upon the addition of cooling water, alkali and detergent to maintain it at a predetermined level, the temperature, alkali and detergency monitors being operable to a temperature below the thermal barrier of the material and articles being laundered.

2. A method as set forth in claim 1 wherein said predetermined rate of change of cooling of the wash liquor is effected by controlled additions of cold water.

3. A method as set forth in claim 1 wherein, when the temperature of the wash falls below the thermal barrier, at least one outlet valve is opened when the rinsing cycles are initiated.

4. A method as set forth in claim 1 wherein, during the cooling process and as dilution takes place, the comparatively clean liquor being discharged through at least one outlet valve and containing alkali, detergent and heat, is stored and transferred to subsequent washing cycles.

5. A method as set forth in claim 1 wherein bleach addition during said rinsing cycle is controlled volumetrically on a timed basis.

6. A method as set forth in claim 1 wherein bleach addition during said rinsing cycle is controlled automatically by reference to a conductivity cell signal.

7. A method as set forth in claim 1 wherein the progress of said cooling cycle is controlled by a programme card designed to control the sequence of the operation by a solid state binary digital system.

8. A method as set forth in claim 1 wherein, during a washing cycle, the liquor discharged through at least one outlet valve and containing alkali, detergent and heat, is stored and transferred to subsequent washing and cooling cycles.

9. A method as set forth in claim 1, wherein, during a rinsing cycle, the liquor discharged through at least one outlet valve and containing alkali detergent and heat is stored and transferred to subsequent washing cooling and rinsing cycles.

Claims (9)

1. A METHOD OF CLEANSING BY LAUNDERING AND LIKE PROCESSES OF A LOAD OF MATERIALS AND ARTICLES MADE FROM POLYESTER-COTTON, SYNTHETIC FIBRES, BLENDS OF SYNTHETIC FIBRES, AND NATURAL FIBRES WHICH HAVE BEEN TREATED TO IMPART A FINISH THERETO, INCLUDING THE STEP OF CONTINUOUSLY SENSING CONDITIONS DURING A COOLING CYCLE OF SAID PROCESS BETWEEN THE WASHING CYCLE AND THE RINSING CYCLE AND CONTROLLING THE PROGRESS THERE OF REFERENCE TO SAID CONDITIONS TO OBTAIN A GRADED AND STEPPED COOLING PATTERN, SAID STEP COMPRISING CONTINUOUSLY MEASURING THE RATE OF COOLING OF THE WASH LIQUOR AND LOAD AND MAINTAINING A PREDETERMINED RATE OF CHANGE, CONTINUOUSLY MONITORING THE ALKALI AND DETERGENCY VALUES OF SAID WASH LIQUOR AND AUTOMATICALLY INTRODUCING FURTHER ALKALI AND DETERGENT INTO SAID WASH LIQUOR IN RESPONSE TO A READING BELOW A PREDETERMINED VALUE THEREBY TO MAINTAIN THE ALKALI AND DETERGENT CONCENTRATION ABOVE SAID PREDETERMINED VALUE, AND CONTINUOUSLY DETERMINING THE LEVEL OF SAID WASH LIQUOR WITHIN SAID VESSEL AND ADJUSTING IT UPON THE ADDITION OF COOLING WATER, ALKALI AND DETERGENT TO MAINTAIN IT AT A PREDETERMINED LEVEL, THE TEMPERATURE, ALKALI AN DETERGENCY MONITORS BEING OPERABLE TO A TEMPERATURE BELOW THE THERMAL BARRIER OF THE MATERIAL AND ARTICLE BEING LAUNDERED.

2. A method as set forth in claim 1 wherein said predetermined rate of change of cooling of the wash liquor is effected by controlled additions of cold water.

3. A method as set forth in claim 1 wherein, when the temperature of the wash falls below the thermal barrier, at least one outlet valve is opened when the rinsing cycles are initiated.

4. A method as set forth in claim 1 wherein, during the cooling process and as dilution takes place, the comparatively clean liquor being discharged through at least one outlet valve and containing alkali, detergent and heat, is stored and transferred to subsequent washing cycles.

5. A method as set forth in claim 1 wherein bleach addition during said rinsing cycle is controlled volumetrically on a timed basis.

6. A method as set forth in claim 1 wherein bleach addition during said rinsing cycle is controlled automatically by reference to a conductivity cell signal.

7. A method as set forth in claim 1 wherein the progress of said cooling cycle is controlled by a programme card designed to control the sequence of the operation by a solid state binary digital systeM.

8. A method as set forth in claim 1 wherein, during a washing cycle, the liquor discharged through at least one outlet valve and containing alkali, detergent and heat, is stored and transferred to subsequent washing and cooling cycles.

9. A method as set forth in claim 1, wherein, during a rinsing cycle, the liquor discharged through at least one outlet valve and containing alkali detergent and heat is stored and transferred to subsequent washing cooling and rinsing cycles.

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