Note: Descriptions are shown in the official language in which they were submitted.
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Technical Field
This invention is in the field of forming solid
products from a fluid evolutive product.
Background of Prior Art
A fluid evolutive product is a liquid in which a
reaction resulting in a physical or chemical transformation
takes place such as producing a solid phase or modifying the
characteristics of a solid phase initially carried by the
liquid.
The present invention is concerned with manufactur-
ing of board by pouring, upon a moving conveyor, a fluid
evolutive product. Plaster powder and water mixture is
exemplary of such a product. As soon as plaster powder is
mixed with water, it starts evolving rapidly until it sets
completely. Continuous process manufacturing of plaster
building components demands a control of the plaster reacting
stage at each moment and at all stages of mixing, from the
initial supplying of pulverized plaster powder and water up to
the end of line where completed building components are ready
to be used.
When an evolutive product has a pasty consistency,
the way to control its evolution inside a tooth type mixer is
known, and the way to spread it in continuous process upon a
moving conveyor having a conveyor belt in order to form a more
or less even plaster strip which may be put into forms in a
continuous process is known. But working with a paste
necessitates heavy equipment since the cohesive forces to be
overcomeare important, and paste flow rate regulation and
paste level measurement are far from accurate. Hence there is
unevenness in the amount of the product supplied to the moving
conveyor and consequently unevenness in the finished product
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quality.
When the evolutive product has a liquid consistency,
as in the case of plaster, the only way known to use it for
the manufacturing of building components is in a non-
continuous process. It is poured into molds where it is leftuntil the plaster sets. Up to now, a liquid plaster mixture
is not used in a continuous process, partly owing to the
difficulty encountered in holding liquid plaster by a valve
during its mixing inside a standard mixer without the mass
setting of deposits at the level of the narrow channel
created by the valve, and partly also owing to the difficulty
encountered in keeping an evolutive product such as plaster
in a continuous process pouring facility without any pre-
mature mass setting of the plaster inside the facility. The
applicants are the first to develop the flow rate regulating
of a plaster fluid mixture coming out of a mixer. In this
connection reference may be had to our copending Canadian
applications entitled "Process and Mechanism for Evolutive
Pulp Flow Regulation" and "Continuous Process Mixing of
Pulverized Solids and Llquids and Mixing Apparatus" both
filed February 7, 1979 under serial nos. 321,010 and 321,011,
respectively.
Being able to control the time of stay of a fluid
evolutive product in a mixer, such as a liquid plaster powder
and water mixture, through runoff flow rate regulation of
said mixture coming out of the mixer, applicants then sought
the use in continuous process of such a liquid mixture for
building panel manufacturing in such a way as to make use of
the advantages inherent in the use of a liquid, i.e., level
detection accuracy, more even spreading of mixture and
lighter equipment.
The way to pour out a product upon a moving bed, and
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to let it spread out by itself is known, the thickness of
plates thus manufactured being a function of bed running
speed. But when working with a fluid evolutive product, it is
difficult to control its spreading and difficulties are en-
countered in thick plate manufacturing. In order to limit andcontrol spreading, it is possible to consider making use of
devices habitually relied upon to pour non-evolutive products.
They generally comprise a bottomless container placed above a
moving conveyor with a slit formed by said conveyor and by the
lower edge of the plate which forms the downstream wall of the
container.
The container is filled with product, thus creating
a storage load above the conveyor and the product runs off on
the conveyor through the slit at the base of the container.
If a plaster powder and water mixture were poured in such a
device, it would set, first along the container's walls and
then on the slit edges and the pouring facility would soon
become blocked up.
The board manufacturing process involving pouring
upon a moving conveyor an evolutive fluid product, such as a
plaster powder and water mixture, which ~s the object of the
invention, avoids such blocking up.
Brief Summary of the Invention
The process of the invention using running off of
product from a reservoir above a moving conveyor is character-
ized by the fact that fresh product is introduced into the
reservoir through a number of nozzles which discharge into the
mass of the product in the reservoir. These nozzles are
placed horizontally side by side and approximately hori-
zontally oriented in the direction opposite to that of therunning of the conveyor.
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According to another characteristic, fresh product
streams come into the product in the reservoir with such a
force that they create agitation along closed flow lines in
the product mass ;n the reservoir.
It is beneficial to make the distance between
streams coming into the reservoir such that closed agitation
circuits created by all streams join and encompass, in the
plane containing the nozzles, the entire product mass.
Advantageously, the storage walls are vibrated. A
reinforcement may be introduced into the product discharged
from the reservoir and multiple layers of product may be dis-
charged onto the conveyor.
The invention offers also a mechanism allowing for
the implementation of the process. This mechanism, including
a reservoir comprising a bottomless small trough placed over a
moving conveyor and with an opening limited by said conveyor
and by the lower rim of a plate forming the downstream wall of
the trough, is characterized by the fact that said downstream
plate is equipped with a number of product supply tubes,
mounted outside of the trough, coming into the inside of the
trough through the downstream plate.
The invention also includes means facilitating the
introduction of a continuous reinforcement in manufactured
board and which are adapted to this pouring facility.
The invention includes products which may be made by
the process of the invention including plaster board having
layers of different densities with or without a reinforcement.
Ornamental plaster panels are included as well as thin plaster
panels having a thickness of less than 3 mm.
Brief Description of the Drawings
Figure 1 is a diagrammatic drawing of a complete
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plaster board manufacturing line;
Figure 2 is a sketch representation of plaster
pouring apparatus;
Figure 3 is a view of a receiving container in which
the mixture runs when coming out of the mixer;
Figure 4 is a multiple outlet distributor which
distributes the mixture to several manufacturing lines or to
various places on one line;
Figure 5 is a pouring head;
Figure 6 shows the detail of a pouring head front
plate;
Figure 7 shows the detail of a pouring head back
plate;
Figure 8 shows various reinforcement placing modes;
Figure 9 illustrates a multiple pouring head;and is
shown on the sheet illustrating Figures 6 and 7;
; Figure 10 is a side elevation partially broken away
of a plaster board of the invention;
Figure 11 is a side elevation partially broken away
of a plaster board of the invention having three layers of
different densities;
Figure 12 is a side elevation partially broken away
of a plaster board of the invention having three layers of
different densities and reinforcement between adjacent layers;
Figure 13 is a side elevation partially broken away
of a plaster board in accordance with the invention having a
reinforcement embedded therein;
Figure 14 is a side elevation partially broken away
of a plaster board in accordance with the invention having a
panel of glass wool fibers secured to one face of a plaster
board;
Figure 15 is a side view partially broken away of a
297
three layer reinforced plaster board in accordance with the
invention;
Figure 16 is a view of an alternative embodiment of
the receiving container of Figure 3i
Figure 17 shows another reinforcement placing mode;
Figure 18 is a side elevation partly broken away of
a plaster board reinforced by a co~ntinuous filament mat
encased between two layers of glass fiber netting;
Figure 19 shows a plaster board with a reinforced
layer of chopped glass fibers; and
Figure 20 is a view in side elevation of plaster
board attached to a glass wool insulating pad.
Detailed Description of the Invention
Figure 1 shows a manufacturing facility for making
plaster board building components reinforced for instance with
fiber glass. This facility includes plaster and water mixture
production means, and means which are objectives of the
present application, making it possible to pour the mixture in
a continuous process upon a moving conveyor and to eventually
reinforce it.
Plaster powder contained in a hopper 1 is distri-
buted on a weight-sensitive conveyor belt 2 set beforehand for
a determined flow rate P of plaster powder and then brought to
a vibrating pouring spout 3 through which it falls into a
mixer M. A water feed regulator 4 having a valve 4A and a
flow meter 4B introduces water in mixer M at flow rate W.
Mixer M is a mixer with a turbine 5, cylindrical, vertical
container 6, with a tapering lower section wall 6A. An inter-
mediate trough bottom 7A is constituted by the top surface of
a solid of revolution core 7, tapering downwardly and placed
inside also tapering casing constituted by the container 6
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lower section wall 6A. This core 7 is centered on the con-
tainer 6 axis and its dimensions are such that a ring-shaped
space remains around it between it and wall 6A to allow
mixture runoff. In a certain type of construction, trough 6
lower se~tion is conical and core 7 is a cone placed inside
it, tip downward, its flat base forming the intermediate
bottom. The mixture coming out of the mixer M is received in
an ejection device 8 comprising a conical casing 9 placed with
its tip upward and with a plane base 10. A collector pipe 11
comes out of ejector device 8 flush with base 10 tangentially
to receiving container 9 and extends in the direction of
rotation of mixer turbine 5. The mixture outcoming flow rate
is regulated by a valve 12 mounted on collector pipe 11. This
valve comprises a rigid cylindrical housing 13, an inner
elastic sleeve 14 and a fluid intake pipe 15 in communication
with the space between rigid housing 13 and sleeve 14. This
fluid intake pipe 15 is connected to a fluid (generally air)
supply, the fluid pressure is adjusted in order to bring about
a desired compression of elastic sleeve 14 resulting in a
certain closing setting of valve 12. In order to prevent any
plaster deposit in the narrow channel created by the valve, a
modulation of the fluid pressure controlling opening of said
valve 12 is provided to constantly change the shape of sleeve
14.
It will be benificial to provide this modula-~ion
with a regulating escape type pneumatic mechanism associated
with a balance of force beam 16 supporting mixer M on one
side, and on the other side gauging the escape of the pneu-
matic circuit supplying the valve, the escape taking place
between beam end 16A and a nozzle 18 in a line 18A connect to
pressure supply line 17 which is also connected to fluid
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intake line 15. Small motions of beam 16, induced by vi-
brations of mixer M resulting from turbine 5 motion, are
picked up and transformed into signals through vibrations of
beam 16 relative to nozzle 18. These vibrating signals modu-
late the regulating fluid pressure supplied to valve 12. Thisresults in constantly varying the shape of elastic sleeve 14
of valve 12, which~ prevents any plaster stagnation and there-
fore any setting of the mixture in the narrow channel of the
valve.
In order to have a continuous process production of
a liquid plaster/water mixture, with a determined fluidity Fo,
one proceeds as follows. First a mixture ratio Wpo giving a
fluidity Fo is selected, Wo being water flow rate, Po being
plaster powder flow rate, and is introduced into mixer M, Fo
being a value expressed in mm (millimeters) given by F.L.S.
test. This FLS test is frequently used by plaster manu-
facturers and it indicates plaster performance when poured.
It consists in filling a hollow cylinder with a diameter of 60
mm (2.36 in.) and height of 59 mm (2.32 in.), placed verti-
cally in the center of a polished metal or glass plate, withplaster mixed with water. At time t set in relation to time
"to" of first contact between plaster and water, the cylinder
is lifted thus freeing plaster which spreads on plate and
forms a disc whose diameter is measured. The size of this
diameter constitutes fluidity F parameter for time t.
Plaster powder and water supply flow rates in mixer
M are set at Po and Wo. A time is selected of the stay To of
mixed plaster in mixer M. The mixer outlet is closed.
Turbine 5 of mixer M is set in motion. Water is introduced in
mixer M at flow rate Wo for time To, and then plaster is
introduced at flow rate Po also for a length of time To
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starting with the shutoff of water supply. Then after mixing,
at the same time the mixer water supply is set at flow rate
Wo, and the plaster powder supply is set at flow rate Po, and
the mixer outlet is opened to allow the mixture to run off,
valve 12 being set for a run off flow rate so that the amount
of product in mixer trough remains constant. Valve control
fluid pressure modulation is provided by vibrations from the
mixer M. Thus, a permanent running range is reached. A
liquid mixture of plaster powder and water with a set fluidity
FLS, measured at t = 1 minute 15 seconds, and which can be
selected at a value as low as 120, can be used in the pouring
facility of the invention to be described below. For more
detail, reference may be had to our aforesaid copending
Canadian applications.
The continuous process pouring facility, shown as a
whole in Figures 1 and 2 includes mixture distribution com-
ponents D, a pouring head C which makes it possible to spread
out the plaster on the moving conveyor, and reinforcement
introduction means R. Mixture distribution components D,
placed after valve 12 below mixer M, include a receiving
container 19 constructed as shown in Figures 3 or 16, a pump
20, a distributor 21 constructed as shown in Figure 4, and
pipes 22 (Figure 1). Receiving container 19 creates a load
break at the output of valve 12 and isolates the mixer from
the downstream part of the facility so as to make it possible
to weigh said mixer free of apparatus downstream of tube 23.
It is made with two vertical tubes 23 and 24, which are apart
and placed on the same axis. Tube 23 passes freely through
top 25A of case 25 and tube 24 forms a connection with bottom
26. The space between these two tubes 23 and 24 is enclosed
in a case 25. Lower tube 24 penetrates into said case 25
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above its bottom 26. A water intake pipe 27 ending in a spray
nozzle 2~ enters case 25 to wash out any plaster splashes.
The lower part of bottom 26 of case 25 is provided with drain-
off openings 29 for this wash water. Lower tube 24 brings the
mixture to pump 20. Pump 20 is a pump able to operate without
a load, capable of absorbing all flow from mixer M, compatible
with a certain amount of accidental air circulation and
capable of transmitting sufficient energy to the mixture in
order to prevent mass setting inside the pipes in the system
and able to work the load whatever it may be. Thus it will be
convenient to use a rotative pump with gears or cams, or a
plastic pipe pump, whose pipe is compressed by rollers or by
an eccentric cam pushing the mixture out to said pump output
openings.
Pump 20 may be directly connected with pouring head
C through a pipe 22. However, inasmuch as several pouring
heads C (Figure 2) are supplied from one sole mixing unit and
inasmuch as pump flow is always constant, a distributor 21 is
placed at the outlet of pump 20 to regularize the flow and
divide the mixture stream provided by pump 20 into many
smaller and identical streams. Distributor 21 (Figure 4) is
funnel shaped, connected through its smaller end to the outlet
of pump 20~ and with its wider end closed by a cover 31, with
radial outlet or distributor tubes 32 starting from the top
section of funnel wall, near cover 31. Preferably, in order
to obtain identical divided streams, distributor tubes 32 are
arranged symmetrically relatively to the funnel axis and the
distributor is mounted with its axis vertical. In order to
allow for more space, distributor tubes 32 are slanted down.
A pipe 22 is connected to each and every distributor tube 32
to bring the mixture to pouring head (or heads) C. A typical
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multiple outlet distributor 21 for a flow rate of 60 Kg/mn has
a funnel having a top diameter of 40 mm and a bottom diameter
of 14 mm, and has 4 outlets each of a diameter of 8 mm. These
outlets are slanted at 15 to the vertical. The funnel is 40
mm high, and the outlet pipes are connected to the funnel at
10 mm lower than the enlarged top 31.
Figure 5 shows in detail pouring head C mounted
above conveyor S; pouring head C and pouring bed S moving in
relation to one another. For convenience, it is preferable to
keep pouring head C and all its supply pipes stationary, and
hence conveyor S is a moving conveyor. Conveyor S is made
from, for example, a stainless metal strip or a rubber strip.
A pair of lateral strips 33 (Figure 2) with same movement as
conveyor S are mounted vertically on either side of conveyor S.
Pouring head C (Figure 5) includes essentially two
obstructing plates 34 and 35 forming, with conveyor S and
lateral strips 33, a reservoir in the form of a small trough
34A placed transversely in relation to the direction of motion
of conveyor S, plate 34 being the downstream one and plate 35
being an upstream counter-plate, upstream and downstream being
defined according to conveyor progress.
Downstream plate 34 is equipped, on its outward face
with a series of supply tubes 36 distributed along all its
width and passing through it to open into small trough 34A.
Each one of these supply tubes 36 is connected with a dis-
tributor tube 32, either one distributor tube 32 being
connected with only one supply tube 36, or one distributor
tube 32 linked through a Y connection 37 (Figure 5) to two
supply tubes. Two distributor tubes 32 may be linked with
only one supply tube 36. Preferably, the supply tubes 36
should be horizontally flared as they pass through obstructing
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297
upstream plate 34 to form distribution nozzles 36A. The
height at which tubes 36 reach downstream plate 34, and their
spacing in regard to one another are functions of operating
conditions: mixture flow rate, mixture fluidity, and level of
mixture inside the trough; in the same way, the distance
between both plates 34 and 35 are a function of operating
conditions. Downstream plate 34 is raised in relation to
conveyor S in order to provide a slit whose height, adjusta-
ble,is at most equal to the projected plaster run thickness.
Both plates are provided with lateral rubber flaps 38, which
touch moving lateral strips 33. Upstream plate 35 has a
gasket 39 in its lower part in order to insure tightness with
conveyor S. Each plate 34 and 35 has a vibrator 40 mounted on
its top, for instance a pneumatic vibrator, creating a vi-
bration vertically at a right angle to the direction of motionof conveyor S. Each of the two plates 34 or 35 is secured by
machine screws (not shown) through two fixed lateral grooves
41A on clamps 41 mounted on general facility frame (not shown).
Either plate 34 or 35 can be moved at will along these two
retaining grooves, independently from each other. Plates 34
and 35 are secured to brackets 41 through vertical elongated
openings 43 in brackets 41 by screws 42A with elastic stops
42 interposed between the plates and the brackets. Elongated
holes 43 in the vertical portion of securing clamps 41 make it
possible to adjust each of plates 34 and 35 in height.
Downstream plate 34 may be fitted with a guide plate 44
(Figure 5) approximately at right angles with plane of plate
34 outside of the small trough 34A constituted by both plates
34 and 35. Preferably this gulde plate 44 is set at a low
angle, about 7 degrees (), divergent upwardly in relation
with the direction of movement of conveyor S. Upstream plate
2;297
35 may be equipped with a reinforcement plate 46 (Figure 5)
making it possible to guide the introduction of a reinforce-
ment 45 inside of or on top of plaster panels (Figure 2).
This plate 46 may be a flange (Figures 2 and 8A) on a slant
mounted outside of the small trough, transversely in relation
to conveyor S and linked with upstream obstructing plate 35 at
the level of its lower rim. Thus, this guide 46 may be
slanted about 45 in relation to conveyor S, depending on the
reinforcement location in relation to obstructing plates.
Reinforcement 45 could be available in rolls. Another way to
facilitate the introduction of a reinforcement may comprise a
rounded padding shown at 47 (Figure 8B) covering the lower rim
of upstream obstructing plate 35. An identical padding, shown
at 47' on Figures 8C and 8G can be put on the lower rim of the
downstream plate 34. One of independent reinforcement guides
46A, 48, 48A, 50, 49, 51 or 48 shown respectively in Figure 8
at D, E, F, H, I, J and K respectively and not secured to the
upstream plate 35 may be used. An independent guide, as the
one shown at 49 in Figure 2 and 8I may include a curved
slanted upstream section 49A identical to guide 46 mounted on
upstream plate 35 of a pouring head C, a horizontal part 49B
and a guide portion 49C with a very narrow upward angle of
about 7 in relation to conveyor S and identical to guide
plate 44 of a pouring head C.
In the case of the embodiment of Figure 8G, the
reinforcement 45 is introduced tangentially to the rounded
padding 47' and in this manner cleans it, thus keeping the
opening between the padding 47' which forms the lower edge of
the downstream plate and the conveyor constant.
An independent guide may be a sole slanted plate 50
(Figure 8H), curved, identical to plate 46 mounted on back
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plate of a pouring head. An independent guide may also
comprise a rounded padding 51 (Figure 8J) parallel to the
conveyor and at a right angle in relation to its direction of
progress either mounted on a plate 51A whose plane is parallel
with the one of pouring head C as shown in Figure 8J, or by
itself, made from a simple bar held at a distance from the
conveyor equal to the height at which the introduction of the
reinforcement within the manufactured products is desired as
shown at 48, 48A and 48B in Figures 8E, 8F and 8K, respective-
ly. Several guides of the above described types can be usedat the same time to introduce several reinforcements at
various levels into a plaster layer poured through one single
pouring head. In addition, several pouring heads, with each
of which one or several guides can be combined, can follow one
another one on the same building panel manufacturing line;
then, each pouring head C may be independent, as shown in
Figure 2, or on the contrary dependent on ones following it,
as shown in Figure 9, with the downstream plate of one pouring
head constituting the upstream plate for the next head. Thus,
it is possible to have one single pouring head C for building
panels, or several successive pouring heads C each pouring a
strip of a certain thickness, the first one directly on
conveyor S, the next ones above the plaster strip already
poured by the preceding head or heads.
The operation is as described below.
A fluid plaster mixture is obtained in mixer M, and
its runoff flow rate is regulated by regulating valve 12. The
mixture runs off through receiving container 19. Spray nozzle
28 throws water in order to wash ~way any plaster splashes
from inside receiving container 19. This wash water drains
off through drain openings 29. Since lower tube 24 opening is
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above bottom 26 inside of case 25, this wash water cannot mixwith the mixture and does not cause any alteration of mixture
proportions. In order to facilitate starting operations of
plaster mixture preparation station, a phase during which
slight variations of plaster fluidity can be recorded, it may
then be desirable to drain off mixture away from the manu-
facturing line to prevent any mass setting in any place on the
said line where not scheduled. At that time, flexible tube 23
coming from valve 12 is taken out of container 19 and directed
toward the outside and put back into place when fluidity has
stabilized. In normal operation, the mixture having passed
through receiving container 19 is introduced into pump 20.
Pump 20 makes it possible to pump mixture up to various
positions where it will be used, sometimes at distances of
many tens of meters. Then, as the case may be, the mixture is
either taken directly to a pouring head C, or sent to multiple
outlet distributor 21. Inside distributor 21, the mixture
runs first up to cover 31 and then it enters radial distri-
buting tubes 32 evenly and continuously. The mixture passes
through tubes 22 rapidly which prevents any mass setting
inside said pipes and then it comes into supply tubes 36 where
it is distributed into smàll trough 34A delimited by plate 34,
35, conveyor S and lateral strips 33, arriving in the di-
rection opposite to the direction of movement of conveyor S.
Distributor 21 makes it possible to supply, from one single
mixing station, with the same weight distribution, all the
areas dependent from one pouring head whatever their width may
be, makes it possible to split a single mixture stream into
many smaller streams giving same total flow rate, ~akes it
also possible to supply several pouring heads.
The mixture piles up in small trough 34A, thus
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creating a homogeneous storage load. Plaster streams coming
through nozzles 36A of supply tubes 36 cross the trough, hit
plate 35, are projected back and stream back toward downstream
plate 34 and so on until they have exhausted their energy.
Thus, they create vortices which stir up mixture and prevent
formation of stagnant zones. The spacing between supply tubes
36, plaster incoming speed and the height at which said supply
tubes 36 are mounted, must be selected or adjusted so that
this circular motion inside of the trough between downstream
plate 34 and upstream plate 35 is preferably immersed in the
mixture but nevertheless affects the surface of the mixture
and so that each flow line creating a circular motion out of a
supply tube 36 and induced by the back and forth motion be
joined to the next circular motion line from the adjacent tube
36 with no stagnant zone between the two lines. Any lack of
motion of plaster in any part of the trough would create a
lack of homogeneity of mixture which would be detrimental to
the quality of manufactured product, would favor a mass
setting which would spread out, and would end up obstructing
the whole of the pouring head.
Nozzles 36A of supply tubes 36 are flared hori-
zontally so that streams coming out of them provide a stirring
distributed over a wider area, so that depth of stirring is
limited, and so that splashing is prevented. The watertight-
ness of upstream plate 35 combined with conveyor S in motionis achieved with gasket 39, but it is beneficial, in order to
prevent formation of stagnant zones in small trough corners
close to said plate to allow for a slight leak underneath the
plate. Thus a round fold forms in the back, which constantly
forms again owing to continuous pouring bed progress, which
contributes to perfecting of watertightness. Such a fold is
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shown at 46B in Figure 8D. Downstream obstructing plate 34 is
raised on loosening screws 42A securing it to clamps 41 in
order to provide between it and conveyor S a slit of height e.
The stationary load upstream from the obstruction provided by
plate 34, causes the mixture to spread on conveyor S through
the slit thus created.
In the case of small thickness panels, it is prefer-
able to use plate 44, said plate 44 then facilitates retention
of the load inside of trough 34A and prevents, when the level
in said trough is very low, stirring which takes place therein
from spreading to the downstream side of plate 34. It is
beneficial, in order to prevent plaster from forming deposits
or from mass setting on plates 34, 35 to subject them to
vertical vibrations at right angles with conveyor S with
vibrators 40.
For the adjustment of a pouring head C, the pro-
cedure is as follows. For a given speed of conveyor, the
dimensions of the board to be manufactured determine the
amount of mixture to be supplied by the mixing station and to
be poured on conveyor S, and therefore the total rate of flow
at the outlet of supply tubes 36, as they discharge into
trough 34A. The section of each supply tube 36, size of
nozzles 36A, number of supply tubes 36 and of pipes 22 are
selected in order to obtain a speed, in said tubes and pipes,
which does not allow deposits, ~.e.~ in the case of plaster, a
speed above 10 centimeters (3.94 inches) per second (cm/s)
(in./sec.). The mixture is received into the trough 34A.
Slit height e is provided under downstream plate 34 and the
distance between upstream plate 35 and downstream plate 34 is
adjusted in order to achieve a constant level in the trough, a
satisfactory agitation, and the immersion of the tubes 36 in
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the mixture in the trough. Agitation of the mixture in the
corners of upstream plate 35 is achieved by raising slightly
said plate in order to create a round~fold about 5 centimeters
(2 inches) long at its middle.
The table below gives, by way of example, two series
of operating parameters for a pouring head.
Example 1Example 2
Speed of conveyor in meters
(feet) per minute 2.50 (8.22) 2.50 (8.22)
Mixture FLS in millimeters
(inches) 230 (9) 230 (9)
Pouring head supply tubes
diameter mm. (in.) 8 (.3) 10 (.39)
Number of supply tubes per 4 4
:
Width and height of dis-
charge opening of supply 12 4 15 5
tube nozzles
Spacing of outlets through
20 front plate, mm (in.) 83-150-150-150-8383-150-150-150-83
(3.27) (;5.91)
Height above conveyor at
which these outlets are 13 (.51)17 (.66)
placed mm (in.)
25 Pouring head width mm (in.) 616 (24.25) 616 (24.25)
Distance between upstream
plate and downstream plate 90 (3.54) 110 (4.33)
mm (in.)
Mixture height in small
30 trough mm (in.) 15 (.59)20 (.79)
Height of round fold under
back plate mm (in.) 2.5 (.098)2.5 (.098)
Pouring slit e height mm
(in.) above conveyor 4 (.15) 8 (.31)
Thickness of panels thus
manufactured mm (in.) 5 (.20)10 (.39)
When there is a succession of pouring heads, as
shown in Figure 2, they are adjusted separately and in the
same way, inasmuch as they are independent.
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With the pouring heads joined to one another, as
shown in Figure 9, the most upstream pouring head is adjusted
first, and then the next pouring head, the pouring slit height
for one head being at the same time the round fold height for
the next head, in this manner building a component 60 of, for
example, a plaster board having layers 62, 64 and 66 of the
same or different densities. When several pouring heads C
fol10w one another, they may all be supplied with same product
or supplied with plaster mixtures of various different densi-
ties and/or with different finely split or chopped reinforce-
ment fibers, which are introduced at the mixing time.
One or several reinforcements 45 may be introduced
in manufactured boards at various levels in their body and at
various positions on the manufacturing line. Under the term
reinforcement, we define all materials which can be set inside
of boards or on their surface, whether they actually serve as
reinforcement to increase said boards resistance to applied
forces or whether they constitute either decorative or
protective lagging. Not only may strip or continuous rein-
forcement be introduced, but also other non-continuous rein-
forcements, such as chopped or finely split fibers, may be
introduced. Exemplary reinforcements are paper, cardboard,
metallic film such as aluminum sheet, glass cloth, fabrics,
non-woven organic materials, continuous threads, for example,
of glass or wires, continuous thread sheets intermixed with
glass, layers of criss-crossed continuous glass threads, or
others. These reinforcements may be introduced upstream from
a pouring head using independent guides as shown in Figures 8D
and 8E. For instance, reinforcement material 45 supplied in
rolls is stretched up to a guide, passed between said guide
and conveyor S and placed underneath pouring head C. As it is
1 9
~ ~ 5Zz9~
caught in the plaster it is drawn away, and a continuous
pulling is exerted on the roll which thus unwinds at manu-
facturing line speed. In this way a reinforcement can be
placed, either on the bottom face of the manufactured board
panel by securing the guide very close to the conveyor, or in
the body of the board by securing the guide at a distance from
the conveyor equal to the height at which the reinforcement is
scheduled to be placed in the board, the distance befng,
however, not exceeding the smallest height at which upstream
plate 35 and downstream plate 34 have been raised in relation
to the conveyor. Several reinforcements can similarly be
introduced at various heights with several independent guides
set upstream from a pouring head. Also, reinforcements may be
placed on the bottom face of the board or in its body by
guiding them through guides 46 and 47 secured on upstream
plate 35 as shown in Figures 8A and 8B, the hefght of the
reinforcement in the body of the board being, however, limited
by the pouring slit height underneath the downstream plate. A
guide 47' (Figure 8C) may also be secured to downstream plate
34 and then the reinforcement height is determined by the slit
height underneath downstream plate 34.
Reinforcement may also be introduced inside of the
trough between downstream 34 and upstream 35 plates. Rein-
forcement height can then be determined through bar shaped
guide 48 as shown in Figure 8F or through round padding 47'
set on the downstream plate (Figure 8G). A reinforcement
introduced through this process must be the most pervious
possible to plaster in order to least interfere with agitation
inside of the trough.
Reinforcement may also be introduced after the
plaster layer has been poured, either on the surface or in the
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~;2297
body of the plaster, through an independent guide 50, 49, 51
or 48B set downstream from the pouring head as shown re-
spectively in Figure 8H, I, J, K. When the reinforcement is
set on the surface of a layer, it can be either porous or
watertight to the plaster fluid mixture. When it is set in a
plaster layer mass, it would be preferable for it to be porous
to allow the fluid mixture to permeate through it to prevent
the reinforced board from tending to split along the rein-
forcement plane. Layers of criss-crossed continuous wires or
threads may be used, in order to provide for a satisfactory
distribution of reinforcement throughout the plaster mass of
the board, a good cohesiveness between plaster and reinforce-
ment, and for the reinforcement to be easily passed through by
plaster at the time of its placement.
Once poured, the plaster strip progresses on the
conveyor S, framed in by lateral strips 33, until the plaster
has set sufficiently to be handled and cut up. Then the strip
passes to another conveyor. Conveyor S and lateral strips 33
are washed off during their return travel.
As already known, it will be possible to intervene
on various plaster reaction phases by adding either before or
after pouring setting delaying or accelerating agents. The
temperature of conveyor S can also be acted upon.
Products manufactured by the above described process
and apparatus may be plaster alone, or plaster reinforced by
glass fiber, for instance; they may be used by themselves or
be combined with other materials to be used as a covering
layer or as ornamental plates. They can be made into thin
plaster panels less than 3 mm (.118 in.) thick reinforced with
or without continuous fiber glass, or made into thicker panels
with a reinforcement to improve resistance, or made without
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~ZZ~7
any reinforcement, and may be covered or not with lagging. It;s possible to pour a very thin plaster film down to about one
millimeter (.039 in.) thick to be used to cover the bottom and
sides of ceiling panels made of fiberglass. In that case, it
is possible to place upon the plaster film just poured a glass
wool strip just downstream from the pouring head, the plaster
itself providing for linkage with the glass wool at the time
of setting, or the glass wool itself can be the pouring bed.
Such a board 90 is shown in Figure 20 and includes a plaster
board sheet 92 attached to a glass wool pad 94.
Plaster boards thicker than one centimeter (.39 in.)
may be used as ornamental boards to build sheath partitions.
Up to now such partitions were made with a glass wool board
with an asphalt agglomerated paper vapor barrier and a rein-
forced plaster plate with a cardboard top layer. From now on,as an application of the invention process, a partition can be
made with a glass wool panel without a vapor barrier and thus
without any asphalt and a plaster plate reinforced with fiber
glass without any cardboard top layer, the junction between
the glass wool and plaster being provided through gluing or
preferably by the plaster itself fastened to the glass fibers
during its setting. Such sheath partitions offer improved
fire-retardant properties compared to older partitions because
they eliminate the paper cover sheets wh1ch are a fire hazard.
The invention process and apparatus make it possible not only
to pour plaster, but also other evolutive products, ~.e.,
products with changing physical or chemical properties, and
all non-evolutive products such as cement.
A completed plaster board panel 100 made using the
process and apparatus described above is shown in Figure 10
and is suitable, for example, for use in building construction
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~152Z9~7
As shown in F1gure 11, a plaster board 102 has
layers 104, 106 and 108 w1th each layer having a~density
different from the densities of the other two layers. Thus,
for example, the densities of layers 104, 106 and 108 may be
1000 kg/m3, 200 kglm3, and 800 kg/m3, respectively, the densi-
ties may be regulated between 150 kg/m3 to 2000 kgjm3 by
adding a forming agent as known in the prior art.
Referring to Figure 12, a plaster board 112 has
layers 114, 116 and 118. Each layer has a density different
from either of the other tw~o layers, ~for example, layers 114,
116 and 118 having densities of 800 kg/m3, 300 kg/m3, and 900
~ kg/m3, respectively. A fabric reinforcement sheet l20 lies
m~ between~layers 114 and 116. ~Similarly, a fabric reinforcement
sheet 122 lies between layers 116 and 118. Sheets 120 and 122
~` :
~ 15 are sufficiently porous so that plaster can penetrate the
`; interstices between the threads forming the fabr1cs.
A plaster board 126 shown in Figure 13 has embedded
~~ in the central portion thereof a fabric reinforcement sheet
128 of, for examplej fiberglass.
Referring now to Figure 1~4, d panel 132 comprises a
plaster board 134 and a fiberglass~mat facing 136 on said
board with the fibers 138 of mat 136 embedded in board 134 and
~- shown on an enlarged scale.
In Figure 15, there is shown a plaster board 142
25 having layers 144, 146 and 148 of plaster with layers 144 and
~; 148 being reinforced by thin sheets of aluminum 150 and 152 ;`
~ respectively.
; All of the foregoing and numerous variations thereof
are readily made using the apparatus and process described
above and are useful, for example? as building elements.
A preferred receiving container 200 which can be
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11~2297
substituted for receiving container 19 is shown in Figure 16.
Container 200 has an open top 202 and receives discharge from
tube 23 which has a valve 204 used to shut off flow from the
mixer M during the start up operation, permitting the setting
of valve 12 to remain undisturbed from the previous operation
if manually operated or to remain connected to automatic valve
settlng means responsive, for ~example, to the weight of the
mixer M. The receiving container 200,~being physically dis-
c~nnected from mixer M while providing for continuity of flow,
permits~mixer M to be weighed so as to determine the amount of
~; material contained therein.
In the embodiment of Figure 16 tube 24 has a funnel
206 connected to its upper end to collect the discharge from
tube 23. Funnel 206 insures the collection of any portions of
the stream discharging from tube 23 which expand beyond the
diameter of tube 23 when discharged.
As shown in Figure 17, pouring head 3 has a vertical
ùpstream plate 220 and a curved downstream plate 222 having a
rounded bottom edge 224 against which runs reinforcement 45 to
keep plate 222 clean including bottom edge 224 and to keep the
distance between plate 222 and conveyor 226 constant.
As shown in Figure 18, a desirable plaster board 240
has a reinforcement layer of continuous filament mat 242 with
layers of glass fiber netting 244 and 246 above and below,
respectively, to confine the layer 242 and restrain it from
spreading apart. This plaster board is advantageous because
the mat 242 makes the board very strong.
As shown in Figure 19, a plasterboard 250 has a
reinforcement layer of chopped glass fibers 252 between an
upper glass fiber netting layer 254 and a lower glass fiber
netting layer 256. This board is advantageous because the
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~2297
chopped fibers are less expensive than mat 242 and yet give
the board 250 great strength. The netting 254 and 256 confine
the glass fibers 252 and prevent them from escaping from the
board and from extending sideways from the side edges of the
board 250. This is very important, especially for thin board.
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