Note: Descriptions are shown in the official language in which they were submitted.
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Fibre mat
In the manufacturing of plywood, frequent defects occur
in the layer that should fcrrm the surface of the plywood
board. The same problems are common in other wood pro-
ducts like chipboards. These surface defects will cause
problems associated with use. If the boards are used in
concrete forms the :Final concrete surface will be uneven
and may require machining. Problems in connection with
lo~ the front rake may also occur. If the plywood board or
the chipboard is to be used in connection with other pro-
ducts, their appearance will be made uglier and the app!-
ication of any decorative final surfaces will be more
difficult.
Until now, these problems have, in principle, been solved
according to the following four different methods:
- by careful selection of the material used in plywood
manufacturing, the surface defects can be minimized;
fit) - by making the surface even by machining, e.g. using
grinding, in particular, when no deep surface defects oc-
cur;
- by filling the cavities, the surfaces of the plywood
boards have been made even;
- by applying a smoothing layer, it has been possible to
make the surfaces of plywood boards, chipwood boards, and
the like even.
The latter method differs from the others in that it
3!3 changes the characteristics of the surface as a whole,
and in that it adapts to, to express it briefly, to all
kinds of boards with wood as their material.
The method can be carried out by, before pressing, apply-
ing a fiber matting, essentially comprising a mineral
ffiber impregnated by a binding material, to one or both
sides of the board material. During pressing, the fiber
matting will level out all. uneven spots and then, after
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the binding material has hardened under pressure, form
hard and firm board surfaces.
The invention relates to this method and constitutes an
improvement of an earlier procedure. In spite of its
rather wide use, this procedure has not appeared to be an
optimal one.
If the surface upon which a fiber matting is to be
applied has a defect in the form of a cavity, one of two
extreme phenomena may occur. In the first of these
extremes, the fiber matting will act as a liquid. Under
pressure, the fiber matting material will flow so that
its density, i.e. its material mass per volume unit,
remains unchanged the whole time. In reality this extreme
case cannot be reached, as the fiber matting, in order to
secure its manageability, must remain as a whole. It is
not desirable either because the material of the fiber
matting could just vanish over the edges if there were no
specific obstacles, which in pratice are not obtainable.
In the other extreme, no material transfer takes place in
parallel with the surface of the board blank. This
results in the fact that the density of the fiber matting
in the middle of the cavity will be considerably lower
than at the other points of the surface. A weakening will
become apparent, after a period of surface wear, in the
form of surface unevenness. This is one of the problems
which the surface coating should eliminate.
Researches have shown that, in reality, we are quite
close to this extreme. The only possibility to compensate
for this phenomenon has been to produce oversize fiber
mattings so that the weakenings, which emerge in connec-
tion with the cavities on the surfaces of the wood
material surfaces, do not reach harmful dimensions.
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However, in practice there is a condition making this
situation more diff_Lcult. fiber mattings for said purpose
are manufactured bared on mineral wool spread upon a band
and then impregnated. It is well known that mineral wool '
mattings are normally chara.cterized-by unevenness so that
the fiber mass vari<~s between different positions. In
thick mattings, i.e. those with a large quantity of fiber
mass per surface ar~aa, there is always a levelling factor
in the form of random. If t:he fiber mass in one layer of
the matting is small within a certain area, there is a
strong likelihood that in t:he other layers the masses
will be normal, or even bigger than normal, whereby a
levelling or compensation has occurred.
1> In thin mattings, having a surface weight actual for
instance in lining of plywood boards, such a levelling
does not take place, or its extend is relatively limited.
This means that in any fiber matting, there may usually
very well be either too much or too little material in
the middle of a cavity in the wood. If there is too much,
the consequences will have no importance a.t all. However,
if there is too little material, this will mean that the
density in the fiber matting in the middle of the cavity
will be even lower than it would have been if the
2'5 material mass in th.e fiber matting had been normal. '
In practice, it is not possible to achieve an absolutely
even fiber matting if the costs have to be taken into
consideration. However, it has turned out that this prob-
lem can be solved t:o a satisfactory extent even when the
uniformity is not perfect, if it satisfies the condition
that the uniformity, measured in the way described below
or in any other way with equal results, reaches 20 o at
the most, calculated as a variation factor.
However, this requ_Lres that in the fiber matting there
should be a flowing binding material which will transfer
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4
the pressure from the press to the individual fibers.
Also some form of a filler may be needed to modify the
lubricating characteristics of the binding material.
Therefore, the objective of this invention is to provide
a fiber matting consisting mainly of mineral fibers, pri-
marily intended to be used as a face for plywood and the
like in order to reliably level out all of the uneven
spots in them in connection with the pressing and curing
of the binding material, hereafter called the filling
capacity, and to otherwise improve its characteristics,
so that the mineral fibers form a uniform structure and
are uniformly distributed over the fiber matting so that
the scattering of the deformation resistance does not
exceed 20 0, calculated as the variation factor, and so
that the distribution of the fiber lengths is bimodal.
The uniformity of a fiber matting can be defined in sev-
eral different ways. for this purpose the surface weights
of small surface elements can be determined. Research
has, however, proved that the deformation resistance
according to the method described below, supported by
Fig. lA, is a better representation of of the filling
capacity of the fiber matting. According to this method,
a metal cylinder A with a diameter of 10 mm, fixed to the
measuring rod B in a measuring clock C, can from above
press against a fiber matting D laying on a horizontal,
even base E. The combined weight of the metal cylinder A
and the measuring rod B is 200 grams.
According to this method, 20 areas of fiber matting with-
in the surface area of 210x297 mm (A4) are measured. The
mean value M of the distances and the standard deviation
s are calculated, and from them the variation factor v is
calculated using the formula
v = 100 * s/M
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A more extensive scattering may lead to the risk of an
unreliable filling capacity. Uniformity is importat even
on surface covers ccmtaining no or only local uneven
spots. Thus, in casE: one, when trying to obtain a
5 strengthened surface:, it is essential that there are no
weak areas on it as, in practice, the technical outcome
will depend on the characteristics of the weakest points.
It is obvious that a certain material mass is required to
make the fiber matta_ng effective, whatever material it is
made of. For most practical purposes, the surface weight
requirement is at least 150 g/mz, preferably at least 250
g/mz
An important precondition for the good functioning of the
fiber matting in practice is that its fiber length dis-
tribution is bimoda:l. It i~; true that a low average
length may result in good filling capacity but it gives
insufficient inner coherence to obtain the treatment
characteristics req»ired in practice. A high average
length gives coherence but lacks in filling characteris-
tics. Looking at th~~ problem superficially, it should be
possible to find an average length in between, with both
sufficient filling ~haractE~ristics and sufficient treat-
ment characteristics, this has, however, not proved
viable. Suprisingly it has been proven that a suitable
fiber matting can be obtained by providing a bimodal
fiber length distribution.
It has been impossible to develop a structurally formu-
lated theory for this phenomenon, but it is most likely
that bimodality results in a mobility of the shorter
fibers forming a mass in re=_lation with the long ones,
with a tendency to form a more immobile grid.
By way of definition, such a bimodal fiber length
distribution is characterized by two frequency peaks.
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Both of these frequency peaks need not be equally high.
If they are not equally high the lower one must, however,
be sufficiently high so that the probability a random de-
viation of a unimodal distribution is in practice eli-
urinated.
Bimodality may form the basis for seeing the fiber mass
as containing two fiber fractions, one shorter and the
other longer.
It has been noted that an increased uniformity down to
the variation factors less than l0 per cent and up to 5
per cent will result in observable advantages but also
that the excessive uniformity obviously does not mean
increased filling capacity, nor any other advantages.
In order to make the longer fibers function optimally and
give strength without greatly reducing the inner mobility
that contributes to the filling capacity, the relation
between those fiber lengths that refer to the two
frequency maxima in the bimodal fiber length distribution
must be greater than 5, preferably also greater than 10.
In this way, good results have been achieved by the mix-
ing of average 25 mm length fibers in a fiber mass, the
average fiber length of which is about 3 mm. When the
longer fibers were reduced to an average length of 10 mm
a large quantity of the longer fibers had to be added to
achieve sufficient strength and the filling capacity
became too low. As the long fibers normally cost more
than the short ones, in this case, even the economy of
the production will suffer.
Fig. 1B shows an example of a bimodal fiber length dis-
tribution with two frequency maxima, one by 3 mm and the
other by 22 mm. The relation between these two fiber
lengths is 7 and thus the shown example should satisfy
the requirement according to Claim 3. Also Fig. 1C, show-
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7
ing a bimodal fiber length distribution with the fiber
length maxima by 3 and 15.5 mm respectively, satisfies
the requirement according t.o Claim 3.
However, and not surprisingly, it has appeared that other
characteristics of i~he fiber matting are also influencing
its filling capacit~~. One ~~uch characteristic is the
orientation of the :~ibers. Depending on the way the
fibers are grouped :in bundles or clusters, their filling
~.0~ capacity is reduced. The same is true if a larger number
of fibers is orient;~ted perpendicular or nearly perpen-
dicular against the fiber matting level. Further, it is
not convenient to 1~'t a large number of fibers take a
certain direction, ~.g. the' running direction of the
fiber matting. Instead, the fibers in the fiber matting
should be mainly randomly orientated on the level of the
fiber matting.
It is very difficult to directly observe that the fibers
are randomly orientated. Instead, it is preferred to
measure the tensile strength of the fiber matting in
longitudinal and transversal directions. The relation
between these values must not be less than 0.5 and not
greater than 2. Preferably, the relation should be
between 0.7 and 1.5. Outside these limits the fiber
orientation is no longer random enough and the filling
capacity may become too minimal.
Treatment of the fiber matting in different phases empha-
3~0 sizes the tensile =,trength requirements of the longitu-
dinal direction move than those of the transversal direc-
tion. Therefore, it: is an advantage if, in any given
interval, the value. of the former is higher than that of
the latter.
In particular, the thicker fiber mattings according to
this invention sometimes have the tendency to delaminate
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under treatment, i.e. to form layers caused by insuffi-
cient inner coherence in their thickness direction. This
is due to the fact that an overwhelming part of the
fibers, and especially the long ones if any of those are
involved, are placed at the level of- the matting and only
a few of them have a significant reach in the perpendicu-
lar direction against this level. This relationship can
be corrected by so-called needling, providing sections of
the longer fibers reach through the fiber structure in
its thickness direction. This is an efficient means to
keep the structure together.
The bimodal fiber length distribution can be achieved by
mixing several fiber materials with distinctly different
length characteristics. If these fiber materials are also
made of different basic materials, e.g. so that one is
inorganic and the other organic, it will be easy to
determine, even after mixing, their respective
proportions, e.g. in volume percentages.
If the bimodal fiber length distribution has been the
outcome of something else, or if the two fiber materials
to be mixed consist of the same basic material, this can
appear more difficult. If the fiber length distributions
are so widely separated that there is between them an
empty fiber length interval, even in this case the pro-
portions between them can be determined. If, on the con-
trary, the fiber length distributions are overlapping,
there are cases when it will not be possible to determine
whether a certain fiber belongs to one portion or to the
other. Therefore, to be able to give the mutual propor-
tions, a convention is used where the fiber length
between the two frequency maxima, showing the lowest
fiber frequency, is used as divisor. If this lowest fre-
quency covers several fiber lengths, or one fiber length
interval, the average value of these fiber lengths or of
the fiber length area is used instead.
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In the example shown in Fig. 1B, the following fiber
lengths between the two frequency maxima are empty: 11,
13, 14, 15, 16, and 18 mm. The average value of these is
14.5 mm, thus giving, by way of definition, the boundary
between the two f ibf=_r materials .
The example shown i:n Fig. 1.C shows the minima by 9 and 11
mm, respectively, a:nd thus the boundary between the two
distributions is, by way of definition, 10 mm.
The researches concerning the present invention show that
the proportion of the longEar ffibers, i.a. of those
belonging to the longer of the two fiber length distribu-
tions, must be up to at least 8 per cent, preferably at
least 15 per cent of the total fiber volume.
Even the length characteristics of the fiber component
with long fibers is significant, although the most
important is that their average length is considerably
more than that of the rest of the fibers. The longer of
the two fiber distributions must have its average length
within 10 to 80 mm, preferably 20 to 40 mm. Any shorter
fibers have a lower strength contribution and any longer
fibers do not seem to be beneficial in relation to the
material mass they represent.
In the experiments, three categories of long fibers have
been shown to be e:~pecially advantageous, regarding dif-
ferent aspects such as functioning, costs, and willing-
ness to be uniformly distributed. In this context, func-
tioning means considering the positive effect that the
long fibers have on the tensile strength of the fiber
matting, and the negative effect they have on its filling
capacity, probably due to the fact that they limit the
mobility of the relatively shorter fibers. One of these
categories comprises organic fibers, e.g. the synthetic
fibers of polyester, polypropylene, polyamid or of
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polyester/polypropylene, polyester/polyethene,
polypropylene/polyethene and polyester/copolyester. This
category may also comprise the viscose fibers. Their
maximum thickness in this case must be 7 decitex. The
5 second category comprises fibers of -glass, conventional
glass fibers or fibers of glass with a basalt like compo-
sition. Their maximum thickness must be 3 decitex. Both
of these categories are characterized by a smooth fiber
surface and a high tensile strength. These result in a
10 good strengthening effect, without a too high reduction
of the mobility of the shorter fibers during the pressing
process.
Even natural fibers such as cotton, jute, linen, and
sisal fiber, or modified natural materials such as cellu-
lose fiber, have been shown to be effective. Although
their surface is not smooth, they are functional, prob-
ably due to the fact that they are, instead, broken by
the powers which influence them during the pressing pro-
cess.
Not unexpectedly, even the fiber thickness of the compo-
nent with long fibers is significant. The optimal value
for this parameter has appeared to be within a fairly
narrow area, i.e.
- for organic polymer fibers 3 to 7 decitex, preferably 5
to 6 decitex
- for conventional glass fibers o.7 to 3 decitex, prefer-
ably 1 to 2 decitex
- for fibers with a basalt like composition 0.2 to 3
decitex, preferably 1.2 to 2.2 decitex.
The desirable inner mobility of the fiber matting
depends, very significantly, on the fiber morphology of
the mineral fiber component. The shorter fibers seem to
play a key role here, and their ratio should be limited,
i.e. the relation between their length and diameter. This
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11
can be expressed so that the fibers with a length under 5
mm have a relation between their average lengths and
their average diameters between 100 and 1000. A lower
ratio leads to a structure with a too insufficient inner
strength, notwithstanding the positive influence of the
long fibers. A too high ratio works against the inner
mobility and leads too lowered filling capacity.
The information about the fiber diameters mentioned here-
by concern the optical microscope measurements magnified
by 500 times. They are given as averages of 200 individ-
ual diameter measurements by using good preparation and
observation methods.
The fiber length in:Eormation indicates direct measure-
ments from a projection picture with the ability to mag-
nify the fiber sample 100 times.
In order to comply 'with it~~ final function, the fiber
matting has to cooperate with a binding material. This
invention also comprises a fiber matting with such a
binding material. The task of a binding material is obvi-
ously to bind, together wii~h the pressing procedure, the
compressed fiber matting into a tight and strong layer.
At the time of pressing, the binding material can also
have the role of a lubricating medium, transferring and
distributing the pressing power to the individual fibers
in the fiber matting. To this end, the most suitable
binding material should flow, at least at high tempera-
tures such as in a thermo-compressing process.
However, the binding material in its cured state has its
most significant impact on the surface against which the
fiber matting has ~>een pressed under heat. In order to
achieve the right combination of tightness, wear resis-
tance, and overall resistance against chemical and
microbe attacks, preferably unsaturated polyester, but
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also vinyl ester, epoxy; phenolformaldehyde, melamine or
the like can be used.
The binding material can include fillers, the task of
which in this case can be manifold,-as they can partly
modify the effect of the binding material to help the
inner movements in the fiber matting during the pressing
process, and partly modify the mobility of the filler
particles in the fiber structure to improve its filling
capacity. Furthermore, the filler particles can improve
the wear resistance of the ready-made outer surface,
other resistances, or some other new or improved charac-
teristics. Suitable filler materials are fine- grained
mineral powders such as limestone flour, talcum powder
and wollastonite flour.
Among the additional characteristics that can be added by
suitable choices of filler, the following can be
mentioned: fine corn pyrite carbide gives the coating of
plywood or chipwood boards high friction characteristics,
grains of materials with a high portion of relatively
lightly splitting chrystal water can give added fire
resistance, graphite flour can improve the release char-
acteristics against e.g. concrete.
Even inorganic filler materials can be used. For
instance, wood powder can regulate the flow characteris-
tics of a flowing binding material and reduce its
required quantity.
The filler material must have a fine-grained structure,
or more precisely, its average grain diameter must be
under 10 ~,m, preferably under 5 Vim.
The filler material element in the completed mix of the
binding material and the filler must be within the range
of 15 to 50 weight per cent, preferably 20 to 30 weight
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per cent, out of the total weight of the binding
material, including the filler.
In order to obtain 1=he highest possible effect from the
filler material°s ability to increase the final outer
surface, the concenl~ration of the filler particles must
be higher on the side of the fiber matting which is
turned outwards during pressing. On the other hand, in
order to obtain the best possible filling capacity the
concentration of th~~ filler particles may need to be
higher on the side ~~f the fiber matting which is turned
inwards during pressing. These two effects can be
combined by making 'the concentration of the filler par-
ticles higher on both sides of the fiber matting than in
its middle. The concentration of the filler particles
needs not be the same on both sides, and not even the
same filler material is necessary. As a matter of fact,
both the method and the concentration can be individually
adapted to the use or to the advantage of strengthening
24) the complete product coated by the fiber matting on one
side, and to the need or to the advantage of increasing
the inner mobility and the filling capacity.
The part of the binding material without filler must be
2!~ 50 to 200 weight per cent, calculated with the weight of
the fiber material, in order to achieve the right filling
and the desired final characteristics.
To make the penetration of the binding material into the
30 fiber matting easier, especially if it is relatively
thick and/or of high density, the fiber matting can with
advantage be equipyed with holes or weakenings, e.g. by
driving needles through it. The art of these, as well as
their density, or mutual distances, is in this case
35 adapted according t:o the need of the penetration help
required by the actual case.
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Normally, a needling with a needle density of 10 to 20
seedlings per cm2 may be suitable, provided that the diam-
eter of the needle is about 0.3 to 1 mmz. The use of
thicker needles brings about deeper penetrations. When
striving to obtain improved and even, but not very deep,
penetrations, thinner needles and smaller distances
should be chosen.
This invention also includes a method of manufacturing a
fiber matting, primarily intended for plywood board coat-
ings and the like, in order to level out, in connection
with pressing under heating, their unevennesses and to
improve their characteristics, whereby the fibers in the
fiber matting form a coherent structure and are evenly
distributed over the fiber matting, so that the scatter-
ing of the deformation resistance does not exceed 20 per
cent, calculated as a variation factor, and whereby the
ffiber length distribution is bimodal.
According to the present invention, the mineral fibers
are dispersed into the air, together with a fiber compo-
nent of long fibers, and then the fiber dispersion is
laid on a mobile, perforated receiving means, without
using gravitation, as a matting, and using air suction.
In a suitable way, the starting point is preferably a
thin web of mineral fibers that are dispersed using two
or more brush rollers, possibly after a fiber shortening
run by crushing them between the rollers.
The receiving part can be made of a band or drums.
In order to achieve sufficient evenness, the dispersing
and the recollection may require more than one stage. In
that case, the fiber component with long fibers will most
conveniently be added before the first dispersing.
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It is convenient to add a binding material to the fiber
matting in a separai~e process, by adding at least one
thin and tight carrier layer, e.g. polyethene foil,
whereby the binding material is inserted between the foil
5 or the foils and th~~ fiber matting before they are put
together. After thi;~, when the foil or foils and the
fiber matting are pwt together, at least a partial
inserting of the binding material in the fiber matting
will take place.
At this stage of the process, it is possible to prepare
one or two mixings of bind_Lng material and filler that
will be laid over one or two foils to be thereafter rote-
grated into the fiber web from the first process part, so
that the side of the foil or foils coated by the binding
material and the filler are turned against the fiber web,
whereafter the integrated :Layers, the fiber web and the
foil or foils will be pres:~ed together.
The process itself can be carried out in several ways,
according to the prevailing conditions. It is possible
either to coat the surfaces of the carrier layer that are
against the fiber matting or the carrier layer with the
binding material, or apply the binding material to the
completed fiber mataing before coating the carrier layer
or the carrier layers, or to use a combination of these
methods so that the binding material is laid directly on
the upper surface of the fiber matting and a protective
layer is laid on the lower surface which is then combined
3.0 with the fiber mati:ing.
If the fiber matting is mainly transferred horizontally
and the binding mai~erial with its possible filler is dry,
it can be strewn on the lower foil and/or on the upper
X35 surface of the fiber matting before the foil or foils are
combined with the :fiber matting.
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In order to ease and control the penetration of the mix
of the binding material and filler in a later phase of
the process, a treatment with needles can in some cases
provide advantages when thinnings or holes are made in
the fiber matting. If there are long fibers, these can be
made to better bind the fiber structure together by using
needles with barbs that make some of the long fibers
stretch through the fiber structure in its thickness
direction.
The needling density is most conveniently within the
range of 10 to 20 needle impacts per cm=. The preferable
cross profile of the needles is the farm of an equilat-
eral triangle with rounded edges, and thickness 0.5 mm,
measured as the height of the equilateral triangle. If it
is not just local thinnings but also the orientetation of
some fibers in the transversal direction that is re-
quired, the needles should be equipped with barbs, pre-
ferably projecting out from the needle point.
The needles are preferably placed on one or several
needle booms with a density of 1000 to 3000, preferably
about 2000 needles per meter, and in about 20 rows, off-
set in relation to each other by a half of the needle
distances in the rows.
In those cases where it seems to be useful, it is also
possible to ease the penetration of the binding
material/filling mix into the fiber structure by treat-
ment after the combination and pressing together, There
are several treatments to be used. Preferably, it can be
carried out by passing the fiber matting through two or
more rollers, with a relatively light pressure on the
fiber matting. Preferably, the rollers can be equipped
with thicker sections or spots causing a periodically
varying treatment in the form of changing compressions
and lowerings of pressure.
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The present invention also comprises a use of the fiber
matting whereby the fibers form a coherent structure and
are evenly distributed over the fiber matting so that the
scattering of the d~=_formation resistance does not exceed
20 per cent, calculated as the variation factor, and so
that the fiber length distribution is bimodal. The use
according to the invention comprises, in the first phase,
the one-sided or dowble-sided impregnation of the fiber
matting and, in connection with this, a ore-sided or a
double-sided coating is applied to it, together with a
protective foil. After the protective layer has been
removed, a material layer, e.g. a plywood board or a lay-
er of wooden particles or :Fragments, is applied to one or
both sides, and then the material layer and the fiber
matting or fiber mattings are transferred to a press
where the layers are pressed together by high pressure,
and the binding material is fixed to it, preferably by
heat under the pressing operation.
Thus, the operation, comprises three part processes, the
manufacturing of true fiber matting itself, its
impregnation, and t:he pressing together of the
impregnated fiber matting with a material layer in combi-
nation with which 3_t will be used. These three processes
can be carried out in one operation, without using any
rolling, storing or transportation of the fiber matting
between the phases. The manufacturing and the
impregnation of the fiber matting can take place in one
single phase, and then the impregnated fiber matting is
?~0 transported, rolled in a ~;uitable way, to its final site
of use as e.g. a coating c>f plywood.
Another alternativf=_ is that the fiber matting is manufac-
turgid at one site and then transported to another site
X35 where the impregnavion with the binding material and the
coating of a material layer takes place, closely
connected with eac'.n other,. In this case it may even be
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28
possible to eliminate the use of a protective foil.
Finally, the manufacturing of the fiber matting, its
impregnation, and its final combination with e.g. a ply-
wood board can take place at three different sites, using
transportation and possibly even storage between each
phase.
In the following, the invention is described in more
detail with references to Figs. 2 and 3. Fig. 2 shows the
manufacturing of a fiber matting, and Fig. 3 a double-
sided impregnation of such a fiber matting.
Fig. 2 shows the insertion of a relatively thin mineral
wool matting 1. This can be manufactured in a
conventional way, by melting minerals, e.g. basalt, with
a lesser addition of dolomite or limestone in the furna-
ce, e.g. a cupola furnace, to a continuous melt flow from
the furnace, leading this flow against the periphery sur-
face of the spinning wheel that is the first one in the
series of wheels arranged in a cascade. From there, the
melt is slung out in the form of e.g, fibers that are
then transferred by air streams to a perforated collec-
tion band through which the air is sucked away, leaving
the mineral fibers as a matting laying on the conveyor
band. The surface weight of the mineral wool matting 1 is
50 to 250g/mz and it is carried by the conveyor band 2 in
the direction shown by the arrow 3 in between the two
brush rollers 4 and 5.
The brush roller 4 rotates anticlockwise and the brush
roller 5 clockwise, although with a lower peripheric
speed than the brush roller 4. The peripheric speed of
the brush roller 5 is higher than the speed of the band 2
and the peripheric speed of the brush roller 4 is at
least three times higher. The density and diameters of
the brush rollers can to a certain extent be adapted to
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the characteristics and surface weight of the mineral
wool matting 1 used as input material.
By the work of the brush rollers 4 and 5, the mineral
wool matting 1 is broken to fine small fragments 6 that
are slung into a first fiber chamber 7 and deposited in
the form of a new fiber matting 8 on its bottom, consist-
ing of a conveyor band 9. The band 9 transports the newly
formed fiber matting 8 out from the fiber chamber 7 under
a tightening roller 10. After hawing come out from the
fiber chamber the fiber matting 8 passes between two
rollers 11 and 12 z~pplying~ such a high adjustable pres- ',
sure against each other that the fibers in the fiber mat-
ting are made considerably shorter by breaking them under
pressure. The rollers are driven and pressed against each
other by conventional arrangements not shown in the fig-
ure. After passing between the rollers, the fiber matting
8 is laid down on i~he conveyor 13. While it is
transferred on thi:~, a long fiber component 14 is added
2;0 to it from above and dosed with a device symbolized in
the figure by the monveyor 15.
The dispersing and recollection processes taking place by
using the elements indicai~ed here by 2 to 13 can be
doubled or tripled. Regarding any dispersing and recol-
lection process, by suitably adjusting the mutual
distances of the brush rollers and their rotation speed,
as well as their tightness and diameters, e.g. the even-
ness of the output fiber matting can be made better than
that of the input matting.
The surface weight of the rebuilt fiber mattings is
important as well. This is regulated by increasing or
reducing the speed of the band or the bands 9. The con-
85 venient adjustment of the device is such that the surface
weight before the last dispersing, to be described below,
remains between 7C to 120g/m'.
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The more or less rolled and once or twice dispersed and
recollected fiber matting 8 is now directed, with a long
fiber component 14, in between a further pair of brush
rollers 16 and 17, corresponding to the brush rollers 4
5 and 5, in a fiber chamber 18, corresponding to the fiber
chamber 7. The brush rollers 16 and 17 now disintegrate
the material of the fiber matting 8 and the long fiber
component, covering it with a dispersion in the fiber
chamber 18. Forced by gravity and an airstream directed
l0 downwards, the reason of which will be described later,
the particles in the dispersion now move mainly
downwards. The possible larger parts and the non-fiber
material is cast as far away as possible by the force of
the brush rollers and, in principle, they follow the path
15 indicated by the curve 19. On the other hand, the fiber
dispersion is sucked by the blower 20, in principle fol-
lowing the path of the curve 21, against the perforated
band 22 so that a new fiber matting 23 can be formed.
Thereby the air sucked by the blower 21 is separated from
20 the flow and passed through the band 22 via the channel
24 to the blower. After the blower, the air passes a fil-
ter 25 and is then led via the channel 26 back to the
fiber chamber 18. This is how the airstream downwards and
past the brush rollers 15 and 17 is created.
The newly formed fiber matting 23 is now directed by the
band 22 over to the conveyor 27 that will remove the
fiber matting from the fiber chamber 18 and then feed it
under the tightening roller 28.
After this, the fiber matting 23 can be taken for needl-
ing in a conventional needling device, here symbolized by
the conveyor 29 and the needling tool 30, with its needle
plate 31, and a device 32 for its movements up and down.
The possible larger parts and the non-fiber material fall
down onto the band 33 and are taken out from the fiber
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chamber 18 under the tightening roller 34 as waste 35.
By adjusting the rotation :peed of the blower 20, or by a
damper in the channel 26, the air flow circulating
through the fiber chamber .L8 can be adjusted so that a
suitable separation grade us achieved. With a small flow,
mainly just the totally free fibers are caught on the
band 22 and a major part of the fiber material falls down
onto the band 33. On the contrary, if the flow is bigger
ld) the balance between the influence of the virtually
upwards directed airstream in the vicinity of the band 22
and gravity is offset so that a larger part of the fiber
material is sucked up towards the band 22.
1:~ The waste 35 may contain considerable quantities of
fibers. Especially because of small air flows and the
high purity of the material collected on the band 22
caused by this, a ~~ignificant quantity of the fibers,
that would as such still be usable, may be directed to
20 the waste side. They can then be recovered to the process
with or without a reparation process set between. One of
the ways to recover- them is to disperse the waste in an
airstream and then direct it to a cyclon where an adjust-
able part of the solid materials is separated, while the
25 rest of them, containing most of the fibers, are recol-
lected to a matting that in turn may be taken back to the
process together with the input fiber material 1.
Due to the fact that gravity does not contribute to the
30 depositing of the :~iber material on the band 22, the
influence of the a:irstream will be the only force to
bring the material there. As the airstream through a cer-
taro part of the active band surface is reduced the more
fiber material is deposited onto it, the airstream
3.5 becomes relatively bigger through those parts of the
active band surface where the fiber material quantity is
not so large. Therefore, z-elatively, the depositing will
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increase there. In this way a levelling of the surface
weight takes place so that, in the end, it will be suffi-
cient.
Thus, the evenness is largely a function of the
efficiency of the dispersing and of the formation of the
depositing process. The important aspect of the latter is
that the gravity force does not contribute to it. This
does not mean that the active band surface of the band
22, i.e. that part of the band through which the
airstream is flowing, should be horizontal when the air
flow, in principle, is vertical in an upwards direction.
The active band surface can also be vertical when the
airstream, in principle, is horizontal. All forms between
25 these can also be considered, e.g. an active band surface
that forms a 45° angle against the horizontal level and
an airstream that is in principle streaming through it in
a direction diagonally upwards.
In more detail, the evenness also depends on certain pro-
cess parameters, like the rotation speed of the brush
rollers, the surface weights of the various parts in the
process etc. It is not possible to give a general deter-
mination of these, as they have to be adapted to the
respective fiber materials input in the process. Several
variations can be considered. For any professionals, it
should anyway be possible to find out, with a limited
input, in which way the process parameters and the number
of dispersings should be chosen in order to achieve the
desired results.
The fiber matting 23 manufactured in this way can be
rolled to the rolls for intermediate storage and trans-
portation to an impregnation plant to be impregnated with
a binding material or to be transported directly to the
plant if the plants are located near each other and it is
otherwise desirable to do so.
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It can also be taken away t:o other operations or uses, ',
for instance to become a ca~pillar-breaking layer in
building constructions exposed to humidity.
Fig. 3 shows the principal layout of a plant for impreg-
nating a fiber matting manufactured by the method
described here, or lay some other method within the range
of the invention. Tl~e binding material is pumped out from
three binding material tanks 36 by dosing pumps 37 and 38
1t) into a guiding system 39 and 40. The binding material
pumped out may contain jusi~ one binding material or a
mixture selected freely wii~hin a certain range. The num-
ber of the binding material tanks, three in the figure,
can be chosen according to needs. The guiding system 39
leads the binding material or the binding material mix
into a mixer 41. A filler or a mix of various fillers is
added to this. From the beginning, the fillers are stored
in filler silos 42. The filler is taken from these by the
dosing input devices 43 and 44 to the horizontal
conveyors 45 and 46. These can be of a screw type. The
conveyor 35 supplies the filler or the filler mix to the
mixer 41 via the feeder pipe 47.
In a similar way tr:e pipe system 40 conducts the binding
material or binding material mixture from the metering
pumps 38 to the mi~:er 48, to which also the horizontal
transport 46, which is fed from the dosing feeders 44,
leaves a filler or a filler mixture via the feeder pipe
49.
The binding material and the filler are mixed in the
mixers 41 and 48 to form am even mix. This mix is then
pumped from the mi:~er 41 by a peristaltic pump 50 via a
pipe 51 to a sweepE~r 52. This spreads an adjustable quan-
tity of the binding material/filler mix to form a thin
and even layer on a carrier layer 53 coming out from a
storage roll 54.
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In a similar way, the mixing of the binding material from
the pipe system 40 and the filler from the feeder pipe 49
takes place to make it to an even mix. This mix is then
pumped from the mixer 48 by a peristaltic pump 55 via a
pipe 56 to a sweeper 57. This spreads out an adjustable
quantity of the binding material/filler mix to form a
thin and even layer on a carrier layer 58 coming out from
a storage roll 59.
The carrier layer 58 coated this way is now transferred
by the transferring rollers 60 over to a conveyor 61.
A fiber matting 63 manufactured using the method
described, or by any other method, is rolled out from the
storage roll 62. It can also come direct, without any
intermediate rollings or rollings out. The fiber matting
is laid dawn by the transferring rollers 64 onto the car-
rier layer 58 on the conveyor 62. Thus, the carrier layer
53 is laid down on the fiber matting 63 by using the
transferring rollers 65. The combination 66 with three
layers is now directed under the band press 67, compris-
ing an upper band 68 and a lower band 69. The band press
68 presses the three layers together so that the mix of
the binding material and the filler is pressed into the
fiber matting.
After the pressing together, the fiber matting 70
equipped with the binding material, the filler, and the
carrier layer, is now lifted from the conveyor 61 using
conveyor rollers 71. At the treatment station, comprising
a series of lower rollers 72 and a series of upper
rollers 73, the fiber matting can be treated 67 in a con-
trolled way whereby the penetration of the binding
material in the fiber matting increases. Finally, the
fiber matting 70 is rolled up into a roll 74 and is now
ready to be used according to its purpose.
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The described impregnation can also be applied on one
side only.
The invention can ~~lso be operated by using dry,
5 powderlike binding materials, possibly mixed with a fil-
ler in a way that is, in principle, compatible with what
is shown in Fig. 3. The means of preparing and transfer-
ring the binding m~cterial and the mix of the binding
material and the f~_ller, respectively, are in that case
1o composed accordingly. They may, advantageously, be closed
pneumatic systems. Fig. 4 shows one such arrangement. The
arrangement of the main parts complies with the one shown
in Fig. 3, the dif~~erence being that the upper side of
the fiber matting :is covered by a binding material in
15 powder form using a delivery device 75 that, with a cell
feeder connected t~~ a vibrator, not shown in the figures,
delivers the bind ing material in powder form, with or
without the filler mixed in, over the width of the fiber
matting 63 and to :be depo~~ited on it. It is then covered
20 by the carrier layer 53, t:he task of which, in this case,
is mainly to act as a protective or covering layer. When
this layer has been laid, the pressing together takes
place in the band press 6',7.
25 Fig. 5 shows an arrangement where the binding material in
powder form is applied to both sides of the fiber matting
63. This is done by feeding both the fiber matting 63 and
the carrier layers 53 and 58 from above and with a cer-
tain distance between them. The carrier layer is then
moved against the fiber matting using the press rollers
76. Immediately before the carrier layer and the fiber
matting are pressed together by the rollers, the binding
material in powder form is added to the mixture from the
feeders 75. After this, the combination of the carrier
:35 layer, the fiber matting, and the binding material can
continue downward~> towards the conveyors 61 and into the
band press 67.
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Designations used in figures and text:
A metal cylinder
B measuring rod
C measuring clock
D fiber matting
E base
1 mineral wool matting
2 band
3 direction arrow
4 brush roller
5 brush roller
6 fragment of fiber matting
7 fiber chamber
8 fiber matting
9 band
10 tightening roller
11 roller
12 roller
13 conveyor
14 long fiber component
15 conveyor
16 brush roller
17 brush roller
18 dispersion of fibers
19 curve for non-fiber material
20 blower
21 curve for fibers
22 perforated band
23 fiber matting
24 channel
25 filter
26 channel
27 conveyor
28 tightening roller
29 conveyor
30 needling tool
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31 needle plate
32 arrangement for needle plate movement
33 band
34 tightening ra~.ler
35 waste
36 binding material tanks
37 dosing pumps
38 dosing pumps
39 pipe system
40 pipe system
41 mixer
42 filler silos
43 dosing feeder
44 dosing feeder
45 conveyor
46 conveyor
47 feeder pipe
48 mixer
49- feeder pipe
50 peristaltic pump
52 pipe
52 sweeper
53 carrier layer
54 storage roll
2.5 55 peristaltic pump
56 pipe
57 sweeper
58 carrier layer
59 storage roll
,30 60 conveyor rollers
61 conveyor
62 storage roll
&3 fiber matting
64 conveyor rollers
35 65 conveyor rollers
66 combination of carrier layer and fiber matting
67 band press
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68 upper band
69 lower band
70 fiber matting with carrier layer
71 conveyor rollers
72 lower rollers
73 upper rollers
74 roll of fiber matting
75 delivery device for binding material in powder
format, with/without filler
76 pressing rollers
