The present invention relates to a process for the production of a floor strip such as a dilatation profile, a transition profile or a finishing profile.

It is previously known to produce floor strips such as metal strips, wood veneer coated strips and strips of homogeneous wood.

There is a strong desire to bring about a floor strip with the same pattern as on a floor of thermosetting laminate. During the last years these floors have become very usual. For instance they are made with wood pattern, marble pattern and phantasy pattern. Possibly you can use a homogeneous wood strip or a wood vene¬ er coated strip for a few of the wood patterned floors. Previously known strips do not go well together with all the other floor patterns.

In addition the purpose of the present invention is to provide a floor strip with improved abrasion resistance.

According to the present invention it has quite surprisingly been possible to meet the above needs and bring about a process for the production of floor strips such as a dilatation profile, a transition profile or a finishing profile. The process comp¬ rises glueing, preferably under heat and pressure a thin decorative thermosetting laminate of postforming quality having an abrasion resistance measured as IP-va¬ lue >3000 revolutions, preferably >6000 revolutions, on a longitudinal carrier, which carrier preferably consists of a fibre board or a particle board with a rectan¬ gular cross-section and at least two opposite rounded-off edges. The postforming laminate is glued in one piece on the upper side and two long sides of the carrier via the rounded-off edges, whereupon one or more floor profiles having the same or different cross-section is machined from the laminate coated carrier.

According to one embodiment the carrier can be provided with a rectangular cross-section with three rounded-off edges.

One great advantage of the process for the production according to the invention is that it is very rational. From the same body, the laminate clad carrier, several profiles with varying shape can be machined. Usually a milling machine is used for machining the different kinds of profiles from the laminate coated carrier.

Preferably the carrier is water resistant. At a preferred embodiment the carrier consists of a high density fibre board made of fine fibres.

At a preferred embodiment the postforming laminate is glued in one piece on three of the four longitudinal s'des of the carrier, preferably on the upper side and two long sides via the rounded-off edges Advantageously, a heat and moisture resi¬ stant glue is used at the glueing. Preferably the glueing is carried out under heat and pressure For instance the pressure can be regulated by means of rollers which press the laminate against the carrier The temperature can for instance be regula¬ ted with heating nozzles which can give an even current of warm air

At another embodiment the carrier can be provided with a rectangular cross-sec¬ tion and three rounded-off edges The postforming laminate is then glued in one piece on all four sides of the carrier via the rounded-off edges

Suitably the postforming laminate consists of at least one monochromatic or pat¬ terned paper sheet impregnated with a thermosetting resin, preferably melamine- formaldehyde resin and preferably one or more sheets for instance of parchment, vulcanized fibres or glass fibres The last mentioned sheets are preferably not imp¬ regnated with any thermosetting resin, but the thermosetting resin from the sheets situated above will enter these sheets at the laminating step, where all sheets are bonded together

Generally the term postforming laminate means a laminate which is so flexible that it can be formed at least to a certain extent after the production thereof Ordinary qualities of thermosetting decorative laminates are rather brittle and cannot be re¬ garded as postforming laminates

Usually the postforming laminate includes at least one uppermost transparent pa¬ per sheet made of α-cellulose and impregnated with a thermosetting resin, prefe¬ rably melamine-formaldehyde resin This so-called overlay is intended to protect an underlying decor sheet from abrasion

Often at least one of the paper sheets of the postforming laminate impregnated with thermosetting resin, preferably the uppermost one is coated with hard partic¬ les for instance silica, aluminium oxide and/or silicon carbide with an average par¬ ticle size of about 1 -80 μm, preferably about 5-60 μm evenly distributed over the surface of the paper sheet

In a preferred embodiment the hard particles are applied on the resin impregnated paper surface before the resin has been dried

The hard particles improve the abrasion resistance of the laminate Hard particles are used in the same way at the production of laminates which are subject to a hard wear such as flooring laminates

The abrasion resistance of the postforming laminates are tested according to the European standard EN 438-2/6: 1991 . According to this standard the abrasion of the decor sheet of the finished laminate to the so-called IP-point (initial point) is measured, where the starting abrasion takes place.

The IP-value suitably lies within the interval 3000-20000, preferably 3000- 10000 revolutions.

Thus, the manufacturing process according to the invention makes it possible to produce laminate clad profiles with the same surface pattern and about the same abrasion resistance as the laminate floorings they are intended to go together with.

Of course the pattern of the profiles can also be adapted to other flooring materi¬ als than laminate floorings, such as parquette floorings and soft plastic floorings.

The present invention will be explained further in connection with the embodiment example below and the enclosed figures of which figure 1 shows a postforming la¬ minate 1 glued to a longitudinal carrier 2. Figure 2 shows a dilatation profile 3 with a postforming laminate 1 glued thereto, while figure 3 illustrates a finishing profile 4 with a postforming laminate 1 glued thereto. Finally figure 4 shows a transition profile 5 with a postforming laminate 1 glued thereto.

On the figures the thickness of the postforming laminate 1 has been magnified as compared to the size of the carrier 2 and the profiles 3-5 respectively to better il¬ lustrate that a postforming laminate 1 is glued to the carrier 2 and the profiles 3-5 respectively.

Of course the figures 1 -4 only show one embodiment of the carrier 2 and the pro¬ files 3-5 respectively which can be produced according to the invention. Various other designs are possible.

Example

A roll of transparent so-called overlay paper of α-cellulose with a surface weight of 25 g/m ² was impregnated with an aqueous solution of melamine-formaldehyde resin to a resin content of 70 percent by weight calculated on dry impregnated pa¬ per. Immediately after the impregnation, aluminium oxide particles with an avera¬ ge particle size of 50 μm were applied to the upper side of the paper in an amount of 7 g/m ² by means of a doctor-roll placed above the paper web

Thus, the hard aluminium particles were applied in the melamine-formaldehyde re¬ sin which had not been dried yet.

The impregnated paper web was then fed continuously into a heating oven, where the solvent was evaporated. At the same time the resin was partially cured to so- called B-stage Thereby the aluminium oxide particles were enclosed in the resin layer and arcordingly concentrated to the surface of the product obtained which is usually called prepreg The prepreg web obtained was then rolled again.

A roll of conventional nontransparent so-called decor paper with a decor pattern printed thereon and having a surface weight of 80 g/m ² was treated in the same way as the overlay paper except for the fact that no aluminium oxide particles were applied and that the resin content was 50 percent by weight calculated on dry impregnated paper.

A roll of unimpregnated parchment with a surface weight of 120 g/m ² was used at the production of the postforming laminate.

The two prepreg webs impregnated with melamine-formaldehyde resin and the unimpregnated parchment web were pressed between two press bands of a conti¬ nuous laminating press to a decorative postforming laminate

At the pressing a prepreg web of α-cellulose was placed on top with the side with the hard particles directed upwards. Underneath followed a prepreg web of decor paper and at the bottom a web of parchment. The prepreg webs and the parchment web were pressed together at a pressure of 35 kp/cm ² and at a temperature of 1 70°C

The decorative postforming laminate obtained was cut with roller knives to strips of suitable length and width

A longitudinal carrier 2 with a rectangular cross-section and two opposite roun¬ ded-off edges according to figure 1 was machined from a fibre board by means of a milling machine The fibre board was a water resistant board of so-called MDF- quality (medium density fibre board quality) of high density made of finely divided fibres

A strip of postforming laminate 1 was glued under heat and pressure to the long¬ itudinal carrier 2 with a heat and moisture resistant glue. The pressure was regula¬ ted with rolls which pressed the laminate against the carrier and the temperature was regulated with heating nozzles which blew an even current of warm air

A dilation profile 3 according to figure 2 was machined from the laminate clad carrier by milling

Instead two finishing profiles 4 according to figure 3 or one transition profile 5 according to figure 4 can be produced from the same carrier This results in a ra¬ tional and cost-saving production

The abrasion resistance of the postforming laminate obtained was measured Then a value for the IP-point amounting to 7000 revolutions was obtained

The present invention is not limited to the embodiments disclosed, since these can be modified in different ways within the scope of the present invention