Method and apparatus for cleaning a textile floor covering and the use of an aqueous solution and a rotating or vibrating body for applying the method

Abstract

A device for cleaning textile floor coverings comprises a housing with wheels (11a, 11b and 11c), a rotating body for applying an aqueous cleaning agent (12) containing a cleaning-active volatile solvent, preferably an alcohol-based cleaning agent, suction nozzles (15a) and a hot gas outlet unit (13a, b) with which superheated or diluted steam is applied to the floor covering moistened with the cleaning agent and on which dirt loosened from the floor covering can be trapped by means of a stretched textile pad. The intensive cleaning process carried out with this device is more efficient in terms of working time, allows for significantly faster re-entry and thus usability, and is more environmentally friendly because it saves water and thus conserves resources compared to previous methods.

Description

[0001] The invention relates to a method for cleaning textile floor coverings and a device for carrying out this method, supplemented by exemplary embodiments for both independent claims.

[0002] The invention can be used in the field of cleaning textile floor coverings, especially on heavily used areas in buildings where a lot of dirt is brought in, but where increased cleanliness requirements are placed, such as rooms and public areas in hotels or office buildings.

[0003] The state of the art in the commercial cleaning of textile floor coverings is described in information sheets and quality marks of the "RAL Quality Association".

[0004] According to RAL 991 A3: 2013, several methods are known today for carpet cleaning, including combination methods depending on the degree of soiling: shampooing, spray extraction (each with and without additional brush use) and a “thermoelectric” method, which contains an enzyme cleaner as a cleaning fluid at a constant temperature and is applied using the conventional “pad method”.

[0005] The RAL quality mark GZ-902 (building cleaning) differentiates between textile and non-textile floor coverings (see section 2.1.2 on page 9) and recommends different procedures for each type. On page 9, section 2.3 explicitly specifies wet shampooing and cleaning using spray extraction as the only known wet cleaning method for textile floors. This method is not listed for non-textile floors; such procedures are also completely pointless for non-textile floors. Steam cleaning is not mentioned at all in the RAL quality mark GZ-902.

[0006] The invention conforms to the definition in the RAL 991 A3: 2013 data sheet, according to which only wet processes can be considered basic cleaning processes, but such processes have only been recognized to date with the involvement of spray extraction. The previous state of the art recognized only spray extraction as a method of wet cleaning. This could be supplemented by the use of cleaning brushes or single-disc machines, but a wet process within the meaning of RAL GZ-902, section 2.3, is defined as a process in which the entire carpet, including the backing material to which the wear layer is applied, is saturated with up to 101 liters per square meter using pressure from the spray extraction device in several stages of application and extraction. In the prior art, wastewater is produced from a large amount of extracted fresh water mixed with cleaning agents.

[0007] In the shampooing process, a relatively concentrated surfactant solution is applied to the carpet and evenly worked into the carpet material using brushes or similar equipment, generating a large amount of foam. German patent DE19511193A1 describes a process that uses salts of certain di- or polycarboxylic acids instead of surfactants. After a certain contact and drying time, which is at least a few minutes, the foam is then vacuumed up along with the collected dirt, or alternatively, one waits until the foam has dried on the carpet before vacuuming up the solid residue.

[0008] In contrast, the spray extraction process involves the application and extraction of a cleaning fluid containing surfactant, citrate, or phosphate in immediate succession using the same device. These devices have a row of nozzles located at the front (in the direction of travel), through which a diluted surfactant, citrate, or phosphate solution is sprayed into the textile material. Behind this is a wide extraction nozzle or a series of extraction nozzles, which remove most of the applied fluid from the carpet and transfer it to a wastewater tank within the device. A brush attachment for incorporating the cleaning fluid can be provided between the application and extraction nozzles. One such device is the "Lavor Sprinter" model from the Italian manufacturer Lavorwash. With this model, cleaning fluid is applied to the floor from a reservoir using a brush.The dirty liquid is sucked out and pumped into a wastewater tank.

[0009] The third widely used deep cleaning method for carpets is the so-called "pad method." After a cleaning solution is applied to the carpet in small quantities, it is distributed and worked into the carpet pile by rotating brushes over which textile pads are pulled. In this method, the dirt dissolved in the cleaning solution is bound to the pads. The machines used are usually single-disc brush machines, which can also be used for shampooing without the pad covers. The textile cover is replaced with a fresh one after a certain amount of dirt has been absorbed. This method is typically used in conjunction with surfactant-based cleaning agents and is only described as a method for interim cleaning, as it does not allow for intensive cleaning.

[0010] German patent DE10200504159883 describes a cleaning device whose energy is supplied by a fuel cell. The cooled liquid from the fuel cell is sprayed onto a textile covering that is pulled over the surface to be cleaned, in order to support the cleaning process, particularly when using a special "FDT enzyme cleaner". This method is not suitable for mass production.

[0011] All the cleaning methods described have in common that a more or less significant portion of the cleaning solution is not removed from the carpet and therefore dries there. The surfactant, phosphate, or other cleaning agent residues remaining in the carpet can, with most particularly active surfactants or other cleaners, cause the textile material to stick together or promote dirt accumulation, which can accelerate resoiling. In addition, there is an individual risk of health reactions (allergies) to residual cleaning agent residues. The equipment commonly used for spray extraction consumes large quantities of cleaning agent and water (approximately 7-10 liters of water per square meter) for intensive cleaning. The recommended waiting time before walking on the carpet again is typically 12-24 hours.During this time, for example, hotel rooms are not available for re-occupancy.

[0012] In a special cleaning process developed by the Belgian company De Wit Royal Manufacturers for historical tapestries and runners, the carpet to be cleaned is placed underside down on a net. An aerosol is created on the carpet's surface by spraying a detergent-based cleaning agent, and this aerosol is then drawn downwards through the carpet by a vacuum created on the underside of the net. After cleaning, any remaining detergent is rinsed out in the same way by drawing in an aerosol of demineralized water.

[0013] It is also known to clean surfaces such as house walls or patio floors with so-called steam cleaners. The gas stream, saturated with water vapor and often containing liquid droplets, is directed straight onto the surface, loosening dirt and carrying it away with the steam-water mixture. However, due to its destructive power, this method is only suitable for very robust surfaces.

[0014] For cleaning hard floors, such as tile or wood floors, the Vileda Steam Plus device is currently available on the market. This device uses a microfiber cover (Vileda Steam Mop) to direct steam onto the dry floor. The steam kills bacteria and viruses. The device rests on the floor by its own weight and is pushed across it. Vileda also offers a "carpet glider" for the steam mop, using a plastic overlay to ensure gliding on textile floor coverings. According to Vileda, this allows for the "refreshing" of dry carpets with steam. The manufacturer primarily associates this with "pile lifting," meaning the flattening of the carpet fibers caused by use.Intensive cleaning of dry textile surfaces, such as delicate textile floor coverings, was not seriously considered, as it must be assumed that hot steam would damage the dry fibers. This device does not have a mechanism to actively lower or raise the cleaning unit to the floor.

[0015] Manufacturers of steam cleaners or steam vacuums, such as Beam, claim a cleaning effect solely through the application of water vapor to dry textile surfaces while simultaneously vacuuming up the dirt loosened by the "dry steam," also without claiming to offer intensive cleaning. Instead, they primarily emphasize the effect of "refreshing and raising carpet fibers," but remain silent about the potential damage to the dry carpet fibers caused by the heat of the explicitly "hot dry steam."

[0016] To clarify RAL Information Sheet 991 A3: In 2013, the working group "werterhalt.org" published an information sheet entitled "Cleaning Procedures for Textile Floor Coverings and Their Steps," which appeared in its 8th edition in 2023. The working group primarily consists of carpet manufacturers. The information sheet describes all currently used cleaning procedures and classifies them according to their application (e.g., intermediate or intensive cleaning), but without ranking them. However, the listed procedures are explicitly distinguished from steam cleaners, the use of which is now described as "not permissible" for carpet cleaning (Chapter 8). This represents a stricter assessment compared to the previous evaluation of steam cleaner use, as earlier editions of the information sheet merely described their use as "unsuitable" under the same Chapter 8.The Fraunhofer Institute for Applied Polymer Research (IAP) has since joined the working group. This tightening of regulations evidently takes into account the fact that manufacturers of steam cleaners and steam vacuums do not provide any information about the dangers, such as scorching, of using water vapor, sometimes hot dry steam, on dry carpet fibers. With the present invention, such dangers are eliminated, as water vapor is only applied to moistened carpet fibers.

[0017] The object of the present invention is to provide a composition for an improved method for cleaning textile floor coverings, a method using this composition as a cleaning agent, and a device for carrying out this method.

[0018] This problem is solved by the features of the independent claims. Advantageous embodiments are specified in the dependent claims. Fig. Figure 1 schematically shows a cleaning device according to the invention in a simple embodiment with a rotating body for applying and distributing a cleaning agent (12) onto the textile floor, a hot gas outlet unit (13b) and a textile covering for incorporation and dirt absorption, and thereby in Fig. 1 non-visible, vibrating induction unit seen from below. Fig. Figure 2 schematically shows a cleaning device according to the invention with a unit comprising the sole hot gas outlet function (13a) and in a position opposite Fig. 1. Version extended by a separate rotating body for incorporating the cleaning agent (14) as seen from below. Fig. Figure 3 schematically shows a cleaning device according to the invention. Fig. 2 in a semi-transparent side view. The essential components are shown schematically. Fig. Figure 4 schematically shows a cleaning device according to the invention, in which units of two individual devices are arranged according to Fig. Two units are connected in series. This design is particularly suitable for continuous cleaning in one direction.

[0019] One object of the invention is a device for cleaning textile floor coverings comprising, among other things: • a unit for applying an aqueous cleaning agent to the textile floor covering (application unit), • a unit with a hot gas-permeable pad (hot gas outlet unit) that can be moved over the textile floor covering, and • a unit for generating steam for transmission through the pad onto the textile floor covering (steam generation unit).

[0020] Textile floor coverings are defined according to EN 1307. They are essentially fibrous, sheet-like coverings that are attached to or applied to floors. Due to their fibrous structure, they are softer than hard floors (stone, parquet, laminate, linoleum, tiles, or smooth PVC) and more comfortable to walk on. They are used particularly indoors. They are also rough and have gaps. Unlike smooth floor coverings, textile floor coverings can absorb larger quantities of dirt without being noticed by people walking on them. Well-known textile floor coverings include carpets and rugs. The invention is particularly suitable for cleaning floor coverings with an area of ​​more than 1.5 m². 2According to the invention, textile floor coverings of various types and qualities can be cleaned. Carpets made of synthetic fibers are preferred, either with an open pile of fibers or with fibers held in loops. Examples of synthetic carpets include velour carpets. Depending on the type of room in which the floor coverings are installed and the level of wear, different fiber materials and fiber lengths are used. Based on previous tests, the invention is particularly suitable for synthetic fiber carpets with a pile height of between 1 and 15 mm.

[0021] The device according to the invention is particularly well suited for the rapid yet intensive cleaning of larger areas, such as those found in public buildings. A single device according to the invention with a processing width of 20 cm can clean a carpet with an area of ​​1 m². 2It can be cleaned in two minutes. Accordingly, a device with a processing width of 1 m can clean an area of ​​5 m² in two minutes. 2 be cleaned. An entrance area of ​​150 m² 2 An area in a hotel could be intensively cleaned in approximately 60 minutes.

[0022] Cleaning textile floor coverings serves to remove solid or liquid dirt that has accumulated in the floor covering over time, particularly in the spaces between the fibers. Common dirt includes, for example, particles such as sand or dust, or liquids or dried liquids such as beverage and food residues, including grease. The dirt can be loose in the floor covering or bound to the textile fibers. Cleaning takes place on and from the top surface of the textile floor covering, the pile side, by moving the device according to the invention over it. Therefore, the floor coverings can remain in their original position on the floor during cleaning.

[0023] An aqueous cleaning agent is a liquid containing water to which other substances are added, dissolved, emulsified, or suspended. Preferably, it is a liquid solution. The cleaning agent serves to remove dirt from textile floor coverings. For this purpose, the floor covering is moistened with the cleaning agent and, for the most intensive cleaning possible, worked into the floor covering. During a contact time, dirt that is soluble in the cleaning fluid or physically or adsorptively bound is released from the floor covering and can then be removed.

[0024] Aqueous cleaning agents are described in the prior art. These essentially contain surfactants, salts of acids such as phosphates and citrates, and / or enzymes. However, these have the disadvantage of being non-volatile and remaining in the floor covering in significant quantities even after the majority of the soiled cleaning agent has been removed. In a particular aspect of the invention according to independent claims 1 and 4, the aqueous cleaning agent is a cleaning agent without non-volatile components or with a non-volatile component content of less than 1% by weight. These non-volatile components can, for example, serve purposes unrelated to cleaning, such as odorization. Non-volatile components are defined as substances with an evaporation rate (measured according to DIN 53170) of more than 500.Preferably, the cleaning agents according to the invention contain a cleaning-active content of volatile solvents, preferably volatile organic solvents.

[0025] Volatile solvents are solvents with an evaporation rate (measured according to DIN 53170) of less than 80, preferably less than 50, and particularly preferably less than 33. Such volatile solvents are, in particular, water-soluble C1-C5 alcohols. The cleaning-active content of volatile solvent is, in particular, up to 50% by weight. Aqueous solutions for cleaning textile floor coverings using C1-C5 alcohols are described in the prior art (CN103849474A, WO00 / 09796A1, DE3530915A1). Their significance and application within the framework of the process according to the invention are explained in more detail below.

[0026] In addition to the aforementioned units—dispensing unit, steam generation unit, and hot gas outlet unit—the device according to the invention comprises further units necessary for cleaning the textile floor covering and may include additional units that support the cleaning process or enable or facilitate the use of the device. Such units are described in more detail below. A unit is understood to be a structural component of a device with a specific function. The device according to the invention has a housing in which these units are located and a control element, for example, a handle, with which the units can be activated and by which the device can be moved across the floor covering. The units are movably mounted in the housing; in particular, one or more units can be moved vertically within the housing relative to others in order to be moved towards or away from the floor covering in a targeted manner.to be lowered onto or raised from the floor covering. Devices with vertical movement units are known in the prior art (DE562545A); their special function within the scope of the independent claims of the invention is essentially that they can be lifted from the floor covering, do not touch the floor covering, and thus do not offer any frictional resistance during other processing steps when the device is moved across the floor covering. Further details are explained below.

[0027] The device also has rollers or wheels (11) on which the device with its units can be moved horizontally over and on the floor surface in a raised or lowered position.

[0028] The purpose of the aqueous cleaning agent dispensing unit is to moisten the textile floor covering before treatment. Uniform moistening is desirable. Suitable dispensing units therefore contain one or more nozzles that can be directed at the floor covering and with which the cleaning agent is sprayed onto the floor covering as evenly as possible. Such units are known from the prior art. In the device according to the invention, the dispensing unit is positioned so that it can be guided over the floor covering to be cleaned. To ensure that the applied cleaning agent actually reaches the floor covering, the dispensing unit should be spatially separated from the extraction units, for example by skirts extending down to the floor covering and surrounding the dispensing unit or the extraction unit.Alternatively or additionally, the dispensing unit in the form of one or more nozzles can be positioned outside the device housing, for example in front of or next to the housing.

[0029] Advantageously, the device according to the invention includes a reservoir for the cleaning agent. Its size and capacity are determined by the duration for which the device is to be operated without refilling the cleaning agent and the quantity consumed. If several cleaning agents are to be used, several reservoirs can also be provided. If the cleaning agent consists of several components, these can also be stored in separate reservoirs and mixed together only shortly before use. This allows for the adjustment of a customized mixing ratio of the components. If the cleaning agent or its components are temperature-sensitive, or if high ambient temperatures are present, the reservoir can be thermally insulated and / or cooled, particularly from units with elevated temperatures.

[0030] The dispensing unit simultaneously performs the task of wetting and mechanically distributing the cleaning agent within the floor covering. Suitable for this purpose is the use of one or more coarse rotating or vibrating bodies adapted to the properties of the floor covering. These bodies serve to wet the soiled fibers with the cleaning agent and to loosen any existing adhesions. They can be rotatable about an axis parallel or perpendicular to the plane of the floor covering. Rotating bodies in the form of brushes for carpet cleaning are known from the prior art (DE3038668A1), as are – in the area of ​​hard floor cleaning alone – electrically driven vibrating bodies that have a cleaning textile stretched across them (DE202013104452U1).

[0031] Suitable for application and distribution are, for example, brush rollers with plastic bristles, such as those found in the "Lavor Sprinter" machine from Lavorwash. Machines with integrated brushes are less suitable for carpets with fibers that tend to shed more, such as pure wool carpets, as they clog more quickly and the mechanical cleaning effect diminishes faster. Furthermore, thoroughly wetting the carpet's pile requires a brush capable of lifting the flattened and often dirt-bound pile in order to saturate it. At the same time, the brush should only be used for this distribution function, as prolonged mechanical action has been shown to lead to material loss in the pile. Simply distributing the cleaning agent into the pile does not, however, remove the dirt.

[0032] The device according to the invention therefore includes a working unit with one or more softer or bristle-free rotating or vibrating bodies for intensive treatment of the wetted surface of the floor covering and for loosening the dirt. For this purpose, a roller covered with a microfiber cover equipped with outwardly projecting textile threads is suitable, for example. In a simple form, the cover consists of the material of a car wash mitt. However, loosening the dirt from the fiber does not necessarily lead to its removal, as the materials of the brushes or surfaces absorb practically no dirt when wet. The degree of wetting and the working time can vary depending on the type of carpet and the associated risk of lint loss during mechanical treatment.In the best-case scenario, more intensive processing can compensate for lower moisture penetration, leading to improved resource conservation and earlier re-entry into the floor. The incorporation unit within the scope of the invention is height-adjustable, so that when not in use it can be lifted from the floor covering, thus preventing it from touching the floor covering and preventing frictional resistance when the device moves across the floor covering during other processing steps.

[0033] The discharge unit and the incorporation unit are always separate. The incorporation unit and the hot gas outlet unit can be separate or, in a simpler embodiment, combined. It is advantageous to house the units in a part of the device housing that is structurally separate from, but connected to, the other units within the housing.

[0034] In a simple embodiment, the cleaning agent is sprayed onto a rotating body (brush roller) and applied by this into the fibers of the floor covering, then distributed and worked in by vibration by the combined incorporation and hot gas outlet unit (see below), thereby loosening the dirt.

[0035] If both a discharge unit and a processing unit are present, they can be activated together or separately using a control system, for example, switched on and off or adjusted in height. In the case of two rotating bodies, these can, for example, be operated at different speeds or directions to achieve different processing intensities.

[0036] In terms of the device aspect of the invention, the device according to the invention features a gas outlet unit, namely a hot gas outlet unit. Its essential component is a unit with a hot gas-permeable textile, preferably in the form of a pad, that can be moved over the textile floor covering. This hot gas outlet unit has two functions: Firstly, it serves to apply hot gas through the pad onto and into the moistened and prepared floor covering; secondly, it serves to pick up dirt onto the pad. Pads for picking up dirt using hot gas through the pad are known from the prior art (EP0032360A1). However, in those cases, the hot gas is used as a solvent, particularly for hard floors. It cannot be used for textile coverings, as described above, due to the aforementioned risk of damage. According to the invention, the hot gas fulfills a purely transport function for already dissolved dirt.The pad has a multitude of pores through which the hot gas can penetrate. Preferably, the pad is a textile fabric with fringes on the side facing the textile floor covering. Suitable textiles (including those from the prior art) are commercially available, e.g., those known for the Vileda "steam mop," or can be determined by a person skilled in the art through simple experiments. It is important that the amount of hot gas penetrating the pad is sufficient to ensure adequate steaming of the portion of the floor covering beneath the pad. Key parameters for the pad's permeability are, in particular, the pore size of the pad, the applied pressure, and the pad's mechanical strength. For the purposes of this invention, superheated steam or mixtures of steam with other gases, such as air, hereinafter referred to as dilute steam or unsaturated steam, are suitable as the hot gas.

[0037] The amount of hot gas flowing through the pad in the tests carried out at a pressure between 7.7 bar and 8 bar was measured as pulsating from 500 g / min to 600 g / min at maximum pulses and at 155 g / min to 180 g / min of continuous hot gas discharge between the maximum pulses.

[0038] The hot gas discharge unit, both in its combined version with the incorporation unit and independently, is height-adjustable within the housing, so that it only makes contact with the carpet when it is activated via the control unit for hot gas discharge and collection of the loosened dirt, or previously for incorporation by means of vibration in the combined version.

[0039] Textiles with a large surface area for dirt absorption are particularly suitable as pads. Materials already used in steam mops are also suitable. Suitable pads typically consist of microfiber cloths with microfiber textile threads attached to them. These textile threads are flexible and, unlike the plastic bristles of brush rollers, do not elastically return to their original shape after deformation. The length of these textile threads can range from 0.2 to 2 cm. They usually have a thickness of between 1 and 5 mm. Commercially available mops have textile threads approximately 1 cm long. The density of the textile threads on the microfiber backing is approximately between 5 and 20 threads per cm². 2The pad is positioned near the floor covering to be cleaned, preferably on the underside of the hot gas outlet unit and the device, so that the textile threads point towards the textile floor covering. It is positioned in such a way that the textile threads can come into contact with the floor covering. In a first embodiment, the pad is stretched over a brush roller, such as those used for incorporating the cleaning agent. The movement of the brush roller in a lowered position on the floor covering, for example by rotating it, simultaneously allows for mechanical loosening of the floor covering during the application of hot gas. Preferably, however, it is positioned within the device such that the textile threads of the pad lie flat against the floor covering when the unit is in a lowered position during operation. The pad can be attached to the underside of the unit, facing the floor covering, in various ways.The hot gas outlet unit can include a motor for generating vibration and a vertical movement unit that can actively or passively lower the pad within the housing onto the floor surface. To ensure a sufficient service life, the pad must be heat-resistant for the duration of its use within the temperature range of the hot gas passing through it.

[0040] In a preferred embodiment of the hot gas discharge unit, the pad is mounted on a body that rests on the surface of the floor covering to be treated during the initial state of the vaporization process. The body is preferably movably mounted and heavy enough that, when exposed to hot gas, it rises due to the pressure exerted on the floor covering by the pad, similar to a steam cushion. This allows the hot gas discharge unit to be moved easily, almost weightlessly, across the textile floor covering by pulling and pushing. The body can also be a vibrating element that can be moved horizontally and vertically.

[0041] The hot gas outlet unit within the scope of the invention is height-adjustable, so that it can be lifted off the floor covering and no longer touches the floor covering, thus providing no frictional resistance during other processing steps when the device is moved over the floor covering.

[0042] The pads are attached to the unit in such a way that they can be replaced as needed or when their dirt-holding capacity is exhausted. This can be achieved using common methods, such as elastic tensioning, springs, or clamps. In the simpler version with a combined incorporation and hot gas discharge unit, the pad must adhere firmly to the unit to allow for vibration. In other versions with separate units for hot gas discharge and incorporation, the pad, which here serves only for dirt collection and is not used for vibration during incorporation, can alternatively be attached in forms that do not need to meet the increased adhesion requirements during vibration. For example, it can be mounted on a supply roll from which it is moved along the body, perhaps via rollers, so that fresh textile can be provided as needed.For example, the pad can be contained in a cassette in which it can be automatically or manually advanced to provide a fresh, clean section. The cassette can then be easily replaced when the entire pad's dirt-holding capacity is exhausted. This contactless pad advancement has the advantage that the cleaning process does not need to be interrupted to allow the pad, which is hot from prior steaming, to cool down.

[0043] Microfiber pads, like those used for mops, are particularly suitable. These consist of very fine textile threads and can effectively absorb dirt particles.

[0044] The hot gas outlet unit can have additional functions. For example, it can also be used to incorporate the cleaning fluid if it has suitable internal components, such as rotating or vibrating elements (see above under Incorporation Unit). These are preferably located on the side of the textile / pad facing away from the floor covering and towards the steam chamber. To incorporate the cleaning fluid, the rotating or vibrating elements can be set in motion before or during the application of hot gas. This also moves the textile, ensuring that the cleaning agent is worked into the floor covering and that dirt is loosened from it. If the movement occurs during the application of hot gas and the pad is in contact with the floor covering, the hot gas can be distributed more effectively within the floor covering, picking up and removing both dirt and cleaning agent.The movement of the pad and the application of hot gas can also be done alternately and several times in succession.

[0045] Another essential component of the device according to the invention is a unit for generating steam (steam generation unit). The generated steam serves either directly as hot gas or for the generation of hot gas. Steam generation units or "steam generators" are known for other purposes, for example, for steam cleaning surfaces. Their output must be dimensioned so that the generated steam is sufficient for applying hot gas to the pad and for the intended drying of the floor covering. Therefore, the required output of the steam generation unit depends on the area of ​​the pad, its permeability to hot gas, the desired speed of movement across the floor covering, and the desired degree of drying of the floor covering. This can be determined by means of simple manual tests. For a pad area of ​​300 cm² 2For a gas flow rate of approximately 200 g / min, an electric steam generation unit with a power output of 2500 W has proven sufficient. This makes it possible to generate pressures between 5 and 10 bar. Such steam generation units are known, for example, from steam irons or steam cleaners. Steam generation preferably occurs depending on the cleaning progress and the movement of the device. Operators can start steam generation manually, or it can be controlled independently by a microcomputer. For energy-saving operation, the steam generation unit can be thermally insulated.

[0046] The steam generation unit is preferably housed within the device casing and is electrically operated. It is connected via a steam pressure line and a controlled valve to the area of ​​the pad facing away from the floor covering, so that when the valve opens, the generated hot gas can escape through the pad onto the floor covering.

[0047] Preferably, the device according to the invention has a reservoir for water, which is heated in the steam generation unit and converted into steam. The size of the reservoir depends on the desired operating time of the device without refilling. The reservoir is connected to the steam generation unit via a controlled metering pump.

[0048] The steam generated in the steam generation unit can be supplied directly to the hot gas outlet unit as superheated steam or, after mixing with other gases, preferably air, as dilute steam. When using the steam directly, the device according to the invention preferably has a steam generation unit suitable for generating superheated steam. This unit must be capable of generating steam at a pressure between 5 and 10 bar, for example 7.7 bar. The valve for opening the steam pressure line from the steam generation unit to the space behind the pad is controlled such that the superheated steam can escape explosively from the steam generation unit in bursts and be applied to the floor covering via the pad. The control system ensures that the valve closes again as soon as the overpressure has been substantially reduced.The valve opening time is therefore advantageously between 0.2 and 2 seconds, preferably between 0.5 and 1 second. The valve is kept closed until sufficient overpressure has built up again. The closing time is therefore dependent on the output of the steam generation unit and is advantageously between 0.5 and 10 seconds, preferably between 1 and 5 seconds. As soon as sufficient overpressure is present, the next steam pressure pulse can be applied. These steps can be repeated until the desired cleaning is achieved. The control system can also be coupled with the movement of the device, so that the steam pulses cover newly treated flooring.

[0049] In the case of unsaturated steam, gas, preferably air, is added to the steam generated in the steam generation unit before it is applied to the floor covering. For this purpose, the device preferably has a mixing valve through which air is added to the steam generated in the steam generation unit. There are several ways to achieve the required temperature in the unsaturated hot gas. Either the supplied air is heated so that the desired final temperature is achieved by mixing it with the generated steam, or the hot gas is subsequently brought to the required temperature, for example, by means of an electrically controlled heater. The latter option allows for more precise temperature control of the hot gas, which is important, for example, for sensitive floor coverings that cannot tolerate gas at a temperature of 100°C.In the embodiment of the invention with dilute steam as hot gas, the control is preferably set such that a continuous flow of hot gas is provided.

[0050] Hybrid configurations are possible between the embodiment with superheated steam and the embodiment with unsaturated steam as the hot gas, for example, using unsaturated, superheated steam as the hot gas, or by controlling both embodiments sequentially. Furthermore, it is possible to implement both embodiments with a continuous or intermittent hot gas flow.

[0051] The hot gas is supplied to the space behind the pad, from where it is conveyed through the pad. For this purpose, the hot gas is preferably under pressure, which is generated by the steam generation unit.

[0052] The drying rate of the floor covering can be adjusted by the saturation level, pressure, pulse frequency, volume, and temperature of the hot gas. The lower the saturation level when the hot gas is applied, the more liquid, such as water, can be drawn from the floor covering into the gas and carried away, thus speeding up the drying process. Conversely, the higher the pressure, the more dirt and cleaning fluid the hot gas stream can absorb from the floor covering. This, in turn, positively impacts the cleaning speed and the ability to walk on the floor again. Increasing the gas temperature can further accelerate the drying process.

[0053] The device according to the invention can optionally include a dry vacuum unit that can be used before the cleaning agent has been applied. This allows for pre-cleaning of floor coverings heavily contaminated with dry, mechanically loose dirt, thereby saving energy and cleaning agent. Suitable units are known from the prior art for so-called vacuum cleaners.

[0054] The device according to the invention advantageously, or also for reasons of occupational safety, further comprises an extraction unit with which hot gas and cleaning fluid can be extracted along with the dirt loosened from the floor covering. This is particularly preferred for alcohol-based cleaning agents when the alcohols are not to be released into the environment. Preferably, this unit is located near the hot gas outlet unit and is structurally separated from the cleaning agent dispensing unit, for example by skirts or by a control system, so that when the device is moved across the floor covering, mainly the dirt-laden hot gas is extracted. For this purpose, extraction nozzles are preferably mounted laterally on the device or on the side facing away from the dispensing unit.

[0055] For cleaning floor coverings requiring maintenance, the device according to the invention can optionally include a unit for applying conditioning or impregnating substances. Application is achieved, for example, by applying suitable compositions to the floor covering. When using alcohol-based cleaning agents, the use of lanolin-containing conditioning agents to replace the wool grease removed during cleaning has proven advantageous.

[0056] In a particularly environmentally friendly version, the device according to the invention further comprises a condensation unit for the extracted hot gas with a collection container for the condensate. The hot gas is cooled in this unit in a known manner. The condensate can then be properly disposed of or reused. Optionally, the condensation unit can also include means for the prior removal of the entrained dirt, for example, a filter or a centrifuge. The purpose of the condensation unit is to prevent the environment from being polluted by the ingredients of the cleaning agent, the dirt dissolved from the floor covering contained therein, and the introduced water vapor. In this version, the device can also be operated in public without any noticeable environmental impact.

[0057] The release of alcohol from the floor covering into the environment can be further reduced by cooling the reservoir for the alcohol and / or the alcohol-based cleaning agent. This reduces the vapor pressure of the alcohol from the point of application of the cleaning agent until the point of application of the hot gas. The greater the cooling, the greater the reduction in vapor pressure. Cooling to a temperature between 0°C and 15°C, preferably between 2°C and 5°C, is sufficient for this purpose. The device according to the invention can therefore include a cooling unit for the cleaning agent or its components.

[0058] The device according to the invention can advantageously be electrically operated. Electric motors can be used both to operate the contained units and to propel the device across the floor. The device housing is conveniently mounted on wheels or rollers, allowing it to be easily moved horizontally across the floor.

[0059] The device according to the invention is moved across the floor covering for cleaning purposes, so that the units are guided together over the floor covering and the cleaning takes place exclusively from the pile side of the textile floor covering. The penetration depth of the floor covering can be adjusted by the amount of cleaning agent applied. Preferably, the application unit, optionally the wetting unit and the incorporation unit, are moved first over the area of ​​the floor covering to be treated, followed by the hot gas outlet unit and optionally the suction unit. If the cleaning is not yet complete, the device can be moved over the floor covering again. In the simplest case, the process is repeated in the same sequence.It is also possible to return the machine to the already cleaned floor surface without activating the units and then repeat the previously treated area in the same sequence with the units activated. Furthermore, it is possible to leave the dispensing unit off during the second pass and activate only the hot gas discharge unit and, if desired, the other units. This allows for particularly thorough removal of dirt and residual cleaning agent.

[0060] The speed of movement is adjusted to the type of flooring, the desired level of cleaning, the amount of cleaning agent to be used per unit area, and the intensity of the treatment.

[0061] For smaller areas, the device can have the shape of a classic handheld vacuum cleaner (e.g., Vorwerk or Hoover products), for medium areas the shape and size of a standard floor vacuum cleaner or floor cleaner with a handle, and for large areas devices with a seat for the operator are possible.

[0062] The sequence of individual work steps of the method according to the invention is advantageously controlled by a control unit. The control can be manual, semi-automatic, or automatic. Such control systems are known in principle and can be programmed accordingly based on the described work steps. Preferably, the control system is designed such that, for a specific sub-area of ​​the floor covering, the step of applying the cleaning agent is initiated before the step of steaming.

[0063] To control the hot gas outlet through the pad, both the steam generation unit and the valve for the hot gas outlet into the hot gas outlet unit must be initialized. Temperature and pressure measuring devices are advantageous for this purpose, as they transmit the measured values ​​to the control unit.

[0064] Furthermore, it is advantageous if the device has a display unit on which the parameters essential for the operation of the device according to the invention can be displayed. These include operational readiness, vapor pressure, the fill level of the storage containers, the fill level of the waste containers, and the operating time of the pad.

[0065] In the tested embodiments, which generate particularly little resistance when moving across the floor surface, only the currently activated unit is lowered onto the floor. This lowering occurs specifically for the units intended to come into contact with the floor surface, namely the incorporation unit and the hot gas outlet unit. The raising and lowering can occur dependently or independently of the device's direction of movement. A vertical movement unit handles the raising and lowering of the units.

[0066] The invention also includes a device for cleaning a textile floor covering. a. one or more units selected from i. a unit for applying an aqueous cleaning agent to the textile floor covering (application unit) ii. a unit for incorporating an aqueous cleaning agent into the textile floor covering (incorporation unit), b. a hot gas outlet unit with a hot gas-permeable pad that can be moved over the textile floor covering, and c. a unit for raising and lowering the units from a. and b. onto the floor covering (vertical movement unit).

[0067] The operation of the units is facilitated by the actuation of appropriate actuators. Control can be achieved via the control unit, which is conveniently operated by pushbuttons or a control panel.

[0068] The size of the device according to the invention depends on the function and number of units that can be used, as well as the size of the area to be cleaned. For example, a simple handheld vacuum cleaner-like device for cleaning smaller hotel rooms can have a width of 20 to 50 cm and a length of 40 to 60 cm, a simple floor-standing device for cleaning larger rooms can have a width of 40 to 60 cm and a length of 50 to 80 cm, while large or ride-on devices for cleaning large areas can have a width of 50 to 100 cm and a length of 60 to 150 cm.

[0069] The following section describes, with reference to the drawings, examples of suitable devices according to the invention for cleaning a carpet, which also include optional units.

[0070] The devices described below, in the Mini, Midi and Maxi variants, have the following common features (reference symbols referencing...). Fig. 1-4): A box-shaped device mounted on wheels / rollers (11) has, in each of the three different versions, at least one vertically retractable and lowerable flat hot gas outlet unit (13a, b) for unsaturated steam, which is supplied by a steam generation unit (3) via a hose. A constant gas flow of approximately 155 g / min, with a pulse-adjustable maximum burst of approximately 500 g / min of steam at a pressure of around 7.7 bar, is discharged downwards onto the carpet at the required frequency via a steam outlet valve (4). A textile is stretched across the outlet surface to collect and absorb the previously loosened dirt. This textile, part of a large textile roll, is replaced as needed by a lockable roller mechanism, rotating the textile roll to replace the soiled section as required.

[0071] The emitted hot gas preferably does not leave the box-shaped unit, but is drawn via a suction device (18) directly after penetrating the textile and contacting the damp carpet through openings (15a) in the base of the unit into the interior of the hollowed-out base (15), where it condenses and the condensate is returned to the cleaning fluid tank (1) for reuse. A skirt (15b) around the base of the unit provides an additional seal between the box-shaped unit and the carpet.

[0072] All three device variants described below have in common the provision of two liquid tanks equipped with hoses and pumps, one of which contains the aqueous-alcoholic solution (1), the other (2) pure water for steam generation. Hoses carry the aqueous-alcoholic solution to several outlet nozzles (6 and 7), which exit the wall of the box-shaped unit on one side in the direction of operation, but are simultaneously directed into the interior of the box-shaped unit and moisten a rotating body for dispensing the cleaning agent (12), which is intended to achieve deep moistening of the carpet.

[0073] The second tank (2) for steam generation is connected to the steam generation unit (3), which in turn is connected to the steam outlet valve (4). Furthermore, all device variants have a pump for both tanks and their hose system for transporting the liquids to the required location.

[0074] All variants have in common a control unit (17) that controls and activates all other units and at least one electric motor (9) that drives the rotating bodies for dispensing (12) and the rotating (14) or vibrating bodies (13b) for working the cleaning fluid into the carpet.

[0075] All variants also feature actuators (8) which are connected to the control unit and allow individual raising / lowering of the rotating / vibrating bodies and the hot gas outlet unit.

[0076] The box-shaped unit, in all variants, features a third, smaller liquid reservoir (5) including a pump. A separate hose system leads from this reservoir to a third outlet nozzle (10), which, depending on the device variant, directs the liquid onto the incorporating rotary or vibrating elements (13b, 14). The purpose of this third tank (5) is to hold and dispense agents for re-oiling or impregnating the carpet after the cleaning steps have been completed. These agents must be worked into the carpet before it has completely dried. The method of incorporation is the same as for the carpet cleaning agent. Mini variant (FIG. 1)

[0077] This variant, in addition to a rotating body for liquid application and distribution, does not have a separate rotating body for incorporating the cleaning agent (14) and, due to its compact design and improved maneuverability, requires only three wheels / rollers (11): two wheels at the rear and one roller at the front in the direction of travel. The incorporation process is achieved by vibration of the suitable, stretched textile on the hot gas outlet unit (13b), with which it forms a fixed unit. For the various work steps, which begin with the application of the cleaning agent, the rotating body (12) and the textile-stretched hot gas outlet unit (13b) are each lowered onto or lifted from the carpet. For this purpose, both units are suspended by controllable actuators (8).

[0078] There is a fundamental functional separation between the brush application and the dispensing of the cleaning agent on the one hand, and the dirt removal using a hot gas nozzle and textile on the other. This separation is implemented differently in the various device variants. In the Mini variant, the direction of operation determines whether the brush application with manually (or optionally via automatic program) metered dispensing of the cleaning agent is used, or whether a hot gas nozzle is used for dirt removal.

[0079] In the first step, the rotating body (12) is lowered onto the carpet and simultaneously moistened with cleaning fluid, while the hot gas outlet unit with the textile cover (13b) is raised so that it no longer touches the carpet. In this device variant, the control of the actuators (8) changes with the direction of travel: When the Mini variant, which is comparable in size to a handheld vacuum cleaner, is pushed forward, the rotating body (12) is lowered onto the carpet. It is recommended that the rotation begins with the initial lowering but only ends once the cleaning agent dispensing and distribution phase with brush operation is complete. It is acceptable if the hot gas discharge phase begins during this initial phase by pulling the unit back in the direction of travel, as long as the brush is raised during the hot gas discharge.Constant switching between switching the rotation on and off is not necessary. With the brush lowered and before use, both nozzles (6 and 7) ensure sufficient moisture penetration of the carpet when manually activated. Retracting the Mini variant triggers a command to the two actuators (8) to change the working unit, causing the rotating body (12) to rise and the hot gas outlet unit with the textile cover (13b) to lower onto the carpet. Depending on the progress of the work, the dual function of the hot gas outlet unit (13b) allows switching between the two functions of vibration for working the dirt in and steaming for dirt removal, via manual control. Midi variant (FIG. 2 and FIG. 3)

[0080] The box-shaped unit features a centrally located hot gas outlet unit (13a) with the stretched textile, flanked by a rotating body on either side (in front of and behind it, in the direction of travel). All three working units are connected to actuators (8) that allow for individual lowering and raising of the units. In this variant as well, the activation of the respective working unit alternates with the direction of travel, as described under variant Mini. The independent functionality of the two rotating bodies for dispensing and distributing the cleaning agent, on the one hand, and for working it into the carpet, on the other, must be ensured. This can only be initiated individually by manual command from the user, depending on the work situation. The user must be able to choose between further moistening of the carpet and more thorough, localized dirt removal through working the cleaning agent into the carpet.The rotating body that is not needed at any given time must therefore be able to be individually raised in phases by the user's command.

[0081] As described in the Mini version, the Midi version also features a fundamental functional separation between the application / distribution of the cleaning agent and the use of hot gas. In addition to changing the direction of travel, switching between applications should also be possible via manual command. This allows for adjustments to individual work situations requiring increased moistening or incorporation by changing the direction of travel, without necessarily requiring the use of hot gas.

[0082] The application of hot gas occurs after the completion of the first two work steps with the respective rotating bodies, such that both rotating bodies are first raised, and only the hot gas outlet unit (13a) is used. The Midi variant is characterized by the fact that a larger area is wetted in the first work step, onto which a similarly sized incorporation then takes place. The working direction is determined by a guide bracket (16) that can be swiveled by approximately 140 degrees. In this way, the working direction can be determined in two ways: If desired, swiveling the guide bracket triggers the command to switch between the two basic functions of rotation or hot gas application, thus avoiding the need to pull the entire device, which in the Midi variant will have a considerable weight, towards the opposite direction of the previous working direction for dirt collection.This also eliminates the need to rotate the Midi variant 180 degrees around its own axis in the desired direction, which is necessary when the work situation requires working in longer sections and there is insufficient space to turn the entire device (e.g., hotel corridors). In this case, swiveling the guide handle also triggers a command to reverse the brush rotation direction, again avoiding the need to pull the device. Fig. Figure 3 also shows a cassette in which the pad is moved from a roller for fresh pad (19a) to a roller for dirty pad (19b). Maxi variant (FIG. 4)

[0083] The box-shaped unit comprises two working units, each consisting of a hot gas discharge unit (13a), a unit with a rotating body for dispensing the cleaning agent (12), and a unit with a rotating body for incorporating the cleaning agent (14), arranged in series. The sequence in the direction of operation is determined by the previously described work steps: rotating body for dispensing (12), rotating body for incorporating (14), textile-covered hot gas discharge unit (13a). In the Maxi variant, the large unit operates in both directions by pushing, similar to the Midi variant, and features a function changer (manual or with automatic program control) to avoid turning the unit. Ride-on units omit the function changer and operate in only one direction, controlled manually.The activation of the respective work unit for the scheduled work step takes place exclusively according to programmed device software, depending on the distance traveled.

[0084] Another object of the invention is a method for cleaning a textile floor covering comprising: • Applying an aqueous cleaning agent to the textile floor covering, and • Moving a gas-permeable pad over the textile floor covering moistened with the cleaning agent. characterized in that the aqueous cleaning agent contains a cleaning-active content of one or more volatile solvents.

[0085] Volatile solvents are components of aqueous cleaning agents that can be driven out of the floor covering using hot gas. A volatile solvent is therefore a solvent with an evaporation rate (measured according to DIN 53170) of less than 80, preferably less than 50, and particularly less than 33. For practical reasons, the evaporation rate should be greater than 1. Such volatile solvents are primarily organic solvents. Advantageously, the volatile solvents are liquids that are soluble in water. The cleaning-active content of volatile solvent or the cleaning-active content of a mixture of volatile solvents is preferably up to 50% by weight. This content is also limited by the fact that the volatile solvent or the mixture should be soluble in water at this concentration to ensure uniform application.A cleaning agent is defined as one in which, due to its solvent content, dirt or dirt particles, especially organic compounds such as fats, can be dissolved from the textile floor covering in the cleaning agent.

[0086] In the following, a percentage for components is understood to mean weight percent (wt%), unless otherwise stated.

[0087] The cleaning agent used in the process according to the invention is a liquid characterized by the fact that it mainly contains volatile components and, at most, small amounts of components that remain in the floor covering after the majority of the soiled cleaning agent has been removed. The cleaning agent may contain small amounts of non-volatile additives for purposes unrelated to cleaning, for example, for odorization, or if it is desired that these additives remain in the floor covering after cleaning. Examples include fragrances, such as perfumes, or textile care products, such as re-fatting agents or other fiber protectants. The content of the non-volatile additives is typically less than 1%, preferably approximately zero%. Substances with an evaporation rate (measured according to DIN 53170) of more than 500 are defined as non-volatile additives.In this aspect of the invention, the content of non-volatile additives in the aqueous cleaning agent is less than 1 wt.%, preferably approximately zero wt.%.

[0088] Preferably, the cleaning agent contains no toxic components in the formulation used. Water is preferred as the main component of the cleaning agent because it can dissolve many common contaminants, such as salts. Furthermore, cleaning agents that can dissolve and absorb liquids or dried liquids, such as dried-on beverage residue, have proven advantageous.

[0089] These conditions are particularly well met by cleaning agents that contain one or more organic alcohols with a chain length of between 1 and 5 carbon atoms as volatile organic solvents. These are referred to below as C1-C5 alcohols. C2-C3 alcohols, such as ethanol, n-propanol, and isopropanol, are especially suitable. Due to their largely non-toxic and high volatility, particularly in combination with water, their solubility in water, and their dissolving power for organic substances, isopropanol and ethanol are excellent choices as volatile solvents. The cleaning agent may also contain other volatile, non-cleaning components.

[0090] In a non-inventive embodiment, the C1-C5 alcohol content can range from 5% to 45%, depending on both the type of soiling and whether the cleaning is for intensive or intermediate cleaning. Preferably, the C1-C5 alcohol content should not exceed 39% by weight. For commonly occurring soiling, a content of between 15% and 39% has proven suitable. The alcohol content can also be selected according to the degree of soiling. For example, in a variant of the method for simple intermediate or maintenance cleaning, the alcohol content for surfaces where water-soluble soiling predominates (such as hotel entrance halls in winter due to road salt) can be lower, for example, 5–15%.Surfaces that are more likely to be soiled with food or drink residue (such as in restaurants) require intensive cleaning with a higher alcohol content, for example, 25-39%. For particularly effective intensive cleaning, the alcohol content is generally around one-third of the liquid.

[0091] In a proven embodiment where carpeting in a household was cleaned, an alcohol content of 33% isopropanol or 33% ethanol in water proved to be very effective in the cleaning fluid. Ethanol is preferred due to its good availability, extensive biodegradability, and suitability for biological production.

[0092] The release of alcoholic vapors is already reduced to a minimum through design features and functions, not least through cooling and thus delaying evaporation. The use of ethanol, in particular, contributes significantly to minimizing subjective odor nuisance, which can be more noticeable with isopropanol. Potential hazards from evaporation can be reliably avoided by using the process as intended.

[0093] The use of the cleaning agent according to the invention in methods for cleaning textile floor coverings is also made possible by the fact that, after a short contact time, it can be quickly driven out of the textile floor covering moistened with the cleaning agent by hot gas. This is not possible with conventional cleaning agents. The (non-volatile) surfactants and enzymes usually used in carpet cleaning agents can be completely dispensed with. This has the major advantage that these do not remain in the carpet and cause it to stick together, nor do they need to be washed out of the carpet again. Therefore, it is possible to work with smaller quantities of liquid according to the invention. Surfactants and enzymes are also more expensive than low-chain alcohols, which can be produced industrially on a large scale and at low cost.

[0094] The method according to the invention includes essential steps for successful cleaning, which, however, can be supplemented by further steps depending on the type of flooring to be cleaned.

[0095] In a key step, the cleaning agent is applied to the textile floor covering to be cleaned. This serves to moisten the floor covering sufficiently so that the cleaning agent can absorb the dirt to be removed. In this respect, the method according to the invention does not differ significantly from known methods, except that a different cleaning agent is applied.

[0096] The amount of cleaning agent applied can be varied depending on the type of floor covering (high-pile / low-pile, dense / loose) or the desired cleaning intensity (deep-cleaning / surface cleaning, intensive cleaning / basic cleaning, heavily soiled, lightly soiled). By using the cleaning agent according to the invention, the amount of cleaning agent required for the same floor covering can generally be reduced compared to known methods, by up to 90% in preliminary tests, and in individual cases, depending on the degree of soiling, the condition of the carpet, and whether the method is used for intermediate or intensive cleaning, even by up to 95%.

[0097] The cleaning agent can be applied in a known manner, for example, by spraying it onto the floor covering from one or more nozzles arranged to moisten as much of the working width of the floor covering as possible. The cleaning agent can then penetrate the floor covering through capillary action. The amount applied can be determined by the operator or controlled by the machine based on the type of floor covering and / or the speed of forward movement. Another suitable and known application method is to treat the floor covering with moistened rotating bodies, through which the cleaning fluid is introduced into the floor covering. In the case of brush rollers, the bristles of the rotating body, as the brush rotates, unravel and straighten the textile fibers of the floor covering, thus enabling better penetration of the cleaning agent between the textile fibers.In this case, the rotating body can be lowered onto the floor surface. These options can also be combined.

[0098] The other essential step is moving a gas-permeable pad over the textile floor covering, which is moistened with the cleaning agent and into which the cleaning agent may be incorporated. For this purpose, the pad can be lowered towards the floor covering.

[0099] This step has at least two functions: On the one hand, gas can be applied to the moistened floor covering via the pad, and on the other hand, dirt can be absorbed from the floor covering by the pad.

[0100] The first function is achieved by introducing gas, as described above for the device according to the invention, into the space behind the pad and guiding it through the openings / pores of the pad onto the floor covering. This causes the gas to penetrate the floor covering, flow through it, and then exit due to the inflowing gas. As it penetrates the floor covering, the gas picks up any cleaning fluid and solids that may be laden with dirt and carries them along with it.

[0101] Depending on whether the gas is hot gas or cold gas, there are different possible embodiments of the method according to the invention, with the embodiment using hot gas being described as preferred.

[0102] For the experimentally tested embodiment with hot gas described in the examples, the above descriptions apply to the device according to the invention. The application of hot gas can be implemented in two variants according to the invention. In the first variant, (undiluted) superheated steam is used as the hot gas, while in the second variant, water-unsaturated hot gas (diluted steam) is used. Both variants have in common that steam is generated in a steam generation unit. For this purpose, water is heated in the pressure-tight steam generation unit until an overpressure of steam is reached. According to initial tests, this pressure is between 2 and 12 bar. The generated steam therefore has a temperature at or above the boiling point of water of approximately 100°C (at atmospheric pressure at the corresponding altitude).The water used for steam generation is preferably pure water, as water vapor leaves no traces on objects (and thus on the floor covering) when evaporating and drying. Small amounts of volatile components, such as alcohols, fragrances, or disinfectants, do not impair this function. The use of deionized water is preferred for steam generation.

[0103] In the first variant, superheated steam is generated at a pressure between 5 and 10 bar, for example 7.7 bar. This steam is applied directly to the floor covering via the pad, preferably in pulses. For this purpose, the valve serves to open the steam pressure line from the steam generation unit to the space behind the pad, allowing the superheated steam to escape explosively from the steam generation unit and be applied to the floor covering via the pad. The valve closes again as soon as the overpressure has substantially dissipated. The valve opening time is therefore advantageously between 0.2 and 2 seconds, preferably between 0.5 and 1 second. The valve remains closed until sufficient overpressure has built up again in the steam generation unit.The sealing time therefore depends on the output of the steam generation unit and is expediently between 0.5 and 10 seconds, preferably between 1 and 5 seconds. As soon as sufficient overpressure is present, the next steam pulse can be applied. These steps can be repeated until the desired cleaning is achieved. The device can be moved across the floor covering so that each steam pulse covers newly treated areas. While not bound by this explanation, it is assumed that the cleaning fluid in the floor covering is heated by the expansion of the superheated steam, mixes with the steam, and is carried away with it.

[0104] In a second embodiment of the invention, the hot gas passed through the pad is not completely saturated with water vapor, i.e., more than 10% but less than 95% saturated. The preferred degree of saturation (proportion of water vapor in the gas) is between 20% and 90%, particularly preferably between 25% and 70%. The hot gas preferably has a temperature between 85°C and 105°C, more preferably between 90°C and 100°C.

[0105] Without being bound by this explanation, it is assumed that hot gas, previously unsaturated with water vapor, becomes saturated with volatile components of the cleaning fluid, such as alcohol and water, and also displaces dirt particles, possibly contained in the cleaning fluid, from the floor covering. Under suitable conditions, this process allows the cleaning fluid to be largely removed from the floor covering, and the dirt to be bound to the pad or, if necessary, extracted by the vacuum unit.

[0106] Mixed forms of these variants are possible, e.g. a hot gas made of diluted superheated steam.

[0107] Another benefit of applying the hot gas through the pad is that the pad can glide more easily over the floor covering than with conventional pad machines. The higher the set pressure, the more easily the device according to the invention can glide over the floor covering on a cushion of steam. However, the pressure should only be high enough to allow the pad to still pick up dirt loosened from the floor covering. The required pressure can also be optimized by providing skirts around the hot gas application unit.

[0108] The second function of moving the pad across the floor surface is to trap dirt. Due to the pad's structure, dirt particles and droplets, which are stirred up or liquefied by the hot gas, become trapped in the pad, particularly on the textile threads, and adhere to them. If the dirt droplets are not yet completely dry, they can be further dried by the incoming unsaturated hot gas, allowing the dissolved dirt particles to adhere even more effectively to the pad.

[0109] The pad's second function can be further enhanced by bringing it into direct mechanical contact with the floor covering. For this purpose, the pad can be mounted on a rotating or vibrating body that moves during the application of hot gas. Textile threads on the pad can then pass through the textile fibers of the floor covering. This also improves the penetration of the hot gas into the floor covering.

[0110] Further steps may be added as optional or advantageous steps of the method according to the invention.

[0111] For example, a dry cleaning step, such as a suction step, can precede the application of the cleaning agent. This step is used to remove loose solids from the textile floor covering before applying the cleaning agent, thus saving cleaning agent, extending the pad's service life, or accelerating the cleaning process.

[0112] The intensity and depth of wetting can be improved by applying the cleaning agent to the floor covering using moistened, textile-covered rotating bodies, such as brush rollers or vibrating bodies. Preferably, a rotating brush with coarser bristles, adapted to the nature of the textile floor covering, is used. Its purpose is to deeply wet the soiled fibers with the alcohol-based cleaning agent, distribute it evenly over the entire surface to achieve uniform saturation of the textile fibers, and to loosen any existing adhesions, preferably mechanically, to conserve resources. This step is advantageously placed between the application of the cleaning agent via spray nozzles and its incorporation using a softer brush.

[0113] If particularly intensive treatment is desired, for example with heavily soiled floor coverings or very stubborn dirt, the application step can be followed by a mechanical (intensive) incorporation step using a second, softer brush or vibrating surface, which can also consist of a textile-covered rotating or flat vibrating body. Preferably, this is a roller body covered with a pad whose surface is equipped with microfiber threads. Due to the intensive contact of the body with the textile floor covering, for example, by rotating the roller body on the floor covering, whereby the threads of the pad compress and comb through the textile fibers of the floor covering, dirt is more effectively removed from deep within the textile floor covering. Details regarding the design are described above for the device according to the invention.However, the incorporation of the cleaning agent can also occur during the application of the cleaning agent, for example when using rotating bodies that are exposed to cleaning agent.

[0114] Applying hot gas to the floor covering can generate significant quantities of hot gas, depending on the intensity, which can then be released into the environment. To prevent this hot gas, potentially containing dirt and cleaning agent even after dirt has been deposited on the pad, from escaping into the surrounding area, the hot gas escaping from the floor covering can be extracted. This can be achieved by incorporating extraction openings (in an extraction unit as described above) positioned to extract not the fresh hot gas, but rather the contaminated hot gas emanating from the floor covering. This can be accomplished by drawing the contaminated hot gas through extraction nozzles located around the unit used for applying fresh hot gas and directing it into a chamber inside the device.There, the hot gas is condensed by cooling and / or the substances it contains are separated, for example by filtration or centrifugation. If the condensable components are successfully separated from the gaseous and solid components, the condensate can be recycled and reused, for example in the cleaning agent or the hot gas itself.

[0115] It is known that some floor coverings require maintenance treatment after or during cleaning. These are known to those skilled in the art and can also be combined with the method according to the invention. Thus, additional maintenance steps, such as the incorporation of lanolin into floor coverings containing virgin wool or the application of impregnating agents using the softer brush roller, can be carried out.

[0116] After the device according to the invention, with the pad, has been moved over the area of ​​the floor covering to be treated, the floor covering exhibits only a small residual moisture content, consisting essentially of condensed water vapor. Due to the heating of the floor covering by the hot gas, this residual moisture also evaporates quickly.

[0117] The inventive method offers numerous advantages, both individually and in combination. Compared to known methods based on spray extraction, the floor covering can be walked on without restriction significantly sooner. This generally allows a hotel room to be reoccupied on the same day. The necessary saturation of the floor covering with cleaning fluid can be significantly reduced compared to known methods based on spray extraction. Due to the properties of volatile solvents, in combination with the excellent dissolving power of, for example, alcohol (especially isopropanol), the cleaning performance of the inventive method is superior to cleaning with surfactants, enzymes, and phosphates.The use of steam to separate dirt from the applied cleaning fluid, which removes the cleaning agent itself in this process through a physicochemical process, leaving no residue and in an environmentally friendly manner, avoids wastewater that would be generated when surfactants and enzymes are washed out. This also saves a considerable amount of the valuable resource of water. Furthermore, the unsaturated steam, with its ability to absorb moisture, accelerates the drying of the damp carpet, allowing it to be walked on again more quickly. Due to the rapid work sequence and the absence of cleaning fluid residue, the carpet cleaning process according to the invention requires no further steps to rinse out the cleaning agent. The invention therefore results in a significantly reduced labor requirement and, compared to spray extraction, also achieves a potentially substantial reduction in overall working time.

[0118] Applying steam only to the dampened textile floor prevents damage to the fibers, because they can withstand thermal heat better in a damp state than dry textiles.

[0119] The embodiment of the inventive method using cold gas can be applied to textile surfaces which, due to their specific requirements, do not permit greater saturation. Unless otherwise stated below, the cold gas method uses the same conditions as the hot gas method. One difference is that the pad is permeable to cold gas. However, the same materials will generally be suitable as for hot gas-permeable pads. The cold gas used is a gas with a significantly lower temperature than the hot gas described above. The same gases are suitable as those described for hot gas. The temperature can be between 25 and 50°C, but is preferably between 30 and 35°C. A cold gas outlet unit replaces the hot gas outlet unit. This cold gas outlet unit is capable of conveying cold gas into the space behind the pad and through the pad onto the floor covering.A steam generation unit is therefore generally not required or is set to produce low-temperature steam. Another modification is that the process described above is carried out under negative pressure, which is generated by a suction unit. The various work steps are performed sequentially, not while the entire device is moving, but while the device is stationary, lowered onto the section of the textile floor covering it. A vacuum is created on this area between the floor covering and the device during or after operation of the dispensing and gas outlet units. After most of the cleaning agent has been extracted, the vacuum is released by the control system, the units involved are raised again, and the device is moved to the next section to be treated.

[0120] This embodiment of the inventive process using cold gas is particularly distinguished by its further increased economy in cleaning agent usage while maintaining the same cleaning performance. This is achieved by applying a smaller quantity of aqueous cleaning agent with a consistently higher concentration of the volatile solvent to the textile floor covering prior to incorporation. This saturates the carpet fibers, but leaves the carpet backing largely unwetted. The negative pressure ensures that all steps following the removal of the dirt from the fibers, including the application of cold gas, can take place at a significantly lower temperature.The low temperature of the gas allows for intensive cleaning of an unsaturated, moistened fiber without any risk of harmful scorching, because the cold gas leaving the gas outlet unit is also able to transport the dirt loosened from the fiber into the collection pad.

[0121] Since the dissolving power of alcohol with respect to the soiled fiber is independent of temperature, and since the use of cooling devices for the alcohol-containing tanks is also provided in previous device variants to keep alcoholic vapors to a minimum, a reduction in the temperature of the vapor does not result in reduced cleaning performance.

[0122] This low-temperature variant of the process, with low moisture penetration of the floor covering, makes this embodiment of the inventive process applicable to water-sensitive textile floor coverings, especially for sensitive carpets, such as those with older, worn or brittle pile, or also older carpets with foam backing, where there is a risk of detachment from the screed due to moisture penetration.

[0123] A device suitable for the described design variant with cold gas shares the external dimensions with the third device variant “Maxi”, but differs from it in that instead of two, only one working unit is provided, but this is used on the entire width of the device in the corresponding sequence and on the entire area of ​​the floor covering covered by the device.

[0124] Given that the device operates while stationary, suitable technical solutions are needed in each work step to arrange and control the actuators used in such a way that the work steps (application and distribution of the cleaning fluid, unbundling and straightening of the fiber, incorporation for mechanical dirt removal, and steaming and dirt absorption in the pad) can be carried out sequentially over the entire area covered by the device.

[0125] Undesirable release of cleaning agent components, such as alcohol vapors, from the moistened floor covering is prevented by the rapid succession of the steaming step to the step of moistening and working the cleaning agent into the floor covering. The steps according to the invention enable the immediate removal of the contaminated cleaning agent after moistening and working it in, and thus a rapid working method by guiding the device over the floor covering to be cleaned.

[0126] Another advantage of the invention is the reduction of wastewater burdened with surfactants, phosphates and enzymes, which are expensive, difficult to biodegrade and responsible for the increasing nutrient richness (eutrophication) in waters.

[0127] A further aspect of the invention is the use of an aqueous solution of volatile, cleaning-active organic solvents, e.g., containing one or more C1-C5 alcohols, wherein the C1-C5 alcohol content of the solution should not exceed 39% by weight, for moistening and cleaning textile floor coverings. Preferred aqueous solutions are described above.

[0128] Another aspect of the invention is an aqueous solution of volatile cleaning solvents, e.g., containing one or more C1-C5 alcohols, in which case the C1-C5 alcohol content of the solution should not exceed 39% by weight, for cleaning a textile floor covering. In a preferred application, the aqueous composition contains alcohol and is cooled as described above. Preferred aqueous solutions are described above.

[0129] Another object of the invention is a method for cleaning textile floor coverings with a device having at least two units for processing the floor covering, wherein the units are moved upwards and downwards by vertical movement units during the cleaning process.

[0130] The inventive method is particularly effective because the units used for cleaning are only activated precisely during the time they are needed. The targeted lowering and raising of the units is neither necessary nor described in known devices. For the incorporation unit, this includes lowering the rotating or vibrating bodies onto the floor covering only during the incorporation step or only onto the portion of the floor covering where the incorporation is to take place. If they remained lowered when not in use, they would generate significant frictional resistance. The same applies to the hot gas discharge unit, which would exhibit considerable frictional resistance, especially with pads of large surface area, if it were not raised outside of its activation phase. Therefore, it can be lowered onto the floor covering when activated.

[0131] This lowering and raising of the units is carried out by vertical movement units. The vertical movement (upwards or downwards) is preferably achieved by activating / deactivating actuators with electromagnets and is triggered manually with a switch or automatically by a controller.

[0132] Another object of the invention is the use of a rotating or vibrating body, the surface of which is provided with a pad containing textile threads, for cleaning a textile floor covering moistened with an alcohol-containing aqueous cleaning agent. Reference symbol list 1 storage container including pump for the cleaning agent 2 storage tanks including pump for water for steam generation 3 Steam generating unit 4 Steam outlet valve 5 storage containers including pump for re-greasing / impregnating agent 6. Outer nozzle for cleaning agent 7 Inner nozzle for cleaning agent 8 Actuator (8a, 8b, 8c) 9 Electric motor 10. Outlet nozzle for re-greasing / impregnating agent 11 wheel / roller (11a, 11b, 11c, 11d) 12 Unit with rotating body for dispensing the cleaning agent / dispensing unit 13 Hot gas outlet unit (13a) or in Fig. 1 Hot gas outlet unit with mounted pad and behind it a non-visible vibrating body (13b) 14 Unit with rotating body for incorporating the cleaning agent / incorporation unit 15 Equipment floor 15a Extraction openings 15b Aprons 16 guide brackets 17 Control unit 18 Extraction unit / condenser 19a Pad supply roll in cassette, fresh, unrolling 19b Pad supply roll in cassette, soiled, retracting Example 1 - Simple Prototype

[0133] A commercially available brush scrubber with different brush rollers for hard floors and carpets, model LAVOR SPRINTER from the company Lavorwash, was modified as follows: Unless otherwise stated, all components of the SPRINTER were retained. Nozzles for applying the cleaning agent were attached to the front sides of the SPRINTER's mobile unit. These were connected via an additional pump to the lower collection tank for the extracted dirty water, which had been repurposed as the cleaning agent reservoir. Furthermore, a surrounding frame was attached to the mobile unit at a height of approximately 3 cm. This frame was mounted near the wheels of the mobile unit so that it could tilt. At the front of the mobile unit, the frame was connected to the unit via an electromagnet, which allowed the front of the mobile unit to be raised approximately 1 cm relative to the frame. Two wheels were attached to the front of the frame for moving it across the floor. Thus, when raised (with the brush roller off the ground), the unit runs on four wheels.

[0134] The front cleaning nozzles were connected to the lower reservoir of the SPRINTER via hoses. The upper cleaning reservoir, which dispenses cleaning fluid onto the brush roller, was filled with 0.75 liters of a cleaning solution consisting of 250 ml ethanol and 500 ml water. The original SPRINTER blower motor, which extracted the soiled cleaning solution from the carpet, was removed. A water pump with a suction opening at the bottom of the SPRINTER's wastewater collection tank was installed. The pump was electrically connected in parallel to the SPRINTER's dispensing pump. A hose was run from the water pump's discharge opening to the auxiliary nozzles mounted at the front of the unit for dispensing the cleaning solution. The wastewater tank was filled with 1.5 liters of the cleaning solution mixture (500 ml ethanol and 1 liter water).

[0135] A pad from the VILEDA Steam PLUS steam mop was stretched across the entire soleplate of a Tefal Pro Express Ultimate GV9567 steam iron using the "silk spacer" accessory, which was cut out down to the frame. This spacer serves two purposes: firstly, it secures the pad over the steam vent of the iron, ensuring a firm connection to the soleplate; secondly, the distance between the pad and the soleplate with its steam vents allows air to mix with the steam from the sides. The steam release switch on the iron was relocated to the handle of the Sprinter. The iron was then attached to the rear of the Sprinter using a 40x40 cm frame, so that the pad rested on the carpet.The frame was mounted on the SPRINTER's mobile unit via a hinge and a Bowden cable operated by a second electromagnet, so that it could be raised high enough that the pad no longer rested on the carpet.

[0136] The steam generator for the "tefal Pro Express Ultimate GV9567" was stored in a basket above the Sprinter's wheeled section and connected to the Sprinter's power supply. The steam generator is connected to the steam iron via a pressure-tight steam hose. Example 2 - Cleaning procedure with ethanol-containing cleaning agent

[0137] The device, constructed according to Example 1, was placed on a velour carpet with a pile height of approximately 4 mm and connected to the power supply. The front of the SPRINTER was lowered so that the brush roller rested on the floor, while simultaneously the frame with the steam iron was lifted from the floor by the second electromagnet. While moving forward, cleaning agent was sprayed from the upper reservoir onto the brush roller and from the lower reservoir onto the carpet via the front nozzles. The device was pushed back and forth several times to roughly dampen the carpet.

[0138] For the second step, the brush roller was put into operation and the device was pushed back and forth several times over the moistened surface, which distributed the cleaning agent evenly on and in the carpet pile through the brush.

[0139] For the third step, the brush roller was replaced by a second rotating body. This was created by shortening the approximately 1.5 cm long bristles of a brush roller by about 5 mm and wrapping the resulting brush roller with a pad made from a microfiber wash mitt, such as those commonly used for car washing. Similar to the pad of the VILEDA steam cleaner, the pad has textile threads pointing towards the carpet. The brush roller was operated with the front section lowered and the rear section (frame with steam iron) raised, and moved across the carpet. The cleaning agent was worked into the carpet pile via the textile threads. This step was performed at the same speed and for approximately four times as long as the second step. Afterwards, the carpet pile was completely and evenly saturated with cleaning agent.Furthermore, the fibers had stood up evenly in both the more and less frequently walked areas. The floor had a distinct odor of ethanol. For the fourth step, the front part of the device was raised using the front electromagnet so that the rotating body for the incorporation process was no longer in contact with the floor covering, and the rear part was lowered using the second electromagnet so that the pad of the gas outlet unit was in contact with the floor covering. Then, steam generation was started using the switch on the device. After a few seconds, the required steam pressure had built up. Then, the trigger for the steam outlet valve of the iron, which was integrated into the handle of the SPRINTER, was activated, directing hot gas through the pad onto the floor covering for approximately 10 seconds. During this time, the device was moved across the floor at a speed of approximately 5 cm / s.This process was repeated for approximately the same amount of time as the initial application. After this step, the carpet was only slightly damp and had at most a faint odor of alcohol. After about 6 hours, the carpet was completely dry and ready to walk on again. For the extremely intensive cleaning of a 6.2 square meter carpet area, 2.25 liters of cleaning agent and about 1 liter of clean water were used (potential reuse was not considered). The carpet pile was very evenly aligned after drying. Upon removing the pad, the discoloration revealed that the dirt had accumulated from the carpet, starting at the tips of the pad's textile threads and continuing into the core. The dirt was easily removed by washing the pad at 60°C in the washing machine, and the pad could then be reused. Example 3 - Cleaning with isopropanol-containing cleaning agent

[0140] Example 2 was repeated, using isopropanol instead of ethanol. The result was the same.

Claims

[1] Method for cleaning a textile floor covering comprising a. Applying an aqueous cleaning agent to the textile floor covering, and b. Incorporation of the cleaning agent and mechanical treatment of the textile floor covering, and c. Moving a hot gas-permeable pad over the textile floor covering moistened with the cleaning agent, while steaming the textile floor covering with hot gas through the pad, characterized by that the aqueous cleaning agent has a cleaning-active content of one or more C1-C5 alcohols of between 15 and 39 wt%. [2] Method according to claim 1 for cleaning a textile floor covering with a device having at least two units for processing the floor covering in a housing, wherein the units are moved upwards and downwards in the housing by vertical movement units during the cleaning method. [3] Use of an aqueous solution for carrying out the method according to claim 1, comprising a cleaning-active content of one or more C1-C5 alcohols of between 15 and 39 wt.% for moistening and cleaning a textile floor covering. [4] Use of a rotating or vibrating body, the surface of which is provided with a pad containing textile threads, for cleaning a textile floor covering moistened with an aqueous solution having a cleaning active content of between 15 and 39 wt% of one or more C1-C5 alcohols with hot gas for carrying out the method according to claim 1. [5] Device for cleaning a textile floor covering comprising a housing a. a dispensing unit (12) for dispensing an aqueous cleaning agent onto the textile floor covering, b. a separate, height-adjustable incorporation unit (14) within the housing for the mechanical treatment of the textile floor covering, separate from the dispensing unit (12). c. a steam generating unit (3) for the production of superheated or unsaturated steam, d. a height-adjustable hot gas outlet unit (13) in the housing with a hot gas-permeable pad movable over the textile floor covering for conveying the water vapor through the pad onto the textile floor covering, and e. a vertical movement unit for lowering and raising the units. [6] Device according to claim 5, characterized by , that it has a suction unit (18) with suction openings (15a) in the base of the device (15) for the extraction of liquids and vapors, and skirts (15b) surrounding the entire device. [7] Device according to one of claims 5 and 6, characterized by, that it further comprises a control unit (17) for controlling the dispensing of the cleaning agent and the generation of steam. [8] Device according to claim 6, characterized by that it has two discharge units (12), two incorporation units (14) and two hot gas discharge units (13). [9] Device according to claim 5, characterized by , that the pad is stretched in an interchangeable cassette, unrollable on a supply roll for fresh pad and rollable on a supply roll for soiled pad.

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