Information
-
Patent Grant
-
6652789
-
Patent Number
6,652,789
-
Date Filed
Thursday, March 26, 199826 years ago
-
Date Issued
Tuesday, November 25, 200320 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Thibodeau; Paul
- Kruer; Kevin R.
Agents
- Kolisch, Hartwell, Dickinson, McCormack & Heuser
-
CPC
-
US Classifications
Field of Search
US
- 425 831
- 425 811
- 425 801
- 425 821
- 264 121
- 264 113
- 264 109
- 264 112
- 264 518
- 264 555
- 156 624
- 156 296
-
International Classifications
-
Abstract
The method and apparatus for forming composite wood products particularly composite veneer like products which may be intermediate products and laminated to form the final composite product. Strands are fed from a source of supply at a metered rate, entrained in an air stream and carried along a confined path between an entrainment zone and the source of supply. Strands are condensed onto a surface to form a veneer lay-up of at least one layer of strands on the forming surface and this veneer lay-up is carried from the path and deposited onto a collecting surface and later consolidated into a composite product. Entraining air and strands not forming veneer are separated in the supply station, the strands fall onto the supply of strands and energy is added to the separated entraining air and it is returned to the entraining zone.
Description
FIELD OF INVENTION
The present invention relates to a method and apparatus for forming a composite veneer product from wood strands and a composite veneer product so produced
BACKGROUND OF THE INVENTION
Generally, forming systems for making composite products employ formers wherein the strands are deposited onto a forming surface to form a mat of strands on the surface (e.g. a caul plate or the like) that is used in the subsequent pressing or consolidating stage to form the surface on the consolidated product.
In making fiberboard wood fibers (as opposed to wood strands) are cast into the air and deposited on a forming surface by gravity or possibly by suction through the forming surface. See for example, U.S. Pat. No. 3,880,975 issued Apr. 29, 1975 to Lundmark. This technique, i.e. condensing of the material into a mat using a vacuum on the side of the forming wire remote from the supply of material, is applied to form fibrous mats from wood fibers, i.e. very small elements (fibers) relative to strand as used in manufacture of strand board products. Each strands, for example, is composed of thousands of fibers bonded together in their natural state.
The fibers used in the manufacture of fiber board are liberated by some form of mechanical disintegration technique e.g. grinding or refining or chemical technique to separate discrete fibers from one another. In fiberboard manufacture the fibers generally are randomly oriented, though it has been suggested to use electrostatic forces to orient the fibers.
In the manufacture of strand board the strands are dispensed from a source of supply, e.g. a bin, and simply fall onto a collecting surface and depending on the process may or may not be oriented. When an oriented strand board (OSB) is made the strands are oriented to be reasonably parallel to an axis of the consolidated product. See for example, U.S. Pat. No. 3,115,431 issued Dec. 24, 1963 to Stokes et al., U.S. Pat. No. 4,380,285 issued Apr. 19, 1983 to Burkner et al. and U.S. Pat. No. 5,325,954 issued Jul. 5, 1994 to Crittenden et al. or U.S. Pat. No. 5,487,460 issued Jan. 30, 1996 to Barnes, all of which show different devices for laying mats for consolidation wherein the strands are oriented before they pass on to the mat so that the mat contains oriented strands.
A plurality of separate forming heads are generally used to each to form a layer of strands directly onto the surface of a preceding layer of strands to form a lay-up that will consist of at least several such layers formed directly one on top of the other. Each of the layers will be several strand thickness' thick and the combined lay-up will be at least about 7 or 8 strand thickness thick.
It will be apparent that in each of these forming systems, the mat or lay-up formed generally consists of a plurality of strands or fibers piled one on top of the other to form a lay-up mat many strands (or fibers) thick so that the resultant consolidated product produced form from such a strand lay-up mat will have a thickness of at least a quarter inch which corresponds for conventional strandboard forming lay-up mat of about 7 strand thickness (assuming about 30% compression of strands 0.05 inches thick).
As above indicated this strand lay-up mat is made using a plurality of forming heads so that each head produces a layer of about 2 to 4 strands thick
It is necessary to make consolidated composite products from a plurality of strand layers i.e. form by a plurality of forming heads forming layers one directly on the top of the other because of the inability of the previously known laying processes to form the mat or lay-up of say a single layer thickness with a sufficiently uniform weight distribution over the area of the consolidated product i.e. when the thickness of the lay-up being consolidated is too small.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
It is an object of the present invention to provide a method and apparatus forming a composite veneer product from strand particularly wood strands.
It is also an object of the present invention to provide a composite product formed from a plurality of composite veneers laminated together into a single layered product.
Broadly, the present invention relates to a method of forming a composite wood veneer product comprising feeding wood strands from a supply of strands in a supply station at a metered rate, entraining said strands in an air stream in an entraining zone and carrying said strands in said air stream along a confined path, forming a. veneer lay-up consisting of at least one layer of strand and less than five layers of strands on a foraminous forming surface communicating with said confined path through a wall defining said confined path by drawing air through said foraminous forming surface in an amount sufficient to hold and distribute said strands on said foraminous forming surface and form said veneer lay-up layer, carrying said veneer lay-up layer so held to said foraminous forming surface from said path, transferring said veneer lay-up layer onto a collecting surface, returning said strands not forming said veneer lay-up layer to said supply station, separating entraining air from said strands, returning at least some said air separated from said strands and of said air drawn through said foraminous forming surface to said entraining zone and returning said strands not forming said veneer lay-up layer to said supply of strands in said supply station.
Preferably, a plurality of different foraminous forming surfaces each form a separate veneer lay-up layer and wherein a plurality of said veneer lay-up layers are piled one on top of the other to form a layered lay-up.
Preferably, said layered lay-up is further processed by consolidation under heat and pressure into a consolidated composite veneer product
Preferably, said strands are oriented as they passed onto said foraminous forming surface to form an oriented veneer lay-up layer with strands oriented in a direction substantially parallel to a longitudinal axis of said oriented veneer lay-up layer.
The present invention also broadly relates to a device for forming a composite product comprising a supply source of strands, means for dispensing said strands from said supply source at a metered rate, wall means defining a confined path, a strand entraining zone, means for passing air through said strand entraining zone and said confined path at a velocity sufficient to entrain and transport said strands along said confined path, forming means including at least one movable foraminous forming surface protruding through said wall means, means for drawing air through said foraminous forming surface from a side of said forming surface remote from said path to condense and distribute some of said strands from said path onto said foraminous forming surface to form a composite veneer lay-up layer of a thickness of at least one and not more than five of said strands on said foraminous forming surface, a movable collecting surface, means for transferring said veneer lay-up layer from said forming surface onto said transfer surface, means to separate air from said strands not forming said veneer lay-up layer and duct means for directing air separated by said means to separate to said means for passing air for recirculation through said path, means for directing air drawn through said foraminous forming surface to said means for passing air for recirculation through said path and means for delivering strands not forming said veneer lay-up layer back to said supply source of strands.
Preferably, said wherein said drawing air through said foraminous forming surface comprises dividing flow of air through said foraminous forming surface into at least 3 separate flows each from a different zone which zones are spaced across of said confined path.
Preferably, said separate flows each have essentially same the flow rate.
Preferably, said means for drawing air through said foraminous forming surface includes partition means constructed to direct air flowing through separate zones of said foraminous forming surface space across said confined path along different passages.
Preferably, said orienter is formed by a plurality of laterally spaced wires spaced from and extending along a portion of said foraminous surface exposed within said confined path.
Preferably, said apparatus further includes an orienter positioned in said path in a position so that said strands condensing onto said foraminous forming surface to form said veneer lay-up must pass through and be oriented by said orienter before reaching said foraminous forming surface so said strands forming said veneer lay-up are oriented in a selected direction.
Preferably, said source of strands comprises a bin containing a pile of said strands onto which fresh strands from the processing stage are passed and means for separating air from said strands is positioned in said supply station so that said strands from which said air is separated by said mean for separating air are deposited on the said pile.
Preferably, said forming means will comprise a plurality of said foraminous forming surfaces spaced along said path each of which forms its respective composite veneer lay-up layer.
Broadly the present invention also relates to a composite veneer product comprising a plurality of discreet veneer lay-up layers positioned in face to face relationship and consolidated to form a consolidated laminated composite veneer produce having a density variation of less than 15% on a 1 inch by 1 inch basis.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features, objects, and advantages will be evident from the following detailed description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings in which;
FIG. 1
is a schematic illustration of the method and apparatus used to carry out the present invention.
FIG. 2
schematically illustrates a system for dividing the flow from a former into a plurality of flows to reduce channeling.
FIG. 3
schematically illustrates a preferred form of orienter for use with the present invention.
FIG. 3A
is a partial cross section of the orienter of
FIG. 3
illustrating the construction in more detail.
FIG. 4
shows a modified form of the device of FIG.
1
.
FIG. 5
shows a modified arrangement for forming veneer over a longer area wherein the forming surface also provides the air separation in the supply zone.
FIG. 6
is an isometric schematic illustration of a layered composite veneer product of the present invention.
FIG. 7
is a partial section through the composite laminated veneer showing the layers and orientation of the strands relative to the face of the composite veneer in the different layers of the composite product through the thickness of the layered composite veneer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in
FIG. 1
, the method and apparatus for forming the composite veneer product from wood strands includes a strand bin
12
which has a live bottom formed by the conveyor
14
and on which a pile of strands
16
is supported. The top of the pile
16
is raked back by a conveyor
18
to maintain the height of the pile
16
at the desired height over a length extending rearward of the discharge end of the pile
16
. A plurality of metering rolls
20
sometimes referred to as picker rolls at the discharge end of the pile
16
draw strands as indicated at
22
from the pile
16
and free them to pass or flow or drop into an entrainment zone
24
.
The pile of strands
16
in the bin
12
is maintained by incoming strands as indicated at
26
which in the illustrated arrangement are passed via a conveyor system
28
to the bin feeder
30
. These strands generally are received from a blender as indicated by the arrow
32
wherein the strands are coated with the appropriate adhesive for subsequent consolidation.
Recirculating strands
34
are returned to the bin
12
to provide another source to keep the bin
12
filled to the required level. The recirculating strands are the strands that are not retained by the forming devices to form the strand lay-up layers and that are separated from the entraining air and returned the pile
16
as will be described further hereinbelow.
The metered supply of strands
22
passes into the entraining zone
24
wherein air is injected via the fan or jet pump
36
and is formed into a venturi type entrainment flow in the zone
24
thereby to entrain the strands and then carry the strands into and through the confined path
38
which in the illustrated arrangement leads from the entrainment zone
24
up to the top of the bin or supply zone
12
. This passage
38
will normally be a relatively wide and thin passage to permit the formation of a veneer lay-up layer as will be described hereinbelow, that is wide and relatively thin, i.e. say 4 feet wide by less than about 5 strand thickness' thick generally less than 3 strand thickness thick i.e. less than about ⅛ inch thick per veneer lay-up layer.
In the illustrated arrangement the air and strands entering the supply station
12
from the path
38
are separated via the jet pump drum screen
40
which is rotated as indicated by the arrow
42
and has a suction gland
44
communicating with a return duct
46
that returns separated air to the jet pump
36
. The strands
48
that return to the supply station
12
are moved toward the drum
40
in the area defined by the suction gland
44
by the flow of air through gland
44
and then are freed to fall after they pass through the area defined by the fixed gland
44
onto the top surface of the pile
16
in the supply station
12
and provide the recirculated strands
34
that are returned to the pile
16
.
It will be apparent that the conveyor
18
has a significant amount of open area and that the strands
34
and
26
may pass directly therethrough onto the pile
16
and may then be swept back by movement of the conveyor
18
rearward as indicated by the arrow
50
relative to the direction of movement of the pile
16
.
It will be apparent that the supply station
12
is a sealed box as defined by the wall schematically indicated at
52
and the bottom conveyor
14
as well as the sealing roll
54
so that air may enter the supply station
12
with the returning strands
48
assuming the strands
48
are to be air-veyed to the station
12
or by passing through the drum
40
or by coming in with the fresh strands
26
. This flow of entering air will be relatively minimal as the station
12
will not normally be under high vacuum conditions.
Positioned along the path
38
is at least one drum screen or moving foraminous forming surface
56
(in the illustrated arrangement, three such surfaces are shown) each of these foraminous forming surfaces
56
have an annular cross section and rotate as indicated by the arrow
58
around a rotational axis aligned with the axis of the annular cross section of the surface
56
. Each of these surfaces protrude into the passage
38
to form a forming zones wherein strands are condensed and distributed uniformly onto the surface
56
by the suction forces applied through suction gland
60
(one in each of the forming screens
56
) which apply suction through the screens
56
over a significant portion of their circumference. In the illustrated arrangement the glands
60
extend over approximately 180° of the surface of the drum screen to draw air through the surface
56
over the majority of the travel of the surface
56
through the duct
38
and continue to apply suction through the surface to hold the composite veneer layer being formed to the surface
56
until it reaches the trailing end of the gland
60
at which time the layer falls from the surface onto the collecting surface or conveyor
75
to be described below.
It is preferred to divide the flow of air through each of the surfaces
56
into a plurality of separate air streams each from a separate annular area or zone on the surface
56
. The zones or areas are arranged in side by side relationship across the flow path
38
i.e. axially space relative to the rotational axis of the surfaces
56
.
A suitable system for so dividing the flow is shown schematically in
FIG. 2
which shows an arrangement for dividing the flow through the surface
56
into 3 equal flows. This is attained by preferably fixed concentric outwardly flaring (in a direction opposite to the direction of air flow) partitions or baffles
200
,
202
,
204
positioned within the annular space
206
defined by the surface
56
. These partitions divide the air flow into 3 different flows
208
,
210
and
212
(more or fewer partitions may be provided depending on the axial length of the surface
56
i.e. width of the passage or path
38
) from each of the axial spaced zones Z
1
, Z
2
, and Z
3
respectively of the surface
56
. The partitions define concentric passages
214
,
216
and
218
the cross sectional areas as indicated at A
1
, A
2
, and A
3
respectively are preferably equal i.e. the zones Z
1
, Z
2
, and Z
3
are of equal area so the air flow though each passage should be the same.
Air is drawn through the glands
60
in drum screens or foraminous surfaces
56
via vacuum fan
64
and is carried via the duct
62
back to the jet pump
36
to be recirculated through the system and thereby aid in entraining the strands in the entrainment zone
24
.
Between each of the drum screens
56
is a sealing roll
66
that cooperates with the off-going side of the drum screen
56
and with a portion
68
of the wall of the passage or path
38
to form a seal between the drum screen
56
onto which a composite veneer lay-up layer consisting at least one and generally up to about five strand thickness' is formed and the wall portion
68
to inhibit loss of air from the passage
38
.
In the preferred embodiment of the present invention, an orienter as schematically illustrated at
70
of any suitable type known in the art is positioned relative to each of the foraminous forming surfaces
56
within the duct or passage
38
so that the strands passing onto and condensing on the surface of the screen
56
are oriented to form oriented composite veneer lay-up layers
72
,
74
,
76
and
77
each formed on the three drum screens
56
. Veneer layer
72
being formed by the drum screen
56
to the right, veneer layer
74
by the middle drum screen and veneer layer
76
by the drum screen to the left.
A preferred form of orienter is schematically shown in
FIGS. 3 and 3A
and is composed of a plurality of side by side wires
250
that extend from the leading edge of the surface
56
entering the passage
38
over and angle a around the circumference of the surface exposed within the passage
38
. An angle α of about 45° has been found to be effective.
The wires
250
as shown each has a circular cross section shape with a diameter d in the range of ⅛ to {fraction (1/16)} inches, preferably of about {fraction (3/32)} inches. The wires
250
at about their mid lengths are spaced from the surface
56
by a distance D of less than about ⅛ inch. The spacing
9
between the wire
250
is determined by the size 9 width of the strands being processed and the desired degree of orientation of the strands in the mat being formed. These dimensions may vary depending on the size of the strands being processed and the flow through the duct
38
.
The veneer layers
72
,
74
76
and
77
in the illustrated arrangement are collected on a collecting conveyor
75
to form a layered veneer lay up mat
78
which is trimmed to size as indicated by the shearing edge
80
to form a trimmed lay up layered mat
82
that is subsequently consolidated in known manner under heat and pressure to form a consolidated composite laminated veneer product.
The strands separated at the edge shearing or trimming station
80
are recycled to the blender
32
or back to the supply source
12
as indicated by the arrow
84
.
It will be apparent that, the lay-ups
72
,
74
76
and
77
that if desired, a plurality of discreet composite veneer products may be laminated together to form a laminated composite laminated veneer product.
The embodiment shown in
FIG. 3
, four forming stations have been shown, each composed of a drum screen
56
similar to the one described above. However, in this case, the suction gland
60
A used is slightly different than the one shown in
FIG. 1
in that the gland
60
A extends between the sealing rolls
66
positioned one on each side of the drum screen
56
thereby to seal the passage
38
except for the area of the drum screen
56
projecting into the passage
38
. In this arrangement, the height of the passage is reduced as the air and strands are drawn therefrom by the drum screens
56
so that the screen
56
at extreme left (upstream end of the forming section
55
) is positioned at the deepest portion of the passage
38
whereas the drum screen
56
at the extreme right (downstream direction of flow of the strands through the passage
38
) provides the minimal height of the passage
38
in the forming section
55
as defined by the drum screens
56
.
FIG. 5
shows a modified version of the device and method of
FIG. 1
wherein the forming section
100
replaces the forming section
55
so that the withdrawal of air in the forming section
100
provides return air to the jet pump
36
and so the jet pump provides the vacuum or develops the vacuum for the forming screen
104
onto which the strands are condensed and distributed on the foraminous forming screen
104
. In this embodiment fresh strands
26
are introduced as indicated by the arrow
102
into the supply station
12
and the area above the pile
16
in the station
12
and the station
12
forms a continuation of the passage
38
so that the strands
34
are separated from the air in the forming section
100
and those not carried on the screen
104
fall through the conveyor
18
as above described and onto the pile
16
, i.e. the foraminous forming surface or screen
104
functions both to form the veneer lay-up layer and replaces the drum screen
40
of the
FIG. 1
embodiment.
In this arrangement, the forming section
100
is formed by the screen
104
trained around rolls
106
and passing a suction gland
108
connected via passage
110
to redirect air back to the jet pump
36
after the air has been separated from the strands in the forming section
100
. The strands not carried by the screen
104
fall and are recirculated as strands
34
in the supply station
12
.
The veneer lay-up
112
so formed is carried by conveyor
114
and is trimmed laterally by in the edge shearing or trimming station
80
, i.e. as in the station
80
of the above described embodiment and then to a consolidation zone or station
116
wherein heat is applied as indicated by the heating zone
118
and pressure is applied via the press belts
120
to consolidate the veneer layer product which will be preferably clipped to length as indicated by the clipper
122
, cooled as indicated at
124
and stacked as indicated at
126
to form a stack of discrete consolidated composite veneer panels formed from strands, i.e. consolidated composite wood strand veneer products which will generally be less than about ten strands thickness thick. Obviously, the composite veneer produced with this system may be thicker than the veneers layers produced using the embodiment of
FIG. 1
since there is a continuous area as defined in the forming station
100
via the gland
108
that is significantly longer than the discrete forming sections of each of the drum screens
56
that are combined within the length of the forming section
55
in
FIGS. 1 and 2
embodiment. Thus, the veneer product formed in
FIG. 5
may be up to about ten strands thick whereas the veneer layers made using the drum screens
56
will normally not exceed about five strands thick.
It will be apparent that the length of the forming section of the drums
56
is defined by the diameter of the drums
56
and the length of the circumference that projects into the duct
38
and thus may also be made relatively long.
The operation of the two systems is essentially the same except in the
FIGS. 1 and 2
embodiment, there are a plurality of discrete forming drums
56
each forming relatively thin veneer lay-up layers whereas the arrangement shown in
FIG. 5
the belt
104
is intended to produce a thicker veneer lay-up.
Generally, the systems operate as follows.
Strands, i.e. elongated wood pieces of say up to 0.05 inches thick and up to 6 inches in length up to ½ inch in width are fed from a blender indicated at
32
where they are coated with a suitable adhesive and then passed into the bin
30
to provide a fresh supply of coated strands
26
into the strand supply station
12
. The strand supply station is similar to many of the strand supply stations in use in the industry in that the bottom of the bin is alive (conveyor
14
) and moves the pile
16
towards the metering picking rolls
20
that pull strands from the pile
16
at a controlled rate so that the free strands may now fall into the entrainment zone
24
where the strands are entrained by high velocity air as generated by the jet pump
36
. The strands then are carried in air through the passage
38
.
In the
FIG. 1
embodiment, some of the strands pass through the orienters
70
and are condensed and distributed uniformly on the screen drums
56
by the flow of air through the foraminous surface
56
to form the veneer lay-up layers
72
,
74
76
and
77
. The remaining strands are carried via the pipe or path
38
up to the top of the supply station or chamber
12
where they are separated from the entraining air fall onto the top of the pile
16
in station
12
. Air carrying these strands is separated in the gland
44
in the jet pump screen and is carried via line
46
to the jet pump
36
while the strands that adhere to the pump screen fall off the screen when they pass the downstream edge of the glad
44
and drop onto the pile
16
.
It will be apparent that air is drawn through the drum screens
56
via the vacuum pump
64
in an amount sufficient to cause condensation and more uniform distribution of the strands forming of layer of strands on the surface of the screens
56
i.e. the composite veneer lay-up layer. This air is returned to the jet pump
36
. The lay-up
78
formed on the collecting surface
75
by the combining of the layers
72
,
74
76
and
77
after trimming to size, etc. as indicated at
80
to form the sized lay-up
82
is then pressed in a conventional manner in a pressing station such as that indicated at
116
in
FIG. 5
to form a consolidated composite veneer product
150
(see
FIGS. 6 and 7
) consisting of a plurality of the composite veneer lay-up layers
72
,
74
and
76
consolidated together.
The
FIG. 4
embodiment is essentially the same as
FIG. 1
embodiment with the exception of the relationship of the forming screens
56
to the duct or passage
38
.
In the
FIG. 5
embodiment, a single layer veneer lay-up
112
is formed in the forming station
100
and the station
100
also functions as the air separation means or stage so that no separate vacuum pump is required and the separation drum
40
is not needed.
The composite veneer product
150
or those formed in the
FIG. 5
embodiment after cooling and stacking, may be combined to form a composite laminated veneer product by consolidating a plurality of the composite veneers
128
into a laminated veneer product of the appropriate thickness.
In tests carried out using strands as described in Table I.
It will be apparent that for a four layer composite veneer layered product
150
, i.e. one containing four veneer lay-up layers, the calculated composite consolidated veneer density variation is on a 1 inch by 1 inch (square inch) basis is less than 15% and in-fact calculates to be about 14% on a square inch bases and on a 6 inch by 6 inch basis calculated to be 3.2%. A product made up to a plurality of such composite laminated veneers to a final thickness of 1½ inches, the density variation on a 1 by 1 basis is less than 5% and on a 6×6 basis, less than 0.7%. It will be apparent that the products of the present invention is very uniform in that its density variation is minimal as compared to other conventional strand board products.
TABLE I
|
|
Composite Veneer (Density Variations)
|
|
|
Strands
|
Average wood density
25.79
lb/ft
3
|
Wood density variation in
2.19
lb/ft
3
8.5%
C.O.V.
|
strands
|
Average strand thickness
0.031
in
|
Strand thickness variation
0.005
in
16%
C.O.V
|
Single Air formed Layer of
|
Strands
|
Average thickness of one
1.5
strands
|
screen layer
|
Layer thickness variation
0.750
strands
50.0%
C.O.V.
|
Wood density variation in one
1.79
lb/ft
3
6.9%
C.O.V.
|
layer
|
Average thickness of one
0.0465
in
|
layer
|
One layer thickness variation
0.006
in
13.1%
C.O.V.
|
One layer density variation
28.1%
C.O.V.
|
Multi-layer Composite Veneer
|
No. of layers in veneer
4
strand layers
|
Average veneer thickness
0.186
in
|
uncompressed
|
Average veneer thickness
0.125
in
|
compressed
|
Wood compression
32.8%
|
Veneer dry wood density
34.2
lb/ft
3
|
Composite veneer density
|
variation
|
1″ × 1″ basis
14.1%
C.O.V.
|
6″ × 6″ basis
2.3%
C.O.V.
|
Composite Veneer Plywood
|
No. of layers of composite
5.0
veneer layers
|
veneer
|
1″ × 1″ basis
6.3%
C.O.V.
|
6″ × 6″ basis
1.0%
C.O.V.
|
Compressed thickness
0.53
in
|
Product dry wood density
40.4
lb/ft
3
|
Laminated Composite Veneer
|
Lumber
|
No. of layers of composite
14.0
veneer layers
|
veneer
|
1″ × 1″ basis
3.8%
C.O.V.
|
6″ × 6″ basis
0.6%
C.O.V.
|
Compressed thickness
1.50
in
|
Product dry wood density
40.0
lb/ft
3
|
|
Note:
|
Aspen example (1″ × 1″ basis) [bold entries are measured values]
|
Having described the invention, modifications will be evident to those skilled in the art without departing from the scope of the invention as defined in the appended claims.
Claims
- 1. A method of forming a composite wood veneer product comprising,providing a supply of wood strands consisting of a plurality of wood strands in a supply station, dispensing wood strands from said supply station at a metered rate to provide a supply of dispensed strands, entraining said dispensed strands in an air stream in an entraining zone, carrying said dispensed strands in said air stream along a confined path, forming a veneer lay-up by drawing a portion of said air from said air stream through an annular foraminous forming surface in an amount sufficient to hold and distribute a forming portion of said dispensed strands on said foraminous forming surface to form said veneer lay-up while permitting said dispensed strands not forming said veneer lay-up to remain entrained in said air stream as returning strands, said veneer lay-up having a thickness of up to the thickness of five of said wood strands, carrying said veneer lay-up so held to said annular foraminous forming surface from said confined path to provide a formed discrete veneer lay-up layer, transferring said formed veneer lay-up layer from said foraminous forming surface onto a collecting surface, separating air from said returning strands, and depositing said returning strands after separation of said air to said supply of strands in said supply station.
- 2. A method of forming a composite wood veneer product as defined in claim 1, wherein said annular foraminous forming surface is moving.
- 3. A method of forming a composite wood veneer product as defined in claim 1, wherein said annular foraminous forming surface is rotating.
- 4. A method of forming a composite wood veneer product as defined in claim 1 further comprising orienting said strands forming said veneer lay-up as they passed onto said foraminous forming surface whereby said veneer lay-up is an oriented veneer lay-up with its strands oriented in a direction substantially parallel to a longitudinal axis of said oriented veneer lay-up.
- 5. A method of forming a composite wood veneer product as defined in claim 1 wherein a plurality of steps of forming a veneer lay-up are applied in sequence one at each of up to four forming stations to form a plurality of separate veneer lay-ups one at each of said plurality of separate forming stations and provide a plurality of said veneer lay-up layers each formed from one of said separate veneer lay-ups and piling said veneer lay-up layers of said plurality of said lay-up layers one on top of the other to form a layered lay-up on said collecting surface.
- 6. A method of forming a composite wood veneer product as defined in claim 5 wherein said strands are oriented as they passed onto said foraminous forming surface to form an oriented veneer lay-up layer with strands oriented in a direction substantially parallel to a longitudinal axis of said oriented veneer lay-up layer.
- 7. A method of forming a composite wood veneer product as defined in claim 5, wherein at least two of said foraminous forming stations simultaneously apply at least two said formed veneer lay-up layers to said layered lay-up.
- 8. A method of forming a composite wood veneer product as defined in claim 1 wherein said drawing air through said foraminous forming surface comprises dividing said portion of said air into at least 3 separate flows each of which is withdrawn through a different zone spaced laterally across of said confined path.
- 9. A method of forming a composite wood veneer product as defined in claim 8 further comprising orienting said strands forming said veneer lay-up as they passed onto said foraminous forming surface whereby said veneer lay-up is an oriented veneer lay-up with its strands oriented in a direction substantially parallel to a longitudinal axis of said oriented veneer lay-up.
- 10. A method of forming a composite wood veneer product as defined in claim 8 wherein a plurality of steps of forming a veneer lay-up are applied in sequence one at each of a plurality of separate forming stations to form a plurality of separate veneer lay-ups one at each of said plurality of separate forming stations and provide a plurality of said veneer lay-up layers each formed from one of said separate veneer lay-ups and piling said veneer lay-up layers of said plurality of said lay-up layers one on top of the other to form a layered lay-up on said collecting surface.
- 11. A method of forming a composite wood veneer product as defined in claim 10 wherein said strands are oriented as they passed onto said foraminous forming surface to form an oriented veneer lay-up layer with strands oriented in a direction substantially parallel to a longitudinal axis of said oriented veneer lay-up layer.
- 12. A method of forming a composite wood veneer product as defined in claim 8 wherein said at least 3 separate flows each have the same flow rate.
- 13. A method of forming a composite wood veneer product as defined in claim 12 further comprising orienting said strands forming said veneer lay-up as they passed onto said foraminous forming surface whereby said veneer lay-up is an oriented veneer lay-up with its strands oriented in a direction substantially parallel to a longitudinal axis of said oriented veneer lay-up.
- 14. A method of forming a composite wood veneer product as defined in claim 12 wherein a plurality of steps of forming a veneer lay-up are applied in sequence one at each of a plurality of separate forming stations to form a plurality of separate veneer lay-ups one at each of said plurality of separate forming stations and provide a plurality of said veneer lay-up layers each formed from one of said separate veneer lay-ups and piling said veneer lay-up layers of said plurality of said lay-up layers one on top of the other to form a layered lay-up on said collecting surface.
- 15. A method of forming a composite wood veneer product as defined in claim 14 further comprising orienting said strands forming said veneer lay-up as they pass onto said foraminous forming surface whereby said veneer lay-up is an oriented veneer lay-up with its strands oriented in a direction substantially parallel to a longitudinal axis of said oriented veneer lay-up.
- 16. A method of forming a composite wood veneer product as defined in claim 14 wherein said layered lay-up is further processed by consolidation under heat and pressure into a consolidated composite veneer product.
- 17. A method of forming a composite wood veneer product as defined in claim 16 further comprising orienting said strands forming said veneer lay-up as they pass onto said foraminous forming surface whereby said veneer lay-up is an oriented veneer lay-up with its strands oriented in a direction substantially parallel to a longitudinal axis of said oriented veneer lay-up.
US Referenced Citations (20)