Note: Descriptions are shown in the official language in which they were submitted.
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PD53300PC.t2elCAL
TITLE
PROCESS FOR THE 1~IANUFACTURE OF AN EXPANDED FIBROUS
MATERIAL
DESCRIPTION
Technical field
'l0 The present invention relates a process for the manufacture of an
expandable fibrous
material as well as a material maJlufactured according to the process. The
invention further
comprises a method for expanding the expandable material.
At caulking or sealing of interspaces between building details, e.g., window
frames and
surrounding beams expanding polymer foam is often used today, e.g.,
polyurethane foam.
Such foam materials can in casse: of fire, irritate skin and air ways.
Furthermore, they are
difficult to apply in a sufficient amount and are relatively costly to use.
Thus there is a need for obtaining an expanding material without these
drawbacks.
WO 98/45565 discloses a sealing strip for filling, isolating and sealing of
air gaps, such as
air gaps present in buildings during construction, whereby the sealing strip
comprises a
compressed material contained in a compressed state retaining agent. The
compressed
material consists of foams of po'.uyurethanes, neoprene rubber, or
polyolefines. Such
synthetic materials do not behave in accordance with surrounding natural
materials, nor are
they innocuous in case of fire, but can be very hazardous.
H. G. Olshausen, "VDI-Lexikoru Bauingenieurwesen", Diisseldorf: VDI-Verlag,
1991, 281
discloses sheets of wooden fibres having different densities.
Summary of the invention
This object can be achieved by the use of expandable elements having a
determined form,
characterized in that a mass consisting of organic fibres is compressed in one
or more
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determined directions to a density of 300 to 1500 kg/m3, preferably 640-800
kg/m3, and that
elements having the determined form are formed from said mass. Such an
expandable
material can easily be placed in a determined place and then become expanded
by the
addition of water or other hydrophilic liquid. At the expansion of such a
material no noxious
compounds are developed or used and such a material thus allows for a
particularly
environmental way to seal interspaces between e.g., window frames and
surrounding beams.
Further one may, by choice the direction or directions, as the fibrous mass
has been
compressed in, to control the direction or directions of expansion.
In a preferred embodiment the elements are given the determined form at the
compression
but it is also possible to think that: the elements can be punched or cut from
the compressed
mass. The mass may consist of spruce fibres and the compression of the fibrous
mass can be
achieved by extrusion, rolling ar ;Form pressing. A water soluble binding
agent in
pulverulent form can be mixed into the fibrous mass prior to compression.
IS
The invention further relates to a method for expanding an element which
consists of a mass
of organic fibres compressed to a density of 300 to 1500 kg/m3 characterized
of adding a
hydrophilic liquid to the element.
~'.0 In a particular embodiment the invention relates to a process for filling
interspaces between
building details which interspace(-s) have a longitudinal as well as widening
extension,
characterized in that an element v~rhich consists of a mass of organic fibres
is compressed in
its thickness direction to a densit~r of 300 to 1500 kg/rn3 and which element
has
substantially the same length as tlxe interspace but a thickness that is
considerably smaller
~!5 than the width of the interspace, is introduced in each interspace
whereupon a hydrophilic
liquid is added to each element in such an amount that the interspace is
filled as the element
expands in its direction of thiclanas while absorbing such liquid. At a
practical use of this
process for sealing interspaces between a window frame and surrounding beams
such
elements are applied around the periphery of the window frame and after having
attached
..0 the window frame to the surrounding beams water is added, e.g., by
spraying. In this way
the elements expand in their direction of thickness to fill the gap between
the window frame
and the neighbouring beam.
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In a preferred embodiment of these expansion processes the liquid added
comprises one or
more additives, such as binding agents, preservation agents, putrefaction
agents or pest
insecticides. Likewise, the dry fibrous material can contain such agents in
dry form which
are activated and absorbed by the expanding fibre.
The invention also relates to an expandable element which is characterized in
that it consists
of a mass of organic fibre, preferably cellulose fibre, compressed to a
density of 300 to 1500
kglm3 and comprising a web in its central portion.
1.0 Figure legends
The invention will now be descrilbed with reference to the attached figures,
of which
FIG. 1 shows schematically a device for the manufacture of an expandable
material in
accordance with one embodiment of the invention;
FIG. 2 shows schematically a piece of an expandable element in accordance with
one
'L S embodiment of the present invention, and
FIG. 3 and 4 illustrate schematically a use of an embodiment of the invention
in which
expandable elements are used to seal the interspace between a window frame and
surrounding beams.
20 Description of embodiments
In figure 1 a process for the manufacture of an expandable material is shown
schematically,
starting from a mass 1 of organic; fibres, e.g., spruce fibres, arranged onto
a conveyor, not
shown, running in the feeding direction A. The spruce fibre mass has been
obtained by
mechanical milling. The fibrous mass 1 is compressed by letting it pass
through the pinch
25 between a pair o.f rolls 2-4, which are placed after each other in the
feeding direction A with
successively decreasing distance between the rolls of the pair of rolls. After
having passed
the last pair of rolls the fibrous nnass has been compressed to a hard board
having a density
of 300 to 1500 kg/m3, preferably 600 to 800 kg/m3. Finally, longitudinal
elements are cut
from this hard compressed fibre board using a suitable cutting device, such as
a punch.
In figure 2 such a cut element 6 is shown which at its left end part (of the
figure) has been
sprayed with water from a spraying bottle 7. The compressed element absorbs
the water
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added and expands simultaneously. It has turned out that the element at the
addition of
water in an amount enough, can expand up to 10 times its thickness when
compressed to a
hard board. After the expansion the element has obtained a foam-like
consistency. After
drying the element maintains its expanded volume.
The compression of the mass can also take place by extrusion or form pressing,
preferably
using a dry mass. At the process described the mass 1 is compressed in one
direction only
when passing the pinch of the pair of rolls. This is of course possible to
compress the block
in a direction perpendicular to this direction and the feeding direction by
letting the side
1.0 walls, as arranged in the device shown, but not shown in figure 1, to
prevent fibrous mass
from expanding side-wise at the passage of the pair of rolls, converge towards
each other in
the feeding direction A. An element produced in this way will at the
absorption of water of
course expand in the cross directional of the element.
:l 5 Wooden fibrous mass can be delivered in the form of compressed sheets or
block and the
expandable elements can also be produced starting from such blocks or sheets
by splitting
and, optionally, a further compression of these .
Figures 3 and 4 show schematically how expandable elements 6 manufactured in
:ZO accordance with the above can be used for sealing the interspaces between
a window frame
7, which has been inserted into a wall opening and the beams 8-11 which
restrict the
opening. The window frame 7 is provided with four pieces of elements 6' which
extend in a
surrounding groove or milled track formed in those sides of the window frame 7
which face
the beams 8-11. Ln figure 4 a cut piece of the window frame 7 is shown having
an element 6'
25 arranged in the groove of the window frame. The elements 6' have a suitable
thickness of 2
to 8 mm.
After having inserted such a window frame in a common way in a wall opening
and
30 attached it to the surrounding beams it is enough to add water, e.g., by
means of a spray
bottle 12 or the similar, onto the outside of the window frame in order to
have the elements
6' expand and fill the interspaces or the whole gap width between the windows
and the
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beams 8-11. Such a use of the invention contributes to a particularly simple
mounting of the
window frame in a wall opening. The elements 6' are further preferably
manufactured in
such a way that They will only expand in the direction of thickness at the
addition of water.
Thereby it is made sure that any after treatment to eliminate excess sealing
material is not
5 necessary, such as is the case when using conventional expanding polymer
foam materials
which expand in all directions. W an expanded state the elements are able to
take up
movements in the construction v~~ithout losing its sealing and silencer
function.
In the embodiment described the elements 6' are factory mounted onto the
window frame
and are suitably covered by a removable, surrounding tape to prevent the
elements from
being subject to unintentional addition of water, e.g., rain water. It is of
course in stead
possible to attach the elements 6' to the window frame when this shall be
mounted to the
wall opening. For this purpose one side of the elements can be covered with a
self adhering
glue or the similar.
The above described expandable elements can of course be used to fill other
interspaces and
voids between or within building details. At voids having a more complicated
three
dimensional form elements having been compressed in all directions, of course,
have to be
used. The elements according to the invention can be adopted to the voids to
be filled by
cutting, figure sawing or treatment in another suitable way.
The expandable elements according to the invention are delivered suitably in
the form of
longitudinal lathes or fillets and are, preferably provided with a self
adhering coating on
their one side to facilitate attachment of the elements to a building detail
or the similar.
In a variation of the process described one or more webs or the similar be
placed in the mass
prior to the compression thereof in order to improve the mechanical strength
of the
expandable elements. It is also possible to bring in liquid blocking layers in
the fibrous
material prior to the compressio~z.
The element according to the invention can also be used as mere sealing
fillets to exclude
water or other liquid. The expanding properties of the elements are used at
such use only to
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have the element expand into unevennesses of the surfaces the interspaces
shall be sealed,
whereby the degree of expansion is little. The abutment pressure against the
two surfaces is,
however, large. Even if the water will be absorbed by such an element so that
its surface
become wet water will, however, not leach out of the element.
The elements described above are made from fibres of spruce. Such fibres are
long and
flexible and the fibrous mass can be compressed to a density of up to 1500
kg/m3 without
destroying the fibres to any substantial degree. At a higher compression it
has fumed out
that the expansion when adding water is reduced, which implies that too a high
degree of
~'~ 0 the fibres have been damaged at l:he compression. For this reason the
density, after
compression should not exceed 1 S00 kglm3. Even other wood species than spruce
can be
used to manufacture the expandalble elements according to the invention and it
is also
thought possible to use other organic fibres, preferably cellulose fibres,
such as certain
species of straw, in order to obtain a material according to the invention.
us
The hydrophilic liquid, preferably water, which is added to the elements, can
advantageously contain additives, such as glue, presen~ing agents,
putrefaction agents or
pesticides. It is also thought possible to mix a water soluble glue in
pulverulent form into
the fibrous mass prior to the-com.pression in order to have the expanding
material adhere to
:20 the surface it expands against in ouch a way, at the subsequent addition
of water.
The expanded material according to the invention can, in sheet form, also be
used as an
insulating material. As the material in compressed form only takes minimal
space such
sheets can be attached in advance onto e.g., wall sheets and then be expanded
prior to or in
25 connection with the mounting of the wall sheets.
The expandable material according to the invention is a mere product of nature
and has
thereby great environmental advantages compared to the expandable polymers and
other
expandable conventional insulatung material, as the material is thought to
replace. The
30 spruce fibre is approved the Astluna and Allergy Society. The spruce fibre
material is also
relatively cheap and the material described can be produced to a relatively
low cost. Further,
the material can be reused in a number of ways. For example, after use it can
be
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recompressed where after it can be used as expandable material again. However,
the degree
of expansion decreases successively with the number of times the material has
been
expanded and recompressed, probably due to the fact that the degree of damaged
fibres of
the material increases at each compression. The expanding material can also be
dismembered and be used as an absorption material for oils, liquid chemicals,
and the
similar.
The embodiments described can of course be varied within the framework of the
invention.
For example, the expandable elements can be given another shape than
longitudinal
elements or sheets at the compression. Further, more pair of rolls thm three
can be used at
rolling. The invention shall thus only be restricted to the contents of the
accompanying
claims.
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