The present invention relates to seals, methods for manufacturing seals, and their use. More particularly, the invention relates to annular seals, and to their use in machines, such as tumble dryers, to prevent moisture loss from the machine. Even more particularly, the present invention relates to tumble dryer seals and methods for producing tumble dryer seals.

Typically, articles are dried in machines such as tumble dryers. The machines typically comprise a housing unit and a rotating tumbler, such as a drum, located therein. Damp articles, such as clothes are placed in the tumbler. The tumbler is supported within the housing of the machine, and it is spun during use. Air is supplied to the tumbler during use, which is typically heated, to assist the drying process. The air passes through the articles as the tumbler spins. The moisture from the articles is collected as steam. The steam is generally passed through an exhaust duct or vent where it is either vented, e.g. through a hose, or is condensed and collected in a reservoir.

The formation of steam in the machine means that water vapour can escape into the machine and the surrounding atmosphere. If water vapour escapes, it can have detrimental effects, such as reducing the efficiency of the machine, damaging the surrounding environment, or damaging the components of the machine. It is, therefore, desirable to reduce the egress of water vapour from the tumbler.

The efficiency of machines, such as tumble dryers, has been determined to date based on a number of different factors, such as the energy consumption of the standard cotton programme at full and partial load, power consumption in “off mode", power consumption in “left-on mode", and presence or absence of a power management system. To date, preventing the egress of water vapour from the tumbler, and the release of humid air from the machine, has not been a high priority. Accordingly, there is a desire to improve the efficiency of seals that are used in machines that reduce the egress of water vapour from the machine without increasing energy consumption.

The use of seals in machines, such tumble dryers is commonplace. The space between the tumbler and the machine is generally wide enough to allow articles to pass through it. Accordingly, the use of seals can serve many purposes, but they have primarily been used in existing machines to close the gap between the tumbler and the machine. An advantage associated with closing the gap between the tumbler and the machine is that articles are prevented from damaging the machine by moving from the tumbler into the machine, and articles are prevented from damage by scraping between the tumbler and the machine. The use of seals can also assist in keeping heat inside the tumbler, which reduces the amount of energy needed to maintain predetermined temperature in the dryer, and reduce fiction between parts of the machine, such as the tumbler and the walls of the machine. Reductions in friction may also result in a reduction of the energy consumption of the machine.

Existing seals that are used in machines, such as tumble dryers, suffer from numerous problems. These problems include challenges associated with the need to retain humid air and moisture in the tumbler. There is therefore a need for an improved seal. The existing seals are commonly made of flexible polymeric materials, such as flexible polyurethane foam, and they may have a textile layer adhered to one side of the seal. Typically, flexible polyurethane foam is produced in large blocks which are then cut into thin sheets. A layer of textile material may be applied to one surface of the polyurethane sheet, which is then cut into long, thin strips. The ends of the strips are curved to form a loop and the two ends stitched together to form an annular seal.

The method of manufacturing existing seals results in them having cut faces, some of which need to be joined, i.e. faces which have been cut after the foam has been formed. The cut faces exhibit an open-cell structure typical of flexible polyurethane foam. The cut faces present a weak point in existing seals and they allow moisture to escape from the tumbler since there is no physical barrier preventing the passage of moisture through the foam. For example, moisture may escape from the joins of the cut faces, e.g. if the join is imperfect or the joining method involves stitching that could cause perforations through which moisture could escape. Further, the cut faces allow the moisture access to the open-cell structure of the polyurethane foam and be absorbed by and/or pass through the foam.

The stitched portion and/or the strip ends may provide a point of weakness in the seal that is susceptible to failure. For example, during use, the adhesion of the textile layer may weaken and/or the ends of the join may weaken. These failures may be gradual over time reducing the efficiency of the machine, or they may be catastrophic resulting in complete failure of the seal and damage to the machine and or articles in the tumbler. The end result is that the lifetime of the machine may be significantly reduced by the failure of the seal.

The adherence of the textile layer to a seal can result in it becoming puckered upon bending to form an annular seal. The puckering can enable gaps to form between the seal and the tumbler that can more easily permit egress of steam and/or moisture from the machine.

In use, the seals may be fitted in a groove or recess in the housing. Existing seals may become dislodged during use and/or spin with the tumbler, requiring additional components such as adhesive layers to maintain the seal in place. Such adhesives may also fail over time. When a seal becomes dislodged and/or moves during use, the effectiveness of the seal may be reduced.

The present invention seeks to provide a solution to one or more of the identified problems by providing an improved seal, a method for manufacturing seals, and their use. The seals may be annular seals, and they may be used in machines, such as tumble dryers, to reduce moisture loss from the machine, to increase the efficiency of the machine, such as energy and/or condensation efficiencies, to increase the lifespan of the machine, and/or to reduce stress on components of the machine. More particularly, the seals my be tumble dryer seals.

According to a first aspect of the invention, a method for producing an annular seal is provided. The method may comprise injecting a polymeric composition comprising polyurethane and/or the constituent monomers and/or co-block polymers thereof into an annular mould, curing the polymeric composition, and demoulding the seal to provide an annular seal.

The seal of the present invention is particularly suitable for use in drying machines, such as tumble dryers. The seal may prevent the egress of moisture from the machine. The seal may act to seal the gap between the tumbler and the machine.

The seal is an annular seal. The seal may be substantially annular in shape or it may be completely annular in shape.

Any suitable mould may be used. The mould may be annular, such as substantially annular or completely annular in shape. The mould may be formed from any suitable material. Suitable materials include metals and alloys. For example, the mould may be formed of aluminium, such as an aluminium C250 tooling plate. The mould may be of any suitable configuration. Suitable configurations include closed moulds. The use of closed moulds may be advantageous to allow a desired density of the polymeric composition in the seal to be achieved.

The polymeric composition may form a foam that expands in the mould during curing. In one arrangement, any suitable polymeric composition may be used as the polymeric composition of the present invention. Suitable polymeric compositions may comprise a mixture comprising a polyol and an isocyanate to enable the formation of a polyurethane, or a polyurethane formed from a polyol and an isocyanate.

In one arrangement, polyol and isocyanate may be present in any suitable ratio. The ratio may be suitable to allow a polyurethane form with a suitable density to be formed. In a further arrangement, the polyol and isocyanate may be present in a ratio of from about 100:50 to about 100:70, about 100:55 to about 100:65, or about 100:55 to about 100:60. In another arrangement, the polyurethane may be formed from a polyol and an isocyanate in a ratio of from about 100:50 to about 100:70, about 100:55 to about 100:65, or about 100:55 to about 100:60.

In one arrangement, the components of the polymeric composition may be premixed before injection into the mould. For example, the components of the polymeric composition may be premixed immediately before injection into the mould.

In one arrangement, the foam that is formed following curing may have any suitable density. The density may be from about 100 kg/m ³ to about 250 kg/m ³ , from about 120 kg/m ³ to about 230 kg/m ³ , from about 140 kg/m ³ to about 210 kg/m ³ , from about 150 kg/m ³ to about 200 kg/m ³ , from about 160 kg/m ³ to about 190 kg/m ³ , or from about 170 kg/m ³ to about 180 kg/m ³ . In another arrangement, the foam may have a density of about 100 kg/m ³ , about 120 kg/m ³ , about 140 kg/m ³ , about 150 kg/m ³ , about 170 kg/m ³ , about 180 kg/m ³ , about 190 kg/m ³ , about 200 kg/m ³ , about 210 kg/m ³ , about 230 kg/m ³ , or about 250 kg/m ³ . It is particularly advantageous if the density of the foam imparts sufficient flexibility to the feel to ensure a good contact is maintained between the tumbler and machine during use, while also imparting sufficient strength to avoid degradation.

In one arrangement, a portion of the textile layer may be adhered to a surface of the polymeric composition. Any portion of the textile layer may be adhered to a surface of the polymeric composition. For example, the textile layer may be completely adhered or partially adhered to a surface of the polymeric composition. Any suitable method of adhering the textile layer to the surface of the polymeric composition may be used. Suitable methods include adhering the textile layer to the polymeric composition during manufacture. The polymeric composition may expand in the mould and during curing adhere to the textile layer, such that no further adhesive means are required. For example, the textile layer may be positioned in the annular mould prior to injecting the polymeric composition, the polymeric composition may be injected into the annular mould, and the seal may be demoulded wherein the polymeric composition is adhered to the textile layer. In an alternative arrangement, the textile layer may be adhered to the polymeric composition using an adhesive means. Any suitable adhesive means may be used. Suitable adhesive means include glue, tape, or double-sided tape for example.

A surface of the textile layer may be in contact with any surface of the annular mould during at least a portion of the moulding process. The textile layer may prevent the polymeric composition from contacting a surface of the mould during moulding. Any suitable surface of the textile layer may be in contact with any surface of the annular mould. In one arrangement, a surface of the textile layer may be in contact with an interior, bottom, top, exterior surface and/or the peripheral circumference of the mould. The textile layer may be formed from any suitable material. In one arrangement, the textile layer may comprise polyester, felt, and/or a polyester felt. In another arrangement, the at least a portion of a surface of the textile material is singed. For example, the singed surface may be positioned towards the polymeric composition in the mould. The textile material is bonded to the polymeric composition. The singed surface may provide for improved bond adhesion with the polymeric material.

In one arrangement, the polymeric composition may be injected into the mould comprising a textile layer. Advantageously, the polymeric composition may saturate at least a portion of the surface of the textile layer, i.e. the polymeric composition at least partially surrounds the fibres of the textile layer prior to curing. After curing, the infiltrated polymer may be intimately adhered to the fibres of the textile layer.

In one arrangement, the textile layer may be any suitable thickness. Suitable thicknesses include between about 1 mm and about 5 mm, between about 2 mm and about 4 mm, or between about 3 mm and about 4 mm. In another arrangement, the textile layer may be about 1 mm, about 2 mm, about 2.1 mm, about 2.2 mm, about 2.3 mm, about 2.4 mm, about 2.5 mm, about 2.6 mm, about 2.7 mm, about 2.8 mm, about 2.9 mm, about 3 mm, about

4 mm, or about 5 mm thick.

The textile layer may be of any suitable density. Suitable densities include from about 500-800 g/m ² , about 550-750 g/m ² , about 600-700 g/m ² , or about 650-700 g/m ² . In another arrangement, the density of the textile layer may be about 600 g/m ² , about 610 g/m ² , about 620 g/m ² , about 630 g/m ² , about 640 g/m ² , about 650 g/m ² , about 660 g/m ² , about 670 g/m ² , about 680 g/m ² , about 690 g/m ² , or about 700 g/m ² .

In one arrangement, the method may be carried out at any suitable temperature. Suitable temperatures include a range from about 15°C to about 30°C, about 20°C to about 30°C, about 25°C to about 30°C. In another arrangement, the method may be carried out at about 15°C, about 20°C, about 25°C, or about 30°C. The temperature may be selected to avoid the need for excessive heating while still enabling a desirable curing time.

In one arrangement, the curing time may be any suitable time prior to demoulding. Suitable times include from about 5-15 minutes, about 6-13 minutes, about 7-11 minutes, about 8-10 minutes, or about 9-10 minutes. In another arrangement, the curing time may be about

5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, about 9 minutes, about 10 minutes, about 11 minutes, about 13 minutes, or about 15 minutes.

The method disclosed herein may be used to form an annular seal. The seal may be continuous. The seal may be a one-piece seal. The seal may be substantially annular or completely annular. The seal may comprise a skin on its surface. The skin may act as a barrier for moisture to enter the open-cell portion of the polymeric composition. The barrier may assist in preventing the egress of moisture from the machine. In one arrangement, the skin may cover all of the surfaces of the annular seal. In another arrangement, the skin may partially cover the surfaces of the annular seal. For example, where the seal comprises a textile material, a skin may not form on the surface in contact with the textile material. Alternatively, the skin may form on all of the surfaces of the polymeric composition, and it may optionally assist in bonding the textile material to the polymeric composition. The skin may be smooth and prevent degradation of the polymeric material during use.

The seal may have any suitable thickness (T), i.e. the cylindrical length of the annual seal, as shown in Figure 5. The thickness of the seal may be determined by its use. For example, the seal may be suitable for use in tumble dryers to provide an effective moisture seal. Suitable thicknesses may be from about 7mm to about 24mm, about 7.5mm to about 23.5mm, about 8mm to about 23mm, about 8.5mm to about 22.5 mm, about 10mm to about 20mm, about 12mm to about 18 mm, about 14mm to about 16mm. Such suitable ranges may include thicknesses from about 8.7mm to about 16.7mm, 10.7mm to about 14.7mm or about 11 ,7mm to about 13.7mm. In another arrangement the seal thickness may be about 7mm, about 7.5mm, about 8mm, about 8.5mm, about 10mm, about 12mm, about 14mm. about 16mm, about 18mm, about 20mm, about 22mm, about 22.5mm, about 23mm, about 23.5mm, or about 24mm. For example, such thicknesses may be about 8.7mm, about 10.7mm, about 11.7mm, about 13.7mm, about 14.7mm or about 16.7mm..

The seal may have any suitable outer diameter. The outer diameter of the seal may be determined by its use. For example, the seal may be suitable for use in tumble dryers to provide an effective moisture seal. Suitable outer diameters, D, may be from about 450mm to about 550mm, about 460mm to about 540mm, about 469mm to about 536mm, about 450mm to about 530mm, about 460mm to about 520mm, about 470mm to about 510mm, about 480mm to about 500mm, about 479mm to about 526mm, about 489mm to about 516mm, about 499mm to about 506mm, about 496mm to about 509mm, about 486mm to about 519mm, about 476 mm to about 529mm, about 513mm to about 518mm, or about 516 mm to about 517mm. In another arrangement the outer diameter may be about 450mm, about 460mm, about 469mm, about, about 470mm, about 476 mm, about 479mm, about 480mm, about 486mm, about 489mm, about 490mm, about 496mm, about 500mm, about 506mm, about 509mm, about 510mm, about 513mm, about 516mm, about 517mm, about 518mm, about 519mm, about 520mm, about 526mm, about 529mm, about 530mm, about 536mm, about 540mm, or about 550mm. Such seals may have a corresponding outer circumference of from about 1300mm to about 1850mm, about 1350mm to about 1800mm, about 1400 to about 1750mm, about 1450mm to about 1700mm, about 1500mm to about 1650mm, about 1550mm to about 1600mm, about 1414mm to about 1728mm, about 1473mm to about 1684mm, about 1473mm to about 1683mm, about 1611 mm to about 1628mm or about 1620mm to about 1624mm. For example, the seal may have an outer circumference of about 1300mm, about 1350mm, about 1400, about 1414mm, about 1450mm, about 1473mm, about 1500mm, about 1600mm, about 1611mm, about 1620mm, about 1624mm, about 1628mm, about 1650mm, about 1683mm, about 1684mm, about 1700mm, about 1728mm, about 1750mm, about 1800mm, or about 1850mm. A textile material may be present on the surface of the polymeric composition. The textile material may be as described above. The textile material may form a continuous or partial surface on the polymeric composition.

The seal may improve the efficiency of the machine, such as a tumble drier. The efficiencies may involve preventing moisture loss from the machine. For example, at least 90%, at least 92% or at least 94% of the moisture may be retained in the machine. The moisture loss may be determined by any suitable method. Suitable methods include those that are set out by industry standards, such as BS EN 61121 - 2021 .

A tumble dryer may comprise the seal of the present invention.

Preferred embodiments of the invention will now be described in greater detail, by way of example only, with reference to the accompanying figures, in which:

Figures 1A-1C depict a conventional annular seal (1A), having open-cell faces (1 B) and a stitched join (1C)

Figure 2 depicts perspective, front and rear views of an annular seal according to the present invention, and produced according to a method of the present invention

Figure 3A-B depicts a mould (3A) and corresponding lid or top portion (3B) as used in a method of the present invention

Figure 4 depicts a closed mould as used in a method of the present invention

Figure 5 depicts a side profile of a part of an annular seal according to the present invention

Figure 6 depicts a part of a tumble dryer housing, including a groove where a seal according to the present invention may be mounted

Figure 6A depicts a close up of a portion of the groove of Figure 6 comprising a conventional seal mounted therein Figure 7 depicts an annular seal according to the present invention identifying aspects of its geometry

Referring first to Figure 2, there is shown an annular seal 1 according to an embodiment of the invention.

The seal 1 may be formed by any process and comprise any polymeric composition to provide a continuous annular seal. Alternatively, such a seal may be made by a method according to the invention, wherein to produce the annular seal, a polymeric composition comprising polyurethane and/or the constituent monomers and/or co-block polymers thereof, is injected into an annular void 5 in the mould 4, as shown in Figure 3. Optionally, a top portion 6 of the mould 4 may then be fitted and clamped in place using clamps 7, as shown in Figure 4. Alternative sealing or clamping means can also be used as appropriate. The mould may optionally then be rotated during a curing period to provide a uniform annular seal. Once cured, the seal is demoulded to provide an annular seal. Alternative closed or unclosed moulds may also be used.

Optionally, the method may involve filling a plurality of moulds with the polymeric material and sealing, spinning, curing and demoulding the seals iteratively to provide a mechanism for producing a succession of seals over an extended period of time. Thus, it may be possible to produce the seals by a time-efficient method.

By utilising a closed mould system, a controlled atmosphere may be provided for curing, and loss of the polymeric material during the injecting and curing process may be avoided.

In addition, where an expandable polymeric composition is used, closed mould 4 may ensure that the expansion of the polymeric foam is controlled to maintain a desired shape and size of the resultant seal. The closed mould may also enable a particularly desired foam density to be consistently achieved by limiting the space available for foam expansion. In particular, the closed mould may restrict the expansion of the foam and create a suitable internal pressure within the mould cavity. Thus, a closed mould may enable a higher density to be achieved than the conventional free rise density for the foaming composition used, wherein the free rise density is determined by allowing a set quantity of material to expand unrestricted therefore achieving the lightest possible structure.

While any suitable foam density may be provided or achieved, preferably, the resultant foam, such as a polyurethane foam, may have a density from about 100 kg/m ³ to about 250 kg/m ³ or greater. For example, the densities may be from about 140 kg/m ³ to about 200 kg/m ³ or from about 160 kg/m ³ to about 180 kg/m ³ . A suitable density may be about 170 kg/m ³ . Such densities may provide an annular seal which has sufficient rigidity to allow for handling the seal to demould it and to mount it in a tumble dryer, while also having sufficient flexibility to ensure that a good fit may be achieved.

While any suitable polymeric material may be used, polyurethane based materials may be particularly preferred. The polymeric material may therefore comprise a mixture comprising a polyol and an isocyanate. These species may be mixed prior to being injected into the mould or the mixing may occur during their introduction to the mould or within it. The polymeric material may have a coefficient of friction that means that it remains stationary during use, and that it does not rotate with the tumbler. This is particularly advantageous because it is not necessary to use other adhesive means, such as tape or glue, to secure the seal in place.

For example, the two components may be dispensed from separate storage tanks into a small mixing or holding chamber and fed from there into the mould. Since the reaction will start as soon as the two species come into contact preferably the species should spend less than about a minute, such as about 30 seconds or less in the mixing chamber before entering the mould. Once in the mould, the mould may be spun to endure good mixing of the species occurs. Alternatively, the species may be mixed in the mixing chamber and then loaded into the mould prior to polymerisation being completed.

A polyol shall be understood to be an organic compound comprising multiple, i.e. two or more, hydroxyl groups. Any suitable polyol may be used. Polyols may be monomeric or polymeric. The polyols may potentially include additional functional groups, other than just hydroxyl groups. Alternatively, the polyols may not include any functional groups other than hydroxyl groups. Suitable polyols include but are not limited to polyether polyols, polyester polyols polycarbonate polyols, polycaprolactone polyols, polybutadiene polyols, polysulfide polyols, and grafted polyols. Polyether polyols may be less susceptible to hydrolysis than some ester-based polyols and thus may be preferred.

In some embodiments, the polyol may be selected from the group including but not limited to poly(tetramethylene etherjglycol, dipropylene glycol, glycerine, sorbitol and Specflex polyols. For example, the polyol may be Specflex NF386.

An isocyanate shall be understood to be an organic compound comprise a functional group having the formula R-N=C=O, wherein the R group may be an organic based group. Any suitable isocyanate may be used. This includes the use of poly-isocyanates and monoisocyanates, aliphatic isocyanates and aromatic isocyanates. Suitable isocyanates include but are not limited to methylene diphenyl diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and Specflex isocyanates. For example, the isocyanate may be methylene diphenyl diisocyanate or Specflex NE135. Where the polymeric composition comprises a polyol and an isocyanate or comprises a polyurethane formed from a polyol and an isocyanate, the ratio of polyol to isocyanate used may be from about 100:50 to about 100:70. Such a ratio may enable a polyurethane foam having a suitable foam density to be achieved.

While the mould 4 provides a circular annular void 5 to provide a circular annular seal, other geometries are also envisioned. This includes non-uniform and/or almost circular rings, ovals and angular seals such as polygons having 8 or more sides.

As shown in Figure 5, the profile of the polymeric material may optionally be moulded to aid in retaining the seal in a desired position when mounted in a tumble dryer. This may include the provision of one or more protrusions, lips, rims, grooves, indentations 8 or the like.

Moulds may be provided in a variety of sizes and/or geometries, and may optionally be tailored to produce sales of specific geometries for particular machines. Since the method provides for annular seals to be produced having any desired shape and size, there may be no need to cut any portion of the polymeric material of the annular seals. As a result, the interior of the polymeric material may not become exposed during the production and/or installation of the annular seal for use in a tumble dryer.

In use, the seal may be fitted to a part of a tumble dryer housing 9, as shown in Figure 6 to prevent moist fluids such as water and/or steam from exiting the drum at undesired locations. The seal may be maintained in an appropriate position by the provision of a groove or channel 10 in the housing, as shown in Figure 6A, which depicts a conventional seal 11 located in groove 10. Seals of the present invention may be correspondingly mounted into such housing grooves. To prevent undesired movement of the seal, such as the dislodgment of the seal from the housing, the channel may provide only a minimal tolerance for geometry variance. The provision of a method in which a mould is used may therefore ensure that each seal produced has a desired thickness, width and diameter.

In addition, where the polymeric material contacts an interior surface of the mould, a smooth skin may be formed as shown in Figure 5.

As shown in Figures 1A-C, annular seals 11 known in the art are formed of a foam-based polymeric material, such as polyurethane foam. The foam is conventionally formed in large blocks which are then cut into long foam strips 12. A textile layer, such as a felt layer 13 is adhered to the strips of foam and, optionally, a layer of adhesive tape 14 is applied to the opposing face. Lengths of the composite strips 15 are then cut according to a desired diameter and bent to form a ring. The felt is then stitched to join the ends of the strips together to form an annular seal comprising a join 16. Once formed into a ring and stitched, the annular seal is then twisted by 90 degrees such that the foam and textile layers form flat rings having the same diameter, akin to the orientation shown in Figure 2 depicting an alternative seal of the present invention. Once twisted, the seal is conventionally mounted in a groove or channel 10 in the housing, as depicted in Figure 6. To retain the seal in the correct position in this groove 10, and to prevent spinning of the seal during tumbler rotation, an adhesive may be used.

Unlike the moulded seal of the present invention as depicted in Figure 2, the exterior foam surfaces of the conventional annular seal are not smooth. Instead, as shown in Figure 1 B, the open-cell network of the foam structure forms the exterior surface of the seal, and provides a pathway for moisture to traverse the seal.

The provision of a skin may therefore provide a barrier over the interior open-cell network of the polyurethane. This may enable the seal to provide a more effective moisture barrier by blocking access to the open-cell structure of the polyurethane which may otherwise a network through which moisture may travel to traverse the seal.

In addition, the annular seal may provide a smooth exterior surface to the seal. This may aid in preventing fragmentation of the polymeric material during use.

As shown in Figure 2, unlike the conventional seals of Figures 1A-1C, the method of the present invention may yield a continuous annular seal 1 , such that there is no need to perform a separate step of stitching, gluing or the like to adhere parts of the seal together to form a loop. This may avoid producing a region of weakness 16 in the vicinity of the glue and/or stitching and avoids the need to perforate a portion of the seal during its formation which may provide a flow path for moisture to traverse the seal. In addition, the seal may be formed in the desired orientation avoid the need to twist the seal after the textile layer has been adhered and stitched.

According to some embodiments, the method of the present invention may be used to produce an annular seal 1 having a polymeric material layer 2 and textile material 3.

As shown in Figure 2, the textile material 3 may take the form of a layer having the same shape and diameter as the polymeric material. Alternatively, it may be envisaged that the textile layer has a different geometry to the polymeric material. For example, the textile layer could have a reduced width compared to the polymeric material and thereby cover over a portion of the polymeric material. Alternatively, the textile material may extend beyond the width of the polymeric material.

Seals of the present invention, including seals formed by a method of the present invention, may therefore comprise two flat faces, one of which is formed of a polymeric material and the other of which is provided by a textile layer. In use, the seal 1 may be mounted in a groove or channel 10 in the housing of a tumble dryer, as shown in Figure 6. Preferably, the textile layer 3 may be configured to be positioned against the drum of the tumble dryer, while the polymeric material may be configured to be positioned against the housing.

Optionally, the seal of the present invention may be maintained in position absent the provision of an adhesive. Specifically, it has been found that the increased surface contact area of the polyurethane skin compared to the open cell polyurethane foam of conventional seals yields a substantially increased surface friction. As a result, the seal may be mounted on a housing component adjacent a tumbler component and maintained in a desirable position without being rotated by the actions of a spinning tumbler in the absence of an adhesive layer affixing the seal to the housing or tumbler.

In various embodiments, the textile layer 3 is adhered to a surface of the polymeric composition 2. This may be achieved by the use of a glue, tape or the like which may be applied to an entire interface between the textile layer and the polymeric material, or to a portion thereof.

In the embodiments shown in Figure 2, no additional adhesive layer is used. Instead, the textile layer is positioned in the mould prior to the polyurethane composition being injected into the annular mould. The polymeric composition may then be injected into the mould 4, such that it contacts at least a portion of the textile layer. The polymeric composition may then cure while in contact with the textile layer such that, when demoulded, the seal provides an annular seal comprising a polymeric composition adhered to the textile layer. Preferably, where the polymeric material contacts the textile material, the polymeric material saturates at least a portion of the textile. Thus, the annular seal may be integrally formed with the textile layer.

This may avoid the need for the provision of any extraneous glue or adhesive to adhere the textile layer to the polymeric material. As a result, the bond between the polymeric and textile materials may be stronger. In addition, since the textile may be suitably cut, shaped and positioned prior to integrally forming and curing the polymeric foam, there may be no need to subsequently bend the textile material to form a loop. Thus, the textile layer may not suffer from wrinkles and/or puckering. This may reduce levels of excess wear during use. In addition, the provision of an unwrinkled textile surface may enable a good contact to be maintained between the textile layer and any adjacent components of the tumble dryer during use, such as the drum. This may reduce the amount of undesired moisture loss from the drum during use.

Where a textile material is added to the mould prior to injecting the polymeric material, a surface of the textile layer may contact a surface of the annular mould during at least a portion of the moulding process. This contact may prevent the polymeric material from completely engulfing the textile layer and provide an annular seal after curing wherein the textile layer is present on an external face of the seal as shown in Figure 2.

While any suitable textile material may be used. In some embodiments the textile layer comprises polyester. Alternatively or in addition, the textile layer may comprise a felt. For example, the textile layer may comprise a polyester felt. Polyester felt may be resistant to crumbling and/or disintegration in moist environments.

In addition, the matted structure of the felt may be particularly suitable for being singed. Singed felt forms a more rigid surface which may enable more robust bonding between the polymeric material and the textile.

According to some embodiments the textile layer, or felt, may be singed on at least a portion of at least one surface. For example, the textile layer or felt may be singed across the entirety of one surface. Preferably this surface may be the textile or felt surface which is configured to contact the polymeric material when an annular seal is formed according to a method of the invention.

In addition to providing an improved surface for bonding to the polymeric material, the singed surface may reduce or limit the depth to which the polymeric material may infiltrate the textile layer to ensure that the exterior portion of the textile, i.e. the portion contacting the interior surface of the mould during production, remains free or largely-free from the polymeric material. Accordingly, in some embodiments a portion or the entirety of a surface of the textile layer positioned away from an interior wall of the annular mould may be singed prior to placing the textile material 3 in the mould 4, while optionally, a portion or the entirety of the surface of the textile layer positioned towards an interior wall of the annular mould may be unsinged.

Thus, according to a method of the invention, a singed textile layer, such as a felt layer, may be positioned in an annular mould with the unsinged portion adjacent to a mould surface and an singed portion adjacent a portion of the mould void. A polymeric composition may then be injected into the mould void wherein it contacts the singed surface and saturates one or crevasses and/or voids present in the singed surface to at least partially infiltrate the fibres and/or surface of the textile. After curing, the infiltrated polymer may be intimately adhered to the fibres of the textile layer. This may prevent the textile layer from becoming separated from the polymeric material during use and may also aid in ensuring that the textile layer remains flat and free of wrinkles and/or puckering. However, as shown in Figure 2, the polymeric material does not saturate the full thickness of the textile layer. As shown in Figure 5, the textile layer 3 may be thinner that the polymeric material 2. For example, the polymeric material may account for around 50-95% of the thickness, T, of the seal, around 55-90%, around 60-85% around 65-90%, around 70-90%, or around 75-90%, more specifically about 74-90 % of the total thickness. For example, the textile may be about 2.2mm thick while the seal may have a total thickness falling within one of the ranges or values disclosed above. This may provide an appropriate level of seal rigidity while maintaining the ability of the seal to conform with drum surface to maintain a good seal. However, alternative ratios may also be envisaged.

The rigidity and density of the textile layer should be suitable to enable the textile material to conform to the neighbouring tumble dryer services, such as the drum surface, to form a tight seal.

The textile layer may be of any suitable thickness to ensure a good contact between the drum and the seal. For example, the textile layer, which may optionally be a felt layer, may be between about 1 mm and about 5 mm thick. For instance, the textile layer may be between about 1.5 and about 3 mm thick. Optionally the textile layer may be about 2.2 mm thick. In addition or alternatively, the textile layer may have a density of about 500-800 g/m ² . For example, the textile layer, such as a felt layer may have a density of about 640-680 g/m ² . One particularly suitable density for the textile layer, such as a felt layer, may be about 660 g/m ² .

The method may be carried out at any suitable temperature. Suitable temperatures are likely to be dependent on the polymeric material used. However, in general, temperatures from about 15°C to about 30°C, such as temperatures of about 25°C to about 30°C, or about 25°C may be suitable. These temperatures may be particularly suitable for polyurethane-based polymeric compositions. Such temperatures may be desirable since they may avoid the need for excessive heating.

In some embodiments, once the polymeric material has been injected into the mould, the seal may be left to cure for a period of about 5 to about 15 minutes prior to demoulding the seal, such as for a period from about 6 to about 10 minutes. Alternatively, the seal may be left for a longer period before demoulding. A curing time of about 6 minutes or about 6 to about 10 minutes may provide a high throughput method for manufacturing the annular seals while ensuring that the seals are not demoulded at a stage where curing is incomplete to the extent that the skin is of insufficient strength and/or thickness to maintain the integrity of the annual seal once demoulded, where the seals may be undesirably deformed.

Methods of the present invention may be used to provide seals of any suitable geometry. As such, methods of the invention may be used to forms seal which are correctly sized for specific models of tumble dryer. Since the geometry of the annular seal may be dictated by the geometry of the mould used, the method may provide for the manufacture of annular seals having an accurate and consistent geometry. Such seals may be particularly suitable for achieving a high moisture barrier efficiency by accurately fitting a mounting point on a tumble dryer, such as a mounting grove as shown in Figures 6 and 6A.

In addition, the provision of a seal comprising uncut polyurethane foam having an exposed skin, may enable the seal to be mounted between a housing and tumbler element in the absence of an adhesive layer affixing the seal to the housing or tumbler, and to be maintained in position or stationary during a drying cycle by friction.

As such, seals of the present invention may be produced and/or otherwise provided having a thickness, T, from about 8.5mm to about 22.5mm, as depicted in Figure 5. Such thicknesses may be suitable for use in conventional tumble dryers to provide an effective moisture seal.

As shown in Figure 7, where a seal is provided and/or a disclosed method is used to provide annular seals having a circular or approximately circular geometry, the annular seals may have an outer diameter, D, from about 469mm to about 536mm, wherein this diameter is the external diameter of the annulus. Additionally or alternatively, the annular seals may have an inner diameter, d, from about may be from about 450mm to about 550mm, about 460mm to about 540mm, about 469mm to about 536mm, about 450mm to about 530mm, about 460mm to about 520mm, about 470mm to about 510mm, about 480mm to about 500mm, about 479mm to about 526mm, about 489mm to about 516mm, about 499mm to about 506mm, about 496mm to about 509mm, about 486mm to about 519mm, about 476 mm to about 529mm, about 513mm to about 518mm, or about 516 mm to about 517mm. In another arrangement the inner diameter may be about 450mm, about 460mm, about 469mm, about, about 470mm, about 476 mm, about 479mm, about 480mm, about 486mm, about 489mm, about 490mm, about 496mm, about 500mm, about 506mm, about 509mm, about 510mm, about 513mm, about 516mm, about 517mm, about 518mm, about 519mm, about 520mm, about 526mm, about 529mm, about 530mm, about 536mm, about 540mm, or about 550mm. Such seals may have a corresponding outer circumference of from about 1300mm to about 1850mm, about 1350mm to about 1800mm, about 1400 to about 1750mm, about 1450mm to about 1700mm, about 1500mm to about 1650mm, about 1550mm to about 1600mm, about 1414mm to about 1728mm, about 1473mm to about 1684mm, about 1473mm to about 1683mm, about 1611mm to about 1628mm or about 1620mm to about 1624mm. For example, the seal may have an outer circumference of about 1300mm, about 1350mm, about 1400, about 1414mm, about 1450mm, about 1473mm, about 1500mm, about 1600mm, about 1611mm, about 1620mm, about 1624mm, about 1628mm, about 1650mm, about 1683mm, about 1684mm, about 1700mm, about 1728mm, about 1750mm, about 1800mm, or about 1850mm. This may provide seals having widths, W, of about 13mm to about 21mm, or about 15mm to about 16mm. For example, the seal may have a width of about 13mm, about 15mm, about 16mm or about 21 mm, such as about 12.7mm, 14.7mm, 15.7mm or about 20.5mm. Such geometries may be suitable for use in conventional tumble dryers to provide an effective moisture seal.

Seals according to the present invention may be at least 5%, 10%, 20%, 50% or more than 50% more efficient in preventing a moisture loss than comparable seals in which the polymeric material has exposed open-cell surfaces. Seals according to the present invention may additionally and/or alternatively have a reduced energy consumption and/or cycle time.

In particular, seals according to the present invention and/or produced according to a method of the present invention may be capable of providing seals having an efficiency rating of at least 90%, at least 92% or at least 94% for preventing moisture loss based on industry standards. For example, according to BS EN 61121-2021 or equivalents, such as BS EN 61121-2013.

While the method of producing annular seals according to the present invention, and seals according to the present invention have been described as suitable to prevent undesired moisture loss from tumble dryers during use, it is also envisaged that such seals may be used in alternative systems or devices where there is a need to produce a moisture proof seal.

It will be appreciated that any of the optional features of any of the embodiments described herein could also be provided with one or more of any of the other embodiments described herein.

As used herein any reference to “one embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” or the phrase “in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

In addition, use of the “a” or “an” are employed to describe elements and components of the invention. This is done merely for convenience and to give a general sense of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

The use of the term “about” in relation to a numerical value shall be understood as encompassing any value which would round to the stated numerical value when rounded to the last significant figure.

In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention. For example, although an embodiment has been described with reference to a particular polymeric material and/or textile, alternative species may be used.

The scope of the present disclosure includes any novel feature or combination of features disclosed therein either explicitly or implicitly or any generalisation thereof irrespective of whether or not it relates to the claimed invention or mitigate against any or all of the problems addressed by the present invention. The applicant hereby gives notice that new claims may be formulated to such features during prosecution of this application or of any such further application derived therefrom. In particular, with reference to the appended claims, features from dependent claims may be combined with those of the independent claims and features from respective independent claims may be combined in any appropriate manner and not merely in specific combinations enumerated in the claims.

Definitions

The term polyol will be understood to be an organic compound comprising multiple, i.e. two or more, hydroxyl groups, while an isocyanate shall be understood to be an organic compound comprise a functional group having the formula R-N=C=O, wherein the R group may be an organic based group.

The diameter of the seal refers to the external diameter of the annulus.

The thickness of the seal refers to the thickest portion of the seal cross-section.

Examples Two exemplary seals were tested under the same conditions on a tumble dryer having an 8kg load which was either fully loaded or loaded as A or B half loads according to the standard testing procedures set out in BS EN 61121-2013, which is incorporated herein in its entirety. The first seal comprised a standard known seal formed of cut flexible polyethylene foam having an open cell structure, with an adhered textile layer, the second seal comprised a seal according to the present invention comprising moulded polyethylene foam having a skin formed on the external faces. A corresponding textile layer was similarly adhered after production of the initial moulded seal was produced in order to provide a direct comparison of cut or open face polyethylene foam-based seals and moulded polyethylene seals comprising a skin.

Both seals were mounted in a consistent manner on a tumble dryer. The drums were then spun according to repeated standard drying cycles for full and half loads. The testing program included 2 Type A loads at 4kg, 2 Type B loads at 4kg and 3 full loads which equate to A+B, totalling 8kg and providing 7 drying cycles in total. Average final moisture contents, condensation efficiencies and power usages were then calculated according to the standards set out in BS EN 61121 , and are summarised in Table 1 .

Table 1

Wherein:

Load is the whole load according to the standards set out in BS EN 61121 for a cotton dry program;

Edry is the average energy consumption for treatment full in kWh;

Edry1/2 is the average energy consumption for treatment half in kWh; Tdry is the average programme time for treatment full in min;

Tdry1/2 is the average programme time for treatment half in min;

Cond. Eff. is the average condensation efficiency, wherein:

The average condensation efficiency C is calculated from the condensation efficiencies of all valid test runs expressed as a percentage:

Where n is the number of test runs; j is the test run number;

Cj is the condensation efficiency of test run j.

Where 100

Where:

W _W j is the mass of water collected in the condenser reservoir during test run j.

Wi is the mass of the test load after wetting but before drying;

Wf is the mass of the test load after drying.

From the above it is shown that, when used in comparable circumstances, the provision of a moulded seal comprising a skin over its exposed faces was found to have a 5% higher condensation efficiency than a corresponding seal formed in the conventional manner formed of cut flexible polyurethane foam having an exposed open cell network. In addition, seals of the present invention were found to have lower energy consumptions and yield dryer loads. Aspects of the Invention

1 . A method for producing an annular seal, wherein the method comprises: injecting a polymeric composition comprising polyurethane and/or the constituent monomers and/or co-block polymers thereof into an annular mould, curing the polymeric composition, and demoulding the seal to provide an annular seal.

2. The method of any one of aspect 1 , wherein the seal is a continuous annular seal.

3. The method of any preceding aspect, wherein the annular mould is a closed mould.

4. The method of any preceding aspect, wherein the polymeric composition comprises a mixture comprising a polyol and an isocyanate.

5. The method of aspect 5, wherein ratio of polyol to isocyanate is from about 100:50 to about 100:70, or wherein the polyurethane is formed from a polyol and an isocyanate in a ratio from about 100:50 to about 100:70.

6. The method of aspect 5, further comprising the step of adhering at least a portion of a textile layer to a surface of the polymeric composition, optionally wherein the textile layer is adhered to a surface of the polymeric composition.

7. The method of aspect 6, wherein: the textile layer is positioned in the annular mould prior to injecting the polymeric composition; the polymeric composition is injected into the annular mould; wherein demoulding the seal provides an annular seal comprising a polymeric composition adhered to the textile layer.

8. The method of aspect 7, wherein a surface of the textile layer is in contact with a surface of the annular mould.

9. The method of any one of aspects 7 or 8, wherein the textile layer comprises polyester.

10. The method of any one of aspects 7-9, wherein the textile layer comprises felt, optionally a polyester felt.

11 . The method of any one of aspects 7-10, wherein a surface of the textile layer is singed, preferably optionally wherein the singed surface is positioned away from an interior wall of annular mould.

12. The method of any one of aspects 7-11 , wherein a portion of the polymeric composition saturates at least a portion of the textile layer.

13. The method of any one of aspects 7-12, wherein the textile layer is between about 1 mm and about 5 mm thick, optionally wherein the textile layer is between about 1.5 and about 3 mm thick, and further optionally wherein the textile layer is about 2.2 mm thick. The method of any one of aspects 7-13, wherein the textile layer has a density of 500-800 g/m ² , preferably wherein the felt has a density of about 640-680 g/m ² and particularly preferably wherein the felt has a density of about 660 g/m ² . The method of any preceding aspect, wherein the method is carried out at a temperature from about 15°C to about 30°C, preferably at a temperature of about 25°C to about 30°C. The method of any preceding aspect wherein the seal is demoulded about 5 to about 15 minutes after injection moulding, preferably about 6 to about 10 minutes after injection moulding. An annular seal produced by a method according to any one of aspects 1-16. An annular seal comprising a polymeric composition, wherein the polymeric composition forms a continuous annular seal. The annular seal of aspect 18, wherein the polymeric composition further comprises a skin, optionally wherein the skin covers all surfaces. The annular seal of any one of aspects 18 and 19, wherein the seal further comprises a textile material. The annular seal of aspect 20, wherein the textile material is present on the surface of the polymeric material, optionally wherein the textile material forms a continuous structure. The annular seal of any one of aspects 20 and 21 , wherein the textile material adheres to the polymeric material by use of an adhesive layer, optionally wherein the adhesive layer is the polymeric layer or a separate adhesive layer, such as glue or tape. The annular seal of any one of aspects 18-22, wherein the textile layer is between about 1 mm and about 5 mm thick, preferably wherein the textile layer is between about 1 .5 and about 3 mm thick and particularly preferably wherein the textile layer is about 2.2 mm thick. The annular seal of any one of aspects 18-23, wherein the textile material comprises polyester. The annular seal of any one of aspects 18-24, wherein the textile material comprises felt, optionally a polyester felt. The annular seal of any one of aspects 18-25, wherein the textile material has an interior surface adjacent to at least a portion of the polymeric material, and at least a portion of the interior surface is singed, optionally wherein a substantial portion of the interior surface is singed. The annular seal of any one of aspects 18-26, wherein the textile material has a density of about 500 to about 800 g/m ² , preferably wherein the felt has a density of about 640 to about 680 g/m ² and particularly preferably wherein the felt has a density of about 660 g/m ² . The annular seal or method of any preceding aspect, wherein the seal has a thickness from about 8.5mm to about 22.5mm, preferably wherein the thickness is about 8.7mm to about 16.7mm, 10.7mm to about 14.7mm or about 11.7mm to about 13.7mm. The annular seal or method of any preceding aspect, wherein the annular seal has a diameter, D, from about 468mm to about 536mm, preferably wherein the diameter is about 513mm to about 518mm or about 516 mm to about 517mm. The annular seal or method of any preceding aspect, wherein the seal has an efficiency rating of at least 90% for preventing moisture loss, optionally wherein the moisture loss is measured by industry standards, such as BS EN 61121 - 2021. A tumble dryer comprising an annular seal according to any one of aspects 17-30.