GB1596313A

GB1596313A - Laundering textiles

Info

Publication number: GB1596313A
Application number: GB4188/78A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-04-29
Filing date: 1978-02-02
Publication date: 1981-08-26
Also published as: FR2388924A1; IT1094723B; DE2719235A1; DE2719235B2; SE7802908L; SE439504B; IT7822525A0; FR2388924B1

Description

(54) LAUNDERING TEXTILES (71) We, BOSCH-SIEMENS HAUSG- ERASE GMBH, seated in Stuttgart, the address for correspondence being Hochstrasse 17, 8000 Munchen 80, Federal Republic of Germany, a limited liability company organised under the laws of the Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a method of laundering textile articles, and an automatic washing machine for performing the method.

Modern, commercially available, package washing powders contain in general, tion to wash-active constituents, framework substances and other active substances which influence the washing processes, bleaching agents and bleaching agent stabilizers. As bleaching agents, perborates are used in those washing powders commonly termed full washing agents, and these perborates do not develop their effect until the wash liquor has reached a temperature appreciably exceeding 60"C. The fixed proportioning by weight of the individual active substances found in the packaged washing agents is adapted to a specific range of water hardness. Different degrees of dirtines, different recommendations about concentrations and different water hardness ranges lead, when the washing powder is introduced as a compact package, to a considerable excess quantity of the individual washing agent active substances, a factor which is also contributed to by the fact that, when the powder is introduced by hand, experience shows that there is a tendency to introduce too much. All these imponderables lead to a considerable polution of the enviroment.

Wash - active substances in packaged washing agents are completely effective at washing temperatures up to approximately 60"C. Therefore, these full washing agents are almost always used both for the preliminary wash and also frequently for the refined wash. However, the bleaching agent active substances contained in commercially available full washing agents do not have any effect at temperatures below approximately 60"C. Thev therefore escape unused with the discharged water. Even when washing in temperature ranges up to boiling point, a considerable proportion of the bleaching agent contained in the washing agent escapes unused into the discharged water. The high proportion of perborates in bleaching agents of the discharged water then leads to a high boron content in the natural water courses and bodies of water, which has an unfavourable effect upon the growth of many plants.

The heating of the washing liquor to temperatures above 60"C which is necessary where known commercial full washing powders are used in order to utilise the bleaching action, leads to an unnecessarily high energy consumption by comparison with the washing effect.

Moreover, for types of fabrics which must not be subjected to temperatures exceeding 600C, no bleaching effect at all can be attained with bleaching agent constitutents of this type.

According to the disclosure of United Kingdom patent specification No.

1 569 697 the above-described disadvantages may be overcome by a laundering process in which the following separately stored active substances or combinations of active substances are supplied in metered quantities in pumpable form to the wash liquor before or during the laundering process: 1. wash-active substances, 2. framework substances, 3. where necessary, a stabilised bleaching agent, 4. where necessary, an activator for accelerating the bleaching process, 5. where necessary, an organic acid, 6. where necessary, a soft rinsing agent, wherein, after the textile material to be treated has been introduced and during or after the addition of water with adjustment of a wash liquor ratio of 1:4 to 1:30, 0.05 to 3.5g of wash-active substances per litre of wash liquor and 2 to 6.5g of framework substances per litre of wash liquor are added, if necessary raised to the washing temperature, the wash is further agitated for an active washing period of up to 50 minutes and 2 to 5 rinsing operations are carried out in known manner. This laundering process has already proved so excellent in tests that its operation in future automatic washing machines is more than probable, since the numerous requirements in regard to reduced pollution of the environment, saving of raw materials and reduced energy consumption are all leading towards a thorough change in the construction of automatic washing machines. For reasons of operation and manufacture, such a change from one type of washing machine to another completely different type of washing machine cannot, however, be carried out in one step.

According to the present invention there is provided a method of laundering textile articles in an automatic washing machine, comprising the steps of introducing the articles into the machine, washing the articles in water at a washing temperature of at most 60"C with a perborate-free washing powder, adding to the water a liquid bleaching agent and an activator reactable in the water with the bleaching agent to accelerate the bleachin action thereof in dependence on oxygen release, and bleaching the articles at the washing temperature for at most 90 minutes.

The bleaching agent preferably comprises hydrogen peroxide stabilised with dipicolin acid and the activator N-acetyl-caprolactam.

In this form no appreciable risk is involved in household use.

The present invention also extends to au automatic washing machine for performing a washing process as defined above, which is one embodiment comprising means enabling washing of textile articles in water at a washing temperature of at most 600C with perborate-free washing powder, and storage means comprising a plurality of storage containers seprately storing at least a liquid bleaching agent and an activator both for addition to the water, the activator being reactable in the water with the bleaching agent to accelerate the bleaching action thereof in dependence on oxygen release, and the containers each being provided with a discharge opening and being connectable to closable water paths which are operable after attainment of the washing temperature for a time sufficient to convey the bleaching agent and the activator through the discharge openings from their respective containers for addition to the water. Apart from small modifications to the electrical circuit of such a washing machine, the only changes required are a modified washing agent storage means and water paths adapted to the storage means. Expediently the machine comprises valves each selectably operable to open and close a respective discharge opening, each valve being resiliently urged into its closed position and being provided with a plunger rod member having an end which is disposed adjacent solenoid means excitable to move said end away from the solenoid means to open the valve.

In another embodiment the washing machine comprises means enabling washing of textile articles in water at a washing temperature of at most 600C with perforate-free washing powder, and storage means comprising a plurality of storage containers separately storing at least a liquid bleaching agent and an activator both for addition to the water, the activator being reactable in the water with the bleaching agent to accelereate the bleaching action thereof in dependence on oxygen release, and the containers each being provided with a suction pipe connectable to suction pump means operable to suck the bleaching agent and the activator from their respective containers for addition to the water. In a washing machine of this type, the bleaching agent and activator may be stored inside the housing of the machine for several operations.

Storage means of this type may. in accordance with patent specification No.

1 569 697, be permanently built inside the machine or may be constructed as an easily handled and replaced container.

In yet another embodiment the washing machine comprises means enabling washing of textile articles in water at a washing temperature of at most 600C with perborate-free washing powder, and storage means comprising a plurality of storage containers separately storing at least liquid bleaching agent and an activator both for addition to the water, the activator being reactable in the water with the bleaching agent to accelerate the bleaching action thereof in dependence on oxygen release, and metering means to meter predetermined quantities of the bleaching agent and the activator from their respective containers for addition to the water. With such an arrangement, a short movement impulse of the pump is sufficient to lift each of the two liquid active substances briefly through its associated suction pipe and then to empty the relevant container by the syphon principle. If, for example, the storage means comprises a feed dish which can be pushed into the machine the other end of the suction pipe can be oriented accurately in the pushing direction of the feed dish.

An example and embodiments of the present invention will now be more particularly described by way of example and with reference to the accompanying drawing in which: fig. 1 is a schematic section view of a washing machine according to one embodiment of the invention and Fig. 2 is a schematic section view of part of a washing machine according to another embodiment of the invention.

For all clear washing operations in which, in addition to cleaning by means of a perborate-free washing powder, textile articles are subjected to a bleaching process, the washing operation is usually commenced with a supply of fresh water and powdered washing agent. If fresh water is obtained from the cold water main and if, in the present laundering method, there is not a cold water washing programme, the wash water is heated at the start of the washing operation by means of an electrical heating device to the desired clear washing temperature. In a clear washing operation for boil-proof textiles, the washing temperature is at most 60"C. After the clear washing temperature has been reached (for boil-proof textiles at most 60"C). a stabilised, liquid bleaching agent, preferably hydrogen peroxide stabilised bv dipicolin acid, is supplied to the wash liquor together with an activator, preferably N-acetyl-caprolactam. If the fresh water is obtained from a hot water main, the bleaching agent and activator can be introduced also at the start of the washing process. In this way the total time for washing and bleaching is reduced.

The bleaching action of the bleaching agent is based upon oxygen released by the bleaching agent. With stabilised hydrogen peroxide, the dissolution process of the oxygen takes place very slowly. A stabilised bleaching agent is therefore preferably used in order that the bleaching agent is still effective after a fairly long storage time and thus can be used without risk. In order to improve the effect of the bleaching agent during the bleaching process and to shorten the bleaching process, the activator is introduced, cancelling out the stabilising of the bleaching agent and accelerating the release of oxygen.

During an active bleaching period of at most 90 minutes, the textile articles are in termittently set in motion. The selected duration of bleaching depends basically upon the type of textiles to be bleached and upon the level of clear wash temperature reached, at which the bleaching process takes place. In general, it may be stated that the lower the selected clear washing temperature, the longer the bleaching process lasts. After the bleaching process has been completed, the wash liquor is removed in a known conventional manner from the wash vessel and the textile material is cleansed of washing agent residues by several rinses.

Fig. 1 shows part of an automatic washing machine equipped with a multi-chamber laundering agent feed dish 1. At least two containers 2 provided for receiving laundering agents are each connected to a closable water path, in order that, when required, washing powder and bleaching agent stored therein can be flushed out. If it is desired that the bleaching agent stored in a container 2 of the feed dish shall be diluted before feeding it into the wash vessel, an opening 22 may be provided in an end wall 21 of the container 2 nearest to the machine, this opening being opposite to a nozzle 31 of a water supply line 3 when the feed dish 1 is pushed in. The water supply line 3 may be connected to the fresh water main or to a circulating line inside the machine.

In an embodiment (not illustrated) of the present invention, the containers for the bleaching agent and activator may be equipped with a syphon pipe, which, when its overflow level is reached by the surface of the bleaching agent or activator diluted with supplied water, automatically discharges the contents of the associated container into a feed line connected to the wash vessel.

At the bottom of the container 2 provided for the bleaching agent or activator, near to its end wall 21 nearest to the machine, is an outlet opening 23 which is normally closed by a valve 24. The valve 24 is connected to an actuating plunger 25, which is mounted axially movable in parts 26 of the outlet opening. The valve 24 is held in a rest position by a spring 27 which bears between a bearing 26 and an abutment 28 mounted fixed on the actuating plunger 25.

A push-in housing 4 for the feed dish 1 continues, at its end nearest the machine, into discharge means 41, which is connected by flexible pipe connections 42 to the washing vessel (not shown). At the wall of the push-in housing 4 opposite to the end wall 21 nearest the machine, and in alignment with the bearings 26 of the pushed-in washing agent feed drawer 1, there is a receiving funnel 43 for the actuating plunger 25.

When the dish 1 is pushed in, the actuating plunger 25 passes through the opening of the receiving funnel 43 and stops a short distance in front of the armature 51 of a stationarily mounted solenoid 5. When the solenoid 5 is energised, the armature 51 pushes the operating plunger 25 together with the valve 25 into the container 2, so that the outlet opening 23 is exposed and the contents of the container 2 flow out through the discharge 41 and pipe 42 into the wash vessel.

The other container (not shown) for the other active substance necessary for the bleaching process can be of identical construction, the operating plunger of the valve associated therewith being functionally con nected to the operating plunger 25. Since the feed of the two active substances necessary for the bleaching process may if desired be carried out simultaneously, one solenoid can be saved in this manner. If, however, it is desired that the individual active substances shall be supplied successively. then a second actuating device for the other valve will need to be provided.

Referring to Fig. 2, which shows part of another washing machine, another possible way of removing the bleaching agent or activator stored in a container 7 of a washing agent feed dish 6 is by the provision of a suction pipe 71 in the region nearest the machine. preferably in an end wall 72 nearest the machine of the container 7. The suction pipe 71 terminates inside the container 7 at its lowest position, illustrated by a bottom depression 73, just short of the bottom 74 of the chamber 7. The other end of the suction pipe 71 passes through the end wall 72 nearest to the machine and terminates in a pipe duct 81 mounted fixed in a dish housing 8, the opening of this duct facing towards the suction pipe being formed as a receiving funnel. There is therefore no difficulty, when the washing agent dish 6 is pushed in, in ensuring that this opening meets the other end of the suction pipe 71.

The opposite opening of the pipe duct 81 is connected by means of a pipe 82 to a pump 83, which leads on the delivery side to a discharge funnel 84, connected to the wash vessel not shown. To empty the container 7, an impulse of the pump 83 is sufficient, which lifts the liquid through the pipes 71 and 82 above the highest point, so that the contents of the container 7 are then emptied automatically by the syphon principle. Similarly to the embodiment shown in Fig. 1, the desire for simultaneous or successive feed of the bleaching agent and activator will determine whether, in the embodiment shown in Fig. 2. a single pump 83 connected to both suction pipes or separately operated pumps, each connected to only one suction pipe, are provided for emptying the con- tainers.

In an embodiment (not shown) (compare Patent Specification No. 1 569 697) the liquid bleaching agent and the activator also present in liquid form can be stored each in a storage means, the volume of which is sufficient for a plurality of metered quantities of bleaching agent or activator intended for one bleaching operation each. For each of these storage means, a known metering device is then provided, so that the relevant storage means may be connected to the wash vessel at the appropriate time, for example after the washing temperature has been reached. With this arrangement. only one dose of bleaching agent or activator necessary for the bleaching process just about to be carried out is taken from the storage means and supplied to the wash liquor in the wash vessel. By means of a device of this type, the manning of an automatic washing machine is further simplified and a further step is taken towards a washing process with separate storage of all the washing agent active substances intended for all desired washing processes.

An advantgae of the embodiments described above by way of example compared with processes disclosed in patent specification No. 1 569 697 is that known mechanical constructions can initially be retained and can be combined with constructions which are initially required to only a limited extent. By the use of perborate-free washing powder, the presence of any boron in the discharged water is avoided. The active washing process is carried out at wash temperature of up to 60"C, without a bleaching agent being prematurely consumed. Only when the desired washing temperature is reached is the stabilised bleaching agent introduced together with an activator, which accelerates the bleaching action of the agent based upon the releasing of oxygen. This bleaching process continues for an active bleaching period of at most approximately 90 minutes. during which the textiles are kept in motion in the washing machine.

WHAT WE CLAIM IS: 1. A method of laundering textile articies in an automatic washing machine, comprising the steps of introducing the articles into the machine, washing the articles in water at a washing temperature of at most 60"C with a perborate-free washing powder, adding to the water a liquid bleaching agent and an activator reactable in the water with the bleaching agent to accelerate the bleaching action thereof in dependence on oxygen release, and bleaching the articles at the washing temperature for at most 90 minutes.

2. A process as claimed in claim 1, wherein the bleaching agent comprises hydrogen peroxide stabilised with dipicolin acid.

3. A process as claimed in either claim 1 or claim 2, wherein the activator comprises N-acetyl-caprolactum.

4. A washing process as claimed in claim 1 and substantially as hereinbefore described.

5. An automatic washing machine for performing a washing process as claimed in claim 1, comprising means enabling washing of textile articles in water at a washing temperature of at most 600C with perborate-free washing powder, and storage means comprising a plurality of storage containers separately storing at least a liquid bleaching agent and an activator both for

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. nected to the operating plunger 25. Since the feed of the two active substances necessary for the bleaching process may if desired be carried out simultaneously, one solenoid can be saved in this manner. If, however, it is desired that the individual active substances shall be supplied successively. then a second actuating device for the other valve will need to be provided. Referring to Fig. 2, which shows part of another washing machine, another possible way of removing the bleaching agent or activator stored in a container 7 of a washing agent feed dish 6 is by the provision of a suction pipe 71 in the region nearest the machine. preferably in an end wall 72 nearest the machine of the container 7. The suction pipe 71 terminates inside the container 7 at its lowest position, illustrated by a bottom depression 73, just short of the bottom 74 of the chamber 7. The other end of the suction pipe 71 passes through the end wall 72 nearest to the machine and terminates in a pipe duct 81 mounted fixed in a dish housing 8, the opening of this duct facing towards the suction pipe being formed as a receiving funnel. There is therefore no difficulty, when the washing agent dish 6 is pushed in, in ensuring that this opening meets the other end of the suction pipe 71. The opposite opening of the pipe duct 81 is connected by means of a pipe 82 to a pump 83, which leads on the delivery side to a discharge funnel 84, connected to the wash vessel not shown. To empty the container 7, an impulse of the pump 83 is sufficient, which lifts the liquid through the pipes 71 and 82 above the highest point, so that the contents of the container 7 are then emptied automatically by the syphon principle. Similarly to the embodiment shown in Fig. 1, the desire for simultaneous or successive feed of the bleaching agent and activator will determine whether, in the embodiment shown in Fig. 2. a single pump 83 connected to both suction pipes or separately operated pumps, each connected to only one suction pipe, are provided for emptying the con- tainers. In an embodiment (not shown) (compare Patent Specification No. 1 569 697) the liquid bleaching agent and the activator also present in liquid form can be stored each in a storage means, the volume of which is sufficient for a plurality of metered quantities of bleaching agent or activator intended for one bleaching operation each. For each of these storage means, a known metering device is then provided, so that the relevant storage means may be connected to the wash vessel at the appropriate time, for example after the washing temperature has been reached. With this arrangement. only one dose of bleaching agent or activator necessary for the bleaching process just about to be carried out is taken from the storage means and supplied to the wash liquor in the wash vessel. By means of a device of this type, the manning of an automatic washing machine is further simplified and a further step is taken towards a washing process with separate storage of all the washing agent active substances intended for all desired washing processes. An advantgae of the embodiments described above by way of example compared with processes disclosed in patent specification No. 1 569 697 is that known mechanical constructions can initially be retained and can be combined with constructions which are initially required to only a limited extent. By the use of perborate-free washing powder, the presence of any boron in the discharged water is avoided. The active washing process is carried out at wash temperature of up to 60"C, without a bleaching agent being prematurely consumed. Only when the desired washing temperature is reached is the stabilised bleaching agent introduced together with an activator, which accelerates the bleaching action of the agent based upon the releasing of oxygen. This bleaching process continues for an active bleaching period of at most approximately 90 minutes. during which the textiles are kept in motion in the washing machine. WHAT WE CLAIM IS:

1. A method of laundering textile articies in an automatic washing machine, comprising the steps of introducing the articles into the machine, washing the articles in water at a washing temperature of at most 60"C with a perborate-free washing powder, adding to the water a liquid bleaching agent and an activator reactable in the water with the bleaching agent to accelerate the bleaching action thereof in dependence on oxygen release, and bleaching the articles at the washing temperature for at most 90 minutes.

addition to the water, the activator being reactable in the water with the bleaching agent to accelerate the bleaching action thereof in dependence on oxygen release, and the containers each being provided with a discharge opening and being connectable to closable water paths which are openable after attainment of the washing temperature for a time sufficient to convey the bleaching agent and the activator through the discharge openings from their respective containers for addition to the water.

6. A washing machine as claimed in claim 5, further comprising valves each selectably operable to open and close a respective discharge opening, each valve being resiliently urged into its closed position and being provided with a plunger rod having an end which is disposed adjacent solenoid means excitable to move said end away from the solenoid means to open the valve.

7. An automatic washing machine for performing a washing process as claimed in claim 1, comprising means enabling washing of textile articles in water at a washing temperature of at most 600C with perborate-free washing powder. and storage means comprising a plurality of storage containers separately storing at least a liquid bleaching agent and an activator both for addition to the water. the activator being reactable in the water with the bleaching action thereof in dependence on oxygen release, and the containers each being provided with a suction pipe connectable to suction pump means operable to suck the bleaching agent and the activator from their respective containers for addition to the water.

8. An automatic washing machine for performing a washing process as claimed in claim 1, comprising means enabling washing of textile articles in water at a washing temperature of at most 600 with perboratefree washing powder, and storage means comprising a plurality of storage containers separately storing at least liquid bleaching agent and an activator both for addition to the water, the activator being reactable in the water with the bleaching agent to accelerate the bleaching action thereof in dependence on oxygen release, and metering means to meter predetermined quantities of the bleaching agent and the activator from their respective containers for addition to the water.

9. A washing machine as claimed in any one of claims 5 to 7, wherein the storage means comprises a drawer member openable and closable from the front of the machine.

10. An automatic washing machine substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

11. An automatic washing machine substantially as hereinbefore described with reference to Fig. 2 of the accompanying drawings.