WO2015101632A1 - A 3-dimensional knitted textile spacer fabric and use thereof in a system for health care - Google Patents

Abstract

A 3-dimensional spacer fabric that is in particular suited for being used as a decubitus mattress or cushion comprises a knitted top layer, a knitted bottom layer and a spacer structure located there between and holding the two layers at a distance from each other, said spacer structure comprising upright pile yarns extending there between. At least the top layer comprises a multifilament yarn and an elastic yarn. The top layer and/or the bottom layer is formed with band-shaped areas that are devoid of pile yarns extending therefrom through the spacer structure. The elasticity of the top layer is different from the elasticity of the bottom layer.

Description

A 3-DIMENSIONAL KNITTED TEXTILE SPACER FABRIC AND USE THEREOF IN A SYSTEM FOR HEALTH CARE

Background of the invention: Foam mattresses and seat cushions should improve in general the comfort of persons resting on them. However, people typically move and shift positions to try to maintain sufficient or even full arteriole, venule and capillary blood flow to high contact pressure body areas. This may however cause problems for more immobile persons, especially in foam mattress manufactured with visco-elastic foam. Moreover, restricted arteriole, venule and capillary flow can also cause discomfort also for healthy persons, as well as high friction and shear forces on the skin and underlying tissues. Elderly and patients with compromised health may have even bigger problems. Often they cannot move sufficiently to prevent the formation of decubitus ulcers, a form of tissue necrosis resulting from lack of nourishing blood flow and tissue degeneration. Consequently, decubitus ulcers or bedsores are a common problem in hospitals and nursing homes. These ulcers or sores are basically caused by three different forces on tissues: pressure forces, shear forces, and friction forces. Aggravating the situation can be other conditions such as excess moisture from incontinence, perspiration or exudates which influence the friction forces between skin and textile etc. Moisture related bedsores are caused by continuous wet skin and often higher temperatures. This may be more severe when high pressures, shear forces and friction occur on and underneath the skin. A dry skin or quickly drying skin and controlled perspiration and temperature is therefore preferred for lesser mobile persons.in lying and sitting positions.

People who are becoming less mobile or immobile due to ageing, health problems, chronic disease and handicaps, lie most of the day on their beds. The mattresses used for these people are in most cases foam (cold- or memory foam) mattresses, static and alternating air mattresses. The raise of pressures and hardening of especially memory or visco-elastic foams after long lying periods, the limited surface enlargement not following the body pressure and contour completely, the very poor microclimate of these foams, the Poly Urethane (PUR) coverings and the top surfaces or coverings being not adapted to easy transfer, are the main limitations of these care solutions nowadays. They result in high pressures, shear and friction forces, a wet skin and high temperatures, which lead in most case to skin damages and tissue destruction (pressure ulcers and moisture wounds).

PRIOR ART:

It is known from many publications that 3-dimensional Raschel knitting structures could have an effect on improving the comfort for persons lying thereon, such as structures described in DE 102009014265A1 , WO 96/01602 and in JP 2002010881.

A overall disadvantage of these patents is that no elastomeric yarns have been used to enhance the 3 axial elasticity that is important to reduce the effects of uneven pressure distribution by following the body contour in combination with the absorption of shear forces acting on a user. It is known, e.g. from the below described patent publications, that elastomeric yarns can regulate the elongation and compression of spacer fabrics.

US 006116059A, relates to a three-dimensional knit or woven fabric for footwear and backpacks, and more particularly, to a three-dimensional knit or woven fabric having first and second fabric layers spaced from and connected to each other. A monofilament or multifilament pile yarn is interconnecting the two layers. Elastomeric yarn is used as or combined with a lay- in yarn, i.a. to enhance the tightness of fit. Stitch yarn and lay-in yarn that may either be multi- or monofilament, with a high tenacity value are used in order to increase toughness. This structure is not adapted to meet vital requirements for bedridden people lying on it. JP2003/015345 (US2006060257A1 and EP 1568808A1) describes a three-dimensional woven fabric and method for production thereof, wherein a bonding layer corrugated in a wavelike shape is arranged between the top and the bottom layer of the fabric. This fabric is not suited for an application for bedsore care. DE 102008020287B3 discloses warp knit spacer fabrics comprising two layers arranged in a distance from each other and spacer yarns connecting the two layers to each other. Observed in plain view from above on the layers, the spacer yarns are arranged in a pattern having island-like areas where the two layers are connected to each other, such that there are two groups of pile-yarn-free channels located between the layers in a crosswise arrangement. These fabrics are used as upholstery materials for car seats where a high degree of air permeability is desired. Both layers usually are knitted with wales in a zigzag form resulting in an open surface structure with holes for letting air pass there through. The layers are knitted from mono- or multifilament yarns; no elastic yarns are mentioned. Fabrics of this construction would not sufficiently follow the body contour, e.g. of a bedridden person lying thereon, to avoid discomfort of this person due to shear and friction forces acting on the skin.

It is therefore an object of the invention to provide a 3-dimensional knitted spacer fabric that can really follow the contour of a person sitting or lying thereon and is therefore suited to be used for health care purposes, and in particular for decubitus preventing articles. To achieve this object the 3-dimensional knitted fabric of the invention comprises the features of claim 1.

Summary of the invention

The present invention concerns a 3-dimensional knitted spacer fabric support structure which has via the use of specific yarns and knitting structures unique properties to enhance the comfort of the user, to preserve the tissue and skin composition and to reduce the physical load of the patient and caregiver. These properties, which can be described as a pressure diminishing and distribution capacity of the 3-dimensional warp knitting structure, a low friction surface as well as ventilation capacity are resulting in a lower incidence and prevalence of skin and tissue wounds due to lower and more even distributed pressures and lower friction and shear forces than with present cold and memory foam mattresses and covers thereof. This will lead to lower care costs due to less wound care and easier and faster care and a higher quality of life. In order to further enhance the caregiving handling, an innovative permanent stay and transfer knitted sheet as described in another patent of the inventors may be used in combination with the 3- dimensional knitting structure as described in this patent application.

Specifically the top layer of the 3-dimensional warp knitted fabric of this invention has in one embodiment of the invention an uninterrupted continuous structure of later to be defined soft, voluminous and/or smooth low friction synthetic yarns, by which specific properties can be functionalized such as a high softness enabling direct skin contact, or a smooth surface with low friction also for direct skin contact and for slide transfers and easy bed movements, a high elasticity and elongation capability in three axial directions to properly follow body contours and raising and enlarging of the pressure contact surface for even distribution of pressures and forces, temperature and moisture regulation and bio-active properties. Through this the system enables a safe and comfortable skin contact, lowers and evenly distributes pressures, limits friction forces and compensates tear forces, facilitates easy transfers and gives a high overall comfort feeling and experience. The upper or top knitted structure is connected via

monofilament and or multifilament yarn, so called pile yarns, preferable in a so called x-shape to a similar or different bottom knitted structure creating by this a pressure distributing compensation structure, in a continuous, repetitive pattern of continuous bands, or semi continuous, rectangular, square shaped patterns, surrounded by open channels without monofilament yarns in the width and length direction, created by omitting or temporarily knitting of the monofilament yarns in the horizontal top and /or bottom layer, before returning back to the opposite layer.

This 3-dimensional warp knitted structure is preferably to be used on present foam and air mattress systems, such as memory foam mattresses, cold foam mattresses, combined memory and cold foam mattresses, static and alternating air mattresses, improving in a significant way the functional properties of these supporting mattresses with regard to aspects such as pressure compensation and even pressure distribution, high skin comfort and relief, ventilation and micro climate control. These foam mattresses are covered nowadays with PUR coated (non) woven fabrics which have a low or no ventilation, no sweat and body fluid transpiration absorption capacity, and a very limited elasticity that makes them unable to follow the contour of the body of a person lying thereon, due to weight effects resulting in the so called hammock effect on the body. Preferably, examples of embodiments of the product of the invention can be classified as "Raschel/Tricot Structure" or 3-dimensional warp knitted structure.

Moreover, the system for complete bed care combines the use of a 3-dimensional warp knitted fabric and elastic knitted stay and transfer textile top layer as a complete

bedsore/decubitus preventing mattress system and that by its 3-dimensional supporting structure does not have a negative impact on the pressure compensation and distribution functionality of the layer of memory foam or other foam mattresses underneath, but moreover has an additional positive pressure reducing and distributing effect and adds also additional functionalities to the pressure compensation and distribution functions (transfer, nursing and patient handling efficiency, micro climate control and ventilation). The invention can therefore be part of an integral system of the inventors to replace bed textiles such as sheets and transfer sheets, incontinence materials, coatings on these products and the like for patients with bedsore problems or indications therefore and to bring improved functionality and additional functionalities on top of foam mattresses (pressure relief and distribution, ventilation, micro climate control). The present invention thus concerns, apart from a 3-dimensional textile spacer fabric, a skin support system to improve the comfort of and preserve the skin and tissue condition and health of bedridden persons, wheel chair users, diabetics, patients lying on tables in operation rooms, and people with orthopaedic problems. The complete system has a soft and or smooth top surface suitable for direct skin contact. An embodiment of the system may to be used in combination with a special stay and transfer sheet acting as skin contact layer, which is described in another patent application of the same inventors, covering a 3-dimensional warp knitted mini mattress according to the present invention. The textile body support system will facilitate a more efficient and easier care in nursery homes and in homecare. This invention can thus preferably be combined with another invention of the inventors, describing an elastic knitted or circular knitted permanent stay and transfer sheet covering a large part or the complete 3-dimensional warp knitted structure of the present invention.

This stay and transfer sheet covering the 3-dimensional warp knitted spacer fabric is also a knitted fabric, more specific a flat or circular knitted fabric and has as top surface layer a knitted elastic and stretchable top structure with raised and recessed areas manufactured from preferably the same type of yarns with a high smoothness and low friction characteristics to enable easy movement on the bed and transfers in and out of the bed. The top layer of the stay and transfer sheet can be in one embodiment a 3-dimensional double knit jacquard fabric, which is used as a complete product which also has a smooth and low friction bottom surface, to enable easy gliding of the sheet on the 3-dimensional knitted spacer fabric mattress, to avoid undesired shear and friction forces. In another embodiment the stay and transfer sheet can be coated at the bottom side with a polyurethane or dendrimer based finish via a foam or spray process, which blocks liquid water, but allows passage of water vapours and gases. A possible further embodiment of the stay and transfer sheet uses an elastic membrane, which is laminated between the 3-dimensional double knit jacquard fabric and a bottom single knit fabric which has also a high smoothness and low friction characteristics. An additional embodiment comprises as a feature to be used between the stay and transfer sheet and the 3-dimensional warp knitted spacer fabric, the use of an elastic membrane that is dot coated to a single knit fabric which is very smooth in all directions and has low friction characteristics. The single knit top layer will allow the bottom plane of the stay and transfer sheet to glide in every direction and by that avoid shear and friction forces on her top layer that is in contact with the skin of the patient. The single knit top layer can, when necessary, be cleaned with special cleaning wipers.

An object achieved by the invention is therefore primarily to reduce pressures, friction and tear forces on the skin and tissues of bedridden, immobile and chronically ill persons, and to provide a more even distribution of pressures and shear forces on the skin and body tissues of these persons via a deformable, stretchable and elastic 3 dimensional, warp knitted structure, a so called 'Raschel fabric', which can partly or wholly be compressed via the bending of the monofilaments due to the pressure of the human body lying on it. This composition also can elongate itself easily in all horizontal directions and in vertical directions to follow the body contour and by this create a larger pressure surface contact area under the body of the person lying on this 3D-spacer fabric structure. This overall stretching capacity of the 3 dimensional knitting structure will lower pressures and will compensate shear forces. This combination of the possibility of enabling the bending of the individual monofilament yarns simultaneously with the elongation of the top and bottom surfaces of the knitting structure and thereof also the enlargement of the horizontal dimensions of monofilament yarn sections will ensure a more even distribution of pressures and prevent the occurrence of peak pressures and shear forces on areas of the body of the patient which are vulnerable for superficial skin damages of pressure damages to deeper lying tissues under the skin such as veins, arteries, nerves, muscles etc. (heel, hip, sacrum, shoulder, elbow areas).

The elongation of the top warp knitted surface structure should therefore be equal to or smaller than the elongation of the bottom knitted surface structure to ensure the 3-dimensional knitted spacer fabric to follow the body contour more easily in a bio-mimicking way, via the above mentioned significant increase of the contact surface area which will result in a lower pressure per square area of the knitted structure and will also lead to a reduction of shear forces on the skin.

Via a combination of specific monofilament PET yarns, multifilament PET yarns, and possibly multifilament PBT yarns and or PA yarns types, of which the multifilament yarns can either be of a texturized (soft) and or non-texturized type (smooth, low friction) , the application of a specific warp knitted fabric, warp knitting structures and the use of elastomeric yarns (such as Elastan) and elastic PBT yarns (such as Trevira X-Band), a 3-dimensional warp knitted spacer fabric mini mattress is created, which can, due to its micro structure (individual knitting loops of yarns) and macro structure, which is represented by the rectangular and square areas with monofilament yarns between top and bottom surface surrounded by open channels without monofilament yarns, reduce pressures and shear forces and can provide a more even pressure distribution. Reduction of pressures is realised through the combination of sufficient resilience strength and the ability of monofilament yarns to bend themselves partly or wholly and absorb forces or pressures simultaneously. Due to the elongation of the top and bottom structures the monofilament pile filaments or yarns will be further apart from each other in both horizontal directions and/or can change their angles relatively to the top and bottom surfaces to absorb pressures and shear forces. This further spacing apart and changing of angles of the

monofilament yarns can be influenced by fixation/steam treatment and the use of extra stiff monofilaments and/or PET shrink yarns.

Via the combination of repetitive rectangular and or square areas with monofilament and pile yarns between the top and bottom planes of the 3-dimensional warp knitted spacer fabric and through the partial absence of these monofilament yarns in small open lines or channels around these square and or rectangular areas, a partly open bottom and if necessary top structure can be created above these lines without monofilament yarns by omitting multifilament PET or PA yarns in a band shaped pattern on bottom and or top side of the fabric or in corresponding rectangular or square shapes following the contours of the monofilament pile yarns. Basically the 3-dimensional knitted spacer fabric has open channels in the width and or length direction, enabling a better pressure uptake and pressure and shear forces distribution, which can be enhanced by open bands without multifilament yarns above these channels. A comparable effect can be achieved via the replacement of these top and bottom layer multifilament yarns with thinner multifilament yarns and or elastic yarns in these top and bottom layer band sections. This results, in the described embodiments, in an ideal combination of pressure distribution capacity and elongation characteristics and will ensure a larger surface contact area for the patient via the individual stretching of top surface and bottom surface, which limits the shear and pressure forces on the skin and body tissue of the patient, when the patient is lying or sitting on top of it. The elongation capacity of this whole macro structure provides the capacity to distribute forces more evenly on a larger surface resulting in lower pressures per square areas by the biomimetic following of the body contour.

The open structure created the channels and bands in width and length direction will contribute largely to a secondary function of the 3-dimensional warp knitted spacer fabric mattress, namely ventilation of the skin of the user and maintaining of a proper microclimate. The use of elastomeric yarns (e.g. Elastan) with a specific decitex value of 76-250, in every knit ( "stitch") or every second or third knit ("stitch") on left and right side of that stitch course, will compress the smooth non-texturized or soft texturized PET-yarns upwardly , covering the monofilaments , creating a soft or smooth, low friction surface with raised areas of yarns (either smooth yarns in a slightly higher layer plane than the elastomeric and monofil yarns or raise of soft multifilament yarns resulting in a soft direct skin contact surface) and also will enhance the individual stretching and elongation capacity of the top and bottom surface. The smoothness of the top surface via the use of non-texturized yarns and or raised areas or bands of yarns is desirable to prevent an increase of shear and friction forces on the skin and tissues of the patient, when he or she is lying on a special transfer and stay sheet covering the 3- dimensional warp knitted mattress. The sheet should be able to slide easily during movement taking up and compensating friction and tear forces. Together with the previous mentioned rectangular and or square monofilament pile yarn sections between the top and bottom surface, an enlargement of pressure and shear force contact surfaces can be achieved, which will reduce the impact on the skin and tissues of the person lying on the 3-dimensional warp knitted spacer fabric as described in this patent.

Detailed description of the invention:

According to the inventors, there is a need for a decubitus preventing mini mattress with a high resilience strength, a 3-dimensional elastic, stretching and elongation capacity (via specific yarn selection and specific knitting patterns allowing the structures to elongate itself), a soft and/or smooth surface on top, which results, in a combination of integrated functions, in facilitating elastic deformation of the 3-dimensional spacer fabric in all 3 basic axial directions, simultaneously following the "indent" of the weight and contour of the human body.

Additionally, the separate stay- and transfer sheet on top of the decubitus preventing mini mattress, described in another patent of the inventors which has as basis, a double knitted and or double knitted 3 dimensional fabric, is suitable for direct and continuous skin contact and can be used for effectively transferring patients and is capable of absorbing body fluids and vapours without rewetting the upper surface. Ideally this stay and transfer sheet may be used more than once and therefore can be cleaned using industrial laundry procedures and will protect the warp knitted mini mattress from easy contamination.

Via a combination of specific PET and or PBT yarns and or PA fibre types, texturized (soft) and non-texturized (smooth), a warp knitted structure and use of elastomeric yarns (e.g. Elastan) interconnecting every stitch course and single stitch or every second, third or fourth stitch of the second course a smooth and soft top structure can be created, able to elongate, to be compressed and follow the body contour and maintain sufficient resilience strength to prevent bottoming out of the 3-dimensional spacer fabric structure. Through the partial absence of the interconnecting monofilament fibres between top and bottom layer planes, these 3-dimensional structures will create square or rectangular areas with monofilaments and surrounding band or channels shaped open areas without monofilament fibres, resulting in a better elasticity and elongation of the overall structure and better individual resilience and deformation capacity of every square or rectangular monofilament area. The limited width of the open areas, bands or channels surrounding the rectangular or square monofilament yarn areas on one, two sides or all sides of these rectangles or squares on the bottom and if necessary the top surface will, together with the use of elastomeric yarns to connect the stitches with multifilament yarns, provide enough elongation and stretching capacity of the complete macro structure. The ratio between the filled and the open area is 5 to 20 times more monofilament yarns in the filled areas than in the width of the areas without monofilament yarns and will prevent collapsing of the monofilament yarns on the borders of the square or rectangular areas. The monofilament pile yarns or fibres can be omitted in the longitudinal direction of the knitted fabric, by leaving them out from the material feeding process, creating by this a partial open bands or channels with no or with less monofilament yarns. This applies also to the multifilament yarns in the longitudinal direction (along the width of the warp knitting production machine), which can also be left out from the material feeding, creating open bands on the top and or bottom surface plane of the 3- dimensional fabric. This multifilament yarns can be omitted in the top and or bottom structure but can also be replaced with a thinner multifilament yarns with a smaller decitex value (overall diameter parameter) and or lesser filaments or can be replaced with an extra elastic yarn such as PBT or an elastomeric yarn. The difference in the diameter and the number of filaments in the top and bottom surface plane can, combined with the monofilament knitting process described directly below, also result in raised areas, lines, or bands which can act as gliding structures for the transfer and stay sheet covering the 3-dimensional warp knitted mini mattress. In the width of the fabric also a similar process can be applied in which case the monofilament yarn is not omitted there due to the absence of the material feeding of it, but is knitted one or two more stitches in the same horizontal top and or bottom surface layer before being knitted back to the other, opposite surface layer, creating a similar open band without monofilament yarns crossing it to the other surface plane. The multifilament yarn cannot be omitted over the width of the fabric with a standard 6 needle bar machine, but could be omitted with an additional auxiliary device or on a 7 needle bar machine creating open bands in the top and bottom surface surrounding the rectangular or square section with monofilament yarns. The 7 needle bar machine also enables more specialized embodiments of the mini-mattress, such as the square or rectangular multifilament- yarn- less patterns in the top and or bottom surface, in the use of more different yarns in these surfaces, in other shapes of the monofilament and multifilament sections etc.

The so called open bands in the top layer of the 3 dimensional warp knitted structure can be filled also with PBT yarns or other elastic or thinner PET-yarns without influencing the effect of the rectangular structures. This makes it possible to apply on the top structure a chemical treatment making it hydrophobic and breathable. This composition can be when necessary wipe-cleaned for intermediate cleaning. The list of figures illustrating the preferred embodiments of our invention can be found below: Fig. 1 shows a schematic sketch of a 3-dimensional warp knitted fabric according to the invention, with rectangular or square shaped monofilament sections interconnecting the top and bottom plane. Fig. 2 shows a 3-dimensional view of a 3 dimensional warp knitted fabric according to the invention, with rectangular or square shaped areas of monofilaments connecting a closed top and bottom surface.

Fig. 3a shows a 3-dimensional drawing of a detail of the closed structure at the top and bottom surface with the indications on these surfaces where the squares or rectangles are in the middle monofilament section.

Fig. 3b shows a 3-dimensional warp knitted structure from the top plane, showing squares formed by omitting monofilament yarns in the middle plane.

Fig. 4 shows a detailed 3-dimensional drawing of an individual knit structure which can be used on the top or bottom surface layer.

Fig. 5 shows a 3-dimensional drawing of the 3 dimensional warp knitted structure with rectangular or square shaped areas of monofilaments connecting a partly open top and bottom surface in which bands without multifilament fibers can be seen.

Fig. 6 shows a side view of a 3-dimensional drawing of the 3-dimensional warp knitted structure with monofilament yarns connecting a closed top and partly open/closed bottom surface in which a band without multifilament yarns can be seen. Fig. 7 shows a 3-dimensional knitting structure with a top layer, an intermediate layer and a bottom layer, showing squares formed by omitting monofilament yarns in the middle layer and multifilament yarns in top and bottom layer. Fig. 8 shows a side view of a photograph of the structure with open bands without multifilament yarns at the bottom.

Fig. 9 shows a 3-dimensional knitting structure of top layer, intermediate and bottom layers, with squares formed by omitting monofilament yarns in the middle layer and multifilament yarns in top and bottom layer.

Fig. 10 shows a top view of the top or bottom surface of the 3d knit structure in which the rectangular, square monofilament yarn sections are made visible by a difference in the structure of the surface.

Fig. 11 shows a detail of a drawing of the top or bottom surface of the 3d warp knitted structure in which the multifilament- less bands 6 can be seen and the individual knits of elastomeric yarns. Fig. 12 shows a side view of channels or bands 8 without monofilament yarns in the machine width direction.

Fig. 13 shows a schematic drawing of the knitting structure and mechanism for monofilament yarns creating the open channels in the intermediate structure between top and bottom surfaces.

Fig 14 shows a schematic drawing of a stay and transfer sheet adapted to be used in a system of the invention. Fig. 1 shows a schematic sketch of the 3-dimensionals knit fabric with a monofilament yarn structure or section 3 interconnecting a top layer 4 and a bottom layer 5, which can have a rectangular or square shape in the X-Y plane. The monofilament yarns of structure 3 are interconnecting the top layer 4 and the bottom layer 5 with a number of individual

monofilament PET pile yarns in areas 11. The pile yarns are extending in an X-shape and are knitted to both the top layer 4 and the bottom layer 5. These areas llcan have a rectangular, square or band shape covering a small section of the knit fabric repeated over the whole width. One can identify at the bottom layer a band shaped part 6 in which the multifilament surface yarns of bottom layer 5 are omitted and only the individual elastomeric yarns make individual knits or stitches connecting the surface areas indicated by 11, which are composed of stitches of the monofilament yarn 3, the elastomeric yarn 2 and the multifilament yarn 1. The arrow indicating "detail see fig 4 "in fig 1 refers to a detail that can be seen more clearly in the separate fig 4 and which shows the individual knits in the rectangular top and bottom surface areas 11.

Fig. 2 shows a 3-dimensional CAD drawing of a 3-dimensional knitted structure with rectangular or square shaped areas or sections 12 with monofilament yarns 14 connecting a closed top surface 4 and bottom surface 5 interconnected by the individual monofilament pile yarns 3 knitted in a so called X-shape. The bands or line shaped parts 7 show the sections in which no monofilament yarns have been fed into knitting needles of the machine and are therefore absent as such in the final knit structure. This can be applied in the longitudinal direction. In the width direction of the fabric the monofilament yarn cannot be omitted physically but is knitted in a different way to create a similar open band as 7, which can be described as making one or more extra horizontal knitting binding loops of the monofilament yarn before it will be connected again to the opposite surface plane in a stitch. This creates an alternative relatively open band 8 (which is indicated in fig.13 and not visible in fig. 2) in the pile yarn structure or section 14, in the width direction of the fabric (see for more details figure 3 and especially fig. 12). These bands 7,8 will allow a more easy deformation and elongation of the complete structure in response to the body weight and contour and also making the deformation of the individual monofilament yarns more easier due to the smaller 'density' or compactness of the fabric.

Fig. 3a shows a 3-dimensional drawing of a detail of a possible embodiment with a closed surface structure at the top and bottom surface and the intermediate structure with

monofilament pile yarns which has a rectangular and or square shape indicated by arrows 12 and which is surrounded by pile- yarn- less knitting courses 13 (7), underneath the top surface, in which no monofilament yarns are present between top and bottom surface as described in the previous paragraph.

It is clear that the pile- yarn- less band- shaped areas 13 (7) can have a width of at least 1 stitch or knit, but can also have a higher width up to a quarter or even up to half of the width of the rectangular or square shaped pile yarn area. The pile yarn rectangular or square areas 12 can be created in the knitting process in the width direction of the knitted fabric (width of knitting machine) and or in the longitudinal direction and can have a width and length dimension of at least 2 knitting courses and small ingots.

Fig. 3b shows a top view of a 3-dimensional drawing of a detail of a possible closed structure at the top and bottom surface and the intermediate structure with monofilament pile yarns which has a rectangular and or square shape indicated by the arrows 12 which is also visible due to the different surface structure and which is surrounded by knitting courses 13, which do not have monofilament yarns underneath them. There are here thus no monofilament yarns present between the top and bottom surface as described in the previous paragraph under these knitting courses.

Fig. 4 shows a detailed 3-dimensional drawing of the individual knit structure indicated as a "detail fig. 4" in fig. 1. One can see the three individual yarns used in the knitting structure: the multifilament top and bottom surface yarn 1 which can be texturized (soft) or non-texturized (smooth), the elastic elastomeric yarn 2 which can be of the brand type Elastan or Lycra or can be a PBT and the monofilament yarn or monofilament pile yarn 3 which interconnects the top and bottom surfaces. The respective layers each consist of stitches which mainly include the multifilament yarn 1 but are connected to each other also by the elastomeric yarn 2 and the monofilament yarn 3. Due to the voluminous character and diameter of the multifilament yarn 1 and the compression of all stitches closer to each other by the elastic compression behaviour of the knitted elastomeric yarn 2, all binding or knit connections of the monofilament yarns 3 are covered by or positioned at a lower vertical level than the multifilament yarns 1. The decitex value and number of filaments value of the multifilament PET yarn 1 at the top surface can be higher than the decitex value and number of filaments value of the multifilament PET yarn 1 at the bottom surface, enabling an easier and larger deformation area and radius at this bottom plane, following by this the body contour more precisely. This also applies to the decitex value of the elastomeric yarn in the top surface which can be higher than the decitex value of the elastomeric yarn of the bottom surface, resulting in a stronger yarn at the top. The same method can be applied to vary the decitex value of both the multifilament, monofilament and elastomeric yarns over the width of the fabric (the so called width direction of the knitting machine) to create specific zones with higher or lower resilience strength and higher or lower stretching capacity. This can be complemented with the creation of more or less bands 6 without multifilament yarns to enhance the stretch ability and elongation capacity of the knitted fabric.

Fig. 5 shows a 3-dimensional drawing of the knit structure with rectangular or square shaped areas of monofilaments connecting a partly open top and bottom surface in which bands 6 without multifilament yarns can be seen perpendicular to the production width of the knitted fabric, in the longitudinal direction. Unlike the embodiment depicted in fig. 2 one can see in fig. 5 that in the top layer 4 and the bottom layer 5 both the multifilament yarns and partly the monofilament yarns have been omitted in band shaped areas 6 resp. in the channel shaped areas 7 via exclusion of these yarns from the yarn feeding process on two sides of the rectangular or square shaped areas 12 consisting of X-shaped monofilaments in the middle structure or section 14. The monofilament yarns in the width direction of the knitting machine are not being omitted to create the other two sides of the rectangular or square area, but are, as mentioned before, knitted into one or more loops in the horizontal top layer 4 and/ or bottom layer 5 to create the similar effect of open band areas without monofilament yarns. The multifilament- yarn- less bands 6 in the top and bottom surface structure can be positioned directly above each other but can also have another repetitive pattern in which every second open band at the bottom coincides with an open band at the top surface. These open bands 6 without multifilament yarns, and channels, bands 7 without monofilament yarns underneath them, enhance the elongation capacity of the complete knitting structure drastically, enabling a more even pressure distribution by creating larger surface areas following the body contour and allowing a more easy deformation (bending) of individual monofilament yarns to take up pressure and shear forces without complete collapsing, flattening or bottoming out of the 3-dimensional knit fabric structure. An alternative embodiment of this constructions as described above can be that the bands 6 without multifilament yarns are filled with another but thinner multifilament yarn (smaller single yarn diameter and or smaller number of filaments, decitex value between 30 - 60) or an elastic polymer yarn such as PBT yarn (Polybutylene Terephthalate PBT-yarn) which still will enhance the deformation capacity and elongation, but will make it possible to apply specific coatings and finishes on the top surface layer 4 and or the bottom surface layer 5, such as Polyurethane like foulard, spray or foam coatings to make the 3-dimensional fabric more water repellent. It even is possible in an embodiment to apply in the top layer and bottom layer a larger amount of PBT yarn to replace existing PET multifilament yarns to enhance the elongation and stretching capacity of the surface which allow the monofilament yarn section to deform more easily, reducing overall pressures and to absorb shear forces. In this case a seventh guide bar of the warp knitting machine is needed. This PBT yarn can have a fineness between 50 and 250 decitex, more specifically between 76 and 185 decitex.

Fig. 6 shows a side view 3-dimensional drawing of the knit structure with rectangular or square shaped areas of monofilaments 14 connecting a closed top surface of layer 4 and partly open/closed bottom surface of layer 5 in which at the bottom a band 6 without multifilament yarns 1 can be seen. Only visible here are the knitting stitches of the elastomeric yarn 2. Also can be seen the channel or band 7 in which one monofilament yarn 3 or more can be omitted from the yarn feeding resulting in a channel 7 in the section between layers 4 and 5 with a lesser density of cross shaped monofilaments. In this embodiment the open bands 6 are only present at the bottom surface, resulting in higher resilience strength than with the version depicted in fig. 5. This embodiment of fig. 6 is intended for more heavy patients. The application of thicker multifilament yarns 1 and thicker or stiffer monofilament yarns 3 and thicker elastomeric yarns 2 can be used to create a higher resilience strength for more heavier persons, combined with the proper selection and dimension of the open bands 6 and channels 7.

Fig. 7 shows a CAD drawing with a detail of the partly open structure at top and the bottom surface. In this figure one can clearly see that, both in top and bottom surface, open bands 6 without multifilament yarns have been created to enhance the deformation and stretch ability of the top and bottom layers and the intermediate monofilament yarn sections. Underneath these surface bands 6 without multifilament yarns are the channels 7 in the area between the top and bottom layers, in which one or more monofilament yarns are missing from the knitting construction resulting in a lower density and resilience strength of the 3-dimensional structure, and enabling also by these folding lines the deformation and stretching of the fabric to follow the body contour, to take up individual pressures and shear forces in the monofilaments and to reduce the same, resulting in a higher comfort and lower risks of skin and tissue damages due to pressure and shear forces. Also visible at the bottom surface are indications of the square or rectangular shaped areas with monofilament yarns which are surrounded by the open channels 7 as described before.

Fig. 8 shows a side view of a drawing of the 3 D structure with open multifilament-yarn- less bands 6 at the bottom surface or layer. One can identify in this photograph the top surface layer 4 and the bottom surface layer 5, both consisting of the three specific yarn types, monofilament yarns, multifilament yarns, and elastomeric yarns. In the bottom surface plane 5 of this embodiment a band 6 without multifilament yarns can be seen. These bands 6 also do not have monofilament yarns underneath the surface within their width, leading to the relative open channels or bands 7 without monofilament within the fabric. The bands can be knitted in the 3- dimensional construction on both sides of each monofilament section, or every two, three sections, or variations thereof via 2 different methods depending on the position of the respective band. If this channel 7 is perpendicular to the production direction of the machine, it can be realised via not feeding in multifilament and monofilament yarns. If the channel

(indicated by number 8 in fig 12) is parallel to the width direction of the machine, then the monofilament can be knitted in such a way that relative open channels or bands 8 are formed via extra knitting loops of the monofilament yarn in the horizontal surface of the top layer or bottom layer. The functions of these bands 8 (see fig 12), which have an open band or structure at the surface 6 is to enhance the deformation capacity of the complete 3-dimensional knit structure, consisting of the top surface layer 4 and the bottom surface layer 5 and the middle structure, which can easily elongate itself at these bands which only consist of individual knits of the elastomeric yarns. This elongation improvement will also allow the monofilaments to be bent more easily under pressure or shear loads. This combined deformations will lead to a large overall pressure contact surface, a reduction and better distribution of pressure and shear forces. As can be seen in drawing of fig 8 the top surface layer 4 is closed. The monofilament sections 12 between the top surface layer 4 and the bottom surface layer 5 have a rectangular or square shape. The width and length of each section 12 can be variable, and will determine also the position of the open channels 7 and 8 (for channel 8 see fig. 12) without the multifilament yarn and the monofilament yarn.

Fig. 9 shows a side and top view of a 3-dimensional drawing of a knitting structure with a top layer, an intermediate or middle layer and bottom layer, showing squares formed by omitting monofilament yarns in the middle layer and multifilament yarns in the top and bottom layers. One can identify in this 3D drawing the top surface layer 4 and the bottom surface layer 5, both consisting of the three specific yarn types: monofilament 3, multifilament yarns 1 and elastomeric yarns 2. In the top surface layer 4 and in the bottom surface layer 5 of this embodiment bands 6 without multifilament yarns 1 can be seen. These bands 6 also don't have monofilament yarns 3 underneath them, within their width, leading to the open channels or bands 7 (here visible in fig 9) and perpendicular to the channels or bands 8 (which are only clearly visible in fig 12) within the fabric surrounding the rectangular or square areas with monofilament yarns. The repetition of these bands can be equal on both surfaces or can be as in this embodiment in a varying pattern: every two monofil sections 12 are at the top surface, bordered by bands 7, 8 without monofilament yarns 3 and multifilament yarns 1. At the bottom surface layer every monofil section 12 is bordered by channels, bands 7, 8. The bands, channels 7, 8 can be knitted in the 3-dimensional construction on both sides of each monofilament section or every two, three or variations thereof on a 6 or 7 bar machine. The open bands 6 without multifilament yarns can be surrounding the monofilament yarn rectangles or squares when the 3 dimensional warp knitted fabric is manufactured on a 7 or 8 bar machine. This embodiment with open bands 6 in top and bottom surfaces, has more elongation and deformation capacity than the embodiment photographed in fig 8. As can be seen in the photograph of fig. 9, the top surface layer 4 has less bands 6 than in the bottom surface layer 5. The monofilament sections 12 between the top surface 4 and the bottom surface 5 have a rectangular or square shape. The width and length of each section 12 can be variable, and will determine also the position of the open bands 6 without the multifilament yarn 1 and the monofilament yarn 3.

Fig. 10 shows in a photograph a top 3-dimensional view of the top or bottom surface of the 3- dimensional knit structure in which open bands 6 without multifilament yarns 1 are clearly visible, consisting of only elastomeric yarns 2, which have underneath the open channel or band areas 7 without monofilament yarns 3 as can be seen better in the other figures. The open band 6 should follow a longitudinal line, perpendicular to the width of the knitting machine and is created as mentioned before through the absence of the material feeding of the multifilament yarn 1.

Fig. 11 shows a detail in a 3-dimensional drawing of the top or bottom surface layer of the 3- dimensional knitted structure in which the multifilament-yarn-less bands 6 can be seen, as well as the open areas 7 without monofilament yarns 3 underneath the top surface layer and the individual stitches of elastomeric yarns 2 in the open band 6 at the surface.

Fig. 12 shows a side view of bands 8 without monofils in machine width direction. One can identify the multifilament yarn 1 at the top and bottom surface, the elastomeric yarn 2 and the monofilament yarn 3. Clearly visible are the open band 8 without monofilaments, created via the knitting 15 of the monofilament yarn in a horizontal direction on one side in the top layer, on the other side in the bottom layer before returning again to the opposite surface layer. This knitting of the monofilament yarn in the horizontal layers in one or two stitches or more before returning to the other horizontal layer will create an additional beneficiary feature in the knitted fabric of a slightly inwardly pressed band of multifilament yarns, if these are all the same type in the surface layer. The use of multifilament yarns with a thinner decitex value in the areas besides these bands and with thicker multifilament yarns directly above the open bands 8 will create upwardly pressed bands, which can be used as raised gliding grids for a stay and transfer sheet covering the 3-dimensional knit structure on which the patient is lying or sitting when repositioned in bed or when he is being transferred. This effect will be enhanced when these upwardly pressed multifilament yarns are non-texturized and smooth. These monofilament yarns will knit one or more stitches with the multifilament and elastomeric yarns in the top layer and produce as a result together a raised band of stitches in the width direction of the top layer when the multifilament yarns in the stitch courses besides the bands 8 have a smaller decitex and number of filaments value than the multifilament yarns in the bands 8 itself. The combination of the horizontal knitting of the monofilament yarns and the variation in thicknesses of the multifilament yarns result directly in raised and recessed areas in the top and or bottom layer of the 3-dimensional knit structure, either for use as gliding structures for additional stay and transfer sheets or as direct skin contact surfaces when the patient or consumer is lying directly on the 3-dimensional knit structure.

Fig. 13 shows a schematic drawing of the knitting structure and mechanism for the

monofilament yarns creating the open channels in the intermediate section between top and or bottom surface layers. One sees in this schematic drawing a cross section of the 3-dimensional knitted spacer fabric (longitudinal direction) in which the channels 8 are formed via the horizontal knitting 16 of the monofilament yarns 1 in the top and or bottom surface layers for, in this embodiment, two stitches at least, but which can also be one stitch, 3 stitches etc. On the left side one can see the knitting pattern when the monofilament yarn is knitted for 2 or more stitches on one surface only, whereas in the middle a section can be seen in which the monofilament yarn is knitted for 2 or more stitches in the top and bottom layers. The difference between the two knitting patterns is that the first one leads to a smaller and less open channel than the second one, in which the channel is slightly wide, and

Fig. 14 shows a 3-dimensional drawing of the top surface and cross section of a double knit two layer 3-dimensional structure of a stay and transfer sheet adapted to be used in a system of the invention. The top surface has honeycomb shaped structures 130 which act as sliding or gliding lines and which are formed by the creation of larger double knitting loops during the knitting process which result finally in the raised rim shaped structures which can have a honeycomb shape, a square or rectangular shape, a diamond shape or any similar shape convenient for the purpose. These raised honeycomb shaped or hexagonal shaped structures 130 form boundaries for recessed areas 160, which are divided by extra horizontal gliding or sliding lines 190 which can be positioned at various positions in the honeycombs 130, horizontally, vertically or under an angle to the side of the honeycomb structure 130. The top and bottom layer of this 3- dimensional knitted structure are interconnected by monofilament yarns 120, which can also be multifilament yarns or can consist of joining a monofilament yarn and a multifilament yarn in every stitch, maintaining by this a sufficient pressure distribution capacity and capillary structure and water transport capacity to the bottom layer. The gliding lines are stripe- or ribbon-like and extending over the length and/or width dimension of the top layer, or as the case may be, the bottom layer. At least the top layer includes, apart from multifilament yarns, elastic yarn to enhance the elasticity of the fabric structure. The raised areas of the fabric have a horizontal dimension of one stitch or more in a direction of its stitch courses and of its stitch wales.

The materials to be used in the warp knitted spacer fabric have already been described previously in terms of types of polymer. Important is the use of an elastomeric yarn 2 with a specific decitex value of 33-250, combined with the knitting of this elastomeric yarn 2 in every stitch or in every second or third stitch on the left and right sides of the stitch, will compress the smooth non-texturized or soft texturized multifilament PET-yarns 1 upwardly (see fig. 4), covering the monofilaments 3, creating a smooth, low friction surface with levelled areas of yarns (smooth yarns in a higher layer than the elastomeric and monofilament yarns) or a soft direct skin contact surface and will enable elongation and elasticity of the structure to follow the body contour.

Secondly important is the use of knitting patterns in the 3-dimensional structure as described above in which not every stitch of multifilament PET-yarn 1 is knitted with elastomeric or of the brand type Elastan yarn 2 (in every parallel or in every second parallel course, left and right sided symmetrical or in opposite construction) combined with the creation of the small rectangular or square areas 12 with monofilament yarns 3 between top layer 4 and bottom layer 5 will enable a better elongation of the complete 3-dimensional spacer fabric to accommodate itself the weight and contour and curves of the patient lying on it.

The width of the above mentioned open band 6 and channels 7, 8 on both sides or all sides of square, rectangular or otherwise shaped areas 12 with monofilament yarns 3 can be varied. Combined with the use of Elastan yarn 2 the effect will be that the top and bottom PET stitches (made from the multifilament yarn 1) above these open areas will be slightly compressed and pressed upwardly creating raised surfaces with low friction characteristics.

Based on the rectangular and square areas 12 a raised surface can be created also by omitting in band 6 multifilament PET yarns 1 in the top or bottom layer structure of the 3-dimensional spacer fabric, together with the specific application of elastomeric yarns 2 in special knitting structures, allowing the remaining PET yarns to be pressed upwardly and is forming a raised course-structure. Thirdly the top structure 4 and or bottom structure 5 above the monofilament yarn areas 12 can be positioned in one vertical line symmetrically opposed to each other to provide the highest resilience strength or in another embodiment can be shifted or translated in X- and or Y- direction for one or more knitting loops (lappings) to enlarge the elasticity and changing, increasing the relative angle of the monofilament yarn to the horizontal surface and influencing the bending characteristics,

On the top- and bottom sides of the 3-dimensional knitted structure either smooth, non- texturized multifilament yarns 1 are used when the top surface layer 4 acts as a gliding layer for a stay and or transfer layer lying on top of this (e.g. this will be skin contact sheet) or will result after knitting in a soft layer with voluminous texturized yarns 1 when the top surface act as a direct skin contact layer, when no extra stay and transfer sheet is being used. Through specific patterns these yarns are pulled or dragged together due to the knitting and use of elastomeric yarns 2 (Elastan) and pushed upwardly to form dots or combinations thereof ( surfaces) on which patients can be positioned , turn and move without too much friction or on which other textile skin contact and transfer layer can easily move when the patient is lying on the bed or has to be moved. For this a 7 bar warp knitting machine with electronic guiding system is needed.

Through the application of specific patterns in which the elastomeric fibre is not connected to every soft or smooth PET stitch, and the use of the so called rectangular or square areas 12 with monofilament yarns 3 and bordered on 2 or 4 sides with open bands 6 and channels 7,8 without monofilament yarns 3 in the midsection 14 and without multifilament yarns 2 in the bottom surface layer 4 and or the top surface layer 5, the 3-dimensional knitting structure is compressed less strongly enabling:

- Easy elongation and stretching in order to follow the body contour

- Reduction of pressures and shear forces due to the bending of monofilament yarns 3 in the monofilament sections 12.

- Better distribution of pressures and shear forces due to a larger surface contact area and having no pressure enhancing influence on the bottom structure ( foam matrass and the like) due to partly use of monofilaments interconnecting the top and bottom surface of the structure, which can be centrally opposed to each other or shifted one or more knitting loops from each other centre in X and or Y direction. The 3-dimensional warp knitted structure also stimulates_liquid and perspiration transport from the top layer to the bottom layer in order to prevent quick rewet of the top structure, especially when multifilament yarns are mixed with monofilament yarns in the intermediate section between the top and bottom surface plane.

Due to the knitting structure it is possible to create with the smooth PET yarns specific upwardly raised easy gliding structures by leaving out monofilament yarns (spacer yarns) in the 3- dimensional knitting structure in the length or width of the fabric.

Also courses or bonding structures will be formed, where around the monofilament yarn areas multiple smooth PET yarns come together, or do cover the present monofilament yarns and can serve as out raised gliding structures.

These raised gliding structures or pattern are formed by the omitting of monofilament yarns in the width of the 3 dimensional knit structure. These monofilament yarns will knit for one or more stitches with the multifil and elastomeric yarns in the top plane and produce a raised line of stitches as a band in the width of the top structure. E.g. in one embodiment in the longitudinal direction minimal 2 knitting rows having a fineness of between 50/33 and 250/36 decitex, more specific between 76/64 and 167/48 decitex non- texturized multifilament yarns will be followed up by min 4 knitting courses having an fineness of between 33/16 and 110/100 decitex, more specific of decitex 50/33 or 50/24 multifilament yarns.

The difference in thickness in the longitudinal direction together with the raised line of stitches in the width of the top plane do form a raster structure allowing easy gliding for the stay and transfer sheet laying on top of the mini spacer fabric matrass. The 3-dimensional fabric is produced on at least a 6 needle bar warp knitting machine with electronic yarn guiding system. The machine gauge used can be between 12- 36 gauge, more specific between 18 and 32 and can have a guide bar opening varying between 1 and 25 mm, more specific between 6-18 mm. For specific embodiments such as knitting structure with open bands without multifilament PET yarn on the side of the rectangular or square monofilament section in top and bottom layer, a 7 needle bars warp knitting machine for one surface side or even a 8 needle bars warp knitting machine is needed.

The preferred yarn to be used in the invention are synthetic and are composed of polyester, acrylic, nylon, copolyester, elastomers, PBT„ PTFE, or the like. These yarns might be texturised non-texturised, spun, or fully oriented. In particular the top surface layer 4 and bottom surface layer 5 of the 3-dimensional fabric is made from a multifilament yarn 1 having a fineness of between 40-250 decitex, more preferably between 70-180 decitex and between 24-100 filaments that is forming the surface layers. The stitch yarn in the backing of the top layer 4 and 5 will be an elastomeric yarn 2 and will have a fineness of between 40 - 250 decitex, more preferably between 70-180 decitex, whereas to enhance the elongation capacity and ability to follow the body contour the decitex value of the elastomeric yarn 2 in the bottom surface layer can be lower than the decitex value of the elastomeric yarn 2 in the top surface layer. In that case the elastomeric yarn 2 in the bottom plane will have a fineness of between 50 and 150 decitex more specific between 70 and 135 decitex. The elastomeric yarn 2 in the top surface will have a fineness of between 80 and 250 decitex, more specific between 130 and 180 decitex.

Preferably, the top surface of fabric layer 4 is only fixated at specific temperatures and furthermore not treated in wet processes. The top surface might be sanded, brushed or napped and thus comprises another kind of raised surface fabric. By chemically treating top layer 4, the layer is rendered substantially hydrophobic. In order to prevent the moisture going through the top layer 4, in such a way that this layer can be wiped cleaned by hand .with special cloths and soap of detergent. This can be in a preferred

embodiment a Polyurethane layer or dendrimer based coating layer, which is applied on the fabric with a spray or foam method. The stitch yarn 1 and backing elastomeric yarn 2 of the 3D fabric layer are respectively made of polyester, polyamide and or polyurethane that can be rendered hydrophobic in order to block the transport of perspiration and thereby keep the rest of the 3-dimensional fabric under the top layer clean. Particularly, layer 4 can be chemically treated or utilizes modified yarns so that it is rendered hydrophobic . This will make it possible to chemically clean with a wiper the top surface when dirty. So no machine washing of the complete 3D warp knitted product is needed for weeks/months.

In another embodiment the Raschel knitting machine is provided with a 7th knitting bar/rail allowing to produce on top of the 3d-spacer fabric-top structure small square or round cushion like structures that enhance pressure reduction and smooth sliding properties: Or an additional machine element is added to a 6 knitting bar machine to allow the formations of pen canals 6 on all sides of the monofilament rectangles 12.

In another embodiment the top of the 3D spacer fabric can be used or provided with a velours structure that enhances softness and smoothness. In another embodiment the 3D spacer fabric can be foreseen with: a. Anti-slip structure.

b. Water repellent membrane or finishes.

c. Antimicrobial yarns/structures.

d. Fungi-static finishes etc.

e. Pressure distributing and compensating printed pattern of silicone or Polyurethane dots/structures on the top surface layer 4 and or the bottom surface layer 5 It will thus be seen that the objects set forth above, and those made apparent from the preceding description are efficiently attained, and since certain changes may be made in the constructions described above without departing from the spirit and scope of the invention, it is intended that All matter contained in this description shall be interpreted as illustrative and not in a limiting sense. A 3-dimensional spacer fabric that is in particular suited for being used as a decubitus mattress or cushion comprises a knitted top layer, a knitted bottom layer and a spacer structure located there between and holding the two layers at a distance from each other, said spacer structure comprising upright pile yarns extending there between. At least the top layer comprises a multifilament yarn and an elastic yarn. The top layer and/or the bottom layer is formed with band-shaped areas that are devoid of pile yarns extending therefrom through the spacer structure. The elasticity of the top layer is different from the elasticity of the bottom layer.

Claims

CLAIMS:

1. A 3-dimensional textile spacer fabric comprising a top layer knitted from at least a first yarn, a bottom layer knitted from at least a second yarn and a spacer structure located there between and holding the two layers at a distance from each other, said spacer structure comprising upright pile yarns extending there through for connecting the two layers to each other, wherein:

At least the top layer comprises a multifilament yarn and an elastic yarn as first yarns, the top layer and/or the bottom layer is formed with band-shaped areas that are parallel to each other and are devoid of pile yarns extending therefrom through the spacer structure, the band-shaped areas are oriented parallel and at right angles to the courses and wales of the fabric, respectively, enclosing square or rectangular areas in which pile yarns are extending through the spacer structure, and the elasticity of the top layer is different from the elasticity of the bottom layer.

2. The spacer fabric of claim 1, characterized in that at least the top layer has an

uninterrupted closed outer surface.

3. The spacer fabric of claim 1 or 2, characterized in that band-shaped areas comprise stitches including a multifilament first yarn .

4. The spacer fabric of any of the preceding claims, characterized in that band- shaped areas comprise stitches including elastic yarn.

5. The spacer fabric of any of the preceding claims, characterized in that band- shaped areas comprise stitches including pile yarn.

6. The spacer fabric of claim 5, characterized in that band- shaped areas comprise stitches that are knitted from pile yarn only.

7. The spacer fabric of any of the preceding claims, characterized in that the lateral stretch ability of the top layer is equal to or smaller than the stretch ability of the bottom layer.

8. The spacer fabric of any of the preceding claims, characterized in that stitches of band- shaped areas of the top and/or the bottom layer comprise multifilament yarn and/or elastic yarns that are thinner than the multifilament or elastic yarns knitted in the square or rectangular areas comprising pile yarn.

9. The spacer fabric of any of the preceding claims, characterized in that at least the square or rectangular areas of the top and/or the bottom layer are knitted in courses with stitches comprising a multifilament yarn and pile yarn and that every first, second or third stitch on both sides of a course includes an elastomeric yarn such that loops of the multifilament yarns will at least partially cover loops of the pile yarn in stitches comprising these yarns.

10. The spacer fabric of claim 9, characterized in that the elastomeric yarn has a decitex value of 33 to 250.

11. The spacer fabric of any of the preceding claims, characterized in that the square or rectangular areas comprising pile yarns of the top layer are in alignment with corresponding areas comprising pile yarn of the bottom layer.

12. The spacer fabric of any of the claims 1 to 10, characterized in that the square or rectangular areas comprising pile yarn of the top layer are laterally offset with regard to the square or rectangular areas comprising pile yarn of the bottom layer.

13. The spacer fabric of any of the preceding claims, characterized in that the number and/or width and/or length of the band-shaped areas of the top layer and of the bottom layer are similar or different from one another.

14. The spacer fabric of any of the preceding claims, characterized in that the top layer and/or the bottom layer are in the form of a knitted fabric having raised and recessed areas on its outer surface.

15. The spacer fabric of claim 14, characterized in that the raised and recessed areas are forming gliding lines for a person lying thereon or on the fabric.

16. The spacer fabric of any of the preceding claims, characterized in that at least the top layer is rendered hydrophobic by a finishing procedure.

17. The spacer fabric of any of the preceding claims, characterized in that at least the top layer is provides with at least one of: Anti-slip structure, water repellent membrane or finishes, anti-microbial fibres/structures, and pressure distributing and compensating printed pattern of silicone or polyurethane dots/structures.

18. The spacer fabric of any of the preceding claims, characterized by its use as one of: a decubitus preventing mattress or cushion, a comfortable mattress or cushion, an under-blanket.

19. The spacer fabric of any of the preceding claims, characterized in that the decitex value of the elastic yarns and/or multifilament yarns used in the top layer is higher than the decitex value of the elastic yarns and/or multifilament yarns used in the bottom layer.

20. A system for improved health care for persons, comprising a mattress made from a spacer fabric according to any of the preceding claims and a stay and transfer sheet covering the spacer fabric.

21. The system of claim 20, characterized in that the stretchable stay and transfer sheet comprises a knit fabric having a user-contacted outer surface comprising raised and recessed surface areas that are arranged in a predetermined pattern adapted to minimize friction with a user contacting the outer surface of its stitch courses and of its stitch wales, wherein raised areas of the pattern are in the form of stripe- or ribbon-like gliding lines for a user supported on the outer surface, the gliding lines extending over the length and/or width dimension of the top layer, and wherein at least the top layer includes elastic yarn to enhance the elasticity of the fabric structure.