Note: Descriptions are shown in the official language in which they were submitted.
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FLOORING AND PROCESS FOR ITS MANUFACTURE
Field Of The Invention
The invention relates to a flooring of rubber having granulates embedded in the
surface thereof which are distinguished from one another in at least one opticaland/or physical property.
Background Of The Invention
DE-42 26 766 A1 discloses a multi-coloured, patterned flooring and a method of
manufacture therefor, whereby a coloured granulate is embedded at an even
distribution in a web of a first colour different from the colour of the coloured
granulate. The web as well as the granulate are made of a cross-linkable
elastomeric material. The granulate includes at least two coloured fractions of
particles which have colours that are different from one another and from the first
colour. The amount and colour of the fractions is selected so that upon a
homogeneous mixing of all components included in the flooring, the colour of theresulting mixture is essentially the same as the first colour. During manufacture,
the fractions are separately granulated, mixed and fed to a roller calender withsubsequent vulcanization. This provides the optical appearance of a mixed coloursurface consisting of coloured surface portions of 1 to 25 mm2which are
embedded in the surface of the flooring. This permits the full recycling of all
flooring waste portions which are generated during manufacture of the flooring,
whereby the shade of the flooring is additively determined by equal portions of the
differently coloured components included therein. However, it is often desired to
have a flooring with discrete surface areas which differ from the remainder of the
flooring in at least one optical and/or physical characteristic.
Summary Of The Invention
It is an object of the invention to provide a flooring with discrete surface areas
which have the same optical and/or physical properties but different in at least one
characteristic of those properties, for example, for the guiding of visitors in
hospitals and public buildings as well as for the identification of discrete working
areas in institutional and commercial set-ups. It is another object to provide a
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flooring with surface areas with different characteristics relative to the physical
and/or optical properties with a continuous and gradual transition from one area to
another.
Accordingly, the invention provides a flooring made of rubber, and consisting of a
web having a caoutchouc granulate embedded therein, the granulate having a
particle size of 0.1 to 40 mm, whereby the flooring has areas of anisotropic
properties in longitudinal and transverse direction, the characteristic of at least one
selected physical and/or optical property of the flooring changing at least onceover the extent of the flooring surface, this change in the characteristic of said
property into another characteristic of the same property being gradual. The
advantages of such a gradual transition are described in more detail in the
following with respect to individual embodiments.
Detailed Description Of The Invention
A flooring in accordance with the present invention is made of rubber material and
in the shape of a web having a surface into which a caoutchouc granulate having
a particle size of 0.1 to 40 mm is embedded according to the desired overall
thickness of the flooring and the desired optical appearance. The flooring includes
areas of anisotropic properties in parallel and transverse to the machine direction.
The characteristic or measurable physical value of at least one selected physical
and/or optical property of the flooring gradually changes into another characteristic
or measured value of the selected property, whereby this transition is preferably
periodically repeated. The continuous and gradual transition of the characteristic is
thereby determined by the type and amount of the embedded granulate.
In a preferred embodiment of the invention, the gradual transition in the physical
and/or optical characteristic between the surface area portions occurs transverse
to the machine direction of the web. This variant is preferred, since it is especially
easy to manufacture and no special procedures need be followed during
installation of the flooring.
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If one focuses on the gradual transition of the optical characteristics of the
different surface areas, for example, the brightness of the flooring area,
aesthetically pleasing effects can be achieved which can be used especially
advantageously in presentation areas such as exhibition halls, and shop windows.
The same can be said for the degree of reflectivity, the intensity of which is
preferably higher in the flooring surface of presentation areas than in areas
frequented by the public where a shine would give the impression of an unduly
slippery floor covering or where wearing of the shine by foot traffic would change
the appearance of the flooring in an unacceptable manner over time.
A pleasing optical appearance can also be achieved with periodically repeating
changes of the colour shade of the flooring surface. Furthermore, the sequence of
the changes can be arranged such that the different colours can be used for the
directing of visitors in shopping malls, hospitals, airports and public buildings. For
example, the visitor would be optically prompted of his imminent entry into another
area of the building.
In all mentioned cases, the optical appearance of the flooring can be further
enhanced or varied by appropriate illumination. Furthermore, it is possible to
provide gradual transitions in the characteristics of more than one property such
as reflectivity, brightness and colour. This allows countless design possibilities in
practical and artistic respects.
In a variant of the invention, the selected property which is changed is the electric
resistivity of the flooring, measured according to DIN 51 953. The resistivity is
continuously varied within the limits of 1 x 103to 10'~ Ohm. For example, for the
production of integrated circuit boards, the floor covering around the production
areas is made electrically conductive to avoid the electrostatic destruction of
electronic components being handled by the assembly workers. Thus, the workers
are always in electrical contact with the floor covering. In view of the spaciallimitation of the working areas, it is not required to provide the whole floor covering
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of a production area with electric conductivity. However, in order for the
employees to be able to readily identify the electrically conductive areas, it is
intended in accordance with the invention to provide a floor covering wherein the
areas of electric conductivity are further provided with gradual variations in the
characteristics of at least one optical property. These variations can be used to
indicate the gradual transition to the non-conductive zones of the flooring. This can
be optically identified by changes in colour, brightness, or reflectivity. The
advantage over an abrupt delimitation, for example, lies in that the working area to
be used by the assembly workers handling the electronic components does not
appear overly confined. Apart from this psychological effect, it is preferably also
guaranteed that even in a zone further away from the work space, the flooring still
has a resistivity which is technically no longer optimal but still sufficiently low so
that there is a certain degree of security that electronic components can be
handled without destruction in that area.
Another embodiment of the invention is directed a flooring wherein the selected
property is the surface roughness of the flooring whereby the flooring has flowing
transitions in the roughness of individual zones of the flooring surface. This is
advantageous in areas potentially subjected to wetness or humidity in order to
reduce the danger of slipping. An example would be the area of a pool between
the wet zone and the entrance where a greater slipping safety upon wetness is
no longer required. The roughness in these zones would thereby gradually
increase or decrease analog to the humidity carried along.
The process in accordance with the invention is carried out by spreading onto a
still soft and elastic, continuously moving web prior to the vulcanization thereof at
least two different types of caoutchouc particles of a particle size or sieve fraction
of 0.1 to 40 mm. The particle size is thereby dependent on the desired properties
of the floor covering and the desired final thickness of the flooring. Suitable values
within a selected range are thereby easily determined by pre testing and the
effects thereof on the surface properties can be measured.
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In accordance with the invention, at least two particle fractions are used, the
physical and optical properties of which are distinguished in relative value from
each other. These properties can be, for example, the brightness, reflectivity,
colour shade, electrical conductivity or resistivity and surface roughness of the
flooring.
It is also desirable for added safety at the workplace to produce a floor covering
the surface of which includes embedded particles which, due to their brightness,define a broad not abruptly delimited emergency guide surface upon a power
failure and, thus, total darkness.
The caoutchouc particles are placed in a feed funnel which is upwardly and
downwardly open and on the surface of a dosing roller located below the funnel.
The longitudinal axis of the dosing roller extends perpendicular to the transport
direction of the soft, elastic web. The circumference of the dosing roller moves in
parallel to the transport direction of the web. Particles in the feed funnel flow into
the gap between the bottom opening of the funnel case and the surface of the
dosing roller upon rotation of the dosing roller. The width of this gap is defined by
adjustable brush rakes. The surface of the dosing roller is provided with a
multiplicity of axially extending grooves and recesses which are of differing depth
and are staggered relative to one another, and which are filled by the caoutchouc
particles. These grooves also function as storage containers from which the
caoutchouc particles are fed to the surface of the caoutchouc web according to the
positioning, depth and number of the grooves.
The difference in depth, the number and the positioning of the grooves parallel to
the roller axis is not limited in any way. These grooves or depressions are easily
manufactured so that the respectively optimal construction for desired flooring
surface appearances can be easily developed through testing. The web including
the particles is then subjected to one of the well known methods available for
vulcanization of the web to achieve a finished floor covering.
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,
Changes and modifications in the specifically described embodiments can be
carried out without departing from the scope of the invention which is intended to
be limited only by the scope of the appended claims.
