WO2000028132A1

WO2000028132A1 - Floor covering material and method for its production

Info

Publication number: WO2000028132A1
Application number: PCT/CH1999/000519
Authority: WO
Inventors: Bengt Johnard
Original assignee: Forbo International SA
Current assignee: Forbo International SA
Priority date: 1998-11-05
Filing date: 1999-11-04
Publication date: 2000-05-18
Anticipated expiration: 2001-05-05
Also published as: AU6323399A; SE9803783L; SE9803783D0; SE513280C2

Abstract

A floor covering material (1) in the form of a rollable web, comprising at least one material layer (2) of thermoplastics, composed of material volumes (4, 5), solidly joined with each other at their boundaries, said material volumes being of at least two kinds, visually separable from each other, so that the material layer obtains uniform patterning at least mainly throughout its entire thickness. The layer contains, on one hand, material volumes (4), which are developed to have such increased hardness that considerable resistance ability against wear and negative change of appearance is achieved during use of the covering material, and, on the other hand, other such material volumes (5), which have an increased softness and deformability. The material in the latter material volumes (5) is adapted mainly solely for ensuring the rollability.

Description

Floor covering material and method for its production

Technical field

The present invention relates to a floor covering material in the form of a rollable web, comprising at least one material layer of thermoplastics. The invention also relates to a method for producing the floor covering material.

State of the art

It has been known for a long time to produce floor covering material in the form of rollable webs. Since the material web is rollable, it can be produced continuous-ly in long lengths and for storing and transportation be given the form of delivery rolls with a suited material length. When laying the material, a length, which is suited to the surface to be covered, is unrolled. During floor covering, the material can be laid loosely on the surface and is in that case allowed to flatten out by its own weight, or also the material can be glued to the surface of the underlayer.

According to what has already emerged here, the invention relates to floor covering materials of thermoplastics. These are known in two main forms: surface-patterned or with a homogeneous patterned main layer. The surface-patterned type has on its surface a printed pattern, which is protected by a transparent plastic layer. This type has grown popular as floor covering in residences, wherein the material is not exposed to significantly heavy wear. The assistance to resist wear is namely limited; when the surface layer with the printed pattern has been worn through, the material completely changes appearance and cannot be restored to the original condition. In particular in an environment where the wear is considerable, such as in professional environments and public environments, one therefore prefers materials with better ability to keep the appearance even under heavy wear. To this end, the use has come to be directed towards homogeneously patterned floor materials. This means a floor material with a patterning, which extends mainly through the whole thickness of the layer, so that a wear will practically not be visually noticeable. Such a homogeneous patterning is achieved by having material volumes with different colours melting together to form a layer, which forms the material web, and in such a way that the individual material volumes keep their distinction of colour.

A homogeneously patterned floor material keeps, as previously mentioned, its pattern until the main part of the patterned layer has been worn down. However, this in itself is not sufficient to ensure that the floor to a high degree keeps its original appearance under the effect of traffic which results in the surface getting dirty, scratched and napped. Such an effect takes place dissimilarly across the surface of the floor and gives, if the floor material has a poor ability to resist this effect, an undesired change of appearance in the form of visual traffic paths. This feature of the material, i.e. to keep its original appearance to a high degree despite stresses during practical use, is in the following referred to as resistance ability".

Concerning plastic materials, the desire to obtain a high resistance ability has proved itself to be difficult to satisfy given the conflicting desires, that the material shall be rollable but at the same time have such a mechanically resistant surface so that wear, scratching, dimimshing of the smoothness of the surface, dirtying and press marks as far as possible are counteracted. To a certain extent, homogeneously patterned floor materials have therefore been produced as plates, which do not have to be rollable. However, such a form makes the work of laying the floor less rational and the floor receives a large amount of joints. There are also materials in the form of webs and of the type which is patterned throughout the thickness, to which one has sought to enhance the resistance ability by a resistant top layer, such as urethane lacquer, which however, opposes the desire that the material shall be wearable into the depth of the material without significant change of function or appearance. It has proved itself particularly difficult to fulfil said requirements concerning plastic materials of the olefin type, since for these materials softness and flexibility, which as mentioned is required for the reliability and resistance ability, counteract each other to a higher degree than in the case of certain other plastic materials, such as polyvinyl chloride. However, for environmental reasons there are requirements of replacing the latter material with the material of the former type, which is followed by the mentioned difficulties to fulfil both of the mentioned functional requirements.

The invention comprises, apart from a floor covering material of the mentioned type that is „patterned throughout its thickness", which is based on thermoplastics, also a method for its production. In known such production methods a step is comprised to form a mass on an underlayer, which mass will form the material layer of the finished floor covering material. According to the invention, this forming of the mass on the underlayer is assumed to take place through any of the known methods, such as deposition through scattering of and applying a doctor blade to a dry mass of dissimilarly coloured material particles on an underlayer, see SE-A-9603812-0 (Johnard) and US-A-5 407 617 (Oppermann et al).

Presentation of the invention

The object of the present invention is to obtain a floor covering material of the type that is patterned throughout its thickness, and with a high resistance ability, of which the layer exposed to wear, consists of dissimilarly coloured material volumes, joined with each other and made of one or many thermoplastic polymers. These material volumes are in their basic condition constituted of particles with such a size and shape, that they are visually separable from each other. During production of the mentioned material layer of the floor covering material, these particles are melted together with each other at their particle boundaries, to form material volumes in the finished material, however, without such complete melting that the individual specific features of the particles cannot be preserved. Thereby, the meaning of the invention is that the material is produced of particles of two main types, on one hand those that has hardness and other features such as dirt- repellent ability, which gives a high resistance ability, through which certain predetermined requirements of use of the floor covering material shall be fulfilled, and on the other hand those that has a softness and deformability that will ensure the features of the floor covering material consisting of rollability and ease of handling when the floor is laid. Thereby, it is assumed that the comprised polymer material is of such a type that, provided with a hardness adapted to the mentioned requirements, rollability of the floor covering material would not be allowed, while on the other hand, a material type which allows rollability should be so soft that the mentioned resistance ability could not be withheld. In other words, one can say that the softer particles act as hinges between the harder particles, which are supposed to take care of the wear resistance. A homogeneous patterned floor includes, as mentioned, dissimilarly coloured material volumes which by contrasting against each other form a pattern. A further characteristic of the invention is to let material volumes which through their softness can be expected to have bad resistance ability, form the darker parts of the pattern, while the harder material volumes can form the lighter elements of the pattern. In this way, the risk of the change of appearance during use being affected negatively by the lower resistance ability of the softer material volumes, is minimized. The invention requires that the softer and harder material volumes retain their features during a long time. This means that the invention is not applicable on traditional floor materials made out of plasticized PVC. The plasticizer is normally not solidly connected to the PVC-material, it can migrate into other surrounding plastic materials. This means that if one to a floor material made of plasticized PVC would try to apply the basic principle of the invention, with material volumes of different hardness, this would not succeed because the plasticizer would migrate from the soft material volumes to the harder ones. Another requirement is that the polymers that are included in the different material volumes have such features that they under heat and pressure can form a solid joint at their boundary surfaces. Especially the possibility according to the invention to obtain a floor covering material with high wear resistance and at the same time good rollability, is of interest if it is built up from the polymer group olefines, to which, among others, polyethylene and polypropylen belong. Among such materials, the harder types are stiff and can give rollability only in very thin layers, whereas soft flexible types have low resistance against mechanical wear and other influence, thus low resistance ability.

Through the invention, a floor covering material is thus achieved which presents good resistance ability as well as rollability even if it is made of polymer types, which by themselves cannot present such a combination of features.

Description of figures

In the amended drawings, Fig. 1 shows the floor covering material in an enlarged cross section at an early stage of its production,

Fig. 2 shows a corresponding cross section of the floor covering material in a completed shape,

Fig. 3-5 show front pictures of the surface of the floor covering material in three different examples of patterns, and

Fig. 6 shows a schematic view of an installation for production of the floor covering material.

Preferred embodiments

Fig. 1 shows a cross section of the floor covering material, referred to by reference number 1. Additionally a ply 2 of material volumes, which rest on a substrate 3, is shown. The substrate 3 can be a support ply, for example a glass fibre mat, which is a part of the finished product and which forms the backside of the finished product, which backside is to be in contact with the floor surface to which the floor covering material shall be applied. Alternatively, the substrate 3 can be a machine part, for example in the form of a steel web from which the floor covering material is separated in a final phase of the production, see also the description with reference to Fig. 6 here below. According to a further alternative, the substrate can be a temporary support ply, such as in the form of a so-called release paper, which accompanies the floor covering material during the production, and possibly during the storage period, but is separated before the application of the material to the surface intended therefore. In the two latter alternatives, the layer, which the ply 2 results in after the completed production, thus forms both the front side and backside of the material. However, this and other ways to form a material layer on a substrate are known and therefore do not need to be described closer here apart from what is stated in connection with description of Fig. 6.

As shown in Fig. 1, the material volumes in the ply 2 are of two kinds, which has been indicated by certain material volumes 4 being represented by non-filled rings while other material volumes 5 are represented by filled rings. The material volumes are of such a size that they are visually separable and because they are present in different levels of colouring, a pattern is created during observation. The expression „dissimilar colouring" in this case refers to that the material volumes, which are to form the pattern, are divided into different appearances in such a way that they can be separated from each other with the eye. A closely related variation in this case is certain material volumes being very light while other particles are dark. One can also consider the variation with close-to-transparent material volumes and darkly coloured ones, respectively. Also, colouring in different colours is possible. Through colouring with certain colour, e.g. red, but in a light and a dark variation, a surface is obtained which from a distance appears pink while when viewed at a closer range is perceived as mixed or texturised. The expression „colouring" does not in this case necessarily mean that some pigment or other colouring matter has been added to the material, but merely that at least some of the variations can have the colour belonging to the polymer material. The fact that two variations with respect to colouring has been mentioned here and shown in the figure, does not necessarily mean that one is limited to only two variations; a corresponding patterning can also advantageously be obtained through a plurality of colours and degrees of saturation of colour.

The material in the material volumes 4 and 5 are thermoplastics of one or more kinds of polymers. A requirement is that at a certain temperature and under a certain pressure, the material volumes can be melted together with each other at their surface boundaries to form a layer that is held together, retaining the respective features of the material volumes, and therefore without completely melting to a homogeneous mass during mixing. According to the invention, the material volumes are namely not only dissimilar with regard to „colouring", but also with regard to their material features. Thus, certain of the material volumes are made of a variant of thermoplastics with good features with regard to resistance ability against change of appearance and against wear during use. Change of appearance during use becomes present through defects, primarily scratching and dirtying. Also, the material being worn down can affect the appearance and is in itself a defect because the wear limits the life span of the material. How the material resists different forms of influence during use thus determines the resistance ability against negative change of appearance. This ability to resist the different forms of influence is largely related to how hard the material is. A hard material resists wear better than a soft material and is less easily scratched, and if scratching nevertheless becomes present, it is limited to its size at the same time as the tendency for dirtying is diminished.

However, there are also other factors that affects the change of appearance, e.g. a high resistance to retain electrical charges generally gives a larger tendency for dirtying. The expression „high resistance ability" here refers to that the polymer in the material volumes is composed to give high resistance ability with regard to the mentioned factors of influence, which gives rise to a negative change of appearance. However, since the hardness in the material volumes in question is an important factor, the expression „harder" is used for these material volumes, which are composed to have high resistance ability.

Thus, it can be established that a floor is exposed to different forms of wear. A floor with homogeneous patterning throughout the whole wear layer is preferably used in public environments where the wear is often significant. With time the wear results in the surface material being used up. However, equally important as a good resistance against the surface material being used up is, as stated above, that the worn surface does not differ substantially from the unaffected one regarding scratches, surface roughness and dirt engagement. If the resistance ability is insufficient towards such influence, profound dirty areas of wear will appear during use, which will disturb the aesthetic view of the total impression and make the maintenance of the floor more difficult. The combined effect of the ability of the floor to resist influence of these types is thus called the resistance ability" of the floor.

The resistance ability of a floor material depends according to experience on different factors. Regarding the dominating plastic floor material, PVC, the resistance ability increases if the amount of filler material and the amount of plasticizer are kept low. It has also been shown that lacquering with a top layer of for example polyurethane means a substantial improvement of the resistance ability of the floor. However, the lacquering gives only a temporarily advantage because it is worn away relatively fast in exposed locations. Olefine-based floors have since a few years been available on the market. These floors have in practice showed themselves to have substantially lower resistance ability than corresponding PVC floors. The disadvantages that the define floors show regarding the resistance ability seem to be connected with the hardness of the surface. A harder olefine plastic, such as polypropylen, has better resistance ability than a softer one such as polyether. The polypropylen material has, on the other hand, such a high stiffness that a homogeneous floor material based on this would not be possible to roll and handle by flexing when the floor is laid. The invention gives a solution to this problem with olefine-based floors but also to floor materials based on other thermoplastics, which can be manufactured to different degrees of hardness and by which the harder types at the same time have low flexibility while the resistance ability against exterior influence is diminished with increasing flexibility and deformability. Through the division into harder and softer material volumes in the floor material, according to the invention, both high resistance ability and rollability as well as convenient handling by means of flexibility can be achieved.

In Figs. 1 and 2, the intention is that the shown lighter material volumes 4 are of the mentioned harder kind while the shown darker ones are of the mentioned softer kind of polymers with good flexibility and deformability. Even if such a pairing can be advantageous, which will become apparent herein below, it is not limiting for the embodiments of the invention; the reverse relation can also be present.

Thus, the colouring does not need to be coordinated to previously mentioned material features, harder material volumes can be light or dark as well as the softer ones. However, it can be advantageous if the softer material volumes have a darker colouring than the harder ones while softer materials usually becomes discoloured more easily during practical use. Such a discolouring however generally becomes less visible on a darker material.

The material volumes consist as mentioned, of thermoplastics, which are compoundable with each other when heated and pressed together. One say that the material is built up by granules with at least two grades of hardness and softness, respectively, and that joins with each other in such a way that they form a stable layer, that is held together through the granules being melted together at their boundaries. This means that when the granules are melted together, the temperature must be kept at such a level, that the surface layer of the granules are melted to such a degree that they are joined when pressed together, but however with such a limited temperature that the mass of granules does not melt to a layer of homogeneous material during mixing. If this happens, the intended effect that certain material volumes keep their hardness is lost, since a complete melting would mean that the whole covering layer receives the same degree of hardness, whereby the resistance ability would get poorer and to some extent also the flexibility. For the same reason, viz. to retain the distinction between hard and soft parts, the material cannot contain a migrating plasticizer, since such a plasticizer also would level the differences between the harder and the softer materials after the completion of the material.

The expression „material volumes" is here understood to mean bodies that despite being joined with each other, are unaffected at their core so that they keep their respective characteristic material features. However, these characteristic material features are limited to two main types, here indicated as harder and softer, but this does not mean that all hard material volumes need to be altogether the same with respect to their material features and neither the softer ones. Thus, there can be a graded scale within both of the types.

A suitable thermoplastics for the harder material volumes, polymers from the group polypropylen can be mentioned. As suitable thermoplastics for the softer material volumes, polymers from the group polyethylene in soft variations can be mentioned. The thickness of the material layer in the completed floor covering material can vary between 0.5 and 5 mm, and is dependent upon such factors as how much of the material is required to be worn down without the material being significantly changed with regard to appearance. Other factors that are dependent on the thickness of the material are how elastic one wants the material to be and to what extent it shall dampen sounds of steps. If there are requirements on the material, for example, for reasons of sound dampening, to have a larger thickness than what is motivated by the mentioned requirement of wear admittance, it can be suitable to let the floor covering material consist of many layers. It was earlier mentioned that a substrate for the material layer 2 can be included in the floor covering material 1 , and this can then be provided to give, for example, the features of sound dampening which are required. Another way is to divide the material layer 2 into two plies, integrated with each other, with different material contents. The upper layer should have the composition described herein and which is characteristic of the invention. According to this embodiment, this layer then rests upon a substantially similarly built layer composed of material volumes which, however, are of a different origin than the ones in the main layer. One can, for example, use a larger amount of softer material for achieving a better elasticity or sound dampening, or one can choose materials that have lower cost than such materials that for reasons of function have to be chosen for the main layer. Suitably, the lower layer has a homogeneous pattern of the same visual character than the upper layer.

Fig. 1 shows a pre-stage of the production of the layer 2. The raw material that is used is here assumed to consist of granules of the harder and the softer thermo- plastic. In Fig. 1 and Fig. 2, the harder material volumes are marked with unfilled fields, and the softer ones with filled fields, and they are referred to as 4 and 5, respectively. In Fig. 1 , these material volumes are substantially unchanged with regard to their shape in comparison with the original shape of the granules. These are namely joined only at their contact surfaces and form a porous, not solid layer. This is presumed to be achieved by the granules being spread on the substrate in a level ply and after that exposed to a low heating, such as through radiation of infrared light. In Fig. 1, the original shape is shown to be spherical, but also other forms, e.g. an edgy form such as received from crushing or grinding, can be used.

A following step in the manufacturing method consists of the material layer being exposed to further heating and pressing, preferably through rolling between two heated rolls. Thereby the material volumes are deformed so that they are packed closely together and joined along all of its contact surfaces with adjacent material volumes. This final phase is shown in Fig. 2. It is also shown that the material layer has obtained less thickness than at the phase shown in Fig. 1. In Figs. 3, 4 and 5, three different examples of pattern formation are shown through front views of sections of the upper surface of the floor material. In Fig. 3, a relatively uniform mixture of hard and soft material volumes 4, 5 is shown with the former shown as being lighter and the latter as being darker in the figure. In Fig. 4, another example is shown, where the harder material volumes are present in a major part of the material, while the softer material volumes 5 can be said to form islands in the mass of material volumes 4. Even if these as well as the softer ones have been formed by particles preferably of approximately the same size as the softer ones, the content of these particles is so dominating that they seem to have floated together to a homogeneous mass. However, as mentioned earlier, a total melting is not assumed but since the particles 4 have the same colour, they can give the impression of uniform colour fields. However, the content of the softer particles must be such that the rollability is ensured. In Fig. 5, a pattern is shown formed by smaller, darker and softer material volumes 5 and with respect to its size, considerably bigger, harder and lighter material volumes 4b. This form is also suggested in the left part of the sectional view in Fig. 2.

The original particle dimension in the dry mass of the raw material is preferably between 0.3 and 3 mm. Depending on how much the particles are pressed together in the final rolling-out of the material, this can lead to different degrees of surface propagation of the particles. The material volumes 4b shown in Fig. 5 with large propagation can then have a original dimension of the particles of a few millimeters, whereas later during the rolling-out of the material, receive a surface propagation of one or a few tens of mm², preferably within the range 10-100 mm².

A device for performing the method is shown schematically in Fig. 6. The device, a production machine for materials in web form, comprises a substrate 11, on which the material is to be formed. The substrate constitutes an endless web, which is tightly stretched over a number of fair-lead rollers and runs around a cylinder 13 against which, at a part of its circumference, the web is pressed by means of pressing rollers 14. The web 11, which forms the substrate, can be made of steel or e.g. a web with a surface of tetrafluoroethylene, which gives good release effect towards the formed material web. The substrate will namely not be part of the completed product but is merely constituting a machine part. The cylinder 13 is heated. Another cylinder 15 is in contact with the substrate. The cylinder 15 is intended to be kept at a relatively low temperature, it will be employed as a cooling cylinder. Furthermore, a support cylinder 16 is present. The substrate is intended to run in the direction of the arrow 18 and thus it will, after having changed direction by means of two of the fair-lead rollers 12, pass over the support cylinder, between one of the pressing rollers 14, around a part of the heated cylinder 13, over the other pressing roller 14, past the cooling cylinder 15, and once again have its direction changed around one of the fair-lead rollers 12 and continue over further such fair- lead rollers to once again reach the support cylinder 16.

Over the support cylinder 16, a raw material feeding device 20 is present, which comprises a hopper 21 arranged for receiving the raw material, which here is referred to as 22. A filling device, not shown, for the particle mass is to be present for sustaining a satisfactory amount of material in the hopper 21. This filling device can, according to what has emerged from the above, have the form of a pump system from a larger storage container for the particle mass or from a manufacturing apparatus for continuous production of the particles.

The deposit ruler or doctor blade 26 shall with its lower edge be positioned at a distance over the substrate 11 resting against the support cylinder 16, which corresponds to the thickness desired for the particle mass deposited onto the substrate when moving in the direction of the arrow 18. From comparison between Fig. 1 and 2, it becomes clear that this thickness should be larger than the thickness that is intended for the completed material. Other alternatives for depositing devices may be present. Therefore, after the particle- feeding device 20, in the direction of the arrow 8, there is a layer of particle mass deposited, which is referred to as 28 in the figure. This layer will be transported together with the moving substrate 11 in the direction towards the heated cylinder 13. Between the particle-feeding device 20 and the nip between the cylinder 13 and the lower pressing roller 14, a horizontal section 29 of the substrate is present. Over a part of this section, a heating device 30 is present. Suitably this consists of a hood 31, open underneath, which surrounds sources 32 for radiation of the underlying area with infrared light, i.e. heat radiation.

The realisation of the method, during use of the described device will now be described below:

The particle mass 12, which consists of particles of the predetermined composition and sizes, is produced and fed up to the hopper 21, so that it always contains a sufficient amount for feeding during the intended production. The fed particle mass is placed on the substrate 11, which moves in the direction of the arrow 18 by means of rotation of the cylinders, suitably cylinder 3 is driven. The output device 16 provides for a level layer of the particle mass to be deposited onto the substrate.

The layer of particles now formed, which are still free to move in relation to each other and which are referred to as 28, are now transported towards an area under the heating device 30. The heat in this is adapted to not melt material elsewhere than at the boundaries of the pellets, so that a layer which is sintered together but still somewhat porous is formed on the substrate 11. This layer is referred to as 35, see also the presentation of the layer 2 in Fig. 1.

The substrate is now transported further by means of the movement of the web and the layer reaches an area between the web, where this runs against the pressing roller 14, and the heated cylinder 13. The cylinder 13 is heated to such a high temperature that the particles in the layer are completely joined during compression performed at the same time between the highly tensed substrate web and the cylinder 13. To give the plastic layer a final stabilisation, it is transported further, past the cooling cylinder 15. The solid layer now formed is referred to as 36, see also layer 2 in Fig. 2. After the nip between a separation roller 19 and the web 11 , which is transported around one of the rollers 12, this layer 36 is separated from the substrate 11 , and the material web, formed in this way, is transported further for a possible post-treatment and is rolled up for a delivery form.

Pressing the particle together when melting takes place at the particle boundaries to form a solid layer, can also take place without previous sintering. The method can also within the scope of the invention be varied so that the forming of a solid layer does not take place through pressing the particles together but solely through heating. Thereby one can by taking the heating to different extents make the layer more or less compact. At short heating, the connecting of the particles means substantially only sintering, so that between the particles voids are formed while on the other hand, a relatively long heating at higher temperature can give a more complete joining of the particles.

If it is desired to put many layers on the same underlayer by means of the described method according to the invention, they can in proper turn be laid after the stabilisation of underlying layers through sintering by means of heating. Alternatively, one can let many complete processes comprising solidifying by means of final heating of the layers, take place in proper turn, so that each new layer is laid with the previous one as a substrate. Hereby, the product can be given special features, for example with regard to sound or heat isolation.

In the above it has been described how the layer 3 is built up from a dry mass consisting of granules. If the granules are spherical and relatively similar in size, they will form a floatable mass, which has the performance similar to a liquid. This is advantageous since one can let this mass run onto the substrate from the hopper 21 to give it a predetermined thickness by means of the doctor blade 26. Such spherical particles must be made through special production methods. However, if it is desired to use particles with edges, such as those received from crushing or grinding, these must be actively distributed onto the substrate. It is thereby known to let this take place through scattering where a shaking device scatters the particles onto the substrate.

Example: The particles are produced in a spherical form in one single dimension with relatively small tolerances. This dimension should be within the range of 0.3-3 mm. The particles of the raw material should consist of thermoplastics, to which ingredients could be added, such as pigment, fillers etc. Those particles that according to the invention shall form the harder material volumes are polypropylen- based and those that shall form the softer material volumes are polyether-based.

The particles are laid in such a layer on the substrate that after solidification by means of adapted heating under pressure, a web material with the thickness 0.5-5 mm is formed.

Claims

1. A floor covering material in the form of a rollable web, comprising at least one material layer (2) of thermoplastics, composed of material volumes (4,5), solidly joined with each other at their boundaries, said material volumes being of at least two kinds, visually separable from each other, so that the material layer obtains uniform patterning at least mainly throughout its entire thickness, characterised in that the material volumes (4,5) through choice of material are divided into such polymers/ copolymers (4), which are developed to have such increased hardness that considerable resistance ability against wear and negative change of appearance is achieved during use of the covering material, and into other such polymers/copolymers (5), which have an increased softness and deformability, so that the rollability of the material web is ensured, whereby the material in the latter material volumes is possible to adapt substantially for ensuring the rollability, whereas said resistance ability is adapted to predetermined requirements through the presence of the harder material in the harder material volumes, which mainly can be adapted to said requirements without substantial consideration to the rollability requirement.

2. A floor covering material according to Claim 1, characterised in that the softer material volumes (5) are made out of materials with darker colouring than the harder material volumes (4), so that present negative change in appearance of the surface of the covering material, during use, which can be expected to mostly affect the material in the softer material volumes, becomes less visible.

3. A floor covering material according to Claim 1 or 2, characterised in that the plastic materials in the material layer are materials without a content of migrating plasticizers, so that a levelling of the hardness between the harder and the softer material volumes (4,5) is avoided.

4. A floor covering material according to any of Claims 1-3, characterised in that the harder material volumes (4) are formed mainly of polypropylene-based olefin plastics and that the softer material volumes (5) are formed mainly of polyethylene.

5. A floor covering material according to any of Claims 1-4, characterised in that the material volumes (4,5) are constituted by bodies joined at their boundaries, having a volume corresponding mainly to a particle size within the range of dimensions of 0.3-3 mm.

6. A floor covering material according to Claim 5, characterised in that in the material layer (2) material volumes (4b) are included with such a size that they, in the completed layer, form surfaces, each having an area of 10-100 mm².

7. A floor covering material according to any of Claims 1-6, characterised in that said material layer (2), which consists of said visually separable material volumes (4,5), is divided into two layers, joined with each other, a first layer forming the wearing surface of the covering material and with a thickness calculated to permit a certain predicted wear with thinning of the layer until it is broken through, and a second layer, on which the former layer rests, and which is intended to constitute a support layer for the first layer and with a uniform patterning, corresponding to the patterning of the first layer, throughout mainly the whole of its thickness, and with its material volumes primarily adapted, with respect to its hardness as well as softness and deformability, respectively, to be joined with, and support the former layer and permit rollability.

8. A method for production of the floor covering material according to any of Claims 1-7, characterised in that a raw material is combined with a content of at least two kinds of material volumes, such as granules, which are visually separable from each other, and with the material volumes divided through material contents, into those which have increased hardness (4) and those which have an increased softness (5) and deformability, and the material volumes, through choice of chemical structure present the feature of being capable of being solidly joined with each other at their boundaries, retaining its respective characteristic features without melting to a mixture of materials when heated to an adapted temperature, and that after allocation of the dissimilar material volumes throughout the whole mass of the raw material, such as through mixing, said material layers are formed by heating to said adapted temperature and pressing to form a homogeneous layer.

9. A method according to Claim 8, characterised in that for the softer material volumes (5) in the raw material, a material with a darker colouring than for the harder material volumes (4) is chosen.

10. A method according to Claim 8 or 9, characterised in that the raw material is consisting of materials without a content of migrating plasticizers, so that a levelling of the hardness between the harder and the softer material volumes (4,5) is avoided in the produced covering material.

11. A method according to any of Claim 8, 9 or 10, characterised in that, in the raw material, for the harder material volumes (4), mainly polypropylene-based olefin plastics and for the softer material volumes, mainly polyethylene (5) are chosen.

12. A method according to any of Claims 8-11, characterised in that the raw material is formulated as a dry mass with the material volumes (4,5) in the form of granules or the like of thermoplastic materials, compoundable with each other, that the mass is spread in a layer on a substrate (3) and that the material volumes are joined through heating, which heating is adapted so that they are joined at their boundaries without such melting that will cause the materials to be mixed together, and thereafter pressed to form the material layer of the covering material.

13. A method according to Claim 12, characterised in that the material volumes (4,5) are produced, at least with regards to its main part as spherical particles, mainly within the range of dimensions of 0.3-3 mm, and that the mass formed in this way with liquid-like fluidness is deposited onto the substrate (3) in a uniformly thick layer, whereupon the compound is formed, by heating and pressing, to constitute the homogeneous layer of the covering material.

14. A method according to Claim 13, characterised in that, in the layer of spherical particles deposited on the substrate, particles (4b) of such a size are supplied that they, when heated and pressed to form said homogeneous layer (2), assume a surface size of 10-100 mm².

15. A method according to any of Claims 12, 13 or 14, characterised in that the raw material is prepared in batches, a first batch in which, through the addition of the softer material volumes (5), provision is primarily made for the rollability of the material, and a second batch in which the proportions between the harder and the softer material volumes as mentioned are adapted to giving a resistance ability during use of the covering material, which is adapted to predetermined requirements, as well as to assuring the rollability of the material web, and that a layer of the first batch is deposited on the substrate, whereupon the material volumes are connected through sintering heating of this layer, whereupon a layer of the second batch of the raw material is deposited on said sintered-together layer, for a final joining of the material volumes and layers through said adapted heat-ing and pressing to form two material layers, joined with each other, whereby the material volumes in both of the batches are combined to give mainly the same patterning to both layers.