GB2619538A

GB2619538A - Laundry method

Info

Publication number: GB2619538A
Application number: GB2208436.2A
Authority: GB
Inventors: Grant Kyle
Original assignee: Oxwash Ltd
Current assignee: Oxwash Ltd
Priority date: 2022-06-09
Filing date: 2022-06-09
Publication date: 2023-12-13
Also published as: GB202208436D0

Abstract

A method for laundering includes the steps of washing a fabric item 11 and feeding the item onto an air permeable conveyer 5. The item on the conveyor is then passed through a sheet of unheated air provided by an air knife 4 above the conveyor, so that moisture is expelled from the fabric item. The expelled moisture is collected with a suction device (9, Figure 3) below the conveyor. A device for expelling moisture from a fabric includes an air permeable conveyer 5 and an air knife 4. The air knife is arranged to direct a sheet of unheated air onto the conveyer. A suction device is arranged on the opposite side of the conveyer from the air knife. In use, the sheet of air is directed onto a surface of the fabric which is positioned on the conveyer to expel moisture from the fabric, and the expelled moisture is collected by the suction device. The sheet of air may be provided at an oblique angle to the conveyor. The fabric may be passed to a heated roller 1 to iron it. Ultrasonic transducers 3 may also be used to atomise and expel moisture from the fabric item.

Description

Laundry Method

Field of the Invention

The present invention is in the field of laundry and wet cleaning, and relates to a method for laundering a fabric item, including a step of expelling moisture from the fabric item without heat and a device for the same.

Background to the Invention

One of the largest, if not the largest consideration facing the world at this time is the climate emergency. The overarching aim of the present invention is to reduce energy usage in laundry and wet cleaning, so that the everyday activity of washing our clothes, bed linen and other fabric items has a significantly lower energy intensity and therefore lower carbon footprint.

In commercial laundry processes, the greatest hindrance to achieving net zero carbon emissions is the drying process, which involves a large amount of energy to evaporate moisture from textiles.

Reducing the level of water retained in fabric items after washing is commonly achieved by spinning the items in a drum of a washer extractor at high speed. This reduces the water content from 100% down to -50%, depending on the type of fabric. This process uses a large amount of energy due to the mechanical action of the high speed three-phase motor.

For items such as towels and clothing, tumble dryers are then used to reduce the moisture content from fabrics down to around 4-6%. Due to the cost associated, this process is commonly powered by natural gas or bottled liquid propane in a commercial context, which have a high carbon footprint compared to electricity from renewable sources.

Alternatively, roller ironers, also called rotary ironing machines, can be used at the end of the laundry process directly after washing to remove moisture from damp laundry with a moisture content of around 50%, with the added benefit of ironing the fabric to remove creases. This is particularly the case for bedlinen, scrubs, lab coats and table linen which are typically flat sheets and very thin. Roller ironcrs typically operate at a temperature of between 165-180°C and are again a significant source of energy consumption in the form of natural gas or liquefied petroleum gas (LPG).

Another problem associated with roller &otters is that residual detergent remaining in the damp fabric can react to the high temperature of the roller iron, resulting in yellowing of the fabric as the chemical oxidises and burns. This reduces the attractiveness of the item and thus can limit its lifetime significantly.

An aim of the present invention is to reduce the energy associated with the laundry process, particularly in the drying and ironing steps.

Summary of the Invention

In a first aspect of the invention, there is provided a method for laundering a fabric item. The method comprises the steps of: washing the fabric item; feeding the fabric item onto an air permeable conveyer; passing the fabric item on the air permeable conveyer through a sheet of air provided by an air knife which is positioned above the air permeable conveyer, so that. moisture is expelled from the fabric item, and collecting the expelled moisture with a suction device, wherein the suction device is arranged below the air permeable conveyer, wherein the sheet of air is unheated.

In a second aspect of the invention, there is a provided a device for expelling moisture from a fabric item. The device comprises am air permeable conveyer; an air knife, wherein the air knife is arranged to direct a sheet of air onto the air permeable conveyer, and wherein the air knife is configured to provide unheated air; and a suction device, wherein the suction device is arranged on the opposite side of the air permeable conveyer from the air knife; wherein, in use, the sheet of air is directed onto a surface of the fabric item which is positioned on the air permeable conveyer to expel moisture from the fabric item, and the expelled moisture is collected by the suction device.

Rapid rotation and/or heated air and/or a healed roller have commonly been used to remove water from washed fabric items. The inventors have advantageously found that moisture can be removed more effectively and energy efficiently from a fabric item by feeding the fabric item through a sheet of air provided by an air knife, wherein the sheet of air is unhealed. The sheet of air forces the moisture out of the fabric item, which is collected by a suction device. This provides the advantage that the moisture content of a fabric item can be reduced significantly, prior to being finished by a lower temperature roller iron if required.

Using an air knife can negate the need for tumble drying and significantly reduce the time required to remove the latent moisture from the textile post washing, which reduce the energy involved in the drying process.

In addition, the operation of the air knife removes creases from the fabric item as it is fed through the air knife, therefore achieving the desired homogenous textile finish across the entire fabric item. Where subsequent ironing is carried out, reducing the moisture content of the fabric item prior to ironing means that the roller iron can be used at a significantly lower temperature, which also reduces the energy involved in the drying/ironing process, and minimises the risk of burning residual detergent within the fabric which leads to fabric yellowing.

The fabric item may be any item made from fabric/textiles. For example, the fabric item may be a knitted, woven or non-woven fabric. Examples of fabric include cotton, polycotton, linen, silk, wool, jute, polyester, rayon, fiberglass, canvas, denim, muslin, satin, leather, polyvinyl chloride, lace, bamboo, spandex, velvet, hemp, among others.

Typically, the fabric item is a garment, an item of bedlinen or an item of table linen. The invention is particularly suitable for drying and ironing flat items such as bedlinen, scrubs, lab coats and table linen.

The invention relates to a method for laundering a fabric item. By "laundering" we mean the process of washing and drying the fabric item. The fabric item may also be ironed as part of the laundry process.

The first step of the laundry method is washing the fabric item. This can be done in any conventional way. It is preferably done at a low temperature, such as 20 or 30°C, so as to keep the energy usage as low as possible. After the washing step, the fabric items typically have a water content of around 50% by weight and need to be dried. The fabric item may be tumble dried or subjected to other drying before the air knife, but preferably is not. Preferably, the fabric item is fed onto an air permeable conveyer directly after washing.

Air knives, also known as air blades, are known in the art and provide a sheet or curtain of moving air to remove debris or liquid from the surface of a product. These are commonly used in washrooms to dry people's hands. The terms "air knife" and "air knife array" are understood to mean a high-intensity sheet of laminar airflow provided by a series of holes or continuous slots through which air exits. The air knife may be any suitable air knife, for example a compressed air knife or a blower operated air knife Preferably, the air knife is a compressed air knife The sheet of moving air may be continuous (e.g., a single continuous sheet) or discontinuous (e.g., a sheet with gaps).

The air knife may be discharged through one or more discharge apertures. In some embodiments, the air knife may be discharged through a plurality of discharge apertures.

In many embodiments, the air knife is present in an array format of multiple air knives.

The discharge apertures may be angled, which provides a focused laminar flow of air that maintains the integrity of the feed of the fabric item as well as removing creases. The discharge aperture(s) may be arranged in any manner. Preferably, the discharge aperture(s) are arranged linearly to span the width of the fabric item. Preferably, the discharge apertures are arranged in two or more rows. The discharge aperture(s) may take the form of air holes arranged in a row, or at least one elongate air slot, or a combination thereof. The air slot(s) and/or air holes may be less than 2 mm wide, intended to provide a laminar, well-defined air knife with minimal wind shear. In one embodiment, the length of the air slot(s) -or length of the row of air holes, or length of the row of air slot(s) and air holes -is at least 5 mm.

The exit airspeed through the discharge aperture(s) is preferably in excess of 80 m/s to ensure that the air knife has an effective expelling action on the fabric item. Preferably, the exit airspeed is in excess of 100 m/s. A particularly effective expelling action can be obtained at airspeeds in excess of 120 in/s. Typically, the exit airspeed is 120-140 m/s. The exit air speed is determined in accordance with general air knife principles by the pressure behind the discharge aperture(s). So, for example, increasing the pressure of the air entering the air knife array will increase the exit airspeed. Decreasing the pressure of the air entering the array for a given discharge area will reduce the exit air speed. The exit airspeed is selected based on the material of the fabric item, the thickness of the fabric item and the latent water content of the fabric item.

The sheet of air is unheated air. In other words, the sheet of air is at room temperature, which is usually 5-40°C, or 10-30°C. Typically, the sheet of air is filtered. Typically, the sheet of air 15-25°C. This provides the advantage that less energy is required to dry the fabric item as the bulk air does not need to be heated.

The suction device may be any suitable suction device and is a term well understood in the art. The suction device removes air from a space which results in a pressure differential. Accordingly, the suction device provides an area of negative pressure that sucks in and removes moisture that is expelled from the fabiic item by the action of the air knife, thereby cooperating with the air knife Typically, the suction device is in fluid cooperation with the air knife, such that the sheet of air provided by the air knife extends between the air knife (e.g., the discharge aperture(s)) and the suction device. This provides the advantage that the air knife directs expelled moisture from the fabric item directly into the suction device, collecting the moisture more effectively and preventing non-linear air flow.

After collection the moisture can be processed in conventional ways. Advantageously, it can be fed back into the washing process, so as to recycle the water.

After washing, the fabric item is fed onto the air permeable conveyer, usually by hand.

The fabric item on the air permeable conveyer then passes through the sheet of air provided by the air knife which is positioned above the air permeable conveyer. This provides the advantage that the air knife can act on and expel moisture from the full length of the fabric item. The air permeable conveyer may pass through the sheet of air at any angle. Preferably, the air permeable conveyer passes perpendicularly to die normalised plane (o) of the sheet of air.

Air permeable conveyers are known to the skilled person, and can be made of any suitable material, for example a reticulated material, such as a mesh of polyester and aramid. This provides the advantage that moisture expelled from the fabric item will exit through the air permeable conveyers and be collected by the suction device and will not get trapped in the fabric item. Preferably the air permeable conveyer is a fine mesh so that the fabric item (e.g., tassels) will not get caught or trapped in the reticulations.

Typically, the air permeable conveyer is flat, i.e., a single plane and may be level i.e., horizonal or substantially horizontal, or may be inclined.

In order to provide fluid cooperation between the suction device and the air knife the air knife is arranged on a first side of the air permeable conveyer and the suction device is arranged on the opposite second side of the air permeable conveyer, i.e., the air permeable conveyer is arranged between the air knife and the suction device. This provides the advantage that moisture is forced out of the fabric item in the direction of the first side to the second side, and the suction device is positioned on the second side to collect the expelled moisture.

The air knife is usually arranged above the suction device, and may be arranged directly above the suction device. This provides the advantage that the sheet of air is directed downwardly onto the surface of the fabric item, forcing moisture out of the fabric item which is collected by the suction device below, and aided by gravity. In these embodiments, the sheet of air is provided onto the top surface of a fabric item, which forces moisture out of the fabric item via the bottom surface.

The air knife may be configured to apply the sheet of air at any angle or direction with respect to the air permeable conveyer (i.e., the loading surface of the conveyor; the surface onto which a fabric item is placed to be conveyed) In some embodiments, the air knife is configured to apply the sheet of air perpendicular to the air permeable conveyer (i.e.. at 900 to the plane of the air permeable conveyer). In other embodiments, the air knife is configured to apply the sheet of air at an oblique angle with respect to the normal of the air permeable conveyer in the direction of travel. For example, the oblique angle may be 1-50°, 2-45°, 3-40°, 4-35°, 5-30°, 10-20°. Preferably, the oblique angle is 20° This reduces creasing of the fabric item.

In various embodiments, the air knife is configured to apply a first sheet of air in a first lateral direction and a second sheet of air in a second lateral direction. In some embodiments, the first lateral direction is opposite the second lateral direction. In particular embodiments, the air knife comprises a plane of symmetry such that one side of the array applies a sheet of air in one direction and the other side of the array applies a sheet of air in a mirrored direction. This provides the advantage of tensioning the fabric item to reduce creasing.

In some embodiments, the air knife is configured to apply the sheet of air at an oblique angle with respect to the normal of the air permeable conveyer in the transverse direction to the direction of travel. For example, the oblique angle may be 1-50', 2-45', 3-40', 435°. 5-30', 10-20'. Preferably, the oblique angle is 10'. For example, the sheet of air may be directed towards the rear of the device. This provides the advantage of generating back tension in the fabric item between the sheet of air and the person feeding the device which flattens and smooths out the fabric item. This provides the advantage of reducing creasing of the fabric item.

In particular embodiments, the air knife is configured to apply the sheet of air at a first oblique angle with respect to the normal of the air permeable conveyer in the direction of travel, and at a second oblique angle with respect to the normal of the air permeable conveyer in the transverse direction to the direction of travel. This optimally reduces creasing of the fabric item. In particular embodiments, the air knife array is configured to apply the sheet of air at 5-15 with respect to the normal of the air permeable conveyer in the direction of travel, and at 10-30° with respect to the normal of the air permeable conveyer in the transverse direction to the direction of travel.

Ironing the fabric item is not an essential step of the method. However, the method may further comprise the step of ironing the fabric item using a heated roller. The ironing step may be a final ironing step. Suitable rotary ironing machines are known, such as the Girbau PBP 5132. In these embodiments, the air permeable conveyer cooperates with the heated roller to pass the fabric item from the air permeable conveyer to the heated roller. Typically, the rotary ironer comprises at least one heated roller positioned to the rear of the air permeable conveyor and providing a gap. Typically, the fabric item is gripped within the gap between the air permeable conveyor and the heated roller to feed the fabric item at least partially around the surface of the heated roller.

The heated roller may be heated to any temperature. In some embodiments, the heated roller may be heated to a temperature between 40°C and 180°C. In various embodiments, the heated roller may be heated to a temperature between 45°C and 140°C, preferably between 45°C and 100°C, or between 50°C and 80°C, preferably between 55°C and 75°C, more preferably between 55°C and 65°C. Advantageously, the heated roller may operate at a significantly reduced temperature compared to conventional rotary ironers (which operate at 170-180°C) because the moisture content of the fabric item has been reduced substantially by the operation of the air knife This significantly reduces the amount of energy used in the drying/ironing process and further minimises the risk of yellowing of the fabric associated with higher heat ironing.

Typically, the heated roller is substantially horizontal or horizontal. This provides the advantage that fabric items, such as bed linen and table linen, can be fed into the roller in a horizontal manner, which allows for easier handling. Typically, the length of the heated roller is greater than the width of the fabric item, such that the fabric item can be fed through the heated roller in an extended and non-overlapping manner. For example, the length of the heated roller may be greater than the width of a standard king size flat bed sheet.

In some embodiments, the method further comprises the steps of: passing the fabric item on the air permeable conveyor over or under a plurality of ultrasonic transducers vibrating at a frequency of 50-2000 kHz, so that moisture is atomised and expelled from the fabric item. In this embodiment, the device further comprises: a plurality of ultrasonic transducers arranged above or below the air permeable conveyor and arranged to vibrate at a frequency of 50-2000 kHz, wherein, in use, vibration of the transducers at a frequency of 50-2000 kHz causes atomisation of moisture from a fabric item which is positioned on the air permeable conveyor, thereby expelling moisture from the fabric item.

The inventors have advantageously found that the combination of an air knife with a plurality of ultrasonic transducers removes moisture from a fabric item even more effectively and energy efficiently. A fabric item is fed through a sheet of air provided by an air knife and is acted on by a plurality of ultrasonic transducers. The sheet of air forces the moisture out of the fabric item, which is collected by a suction device. The transducers atomise moisture in the fabric item, which is also collected by the suction device. The moisture content of the fabric item is reduced compared to the action of the air knife alone. If ironing is desired, the fabric item can be finished by a lower temperature roller iron, which does not need to be as hot as conventional roller ironers as the moisture content of the fabric item is lower. Thus, less energy is needed in the drying process and the roller iron can be used at a significantly lower temperature, which reduces the energy involved in the ironing process, and minimises the risk of fabric yellowing.

The term "ultrasonic transducer" is well known in the art and is understood to mean a device which converts energy from one form into an ultrasonic vibration. Any suitable ultrasonic transducer may be used, provided it can vibrate at a frequency of 50-2000 kHz.

In some embodiments, the transducers vibrate at a frequency in the range of 100-1500 kHz. In preferable embodiments, the transducers vibrate at a frequency in the range of 120-200 kHz. Most preferably, the transducers vibrate at about 135 kHz. The skilled person will recognise that different frequencies may be appropriate for different fabric types or compositions, and thus may select a transducer frequency based on the fabric item being dried. For example, a frequency of 135 kHz provides optimum atomisation for a 300 gsm 50:50 cotton:polyester material composition.

The ultrasonic transducers may be any suitable type of ultrasonic transducer. For example, the ultrasonic transducers may be linear transducers, convex (standard) transducers, straight beam contact transducers, angle beam transducers, dual element transducers or immersion transducers. The plurality of ultrasonic transducers may be all of the same type, or may comprise different types of ultrasonic transducers. In some embodiments, the ultrasonic transducers are piezoelectric transducers. In various embodiments, the ultrasonic transducers are piezoelectric atomising transducers. In preferable embodiments, the ultrasonic transducers are metal mesh piezoelectric atomising transducers. These are particularly advantageous because they allow atomised moisture to escape both in the direction away from the transducers (i.e., through the fabric sheet), and in a direction towards the transducers. This is particularly useful in embodiments where the transducers are in contact with the fabric item.

The plurality of transducers may comprise any number of transducers that is greater than one. In sonic embodiments, the plurality of transducers comprises or consists of 50-500 transducers. In various embodiments, the plurality of transducers comprises or consists of 75-400 transducers. In many embodiments, the plurality of transducers comprises or consists of 100-300 transducers. In particular embodiments, the plurality of transducers comprises or consists of 125-200 transducers. In preferable embodiments, the plurality of transducers comprises at least 100 transducers. Typically, there are at least 20 transducers for every metre in width of the air permeable conveyor. For example, if the air permeable conveyor is 3 metres in width, there may be at least 60 transducers. More typically, there are at least 50 transducers for every metre in width of the air permeable conveyor. Preferably, the plurality of transducers comprise at least 50 transducers aligned linearly over the width of the air permeable conveyor. More preferably, the plurality of transducers comprise at least 50 transducers aligned linearly in a first row over the width of the air permeable conveyor and at least 50 transducers aligned linearly in a second row over the width of the air permeable conveyor.

Preferably, the plurality of transducers are arranged in an array By "array", it is meant that the transducers are positioned in an ordered arrangement. Typically, the transducers are arranged in a series of rows. For example, the transducers may be arranged in two, three or four rows. The rows may be offset or staggered. This provides the advantage that there are fewer or no areas of the fabric item that are not acted on by the transducers, thus avoiding lines of 'undried' fabric as the item passes over or under the transducers.

Preferably, the transducers are arranged in three rows, wherein the second middle row if offset by 50% with respect to the first and third rows. This provides the advantage of full contact coverage in both the x-and y-axes of the fabric item being dried. In preferable embodiments, the plurality of transducers are distributed across the width of the air permeable conveyor such that they act upon the width of the fabric item on the air permeable conveyor.

The transducers may be arranged above or below the air permeable conveyor. Typically, the transducers are arranged above the air permeable conveyor. M some embodiments, the plurality of transducers are arranged within 10 mm of the surface of the air permeable conveyor. For example, the plurality of transducers may be arranged within lOmm above the surface of the air permeable conveyor. In various embodiments, the plurality of transducers are arranged within 5 mm of the surface of the air permeable conveyor. For example, the plurality of transducers may be arranged within 5 mm or within 4 mm or within 3 mm or within 2 mm or within 1 mm above the surface of the air permeable conveyor. Preferably, the plurality of transducers are arranged to contact the fabric item passing on the air permeable conveyor.

The fabric item on the air permeable conveyer then passes over or under the plurality of ultrasonic transducers. This provides the advantage that the vibrations from the transducers cause moisture within the fabric item to atomise which expels moisture from the full length of the fabric item as it passes over or under the transducers.

The transducers may be arranged before or after the air knife (or air knife array), so the fabric item may pass through the sheet of air provided by an air knife before or after being acted on by the transducers. Preferably there is an air knife (or air knife array), then the transducers, then another air knife (or air knife array).

A skilled person will appreciate that all aspects of the invention, whether they relate to, for example, the device or the method, are equally applicable to all other aspects of the invention. However, the skilled person will appreciate where more detailed information has been given for a particular aspect of the invention, this information is generally equally applicable to other aspects of the invention.

Brief Description of the Drawings

The invention will now be described in detail by way of example only with reference to the figures in which: Figure 1 shows a perspective view of a typical roller ironer that is contained in the prior art.

Figure 2 shows plan views of exemplary embodiments of the device according to the disclosure with (A) a single air knife. and (B) an air knife array.

Figure 3 shows an x-axis side view of an exemplary embodiment of the device according to the disclosure.

Figure 4 shows y-axis side views of exemplary embodiments of the device according to the disclosure with (A) a single air knife, and (B) an air knife array.

Figure 5 shows a plan view of an exemplary embodiment of the device according to the disclosure with a combined air knife and transducer array.

Detailed Description of the Invention

Figure 1 shows a typical commercial rotary ironer 10 that is contained in the state of the art, and is exemplified in EP0241176 Al. The rotary ironer 10 has an ironer section 12 and a feeding mechanism 14 adjacent to and integrally housed with the ironer section 12, for feeding fabric items to the ironer section. The ironer section 12 has two roller irons 16, 18 which are driven by a diiving arrangement (not shown). The ironer section 12 has a plurality of tape tensioncr mechanisms 20 spaced at frequent intervals across the width of the machine in order to maintain the fabric items being ironed in contact with the roller irons 16, 18. The feeding mechanism 14 includes a conveyor belt arrangement 22 comprised of a plurality of separate belts 24 supported side by side about two common end support rollers, and suction means (not shown). The feeding mechanism 14 also includes a guide roller 36 to "smooth out" fabric items prior to such contacting the conveyor belt arrangement 22, the guide roller 36 being positioned adjacent the leading edge of the conveyor belt arrangement 22. The end support roller of the conveyor belt arrangement 22 is driven by the drive means (not shown) of the first roller iron 16 via chains and gears (also not shown) in order that the fabric item is synchronisedly fed by the belts 24 to the roller iron 16, while the guide roller 36 is separately driven by a motor (not shown) at a greater speed than the end support roller. A belt tensioning mechanism (not shown) is provided to tension the belts 24 just sufficiently to allow drive to take place.

In operation, the operator of the ironing machine 10 lays the leading portion of a fabric item onto the belts 24, and allows the remainder or trailing portion of the fabric item to become draped over the guide roller 36 and an opening 46 of a suction chamber (not shown). The leading portion of the fabric item is retained on the belts 24 due to the suction means, while die whole of the remainder or trailing portion of die fabric item is drawn in the form of a U-loop into the suction chamber, by means of firstly the guide roller 36 rotating at a greater speed than the end support roller 26 of the conveyor belt arrangement 22, and secondly the strong suction of the suction chamber. After the trailing edge of the fabric item has passed over the guide roller 36, the suction of the suction chamber causes the now unlooped fabric item to flap and pull taut due to air cut-rents, the resultant effect being that the trailing portion of the flatwork piece is smoothed out and straightened prior to contact with the belts 24 and the roller irons 16 and 18.

The machine 10 is provided with a smooth drag plate 50 just in front of the leading edge of the conveyor belt arrangement 22 in order to pull taut the fabric item just prior to contact thereof with the belts 24, thereby ensuring even tension across the full width of the fabric. The machine 10 is also provided with a see-through guard plate 48 on each side for safety purposes. The guide roller 36 is, also for safety purposes, provided with a torque limiting device (not shown) which stops drive of the roller 36 in case an operator traps their fingers and/or hand on the guide roller.

The roller irons are made from metal and are heated to approximately 165-180°C, using natural gas or LPG. Operation of the conveyor belt arrangement 22 moves the fabric item in a front to rear direction underneath the two roller irons 16, 18. When the fabric item reaches the rear side of die roller irons 16, 18, the fabric item exits the device and is collected by the user at the rear of the device for folding and storage.

Figure 2 shows exemplary embodiments of the device according to the disclosure.

Similar to the prior art rotary ironer, the device has a front-loading flat bed air permeable conveyor 5 formed of belts and support rollers (not shown) which are driven by conventional drive means (also not shown). The conveyor 5 is positioned in front of a horizontal heated roller 1. The conveyor 5 functions in feeding a fabric item 11 over the heated roller I. The uppermost. surface of the air permeable conveyor 5 provides the conveying or loading surface on which a fabric item 11, such as a rectangular cotton sheet, can be placed. The conveying surface is an elongate rectangle with dimensions 325 x 30 cm. The conveying surface is substantially horizontal. However, in alternative embodiments, the conveying surface is at an incline, similar to the conveyor shown in Figure 1. The air permeable conveyor 5 is driven by conventional drive means. The air permeable conveyor is typically formed of high temperature polyester aramid.

The conveyor 5 is adjacent to a heated metal roller 1 that is an elongate metal hollow cylinder that can be heated to a desired temperature. The roller 1 is substantially the same length as the conveyor 5 and is positioned perpendicular to the direction of travel of the conveying surface. The roller 1 is driven by conventional drive means (not shown) to rotate about its longitudinal axis in a front to rear direction as indicated by the arrows. Accordingly, the fabric item 11 that is placed onto the conveying surface is fed towards the roller 1 and over the roller 1.

As shown in Figure 2A, an air knife 4 is positioned above the air permeable conveyor 5, at a distance of approximately 10 mm above the conveyor 5. The air knife 4 is positioned in a support manifold 2. The air knife 4 is centred over the length of the air permeable conveyor 5 and is positioned approximately 30 cm in front of the roller 1. The air knife 4 extends across the length of the conveyor 5 and has two elongate apertures in an inverted 'V' shape. The left side of the device is a mirror image of the right side of the device.

Both apertures are approximately 1580 mm in length The exit airspeed of the air knife is about 120 tn/s.

As shown in Figure 2B, the device may comprise a plurality of air knives 4. In Figure 2B, the plurality of air knives 4 are positioned as an array of two identical rows of ten air knives 4. However, the skilled person would recognise that any format of air knives would be possible. In each row, the centre of each air knife 4 is aligned along the length of the air knife array. The left side of the array is a mirror image of the right side of the array. The two rows of air knives are positioned approximately 10 cm apart. The air knives 4 in the left half of the array are angled 150° from the x-axis. The air knives 4 in the right half of the array are angled 30° from the x-axis. Each air knife 4 is approximately 316 mm in length. The exit airspeed of each air knife 4 is about 120 m/s.

In use, the fabric item 11 is positioned on the air permeable conveyor 5. Operation of the conveyor causes movement of the conveying surface in a front to rear direction which feeds the fabric item 11 underneath the air knife or air knife array 4. The air knife or air knife array 4 projects high speed air at the uppermost surface of the fabric item 11, which forces moisture to exit from the rearmost surface of the fabric item 11, which dries the fabric item 11. The air knife or air knife array 4 projects high speed air across substantially the entire length of the fabric item 11. Owing to the continuous movement of the conveying surface, the fabric item 11 continuously moves underneath the air knife array 4 and over the heater roller 1, such that the entire length and width of the fabric item 11 is acted on by first the air knife or air knife array 4 and subsequently by the heated roller I. As can be seen in Figure 3, the air knives 4 in the left half of the array are angled at 20° (01) from the vertical (0; i.e., the gravity normal) to the left (i.e., in the x-axis of the device), and the air knives 4 in the right half of the army are angled at 20' (01) from the vertical (0) to the right, which functions in tensioning the fabric item 11 in equal and opposite directions such that the fabric item 11 remains flat as it passes under the air knife array 6 and over the heated roller 1, thereby removing lateral creases.

Figure 3 further shows the support manifold 2 and a base support manifold 6 which contain the air knife or air knife array 4. Further shown are radiator fins 8 for eliminating excess heat from the device, and an air permeable lower base support 9 over which the air permeable conveyer 5 passes. The air permeable lower base support 9 contains an elongate suction device spanning the length of the air permeable lower base support 9.

Thc elongate suction device is positioned below the air knife or air knife array 4 to fluidically cooperate with the air knife or air knife array 4. The moisture that is expelled from the fabric item 11 from the action of the air knife or air knife array 4 is collected by the suction device, drying the fabric item 11. The components of the suction device are standard and known in the art.

As can be seen in Figures 4A and 4B, the air knife or air knife array 4 is angled at 100 (02) from the vertical (0) towards the rear of the device (i.e., in the y-axis of the device). This assists in tensioning the fabric item 11 and helps to prevent longitudinal creasing.

Accordingly, the sheet of air is angled both towards the sides of the device and towards the rear of the device.

Figure 5 shows an exemplary device using a combined air knife 4 and transducer 3 array. A plurality of ultrasonic transducers 3 are positioned above the conveyor 5, at a distance of approximately 5 mm above the conveyor 5. The ultrasonic transducers 3 are metal mesh atomizing transducers and are circular components of 20 mm in diameter. The transducers 3 are arranged in an array or matrix of three rows, with the middle row offset by 50% along the x-axis to provide a staggered foimation. There are 159 transducers per row (only 17 have been shown in Figure 5), which completely covers the length of the air permeable conveyor 5 (3165 mm) The transducers 3 vibrate at a frequency of 135 kHz, which provides optimum atomisation for a 300 gsm 50:50 cotton:polyester material composition. However, the skilled person will recognise that different frequencies may be appropriate for different fabric types.

The transducers 3 are positioned in the same support manifold 2 as the air knife array 4, with the transducer array positioned approximately half way between the first row of air knives 4 and the second row of air knives 4. The support manifold 2 is centred over the length of the conveyor 5 and is positioned approximately 30 cm in front of the roller 1.

In some embodiments, the device has two support rollers (not shown) positioned either side of the support manifold 2, which function in maintaining optimal contact of the fabric item with the air knife -transducer array 3,4.

Although the invention has been described in relation to one or more preferred embodiments, it will be appreciated that various changes or modification may be made without departing from the scope of the invention as defined in the appended claims.

Claims

Claims 1. A method for laundering a fabric item, the method comprising the steps of: washing the fabric item; feeding the fabric item onto an air permeable conveyer; passing the fabric item on the air permeable conveyer through a sheet of air provided by an air knife which is positioned above the air permeable conveyer, so that moisture is expelled from the fabric item; and collecting the expelled moisture with a suction device which is arranged below the air permeable conveyer; wherein the sheet of air is unheated.A method according to claim 1, wherein the air knife is arranged directly above the suction device; and/or wherein the air knife is arranged so that the sheet of air is provided at an oblique angle to the normal of the air permeable conveyer, preferably wherein the sheet of air is provided in the same direction as the direction of travel of the air permeable conveyer, and wherein the suction device is arranged to cooperate with the air knife A method according to any preceding claim, further comprising the step of: passing the fabric item from the air permeable conveyer to a heated roller, to iron the fabric item.A method according to claim 3, wherein the temperature of the heated roller is between 40°C and 140°C.A method according to any preceding claim, wherein the fabric item is selected from a garment, an item of bedl i nen or an item of table linen.A method according to any preceding claim, wherein the sheet of air is provided by at least one air knife array.A method according to any preceding claim, further comprising the steps of: 2. 3. 4. 5. 6. 7. 8. 10. 11 12. 13. 14.passing the fabric item on the air permeable conveyor over or under a plurality of ultrasonic transducers vibrating at a frequency of 50-2000 kHz, so that moisture is atomised and expelled from the fabric item.A method according to claim 7, wherein the plurality of transducers are arranged in an array.A method according to claim 7 or 8 wherein the plurality of transducers comprise at least 100 transducers.A method according to any of claims 7-9, wherein the plurality of transducers are piezoelectric atomising transducers, preferably wherein the plurality of transducers are metal mesh piezoelectric atomising transducers.A method according to any of claims 7-10, wherein the plurality of transducers are distributed across the width of the air permeable conveyor such that they act upon the width of the fabric item on the air permeable conveyor.A method according to any of claims 7-11, wherein the plurality of transducers are arranged within 10 mm of the surface of the air permeable conveyor, preferably wherein the plurality of transducers are arranged within 5 mm of the surface of the air permeable conveyor, more preferably wherein the plurality of transducers are arranged to contact the fabric item passing on the air permeable conveyor.A method according to any of claims 7-12, wherein the plurality of transducers vibrate at a frequency of 100-1500 kHz, more preferably wherein the plurality of transducers vibrate at a frequency of 120-200 kHz, more preferably wherein the plurality of transducers vibrate at a frequency of about 135 kHz.A device for expelling moisture from a fabric item, the device comprising: an air permeable conveyer; 15. 16. 17. 18. 19.an air knife, wherein the air knife is arranged to direct a sheet of air onto the air permeable conveyer, and wherein the air knife is configured to provide unheated air; and a suction device, wherein the suction device is arranged on the opposite side of the air permeable conveyer from the air knife; wherein, in use, the sheet of air is directed onto a surface of the fabric item which is positioned on the air permeable conveyer to expel moisture from the fabric item, and the expelled moisture is collected by the suction device.A device according to claim 14, wherein the air knife is an-anged directly above the suction device; and/or wherein the air knife is arranged so that the sheet of air is provided at an oblique angle to the normal of the air permeable conveyer, preferably wherein the sheet of air is provided in the same direction as the direction of travel of the air permeable conveyer, and wherein the suction device is arranged to cooperate with the air knife A device according to any of claims 14-15, which additionally comprises a heated roller ammged so that the fabric item can pass from the air permeable conveyer to the heated roller.A device according to claim 16, wherein the temperature of the heated roller is between 40°C and 140°C.A device according to any of claims 13-17, wherein the device comprises an air knife array, wherein the air knife array is arranged to direct one or more sheets of air onto the air permeable conveyer, and wherein the air knife array is configured to provide unheated air.A device according to any of claims 13-18, the device further comprising a plurality of ultrasonic transducers arranged above or below the air permeable conveyor and arranged to vibrate at a frequency of 50-2000 kHz; 20. 22. 23 24. 25.wherein, in use, vibration of die transducers at a frequency of 50-2000 kHz causes atomisation of moisture from a fabric item which is positioned on the air permeable conveyor, thereby expelling moisture from the fabric item.A device according to claim 19, wherein the plurality of transducers are arranged in an array.A device according to claim 19 or 20, wherein the plurality of transducers comprise at least 100 transducers.A device according to any of claims 19-21, wherein the plurality of transducers are piezoelectric atomising transducers, preferably wherein the plurality of transducers are metal mesh piezoelectric atomising transducers.A device according to any of claims 19-22, wherein the plurality of transducers are distributed across the width of the air permeable conveyor such that they act upon the width of the fabric item on the air permeable conveyor.A device according to any of claims 19-23, wherein the plurality of transducers are arranged within 10 mm of the surface of the air permeable conveyor, preferably wherein the plurality of transducers are arranged within 5 mm of the surface of the air permeable conveyor, more preferably wherein the plurality of transducers are arranged to contact the fabric item passing on the air permeable conveyor.A device according to any of claims 19-24, wherein the plurality of transducers vibrate at a frequency of 100-1500 kHz, more preferably wherein the plurality of transducers vibrate at a frequency of 120-200 kHz, more preferably wherein the plurality of transducers vibrate at a frequency of about 135 kHz.