U.S. patent application number 15/863774 was filed with the patent office on 2018-05-10 for method and apparatus for forming objects having a core and an outer surface structure.
The applicant listed for this patent is Great Dane LLC. Invention is credited to Richard B. Mullininx, P. Alan Whiten.
Application Number | 20180126610 15/863774 |
Document ID | / |
Family ID | 52814220 |
Filed Date | 2018-05-10 |
United States Patent
Application |
20180126610 |
Kind Code |
A1 |
Mullininx; Richard B. ; et
al. |
May 10, 2018 |
METHOD AND APPARATUS FOR FORMING OBJECTS HAVING A CORE AND AN OUTER
SURFACE STRUCTURE
Abstract
A method of making at least partially foam-filled sandwich
panels includes providing a panel shell, moving at least one of a
portion of a first and/or second panel facer or a side member away
from the panel volume, thereby defining an opening between the
volume and an exterior area. A dispenser proximate the opening
moves across at least a portion of the opening while dispensing an
amount of a foam agent into the volume through the opening. A press
has three platens, a third platen of which is secured to at least
one of a portion of the first and/or second facer and the at least
one side member and is moveable with respect to the first platen
and the second platen in response to a control system.
Inventors: |
Mullininx; Richard B.;
(Savannah, GA) ; Whiten; P. Alan; (Savannah,
GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Great Dane LLC |
Chicago |
IL |
US |
|
|
Family ID: |
52814220 |
Appl. No.: |
15/863774 |
Filed: |
January 5, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14220045 |
Mar 19, 2014 |
9862126 |
|
|
15863774 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 44/1233 20130101;
B29L 2009/00 20130101; B29C 44/388 20130101; B29K 2075/00
20130101 |
International
Class: |
B29C 44/12 20060101
B29C044/12; B29C 44/38 20060101 B29C044/38 |
Claims
1. A press for making a sandwich panel enclosing an amount of foam,
comprising: a first platen having a generally planar engagement
surface; a second platen having a generally planar engagement
surface; a third platen having a generally planar engagement
surface; a control system; a frame upon which the first platen, the
second platen, and the third platen are disposed, wherein the first
platen engagement surface opposes the second platen engagement
surface, at least one of the first platen and the second platen is
movable with respect to the other of the first platen and the
second platen on the frame in response to the control system, and
the third platen is movable with respect to the first platen and
the second platen in response to the control system; and a foam
agent dispensing head that is in communication with a foam source,
movable on the frame over a range of motion in response to the
control system, and positioned on the frame so that, upon
positioning of the first platen and the second platen so that the
first platen engagement surface and the second platen engagement
surface oppose and are parallel to each other and define a volume
therebetween, and movement of the third platen away from the
volume, the foam agent dispensing head is in dispensing
communication with the volume.
2. The press as in claim 1, wherein the dispensing head comprises a
conveyor in engagement with the frame and actuatable by the control
system.
3. The press as in claim 1, comprising a negative pressure source
in communication with the third platen engagement surface.
4. The press as in claim 1, wherein the third platen is disposed
pivotally with respect to the first platen.
5. The press as in claim 4, wherein, in a first position of the
third platen, the third platen engagement surface is co-planar with
the first platen engagement surface, and in a second position
pivoted away from the volume, the first platen engagement surface
forms an obtuse angle with respect to the first platen engagement
surface.
6. A press for making a sandwich panel enclosing an amount of foam,
comprising: a panel shell comprising a first generally planar
facer, a second generally planar facer generally parallel to and
spaced apart from the first facer, and at least one side member
extending between the first facer and the second facer so that the
first facer, the second facer, and the at least one side member
enclose a volume; a first platen having a generally planar
engagement surface in engagement with the first facer; a second
platen having a generally planar engagement surface in engagement
with the second facer; a third platen having a generally planar
engagement surface in engagement with at least one of a portion of
at least one of the first facer and the second facer, and the at
least one side member; a control system; a frame upon which the
first platen, the second platen, and the third platen are disposed,
wherein the first platen engagement surface opposes the second
platen engagement surface, at least one of the first platen and the
second platen is movable with respect to the other of the first
platen and the second platen on the frame in response to the
control system, and the third platen is secured to the at least one
of the portion and the at least one side member and is movable with
respect to the first platen and the second platen in response to
the control system; and a foam agent dispensing head that is in
communication with an insulating foam source, movable on the frame
over a range of motion in response to the position control system,
and positioned on the frame so that, upon movement of the third
platen with respect to the first platen and the second platen, so
that the third platen moves the at least one of the portion and the
at least one side member away from the volume to thereby define an
opening between the volume and an area exterior to the panel shell,
the foam agent dispensing head is in dispensing communication with
the volume via the opening.
Description
CLAIM OF PRIORITY
[0001] This application is a division of U.S. patent application
Ser. No. 14/220,045, filed Mar. 19, 2014 (now U.S. Pat. No.
9,862,126), the entire disclosure of which is hereby incorporated
by reference as if set forth verbatim herein and relied upon for
all purposes.
BACKGROUND OF THE PRESENT INVENTION
[0002] The present invention relates to foamed sandwich objects,
such as but not limited to sandwich panels having opposing facers
between which a core is disposed, and in particular methods and
apparatus for manufacturing such objects.
[0003] Insulated structures, for example buildings, containers,
truck bodies and trailers, may be constructed utilizing insulated
sandwich panels having two major surfaces and four minor side
surfaces. The side surfaces are "minor" in that they encompass the
panel's shortest dimension, whereas the facers encompass the
panel's largest dimensions. The ratio between the largest and the
shortest dimensions is such that the panels may be considered
generally planar. The facers are formed of solid materials, such as
aluminum or other metals, polymers, or wood, that may exhibit
flexibility in response to forces in the panel's shortest dimension
but rigidity in the plane defined by the other two dimensions.
Between the two facers is an insulating foam. The facers are
generally strong and stiff as compared to the foam core, which is
of lighter weight and lower density than the facers. The foam core
provides structural support, e.g. resisting shear stresses and
deflection, and it may provide thermal insulation.
[0004] Insulated sandwich panels may include various structures in
the interior volume between the facers that is otherwise filled by
the foam, for example vertical or horizontal support posts or ribs
that attach to and extend between the inner and outer facers or
that attach to just one of the facers. Electrical conduit lines may
run through the panel, and troughs or raceways may be provided in
the panel facers, attached to and opening through one of the
facers, to provide a path for the conduit lines. Wooden or plastic
blocks or other structures may be disposed in the volume, extending
between the facers, to provide a structure into which screws or
nails may be driven as objects (such as logistics tracks) are
attached to the sandwich panel facer before or after assembly.
Particularly where a panel is used in the roof of the insulated
structure, lighting or other electrical fixtures may be secured in
the panel within the volume and extend through a hole made in the
facer to receive the fixture. These holes may be provided with tape
or weather stripping as a seal between the facer hole and the
fixture, or trough, to prevent foam leaks and otherwise seal the
panel interior.
[0005] Various types of foam may be used to form insulated sandwich
panels. In typical two-part insulating foams, two monomers react to
form a longer chain polymer, releasing gas in the reaction that
becomes trapped in closed cells that, in turn, form the foam
structure. The trapped gas has a low thermal conductivity, and thus
acts as the insulating agent, while the foam cell walls provide the
foam's structural characteristics. The volume ratio of gas to solid
cell structure is large.
[0006] Polyurethane foams, which are commonly used in insulated
sandwich panels, are formed from the combination of a polyol and an
isocyanate. The isocyanate is generally consistent among
polyurethane foams, the variability of which is attributable
primarily to the polyol. The polyol's selection generally
determines a given polyurethane foam's in place density, its
thermal properties, and the timing or reactivity at which the
components react to generate foam and subsequently cure.
[0007] In so-called spray foam applications, for example, the
polyol is chosen so that when the polyol and the isocyanate come
together at a foam sprayer head, the resulting liquid or
semi-liquid foam agent has a consistency such that the foam agent
clings well to vertical surfaces. The reaction rate is slow enough
to allow a user to spray a relatively large area before foaming
begins or reaches a point at which foaming interferes with the
foam's application to desired surfaces. Typically, a panel to be
insulated by spray foam would be initially constructed with one
facer, the short-side structures and the internal structures, if
any, but without the opposing facer. That is, the panel is open at
one of its two major sides. The user then sprays the panel's
interior volume. Because of the foaming agent's tendency to cling
to the sprayed surface, and the agent's relatively slow reaction
rate, the user can adequately fill the panel volume, including
irregularly-shaped spaces within the volume, if any, before foaming
begins or before enough foam expands to inhibit the spray's
effective deposition. The user can then place and secure the
opposing facer onto the panel's open major side before the foam
expands, thereby enclosing the panel interior volume. The sprayed
foam then completely expands or rises and thoroughly fills the
panel volume. As should be understood, vent slits or holes may be
provided in the short sides or facers as necessary to allow the
escape of gases as the foam fills the volume. The vent holes may be
covered with gas permeable filter material that allows the escape
of air or other gases but that blocks passage (leakage) of
foam.
[0008] Because it is necessary to expose the entirety of the panel
volume in order to apply foam by spraying, spray-foamed panels are
opened for foaming at one of the facer sides, rather than at one of
the short sides. This means, however, that the omitted facer cannot
have mechanical or sealed attachments or engagements to interior
structures within the panel that would otherwise require the
facer's assembly to such structure prior to foaming. Accordingly,
while spray foaming is utilized in insulating panels having
relatively simple internal structures, for instance those used in
buildings, such methods are often unsuitable for insulating panels
having more complicated internal structures, for example those used
in vehicles.
[0009] It is also known to foam sandwich panels through open-pour
methods, in which a panel shell that is enclosed on five sides, but
open at one of its major sides (e.g., a vacuum element in a press
can secure or hold one of the facers and facilitate temporary
removal of the second facer from the shell), is moved on a conveyor
relative to a foam dispensing head. The open panel shell can be
moved along a conveyor system under an elongated dispensing head
that extends across the panel's width so that as the panel moves
under the dispensing head, the dispensing head deposits liquid for
semi-liquid foam agent into the panel's interior. After passing
under the dispensing head, the panel shell can be shuttled into a
press mechanism, the bottom facer of the open panel shell being
received on a platen of the press. An opposing platen holds the
other facer (which the platen had earlier removed), for example by
suction, opposite the shell's open major side. The press moves the
second platen down onto the shell, so that the removed facer again
engages the panel shell sides, thereby enclosing the panel's
internal volume. The mixed foam agent's chemistry is such that the
foam does not rise to fill the volume before the opposing facer is
placed down onto the open shell. The press then applies sufficient
force to the platens, in opposition to the outward force that the
expanding foam applies as the foam agent exotherms. As should be
understood, a combination of aluminum or plastic extrusions and
wood or polymer strips or blocks may be placed along the panel
edges to construct the short sides and maintain the foam within the
side surfaces. The press mechanism generally does not provide
platens to apply resistive pressure to the side surfaces. Rather,
the pressure applied by the major-side platens compresses or
pinches, without crushing, the side members between the facers,
holding them in place sufficiently to resist the foam's outward
pressure. Again, vents may be provided in the side members to allow
air and other gases to escape as foam fills the panel volume, and
semi-permeable filter material may be placed over the vents to
block the interior foam's escape.
[0010] As with spray foaming methods, open pour methods require a
facer's removal, thus precluding use with foam panels that have
internal structures that would require attachment prior to
foaming.
[0011] It is also known to pre-form insulation foam into blocks,
cut the block foam into desired shapes to fit a panel interior, and
then secure the one or more resulting foam pieces into the panel.
This procedure can accommodate complicated interior panel volumes
but tends to limit a panel's thermal performance. When a foam agent
is allowed to react and foam within an enclosed volume, and when
there is sufficient foam agent such that the resulting foam fills
the volume and exerts pressure against its sides, the restricted
enclosure increases foam density and tends to promote a more
uniform cell structure. This, in turn, generally improves the
foam's thermal characteristics. Block-formed foam, however, is
formed within a structure that may be bounded on some, but not all,
sides, thereby allowing the foam to rise freely, with the foam's
weight being its primary restriction. This results in a cell
density lower than, and a cell structure more irregular than, foam
that is formed in a confined volume. Even if the foam to be cut is
formed in a completely enclosed cavity, the subsequent cutting
operation allows cell gases to escape and degrades the ability of
the cut blocks to insulate effectively. Heavy or high density
Styrofoam, for example, may have a density in the range of 2.1-2.5
pounds per cubic foot. Furthermore, block urethane foam tends to
shrink for some period after initial curing. Thus, block-formed
urethane foam cannot be used immediately after its formation and
must be allowed to rest for some intervening period of time. During
this time, however, the foam can experience some degree of loss of
foam cell gas (outgassing), further impairing the foam's thermal
performance. Finally, while block foam may be cut to closely fit a
panel's internal structure, the fit is not as close as that
resulting from foam that is initially inserted into the panel as a
pre-expanded or foamed liquid and allowed to rise to fill and fill
the panel's interior. While adhesives may be used to fill gaps
around, and otherwise secure, block foam within a panel, the
adhesive generally has a lower thermal performance than the foam
and adds weight and cost. The formation of sandwich panels using
block foam can also be labor intensive.
[0012] Where an insulated sandwich panel includes interior
structure that interacts with the facers or external elements that
attach to or through the facers, it is known to insert the foam by
injection of pre-foam or semi-foamed liquid into an enclosed panel
volume. The sandwich panel shell is generally first constructed so
that the two facers and the separating side members completely
enclose the panel's interior volume and, therefore, the panel's
interior structures. One or more holes is drilled or otherwise
formed in one or both facers and/or a side member. A user places a
foam injection nozzle at a hole and injects liquid or semi liquid
(froth) foam agent into the enclosure. One such hole may be
sufficient for a small panel, but larger panels may require
multiple interior enclosures or segments, sometimes referred to as
cavities, and corresponding foam access holes. Accordingly, it is
known to divide a panel's interior volume into discrete segments or
cavities that are sealed from each other with respect to the foam.
Respective holes are drilled to each segment through the side
members to provide for foam dispensing and escape of gases from the
segment interior. The panel shell is then placed into a press
having opposing platens that abut the facers and possibly including
a fixed position perimeter board or mold board abutting and
supporting the short sides to resist the forces resulting from the
core material's expansion. The platens apply opposing pressure to
the facers, again pinching the side members to hold them in place.
The access holes are typically along one of the panel's sides, and
the panel is generally installed in the press so that this side
faces upward, or at least oriented such that this side is exposed
to an operator working at the press. The foam nozzle is disposed
proximate the panel edge on a moveable structure at the press by a
counterbalance so that the operator may deploy the nozzle and move
the dispensing head and nozzle down the panel's length,
sequentially engaging the foam nozzle at the panel shell's access
holes to thereby fill the panel's volume.
[0013] At the time the panel's layout is designed, the volume of
each interior segment can be determined. This information, and the
sequence in which the individual segments will be filled, may be
provided to a computer that controls the foam machine's operation.
The foam machine computer may also be programmed with or has access
to the amount of foam agent needed per unit volume in order to
result in foam (within a given volume) having the density and cell
formation desired for a given panel. Alternatively, all of these
calculations can be made outside of the computer programming, so
that the computer (including a corresponding database) receives
information describing only the number and sequence of foam agent
injections to be made for a given panel and the respective amounts
of foam agent to be provided in each of the injections.
[0014] When the panel shell is placed in the press, an operator
initiates the foaming sequence. The operator actuates the press
controls to direct the press platens to apply pressure to the
opposing shell facers and actuates the foam machine computer to
assume the beginning of the injection sequence. For the latter
step, the operator places the foam injection nozzle at the access
hole for the first volume segment in the sequence (the first hole,
at one end of the panel edge) and actuates the trigger. This causes
a signal to be received at the foam machine computer, and the
computer correspondingly controls fluid valves and pumps from the
polyol and isocyanate sources to deliver respective amounts of
those substances to the foaming head so that the foaming head mixes
and dispenses the predetermined amount of foam agent into the first
segment. After the amount of foam agent has been dispensed, the
operator removes the dispensing head from the first access hole,
moves the dispensing head to the second hole in the sequence,
engages the second access hole, and actuates the trigger. This
causes the foam machine computer to control the system to deliver
the amount of foam agent corresponding to the second volume
segment. Generally a second operator follows the first operator,
plugging the holes after the liquid foam agent has been deposited
into the respective volume segment. This process repeats until
corresponding foam agent amounts have been injected into all the
panel's interior volume segments.
[0015] As noted, the press platens apply pressure to the facers as
the operator injects liquid foam agent into panel shell interior.
Supports may be provided in the panel interior to provide structure
and/or prevent the shell's deformation into the volume. As the foam
agent exotherms, i.e., as the foam expands or rises, pressure and
temperature build within the panel shell interior. As should be
understood in this art, it is desirable to maintain the panel
system at a relatively constant temperature range during foaming,
and for this purpose the press platens may be provided with a
series of fluid paths within each platen. When the platens close
upon the non-foamed panel shell, fluid, heated to a pre-determined
temperature that is desirable for the foaming process, for example,
110.degree. F., circulates through the platens, warming the facers
to approximately the same temperature. As the foam exotherms,
however, and as the temperature within the panel rises, the fluid
flowing through the platens becomes a cooling agent, carrying heat
away from the platens to the temperature control system, which now
cools the water to 110.degree. F. The temperature regulation of
foam insulated sandwich panels should be well understood in this
art. Such procedures may be used with the embodiments of the
present invention discussed herein but are not, in and of
themselves, part of the present invention and are, therefore not
discussed in further detail herein.
[0016] As with panels made by a spray foaming and open pour
methods, vent holes may be provided in the panel shell facers or
sides, with suitable filter material, to allow escape of gases
during foam expansion while retaining foam within the panel
interior.
[0017] Once the foam has risen, and thereby completely filled the
panel interior volume, the panel remains in the press for a period
of time sufficient to allow the foam to cure. As should be
understood in the art, curing is the process by which the foam
cross links and the cell structure solidifies into its final
form.
[0018] As noted, the press is operated in such a way as to maintain
the panel at a desired temperature range, for example 110.degree.
nominal, or within a range of about 105.degree.-115.degree.. As the
facers' temperature increases during initial warming, and, to a
lesser extent as the foam agent exotherms and the foam cures, the
facer material slightly expands. To avoid wrinkles and other
possible deformities in the facer surface, the facers and side
members are sealed against each other using a foam tape (e.g. as
used in or as common weather-stripping material) that allows some
degree of slip or relative movement between these components.
[0019] As noted, the opposing pressure from the press, pushing the
two facers toward each other and against the side members, holds
the facers and the side members to each other during the foam
injection and curing process. The foam, in turn, holds these panel
surfaces together with the core in the finished panel. In some
instances, however, the side members are not intended to be a part
of the finished sandwich panel, and the side members can be removed
after the panel is removed from the press. This can be accomplished
by trimming the post-cured panel or by using side members coated to
prevent the foam's adhesion to the side members, thereby
facilitating their removal.
[0020] Various types of presses can be utilized for enclosed
injection foaming. Referring, for example, to FIG. 1, a mandrel
press 10 comprises a three-sided press having a cantilevered inner
portion 12 upon which three inner platens 14 are disposed. Opposite
inner portion 12 are two outer clamshell portions 16, each having
one side platen 18 and a top platen half 20. Press 10 is designed
for use in manufacturing insulated panels which are a part of
insulated semi-trailers. Prior to injecting the foam insulation,
the panel shells for the trailer's sides and roof are constructed
and assembled onto a semi-trailer chassis. As described above, the
panel shells comprise opposing facers with side members extending
around the panel edges to thereby completely enclose the panel
shell interior volume. Each panel may be a continuous structure
extending the entire length of the trailer, or the trailer may be
formed by connecting multiple discrete panel segments in each of
the two sides and the roof. Regardless of such arrangement, each
panel shell has interior structures, and each panel's interior
volume is generally divided into discrete segments. Each side panel
has a top rail portion and a bottom rail portion, whereas the roof
panel has top rail portions on each longitudinal side. The side
panel top rail portions connect to the roof panel top rail portions
to secure the panels together. Access holes are drilled in the top
rail portions of the side panels in communication with respective
interior volume segments so that the holes are accessible from the
top of the trailer when the trailer body is assembled. Access holes
to the roof panel interior volume segments are also drilled into
one of the top rail portions, but these holes are accessible from
the side of the roof panel when the panels are assembled onto the
trailer chassis. Once the panels are assembled onto the chassis,
the nearly-formed trailer (the trailer's rear frame and doors are
not yet assembled) is backed up to press 10 while side structures
16 are pivoted outward, as shown in FIG. 1. The trailer's rear
opening is backed up to and over central cantilevered press portion
12 so that press portion 12 extends into the trailer's interior and
so that respective platens 14 face the trailer's side panels and
roof panel. Clamshell side press portions 16 are then pivoted
inward toward the trailer so that the top edges of the side
portions meet. Central portion 12 is expanded and side platens 18
contracted to oppose the outer portion of the trailer side panels,
and ultimately platen surface 20 oppose the outer portion of the
roof panel. The inner and outer platens apply pressure to their
respective panel surfaces. Press 10 includes a series of holes that
align with the access holes in the panels. An operator may then
insert a foam head nozzle through the holes in the press, engage a
corresponding access hole in one of the panel shells, and begin
injection of foam agent into a corresponding panel interior volume
segment. Once the foam has been deposited, expands, and cures,
outer portions 16 are opened, the trailer shell is removed from the
press, and the trailer's construction is completed.
[0021] It is also known to manufacture the panels individually,
prior to their installation in a trailer. Referring to FIG. 2, for
example, a press 22 includes two individual press portions 24 on
each side of a central frame. Each press portion 24 includes an
inner platen 26 and outer platen 28 that can be pivoted toward and
away from platen 26 by actuation of a series of hydraulic pistons
30. A panel shell constructed as discussed above is inserted
between platens 26 and 28. Cylinders 30 close platen 28 onto the
panel shell so that the panel shell is held securely between the
two platens, and pressure is applied. The holes in one of the
panel's side members, which provide access to the panel's interior
volume segments, are on the side of the press facing upward and are
thereby accessible to a user operating the foam injection nozzle
from a catwalk above the platens in the central frame.
[0022] It is also known to arrange a press so that the platens are
disposed horizontally. The assembled panel shell is inserted into
the press between the platens so that the facers are also aligned
horizontally against the respective platens and so that the side
edge in which the access holes are defined is vertically aligned.
The foam agent is therefore injected into the respective spaces in
a horizontal direction. One example of a horizontally oriented
press is U.S. Pat. No. 5,722,276, the entire disclosure of which is
incorporated by reference herein.
[0023] Referring to FIG. 3, a six-sided polyhedron panel shell 30
for use in a press system for injecting insulating foam into
individual interior shell volume segments includes an aluminum
outer facer 32 in the form of a relatively thin, planar sheet. The
side of aluminum facer 32 facing inward to the panel's interior
volume is first covered with an epoxy, polyester or a similar
coating to facilitate foam adherence to the facer, as should be
understood. A series of extrusion and strips or blocks 34 are
disposed along the four edges of aluminum facer 32 and extend
upward therefrom for a short distance (compared to the panel's
longitudinal dimension) to form the panel's side members. These
side members may be made of any desirable material, for example
aluminum, wood or various plastics including plastic foams such as
Styrofoam. A series of foam tape segments or adhesives 36 are
disposed along both rims of the side members in order to adhere the
side members to the aluminum facer and to a polymer laminate inner
facer 37 (FIG. 4). As the illustrated panel shell 30 is to be used
to form a trailer side panel, an aluminum top rail and aluminum
bottom rail are attached to the panel's longitudinal edges. For
example, a bottom rail 38 is attached to the side members 34 by a
series of rivets 40, adhesive or other suitable means.
[0024] Side members 34 enclose a volume 42 adjacent the interior
surface of facer 32. Within that volume, a series of elongated
reinforcing ribs 44 extends across the interior surface of facer 32
between the top and bottom longitudinal side members 34. Ribs 44
attach to facer 32 and provide structural support thereto. As
should be understood, such supports in a non-insulated trailer
panel would typically extend entirely between the inner and outer
facers and attach to both. In this insulated panel, however, it is
desirable to maximize the foam's continuity to thereby optimize the
panel's thermal characteristics, and lower profile ribs 44 are used
instead of fully-extending posts. It should also be understood,
however, that J-shaped and Z-shaped posts may also be used in
insulated panels, extending entirely between the two facers.
[0025] A series of wooden or polymer blocks 46 may be disposed
adjacent respective ribs 44 and abut the bottom longitudinal side
member 34, just above bottom rail 38, so that blocks 46 extend in a
row along the bottom of the panel shell. Upon installation of the
inner liner facer, which will abut blocks 46, the blocks provide a
backing surface so that a scuff band may be disposed on the side of
the inner facer opposite the blocks, and may be secured to the
panel at that position by screws extending through the scuff band,
the inner facer, and into blocks 46 or alternatively through blocks
46 and into ribs 44. A similar row of blocks are also attached to
ribs 44 and extend in a line parallel to the longitudinal side
members 34 and extending through the middle of the panel. A similar
row of blocks 50 extend longitudinally through the panel near the
panel top. The polymer inner liner facer also abuts these blocks,
which provide support for the attachment of longitudinal logistics
tracks that extend along the panel's length on the inner side.
Referring also to FIG. 4, an aluminum support plate 52 extends
along the panel's upper longitudinal side member 34, within the
interior volume of the panel, from the panel's back side edge 34
toward, but stopping short of, its front side edge 34. Plate 52
provides support for a sliding track for subsequent attachment to
permit installation of an overhead or garage type rear door that
will be disposed within the trailer interior and attached to the
panel through the inner facer. An aluminum top rail portion 54 is
disposed at the top of the panel and attaches to aluminum facer
32.
[0026] Also attached to some of the ribs 44 intermittently along
the panel's longitudinal length are a plurality of PVC plastic foam
dams 55. In this instance, a foam dam 55 is attached to every third
support rib 44. As can be seen in FIG. 3, the base of each foam dam
has a cut out for each block 48 and 52 in its path and slightly
overlaps an end of a block 46. As can be seen in FIG. 5, foam dams
54 all slope toward the same one of the panel's two vertical edges
34 or side members.
[0027] As can be seen in FIGS. 3 and 5, a series of holes 56 is
drilled through bottom rail 38 and the longitudinal side member 34
behind it communicating with respective inner volume segments 58
defined between adjacent foam dams 55 or between a foam dam 55 and
an opposing vertical side member 34. When the polymer inner facer
is applied to the panel shell's open major side, such that the
laminate polymer facer abuts the tops of blocks 46, 48, and 50, the
inner facer also abuts the distal edges of foam dams 55, even with
their slope or bend.
[0028] A combination of (possibly double sided) foam tape 36 and
adhesive initially holds the inner facer and outer facer onto the
side members, thereby holding the panel shell together. Clamps
placed along the bottom edge of the now-assembled panel shell are
attached to carrying lines of a bridge crane disposed along the
ceiling of a manufacturing facility. The bridge crane pulls the
panel upward so that it is suspended vertically, upside down, with
bottom rail 38 oriented upward. The crane conveys the suspended
panel shell to a press, such as an A-frame or book-type press 24 in
FIG. 2, and disposes the assembled shell between the press platens.
The press closes, as described above, and an operator injects foam
agent into the respective volume sections 58 sequentially as
described above. The first section 58 to be injected with foam is
indicated at 58A in FIG. 3, followed sequentially by 58B, 58C, and
58D. As each volume segment fills with foam, the foam pushes a
sloped or bent foam dam 55 toward the still-unfoamed adjacent
section 58. This further pushes or forces the foam dam against the
inner polymer liner facer, strengthening the seal between the panel
and the dam. Blocks 48 and 50 laterally support the dam, preventing
the dam from pushing over center, further toward the adjacent open
volume section, and thereby comprising the foam seal between
adjacent sections. The foam dam is unnecessary at the lower end of
the panel, due to the presence of blocks 46, but it should be
understood that where no blocks 46 are used, the foam dams, if
employed, would extend to the panel bottom.
[0029] Accordingly, foam dams 55 and blocks 46 seal adjacent volume
segments 58 from each other, so that foam expanding in one segment
or cavity 58 doesn't leak into an adjacent segment in which foam
has not yet expanded. If a foam dam does not properly seal between
adjacent volume segments, or if any other leaks occur therebetween,
expanding foam in the segment in which foam is rising can leak or
inject under substantial pressure (above atmospheric pressure) into
the adjacent volume segment, in which the foam has not yet risen.
The leaked foam, being injected into the adjacent volume segment
under higher than atmospheric pressure and without spatial
restriction, tends to have irregular, elongated cell structures,
and is partially stripped of contained cell gases, resulting in
excessive density. The resulting leaked foam has correspondingly
poor thermal characteristics. When foam in the volume segment into
which foam from the adjacent segment has leaked then rises up and
around the leaked foam to fill the volume space, and the leaked
foam forms a sub-volume of poor thermal performance within the
volume segment. To prevent such leaks, therefore, foam dams must be
carefully installed, and the dams and other partition materials
between volume segments must be carefully constructed and
arranged.
SUMMARY OF THE INVENTION
[0030] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate one or more
embodiments of the present invention.
[0031] In one embodiment of a method of making a at least partially
foam-filled sandwich panel enclosing an amount of foam, a panel
shell is provided having a first generally planar facer, a second
generally planar facer generally parallel to and spaced apart from
the first facer, and at least one side member extending between the
first facer and the second facer so that the first facer, the
second facer, and the at least one side member enclose a volume. At
least one of a portion of at least one of the first facer and the
second facer, and the at least one side member, is moved away from
the volume, thereby defining an opening between the volume and an
area exterior to the panel shell. Where the portion is moved, it is
moved with respect to a respective remainder of the at least one of
the first facer and the second facer. A moveable dispenser is
provided proximate the opening and is moved across at least a
portion of the opening while the dispenser dispenses an amount of a
foam agent into the volume through the opening that is sufficient
to generate the entire amount of foam. After the dispenser
dispenses the sufficient amount, the at least one of the portion
and the at least one side member is moved to a position in
communication with at least one other of the first of facer, the
second facer, and the at least one side member to thereby close the
opening and enclose the volume.
[0032] An embodiment of a method of making a sandwich panel
enclosing an amount of foam includes providing a panel shell having
a first generally planar facer, a second generally planar facer
generally parallel to and spaced apart from the first facer, and at
least one side member extending between the first facer and the
second facer so that the first facer, the second facer, and the at
least one side member enclose a volume. The panel shell forms a
generally rectangular prism. A panel may be taller at one end than
the other, and thus have wedge yet is still considered a generally
rectangular prism shaped panel; similarly, opposing facers of a
wedged panel are considered to be generally parallel to each other
herein. The panel shell is inserted between opposing platens of a
press, so that the first facer abuts a first platen and the second
facer abuts a second platen. The press comprises a third platen
that is pivotable with respect to the first platen. A portion of
the first facer is secured to the third platen. The third platen is
pivoted with respect to the first platen, thereby moving the
portion of the first facer to a first position away from a portion
of the at least one side member and defining an opening between the
volume and an area exterior to the panel shell. The opening has a
first end and a second end opposite the first end. A moveable foam
dispenser is provided proximate the opening and is moved between
the first end and the second end. The foam dispenser dispenses an
amount of a foam agent into the volume through the opening that is
sufficient to generate the entire amount of the foam. After the
sufficient amount has been dispensed by the foam dispenser, the
portion of the first facer is moved to a second position in
communication with the at least one side member to thereby close
the opening and enclose the volume.
[0033] An embodiment of a press for making a sandwich panel
enclosing an amount of foam has a first platen having a generally
planar engagement surface, a second platen having a generally
planar engagement surface, a third platen having a generally planar
engagement surface, a control system, and a frame upon which the
first platen, the second platen, and the third platen are disposed.
The first platen engagement surface opposes the second platen
engagement surface. At least one of the first platen and the second
platen is moveable with respect to the other of the first platen
and the second platen on the frame in response to the control
system. The third platen is moveable with respect to the first
platen and the second platen in response to the control system. A
foam agent dispensing head is in communication with a foam source.
The foam agent dispensing head is moveable on the frame over a
range of motion in response to the control system. The dispensing
head is positioned on the frame so that, upon positioning of the
first platen and the second platen so that the first platen
engagement surface oppose and are parallel to each other and define
a volume therebetween, and movement of the third platen away from
the volume, the foam agent dispensing head is in dispensing
communication with the volume.
[0034] In a still further embodiment, a press for making a sandwich
panel enclosing an amount of foam has a control system and a panel
shell with a first generally planar facer, a second generally
planar facer parallel to and spaced apart from the first facer, and
at least one side member extending between the first facer and the
second facer so that the first facer, the second facer, and the at
least one side member enclose a volume. A first platen has a
generally planar engagement surface in engagement with the first
facer. A second platen has a generally planar engagement surface in
engagement with the second facer. A third platen has a generally
planar engagement surface in engagement with at least one of a
portion of at least one of the first facer and the second facer,
and the at least one side member. The first platen, the second
platen, and the third platen are disposed on a frame. The first
platen engagement surface opposes the second platen engagement
surface. At least one of the first platen and the second platen is
moveable with respect to the other of the first platen and the
second platen on the frame in response to the control system. The
third platen is secured to the at least one of the portion and the
at least one side member and is moveable with respect to the first
platen and the second platen in response to the control system. A
foam agent dispensing head is in communication with an insulating
foam source and is moveable on the frame over a range of motion in
response to the position control system. The dispensing head is
positioned on the frame so that, upon movement of the third platen
with respect to the first platen and the second platen, so that the
third platen moves the at least one of the portion and the at least
one side member away from the volume to thereby define and opening
between the volume and an area exterior to the panel shell, the
foam agent dispensing head is in dispensing communication with the
volume via the opening.
[0035] A further embodiment of a method of making a sandwich
structure enclosing an amount of a core material generated by an
expanded agent material includes providing a shell comprising a
first facer, a second facer spaced apart from the first facer, and
at least one side member extending between the first facer and the
second facer about a circumferential periphery of the panel shell
so that the first facer, the second facer, and the at least one
side member enclose a volume. An opening is provided in at least
one of the first facer, the second facer, and the at least one side
member, or between the at least one side member and at least one of
the first facer and the second facer, at or generally parallel to a
seam between the at least one side member and one of the first
facer and the second facer and extending a distance of at least
about 2% of the entire length of the circumferential periphery. A
moveable dispenser is provided proximate the opening, and the
dispenser is moved across at least a portion of the opening, while
the dispenser dispenses an amount of the agent material into the
volume through the opening that is sufficient to generate the
entire amount of core material.
[0036] In a further embodiment of a method of making a sandwich
structure enclosing an amount of a core material generated by an
expanded agent material, a shell is provided that encloses a
volume. A press has a plurality of platens and has a frame and a
control system. A dispenser is moveable on the frame responsively
to the control system at a predetermined speed and is operable to
dispense an amount of the agent material at a predetermined rate.
The shell is disposed within the press so that platens secure the
shell in a position. An opening is provided in the shell sufficient
so that a pour of the agent material into the volume through the
opening at the predetermined rate and across the distance at the
predetermined speed deposits an amount of agent material into the
volume that is sufficient to generate the entire amount of core
material. The dispenser is moved proximate the opening and across
at least a portion of the distance while dispensing the amount of
foam agent into the volume through the opening.
[0037] In an embodiment of making a sandwich panel enclosing an
amount of foam according to an embodiment of the present invention,
a panel shell is provided that comprises a first generally planar
facer, a second generally planar facer spaced apart from the first
facer, and at least one side member extending between the first
facer and the second facer about a circumferential periphery of the
panel shell so that the first facer, the second facer, and the at
least one side member enclose a volume. A press is provided having
opposing platens and having a frame and a control system. A
dispenser is moveable on the frame responsively to the control
system at a predetermined speed and is operable to dispense an
amount of foam agent at a predetermined rate. The panel shell is
disposed within the press so that the platens secure the panel
shell in a position. An opening is provided in at least one of the
first facer, the second facer, and the at least one side member, or
between the at least one side member and at least one of the first
facer and the second facer, at or generally parallel to a seam
between the at least one side member and one of the first facer and
the second facer extending a distance sufficient so that a pour of
the foam agent into the volume through the opening at the
predetermined rate and across the distance at the predetermined
speed deposits an amount of foam agent into the volume that is
sufficient to generate the entire amount of foam. The dispenser is
moved proximate the opening and across at least a portion of the
distance while dispensing the amount of foam agent into the volume
through the opening.
[0038] In a still further embodiment, a method of making a sandwich
structure enclosing an amount of a core material generated by an
expanded agent material includes providing a shell that encloses a
volume. A press has a plurality of platens and has a frame and a
control system. A dispenser is moveable on the frame responsively
to the control system at a predetermined speed and is operable to
dispense an amount of the agent material at a predetermined rate.
The shell is disposed within the press so that the platens secure
the shell in a position and so that one of the platens secures a
surface of the shell. One of the platens is moved so that the one
of the platens moves at the surface away from a remaining surface
of the platen shell, thereby defining an opening in the shell
between the volume and an area exterior to the shell. The dispenser
is moved across at least a portion of the opening while dispensing
agent material into the volume through the opening.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Aspects of the invention can be better understood with
reference to the following drawings. The components in the drawings
are not necessarily to scale. An enabling disclosure of the present
invention, including the best mode thereof, is set forth in the
specification, which makes reference to the appended drawings, in
which:
[0040] FIG. 1 is a schematic view of an insulated foam press as in
the prior art;
[0041] FIG. 2 is a schematic view of an insulated foam press as in
the prior art;
[0042] FIG. 3 is a partial perspective view of a panel shell for
use in a prior art method of insulating sandwich panels;
[0043] FIG. 4 is a partial perspective view of a panel shell for
use in a prior art method of insulating sandwich panels;
[0044] FIG. 5 is a partial perspective view of a panel shell for
use in a prior art method of insulating sandwich panels;
[0045] FIG. 6 is a partial perspective view of a panel shell for
use in a method of constructing an insulated sandwich panel
according to an embodiment of the present invention;
[0046] FIG. 7 is a partial perspective view of a panel shell for
use in a method of constructing an insulated sandwich panel
according to an embodiment of the present invention;
[0047] FIG. 8 is a rear perspective view of a van type trailer
embodying insulated panels made in accordance with an embodiment of
the present invention;
[0048] FIG. 9 is a schematic view of equipment for practicing an
embodiment of a method according to the present invention;
[0049] FIG. 10A is a side view of a press according to an
embodiment of the present invention;
[0050] FIG. 10B is a side view of a press according to an
embodiment of the present invention;
[0051] FIG. 10C is a side view of a press according to an
embodiment of the present invention;
[0052] FIG. 10D is a perspective view of a press according to an
embodiment of the present invention;
[0053] FIG. 11 is a schematic illustration of a panel shell for use
with a press and method according to an embodiment of the present
invention; and
[0054] FIG. 12 is a schematic illustration of a panel shell for use
with a press and method according to an embodiment of the present
invention.
[0055] Repeat use of reference characters in the present
specification and drawings is intended to represent same or
analogous features or elements of embodiments of the present
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0056] Reference will now be made in detail to presently preferred
embodiments of the invention, one or more examples of which are
illustrated in the accompanying drawing. Each example is provided
by way of explanation of the invention, not limitation of the
invention. In fact, it will be apparent to those skilled in the art
that modifications and variations can be made in such examples
without departing from the scope or spirit thereof. For instance,
features illustrated or described as part of one embodiment may be
used on another embodiment to yield a still further embodiment.
Thus, it is intended that the present invention covers such
modifications and variations as come within the scope of the
appended claims and their equivalents.
[0057] As described in more detail below, the systems and methods
of the embodiments described below allow the pouring, for instance
by a single continuous pour or a sequence of discrete continuous
pours, of liquid or partially foamed or froth foam agent to the
interior volume of a panel shell without requiring the sequential
injection of foam agent into individual interior volume segments or
otherwise into a panel interior having a complex spatial
arrangement, even when the panel includes interior structures that
interact with the facers. In the embodiments discussed herein, the
continuous pours are made from a dispensing device that moves
(continuously or intermittently) along a path that maintains a
substantially constant offset from the panel shell's periphery,
without the need to diverge from that path to engage injection
access holes. Accordingly, the apparatus and methods of these
examples allow the deposit of all the foam agent needed for a given
panel in one movement of a dispensing head over the panel shell,
rather than requiring discrete insertions of a dispensing head into
one or more injection access holes. An example of such a panel
shell is the rectangular prism-shaped panel shell 60 shown in FIG.
6, which may be used to form the sides of a trailer, for example an
insulated, refrigerated trailer. A generally rectangular polymer
facer forms the panel's inner surface when the panel is assembled
as part of the trailer, whereas a rectangular aluminum facer forms
the panel's outer surface. The facers are spaced apart from each
other by the side members and are generally parallel to each other,
which should be understood to accommodate slight angles between the
two facers (for example up to about 2.degree., and in one preferred
embodiment up to about 0.5.degree., and in a further embodiment
between about 0.09.degree. and about 0.2.degree.), also referred to
as wedge, or stepping of one or both facers, as should be
understood. The shell is constructed in the same manner as the
shell of FIGS. 3-5, except that foam dams 54 (FIG. 5) and injection
access holes 56 (FIG. 5) are omitted. In another embodiment, the
foam dams remain as shown in FIGS. 3-5 in order to define discrete
compartments or volumes distinct from each other with respect to
the formation of foam, but the access holes remain omitted. Foam
tape 36 (and/or adhesive or mechanical fasteners) again lines side
members 34 and in part secures the polymer inner facer (not shown)
and outer facer about the shell's perimeter to thereby fully
enclose the interior volume. Seams are thus defined at the meeting
between the side members and the inner facer and between the side
members and the outer facer. The inner polymer facer may be
constructed as a laminate as described in U.S. Pat. No. 7,025,408
or 7,901,537, or United States Published Application 2013/0207413,
the disclosures of which are incorporated herein by reference for
all purposes. As discussed in those references, mechanical
structures such as scrim may be provided on the side of the inner
facer facing the panel interior volume to strengthen the panel
and/or to facilitate the foam's adherence. Coatings, such as epoxy
or polyester coatings, may also be used to facilitate adherence
between the inner liner and the foam and also between the inner
side of the aluminum facer and the foam. And as noted below, the
foam can adhere to the side members when the side members are
retained in the panel. Thus, the foam generally holds the panel
surfaces together in the finished panel. In this embodiment, there
are four discrete side members, one for each linear side of the
rectangular prism.
[0058] Referring also to FIG. 7, a sandwich panel shell 70 for use
as a roof panel includes a generally planer aluminum sheet facer
72, an opposing polymer inner facer 73, and
perpendicularly-oriented wood or polymer side members 74 extending
between the inner and outer facers around the periphery of the
panel shell defined by the facer edges. As described above, the
inner and outer facers can be held to the side members in the
assembled shell by foam tape, other adhesives, or other mechanisms.
Support ribs 76 extend between the longitudinal side members 74
parallel to each other and provide support to outer facer 72,
similarly to the side panels' ribs 44. In this example, there are
no logistics tracks or scuff band to be attached to the roof panel,
and the sandwich panel therefore has no rows of corresponding
support blocks as are present in the side panels. The roof panel
does, however, have intermittently spaced support blocks disposed
on ribs 76 throughout the volume, at a height just below the height
of polystyrene members 74. When the polymer inner liner facer is
applied to the open shell as shown in FIG. 7, and the panel is
inserted into the press, the polystyrene side members compress to
some degree, to the depth of blocks 78. Auxiliary blocks are
disposed between the platens, outside the panel, to provide a final
stop depth and present crushing of the panel. One or more light
fixture enclosures 80 are secured to facer 72 by support blocks 82
attached to the underlying rib 76. A hole is cut in the inner
polymer facer (not shown) so that the front face of light enclosure
80 extends into the facer hole so that activation of the
subsequently installed light can illuminate a trailer interior.
[0059] A conduit tray or trough (raceway) 84 runs the length of
panel shell 70, parallel to longitudinal side members 74. A center
trough depression 86 extends inward from side rails 88 so that the
trough extends into the panel shell interior volume, resting on
support blocks that are, in turn, secured to respective ribs 76.
The polymer inner facer is formed into sections in order to
accommodate conduit track 84. A first section extends from one of
the side rails 88, away from center trough 86, to attach to one of
the rails adjacent side member 74. A second, shorter, section of
the polymer inner facer extends from the opposite rail 88 to the
other longitudinal side rail below side number 74. The polymer
facer attaches to the rails by foam tape or other suitable means.
As noted, the short facer section includes a hole to accommodate
light 80. Trough 86 can be used to accommodate electrical and
hydraulic conduits running the trailer's length, as well as
refrigerant lines used in the operation of one or more
refrigeration devices eventually mounted to various points in the
trailer and supported by the trailer roof. As the trough 86 opens
downward, into the trailer interior, it may be covered with a still
shorter section of the polymer inner facer, extending over trough
86 between the opposing rails 88. When the three polymer facer
sections are assembled onto panel shell 70 (although in multiple
pieces, considered herein as the roof panel facer), the outer and
inner facers, along side members 74, completely enclose the
sandwich's interior volume. As with the side panel described with
regard to FIG. 6, the roof panel has no foam dams nor access holes,
although it should be understood that the roof panel, like the side
panel, may be formed with discrete volume segments within its
interior volume, separated by foam dams. As noted above, aluminum
top rail portions 90 are disposed on either longitudinal side of
the roof sandwich panel.
[0060] Both the side and roof panel shells include vents, which in
certain embodiments are made at multiple points around the panel's
perimeter in the side members. The vents allow air or other gases
to exit the panel interior as the foaming agent exotherms and foam
expands in the interior volume. Strategic placement of the vent
openings allows the expansion of the foam agent to completely fill
the volume, reducing the likelihood of entrapped gas volumes or
voids in the insulated panel core. As discussed above, filter
material is placed the vents, on the interior side, to allow the
exit of air or other gases but block passage of foam from the
interior.
[0061] While the presently described embodiments include, form, or
are used in the manufacture of panels utilizing foam as the panel
core, it should be understood that a core of a panel as described
herein can be an expanding material such as foam.
[0062] Referring to FIG. 8, an insulated van trailer in accordance
with an embodiment of the present invention is illustrated
generally at 86. While an insulated van trailer is referred to
throughout the present application for convenience, the description
of insulated structures herein is intended to encompass both fully
insulated and partially insulated refrigerated and non-refrigerated
trailers, as well as bimodal type shipping containers or similar
insulated boxes or other structures such as railway cars or the
like used to carry cargo and constructed in accordance with the
principles of the present invention. Moreover, panels constructed
as described herein could be used in insulated truck bodies or
buildings. Insulated van trailer 86 includes top rails 88 and
bottom rails 90 (only one shown). Top rails 88 and bottom rails 90
are connected by a side wall structure 92 comprised of one or more
panels as discussed above with regard to FIG. 6. A front wall
assembly 94 and rear frame assembly 96 are connected on opposite
ends of the top and bottom rails 88 and 90. A front wall (not
shown) can also be constructed of an insulated panel as discussed
above with regard to FIG. 6. A roof structure 98 and rear doors 100
for permitting entry and exit of cargo cooperate with a floor
structure 102 to form a monocoque construction insulated van
trailer. Running gear assembly 104 and front support members 106
are also provided as is well known in the art. With the exception
of the method of inputting foam into the sandwich panels forming
the wall and roof structures, the construction of insulated van
trailer 86 is in accordance with known prior art trailer
constructions. Although not detailed in the presently described
examples, it should also be understood from the present disclosure
that the present methods may be used to form foam-enclosing trailer
floors and end panels, and a trailer, container, truck body, or
other insulated vehicle constructed of side, roof, floor, and/or
end panels constructed as discussed herein is expressly part of the
present disclosure.
[0063] FIG. 9 provides a schematic representation of various
stations utilized in a manufacturing method according to an
embodiment of the present invention. Aluminum sheet material used
for the outer facer is stored in rolled form at 108 or in
individual sheets with pre-riveted ribs. Polymer inner liner
material may be stored in rolled or stacked one-piece form at 110.
To begin construction of a panel, aluminum sheet facer material is
rolled from supply 108 onto a long table 112 and cut to the
approximate size of the panel. That is, the facer is a rectangular
sheet of dimensions approximating the size of the finished sandwich
panel. Once cut to size, wood or polymer side members are secured
about the perimeter of the aluminum outer facer by foam tape or
other adhesive or connector materials that may generally permit
relative movement or slip between either or both of the side
members and the facers. Transverse ribs are attached with rivets or
adhesives to the inner side of the aluminum facer for support.
Support blocks may be added, if the panel is a side or a front
panel, to support a scuff band and/or logistics tracks (or other
attachment such as lighting or other devices requiring support), as
discussed above. If the sandwich panel is to be used in the trailer
roof, lighting or other utilities may be secured in the panel
volume and/or a conduit trough may be installed. Polymer inner
material from source 110 may then be rolled or otherwise placed
onto the side members opposite the outer facer, cut to
corresponding size, and secured to the side members by foam tape or
other suitable adhesive. Again, for the roof sandwich panel, the
inner facer may comprise multiple discrete sections to accommodate
the conduit trough.
[0064] The side members may become part of the panel, or they can
be included in the panel shell in the press but later removed from
the finished panel after foaming. In the embodiments described
herein, the wooden or polymer side members adhere to the foam when
the foam expands into the panel volume, thereby holding the side
members in place. If it is desired to remove the side members after
the panel is removed from the press, however, they may be covered
with wax or plastic or crepe sheeting or similar material on the
foam side, so that the foam does not attach to the side members and
so that they may therefore be pulled away from the panel after
foaming. Still further, even in panels in which the side members
attach to the foam, the side members may be trimmed from the
finished panel if desired.
[0065] Once the sandwich panel shell is assembled, clamps are
placed along one of the two longitudinal edges, and carrying lines
of a bridge crane mounted proximate to the ceiling of the
manufacturing facility are attached to the clamps. The bridge crane
lifts the panel and transports the panel, as indicated at 114, to a
press 116, depositing the vertically oriented and slightly tilted
panel between the press platens with the clamped longitudinal edge
facing upward.
[0066] As will be apparent from the discussion below, the clamped
longitudinal edge, because it will be the edge of the panel facing
upward in the press between the platens, should be one in which at
least one of the two facers is attached by the foam tape to the
side members but is not otherwise attached to any interior
structure within the panel interior volume for a distance from the
edge at least equal to the depth of a platen that is moveable with
respect to the main press platens (see facer portion 190, as
indicated at FIG. 11), as described in more detail below. In the
presently-described embodiments, this is a distance of about two to
about four feet (of an eighty inch to one hundred inch height
facer), but it will be apparent that this distance can vary. In one
embodiment, about 40% to about 50% is moved with respect to the
main press platen (about 39 inches of an eighty to one hundred inch
height facer), and in another embodiment about 30% to about 60%. In
the presently-described embodiments, and for example as indicated
at 190 in FIG. 11, the polymer inner liner is bent to allow access
to the panel interior. It is also possible to bend the aluminum
outer facer constructed without supporting ribs, but in these
examples this is not preferred, due to the structural ribs attached
to the outer facer.
[0067] Referring to FIGS. 10A-10C, press 116 is formed on a frame
118 and supports two identical, mirror image discrete sub-presses
120 and 122, each comprised of a stationary inner platen 124 and a
moveable outer platen 126. Each inner platen 124 is disposed at an
angle of approximately fifteen degrees with respect to vertical and
defines an engagement face 127. Each outer platen 126 is pivotally
secured to a track 128 at opposing corner hinges 130 that are
reciprocally slidable on track 128. A series of hydraulic cylinders
132 are pivotally secured to a ramped base 134 at pivotal joints
136 and attached to a back surface of platen 126 at pivotal joints
138. Platen 126 defines a generally planer front engagement face
140.
[0068] When hydraulic cylinders 132 are in the retracted position,
as shown on the left side of FIG. 10A, the cylinders pull platen
126 away from platen 124, causing platen 126 to slide up ramped
base 134 on hinges 130 and track 128. This tilts platen 126 away on
hinges 130. When hydraulic cylinders 132 expand, this pushes platen
140 down track 128, pivoting the platen so that front face 140
becomes parallel to and opposite front face 127 of platen 124, as
shown on the right side of FIG. 10A.
[0069] Platen 126 is smaller than platen 124, but attached to the
top of platen 126 is a pivotable third platen 129 that defines an
engagement surface 131 that, in combination with surface 140,
approximately equals the surface area and shape of the opposing
engagement surface 127. Third platen 129 is pivotally disposed with
respect to platen 126, and moveable with respect to platen 124,
about an axis indicated at 142. Support structures 144 extend
rearwardly from the back surface of platen 126. A plurality of
hydraulic pistons 146 are attached at one end to supports 144 and
to the back surface of platen 129 so that contraction of cylinders
146 pivots platen 129 about axis 142 so that planar engagement
surface 131 moves away from the plane defined by planar surface
140. Expansion of cylinders 146 pivots platen 129 back to a second
position in which surfaces 131 and 140 are co-planar.
[0070] At the top of supports 144 are a plurality of retractable
lock arms 148. Arms 148 are reciprocal within a powered sleeve 150
to engage and disengage receiving locks 152 at locking heads 154.
Lock arms 148 assist the press hydraulics in resisting opposing
force generated by the expanding foam.
[0071] Tanks 156 and 158 respectively store the polyol and
isocyanate components for the dispensing head's polyurethane liquid
or partially foamed foam agent. Respective pumps 160 and 162 pump
both components through liquid conveying conduit hoses to each of
two foam mixing and depositing heads 164, one for each of the
sub-presses. Each mixing head 164 has a mixing manifold or chamber
in which the polyol and isocyanate mix and from which the resulting
liquid or partially foamed foam agent is deposited out of a pouring
tip or nozzle 166. In the presently described embodiments, a high
pressure impingement mixing-type (HPIM) dispenser is used, but it
should be understood that other types of dispensing could be used.
Further, while it should be understood that an insulating foam
agent (i.e. a foam agent that generates an insulating foam) is
described herein, the present system and method may be used to
manufacture panels that enclose foams utilized solely for
structural support.
[0072] Each mixing head 164 includes a set of powered wheels or
gears driven by an electric or hydraulic motor located on the head
and secured on a rail system 168 so that automated operation by
computer control may be employed to cause actuation of the motor
drives, moving the rollers to thereby move mixing heads 164 back
and forth along the length of press 116 on rails 168, as indicated
by arrow 170. Each mixing head is attached to a respective cat
track 172 that festoons supply hoses from pumps 160 and 162 for the
polyol and isocyanate, as well as electrical or hydraulic lines for
the electrical or hydraulic motors on the mixing heads, and
electrical communication lines between electrically controlled
valves and other electrical control components on mixing heads 164
and respective control computers 176. Respective heaters 174 and
176 heat water or other suitable fluid to a desired temperature,
for example 110.degree. F., and feed the fluid via pumps 178 and
180 and respective hose lines to platen pairs 124/126 of the
respective sub-presses 120 and 122. As described above, the heated
fluid circulates through passages in both platens to initially heat
the facers of the empty panel shells and then to carry heat from
the panel as foam exotherms (i.e. gives off heat) within the panel
volume. Computers 176 control the delivery of water to and
circulation through the platens by operation of pumps 178 and
180.
[0073] With regard to the control system, i.e. computer systems 176
and its associated relays, valves and other associated electrical
and mechanical control apparatus in the presently described
embodiments, it will be understood from the present disclosure that
the functions ascribed to computer systems 176 may be embodied by
computer-executable instructions of a program that runs on one or
more computers. Generally, program modules include routines,
programs, components, data structures, etc. that perform particular
tasks and/or implement particular abstract data types. Moreover,
those skilled in the art will appreciate that the systems/methods
may be practiced with other computer system configurations,
including single-processor, multiprocessor or multi-core processor
computer systems, mini-computing devices, mainframe computers, as
well as personal computers, hand-held computing devices, micro
processor-based or programmable consumer or industrial electronics,
and the like. Aspects of these functions may also be practiced in
distributed computing environments where tasks are performed by
remote processing devices that are linked through a communications
network. However, some aspects of the claimed subject matter can be
practiced on stand-alone computers. In a distributed computing
environment, program modules may be located in both local and
remote memory storage devices. With reference to FIG. 10, an
exemplary environment 176 for implementing various aspects
disclosed herein includes a computer (e.g. desktop, laptop, server,
hand-held, programmable consumer or industrial electronics). The
computer includes a processing unit, a system memory, and a system
bus. The system bus couples the system components including, but
not limited to, system memory to the processing unit. The
processing unit can be any of various available microprocessors. It
is to be appreciated that dual microprocessors, multi-core and
other multiprocessor architectures can be employed as the
processing unit.
[0074] The system memory includes volatile and nonvolatile memory.
The basic input/output system, containing the basic routines to
transfer information between elements within the computer, such as
during start-up, is stored in nonvolatile memory. By way of
illustration, and not limitation, nonvolatile memory can include
read-only memory (ROM). Volatile memory includes random access
memory (RAM), which can act as external cache memory to facilitate
processing.
[0075] Computers 176 also include removable/non-removable,
volatile/nonvolatile computer storage media, for example mass
storage. Mass storage includes, but is not limited to, devices such
a magnetic or optical disk drive, floppy disk drive, flash memory
or memory stick. In addition, mass storage can include storage
media separately or in combination with other storage media.
[0076] Software applications may act as an intermediary between
users and/or other computers and the basic computer resources 176,
as described, in suitable operating environments. Such software
applications include one or both of system and application
software. System software can include an operating system, which
can be stored on the mass storage, the acts to control and allocate
resources of computer system 176. Application software takes
advantage of the management of resources by system software through
the program modules and data stored on either or both of the system
memory and mass storage.
[0077] The computer also includes one or more interface components
that are communicatively coupled through the bus and facilitate
interaction with the computer. By way of example, the interface
component can be a port (e.g., serial, parallel, PCMCIA, USB or
FireWire) or an interface card, or the like. The interface
component can receive input and provide output (wired or
wirelessly). For instance, input can be received from devices
including but not limited to a pointing device such as a mouse,
trackball, stylus, touchpad, touch screen display, keyboard,
microphone, joy stick, gamepad, satellite dish, scanner, camera, or
other component. Output can also be supplied by computers 176 to
output devices via the interface component. Output devices can
include displays (e.g. cathode ray tubes (CRT), liquid crystal
display (LCD), light emitting diodes (LED), plasma), whether touch
screen or otherwise, speakers, printers, and other components. In
particular, by such means, computers 176 was receive inputs from,
and direct outputs to, the various components with which computers
176 communicate, as described herein.
[0078] A vacuum source 182 draws air through ducts 184 from platens
126 and 129. The vacuum is applied to surfaces 140 and 131 at small
holes extending across the entirety of these surfaces. Once between
the platens, metal or wooden spacers disposed between the platens,
outside the panel, maintain the opposing platens spaced apart at a
distance suitable for the panel.
[0079] In a still further embodiment, platen 126 has the same
dimensions as platen 124, such that engagement surface 140 and
engagement surface 127 are of the same shape and size, each being
at least sufficiently large to encompass the major surface of the
largest panel shell to be received by the press. Third platen 129
remains atop platen 126 in this embodiment, but on extensions which
position third platen 129 slightly inward of platen 126. Platen
129, in this embodiment, pivots between a first position in which
surface 131 faces downward, in the perspective of FIG. 10A, and a
second position in which the platen pivots about an axis at the end
of the extensions, in the counterclockwise direction, so that
surface 131 is vertical, in the perspective of FIG. 10A, 90.degree.
offset from the first position. The width of surface 131 is
shortened to be approximately equal to the width of the panel shell
side members. In this embodiment, when engagement surfaces 127 and
140 engage and secure the two major panel sides (i.e. the facers),
engagement face 131 engages and secures (for example, via suction)
the top side member, which is separate from the one or more side
members that encompass the three other panel sides. Computers 176
control pistons 146 to pivot third platen 129 counterclockwise,
thereby moving the top side member away from the panel's interior
volume and exposing the panel's interior volume to dispensing head
164 and its dispensing tip 166 (see moved-away portion 190, in FIG.
11). This embodiment may be particularly advantageous, for example,
when the panel shell includes support posts that, unlike ribs 44
shown in FIG. 6, extend entirely between the inner and outer panel
facers, thereby segmenting the panel's internal volume. Pulling a
side member away, as opposed to bending open a top portion of the
outer facer, may provide more direct access to the segmented volume
interior, although it should be understood that an opening defined
by one or more (subsequently plugged) through holes in the top
facer portion may also provide sufficient access. (In a still
further embodiment as described below, one or more through holes
may be provided in the side member to allow pouring through the
hole(s) and subsequent plugging of the hole(s).) Also, in such an
embodiment, supports 144 may extend further upward and as shown in
FIG. 10A, to accommodate a higher profile of platens 126 and 129.
Correspondingly, opposing receiving locks 152 are disposed further
above platen 124 on the press frame. This, in turn, moves rail
system 168 further upward, and tip 166 of mixing head 164 may be
accordingly elongated to reach a suitable position proximate the
opening to the panel interior volume created when platen 129 moves
the top side member away from the volume.
[0080] In operation, a liner panel shell 60/70 is constructed so
that the facers and side members completely enclose the panel's
interior volume, for example as described above with respect to
FIGS. 6, 7, and 11. As noted herein, the present system and method
can accommodate panels in which structure internal to the panel is
attached to or otherwise interacts with one or both facers, thereby
preventing the complete removal of a given facer to allow input of
the foam agent. As should be apparent from the present disclosure,
however, the presently described system may be used to input foam
into panels in which internal structure does not attach to or
otherwise interact with one or both facers. Also, the internal
volume may comprise a continuous void, or it may be divided into
segments, for example by J-shaped or Z-shaped structural posts with
or without attached foam dams to create discrete volumes. Where the
panel defines a continuous void, the void is exposed to the opening
as discussed below so that an amount of foam agent may be poured
into the void through the opening in a single linear movement of
the dispensing head (whether continuous or intermittent, but
without diverging movements) so that foam generated by the agent in
the void completely fills the panel's interior volume. Where the
volume is segmented, all segments may communicate with the opening
so that the poured foam agent poured in a single movement of the
dispensing head is sufficiently deposited into each segment so
that, again, foam generated by the agent completely fills the
panel's interior volume. Certain segments, however, for example a
segment that will later be cut out of the panel to allow for
another trailer structure such as a door, may be sealed from the
opening so that foam generated by the foam agent only partially
fills the panel's overall volume. In any event, in this described
embodiment, panel 60/70 is constructed so that (a) there are no
attachments or other interactions between the panel's interior
structure (if any) and at least one of the two facers (or between
such interior structure and the top-oriented side member, as
described above with respect to the second embodiment) along the
entirety of one the edges of the panel at the interface with the
volume such that an opening of the panel at that edge exposes the
entirety of the panel interior volume for input of the foam agent,
(b) this condition exists from that edge for a distance at least
equal to the depths (i.e. the vertical length, as shown in FIG.
10A) of platen face 131, and (c) the relevant facer is flexible
over the bending range of third platen 129. In the example
discussed above with respect to FIG. 6, these conditions exist with
respect to the polymer inner facer of panel shell 60 along the
longitudinal edge on the side adjacent the top rail, as indicated
schematically at 190 in FIG. 11. With regard to the example
discussed at FIG. 7, these conditions exist with the polymer inner
facer, along the longitudinal edge of the panel further from the
light fixture and the conduit track.
[0081] As noted above, upon the panel shell's assembly, clamps are
placed along this edge both to hold the shell together at that edge
and to provide points of attachment of the bridge crane's carrying
lines. When the crane lifts the panel, this panel edge therefore
faces upward, and the crane conveys the panel to press 116 in such
orientation. The crane moves the panel into either sub-press 120 or
122 (which is in the open state, as shown in FIG. 10A at press
122). The crane orients the panel so that the aluminum outer facer
faces platen face 127, the polymer facer faces platens 126 and 129,
and the longitudinal panel edge facing upward is aligned parallel
to and even with the top longitudinal edge of platen 129. Since the
platen top edge is aligned at a constant distance from the
dispensing head's travel rail, i.e. at a constant distance from the
dispensing head's travel path, this aligns the panel's top edge
(and the length of opening 192, as shown in FIGS. 10A and 11) at a
constant distance from the dispensing head's travel path. An
operator 186 actuates a computer control system 176 associated with
the appropriate sub-press so as to move platen 126 toward platen
124, sandwiching the panel shell between platens 124 and 126 (and
129), with metal or wooden spacers disposed between the platens
outside the panel shell to maintain the platens apart from each
other at a distance appropriate for the panel. Control system 126
actuates vacuum system 182 to draw a vacuum from platen 126 and
129, thereby drawing air through holes in face 140 and 131 and
through duct 184. As the panel shell, and more particularly the
polymer-side facer, is brought into contact with platen faces 140
and 131, this negative pressure secures the panel to the
platen.
[0082] At this point, platen 126 is in a position away from platen
124, as indicated on the left side of FIG. 10A. Hydraulic arms 146
are extended, so that platen 129 is pivoted forward about axis 132
and platen surfaces 140 and 131 are co-planar. From such
conditions, control computer 176 operates a hydraulic pump (not
shown) to drive hydraulic pistons 132 to expand, thereby moving
platens 126 and 129 toward platen 124 so that platen surfaces 140
and 131 engage polymer liner facer 188. Lock arms 148 are in the
withdrawn position, as shown on the right side of FIG. 10A.
Computer control system 176 actuates vacuum source 182 to apply
negative pressure to the holes in engagement face 131 of third
platen 129, and optionally to the holes in engagement surface 140.
Referring also to FIG. 11, which schematically illustrate a panel
60/70 in absence of the platen, for ease of explanation, this
causes face 131 to secure the free upper edge portion 190 of panel
shell 60/70. Computer control system 176 then actuates the
hydraulic system to close hydraulic arms 146, thereby pivoting
platen 129 away from the plane of the panel, and more specifically
bending a portion 190 of polymer inner facer 191 away from the
panel plane (and away from the main portion of the facer and from
long side member 34d and short side members 34a and 34c, overcoming
the adhesion of the foam tape between the facer and the side
members), thereby creating an opening 192 between the panel shell's
internal volume 42 and the area 193 exterior to the panel shell.
This opening runs the entire length 195 of volume 42 along the
panel's upward-facing longitudinal edge. Still referring to FIG.
11, a second long-side side member 34c is not visible in the Figure
but is a mirror image of side member 34d. The side members and the
facers (when facer portion 190 is moved back into engagement with
side members 34a, 34b and 34d) enclose volume 42.
[0083] Computer system 176 controls the motorized carriage
supporting mixing head 164 to move the foam agent mixing head along
rail 168 to one extreme end of opening 192. Computer system 176
controls pumps 160 and 162 to deliver polyol and isocyanate to
mixing head 164, so that these components mix in the mixing head
and are poured out of mixing tip 166 through opening 192 and into
the panel shell's interior volume. Computer system 176
simultaneously actuates the motorized carriage that supports the
mixing head to thereby drive the mixing head down rail system 168,
propelling the mixing head along the rail at a predetermined speed
(which may be continuous or intermittent, for example to
accommodate discrete voids in the panel volume) along opening 192,
the mixing head pouring foam agent through the opening at a
predetermined rate (which may also be continuous or intermittent,
for example to accommodate variations in the panel's internal
volume) and into the panel shell volume. Whether continuous or
intermittent, the dispensing head moves along a path that is offset
from and corresponds to the shell's periphery (in this example, a
single linear movement, in that the shell's sides are linear), i.e.
the dispensing head moves in a path having a substantially constant
offset from the panel periphery so that the path corresponds to the
panel periphery, without diverging from that path, as the
dispensing head pours all of the foam agent needed for the finished
panel. This single-type movement improves operational speed over
systems requiring diverging movements to engage and subsequently
plug injection access holes.
[0084] The movement down the rail and the rate of pouring and flow
from mixing head 164 determines the volume of liquid foam agent
deposited per unit length of opening 192 into the panel shell
interior volume. These parameters, and the chemistry of the liquid
foam agent (specifically, the polyol) are chosen so that a
sufficient amount of liquid foam agent is deposited into the panel
interior volume, across the continuous or sectioned cross-sectional
area of that volume, so that foam expanding from the deposited foam
agent completely fills the intended portion of the panel shell's
interior volume but does not generally begin expanding until foam
mixing head 164 completes the deposition of foaming agent into the
panel shell.
[0085] The particular speed at which the foam depositing head
moves, the rate at which the foam depositing head deposits liquid
foam agent, and the liquid foam agent chemistry, can be selected as
desired by the user to accommodate the particular volume of the
sandwich liner panel shell being foamed. Since the panel's volume
characteristics are known beforehand, then computer system 176 can
be programmed to control the system accordingly. In particular, as
the vertical cross-section (perpendicular to the planes of the
facers) changes, when considered moving along the length of opening
192, the rate (continuous or intermittent) at which liquid foam
agent is deposited from foam mixing head 164 into the panel shell
interior volume may also vary accordingly.
[0086] As mixing head 164 moves along rail 168 past successive lock
rods 148, control computer system 176 actuates each lock rod's
drive mechanism 150 to close the respective lock rod 148 behind the
liquid foam mixing head as the mixing head passes by, so that the
respective rod's threaded lock end 152 threadably or otherwise
engages its locking head 154. When mixing head 164 reaches the end
of opening 192, therefore, all locking rods 148 are engaged. At
this point, computer system 176 actuates the hydraulic system to
expand hydraulic pistons 146, thereby pivoting platen 129 back to
its flush position, so that platen faces 140 and 131 are again
co-planar, and polymer liner portion 190 again engages the panel
shell side members, thereby again enclosing the panel shell
interior volume. Computer system 176 then actuates drive system 150
to pull platen 126 toward platen 124, thereby applying pressure to
the opposing facers of the panel. The deposited foam agent expands
within the panel interior, forcing gases and air within the
enclosed volume to escape through the vents. Computer system 176
also controls operation of the chiller and pumps 178 and 180 to
circulate fluid through the platens as the foam exotherms. The
press remains in this condition for a time sufficient for the foam
to fully expand and subsequently cure. After this time, computer
system 176 disconnects and withdraws lock rods 148 from their
opposing locking heads 154, and contracts hydraulic pistons 132 to
draw platens 126 and 129 away from platen 124. The bridge crane
then removes the panel from the press.
[0087] The embodiments described herein provide a panel shell with
an opening having a dimension in the dispenser's direction of
movement that is sufficient, given the dispenser's (continuous or
intermittent) speed and (continuous or intermittent) rate of
depositing foam agent, to dispense an amount of foam agent that is
sufficient to generate the entire amount of foam needed for the
panel in its final condition as assembled into a trailer or other
structure. The opening may be made in any surface of the panel
shell, and can be made, for example, by pulling or bending away
part of the panel shell surface (see portion 190 in FIG. 11) from
the remaining panel shell surface, as described above, or by
opening a through hole(s) in any of these surfaces that is/are then
plugged, that provide(s) access to that portion of the panel shell
interior volume that is to be foamed or otherwise filled with an
expanding core material. Consider, for example with regard to the
schematic illustration of FIG. 11, a rectangular prism type panel
such as described above, in which the panel shell's circumferential
periphery is defined by the one or more side members (34a-34d in
FIG. 11). Where the opening comprises one or more discrete holes,
for example, the opening may extend on or offset from the panel's
circumferential periphery (i.e., on one or more of the side members
or on a facer, depending on the panel and the configuration of the
press). If the opening comprises a single hole, the hole opens to
the panel volume's single continuous void or to all discrete voids
which are to be filled with foam. Similarly, if the opening
comprises multiple holes, the set of holes collectively opens to
the panel volume's single continuous void or to all discrete voids
which are to be filled with foam. The opening (i.e. the single or
multiple holes) is aligned proximate to and along the dispensing
head's path of travel (e.g. parallel to distance 195, as shown in
FIG. 11, and into and out of the page from the perspective of FIG.
10A), so that as the dispensing head moves along its path of travel
and dispenses foam agent into the opening, the dispensing head
dispenses foam agent through the opening and into the volume in a
movement of the dispensing head along a path that corresponds to
the panel shell periphery, without need to diverge from that path.
As discussed above, since the panel interior's total volume,
dimensions and configuration are known, the control system can be,
and is, programmed to dispense an amount of foam agent into the
opening so that the foam generated by the then-deposited foam agent
fills all or an intended portion of volume 42 in the final panel.
Still referring to FIG. 11, for example, assume that portion 190 is
not pulled away from side members 34a, 34b, and 34c, so that the
two facers and the four side members enclose volume 42. A through
hole (shown in phantom at 197, which may be omitted in an
embodiment in which portion 190 is pulled away from the remainder
of the shell in order to define the opening) formed through side
member 34d has a dimension in the direction of distance 195 that
is, as illustrated, less than (and, e.g., approximately 40% of)
distance 195, but opening 197 nonetheless communicates with a
single void that comprises volume 42 or, if volume 42 is segmented,
with all such segments that are to be foamed in the finished panel.
Thus, as the dispensing head moves along its path of travel in the
direction indicated by distance 195, along the length of elongated
hole 197, dispensing foam agent through the hole into the volume in
response to the pre-programmed control system, the dispensing head
dispenses sufficient foam agent into the volume so that the
resulting foam fills all or the intended portion of volume 42. Hole
197 could also comprise multiple, discrete holes spaced apart over
distance 195 but nonetheless opening to volume 42 (again, which may
be a continuous void or the sum of a plurality of discrete voids)
so that when the dispensing head moves (again, under the control
system's control) at its predetermined (in this case intermittent,
hole-to-hole) speed in a single movement and dispenses foam agent
intermittently at each hole, the resulting foam agent deposited
into volume 42 is sufficient in amount and disposition within
volume 42 so that the resulting foam fills all or the intended
portion of volume 42 in the finished panel. After the dispensing
head dispenses foam agent, the control system may automatically
plug the hole, e.g. via a robotic member or (where the hole is
formed by removal of side member 34d) by replacement of the side
member by a press platen. Thus, it will be apparent that hole 197
may extend the entire distance 195 or some portion thereof, as
appropriate in view of the volume and configuration of volume 42,
the rate of deposition of foam agent from the dispensing head, and
the speed at which the dispensing head moves along its path of
travel (see 195). Still further, portion 190 may be bent away from
the remaining portion of the shell over a distance less than the
entire length of the panel edge. In one embodiment, hole 197 or
opening 192 has a distance in or parallel to the circumferential
peripheral dimension that is at least about 2%, and in embodiments
about 5%-25% or about 5%-40% of the total circumferential direction
(i.e. the lengths of side members 34a-34d in the FIG. 11
embodiment), or at least about 6%, and in embodiments about 15%-75%
or about 10%-100% or about 50%-100% of the total length of one of
the panel's longitudinal side portions (e.g. the length of side
member 34d, or distance 195). The through hole should extend a
sufficient distance to provide access to all volume segments or
cavities that are to receive the core agent. For example, where
foam dams are used in the panel, the dams may be spaced apart by
distances of, e.g., four feet, eight feet, or sixteen feet,
depending on the complexity of the structural arrangements in the
cavities. Thus, hole 197 may extend the entire length of distance
195, or may be formed by the removal of side member 34d.
[0088] Further, it should be understood that variations in the
press and panel may be made from the particular embodiments
discussed herein. Referring to FIG. 10D, for example, platens 124
and 129 are held in part by opposing side brackets 199 (one of
which is shown in FIG. 10D, which provides a back stop against
rearward movement of platen face 131 with respect to platen face
140. Moreover, it should be understood that the apparatus and
methods described herein may be used to form core-filled sandwich
objects for uses other than structural panels. Thus, the panel-type
object described herein is provided for purposes of example only,
and it should be understood that various other object structures
and configurations, and corresponding press configurations for
accommodating such object structures, fall within the scope of the
present disclosure.
[0089] Also, it should be understood that while the examples
discussed above disclose the use of planar panels, non-planar
shaped panels could also be used. For example, as noted above and
referring to FIG. 12, front panels for trailers can be constructed
in accordance with an embodiment of the present invention. As
should be understood, a front panel 60/70 may have a generally
planar central portion and two curved sides, which bend around from
the central portion to meet and attach to respective side panels.
In such a panel, the central portion is constructed as discussed
above, with general planar, opposing facers (as illustrated in FIG.
11). At each side, however, curved facers are discrete from and
attached to planar facers in the central portion, or are formed
unitarily with the central portion facers, so that the sides curve
and define curved sides of the internal volume 42 therebetween.
Similar to the side and roof panels, the panel shell's periphery is
bounded by one or more side members 34a-34d. The press platens are
correspondingly curved, so that the curved panel is received
between the curved platens, which apply pressure that resists the
pressure from foam expanding in the volume. In one embodiment, the
press includes a top platen that secures the top side member 34d by
suction and removes the top side member from the remainder of the
shell, thereby exposing the curved interior volume 42 to the
automatically movable dispensing head at an opening 192. The press
frame is disposed so that the rail upon which the dispensing head
travels corresponds to the volume's curved profile. When the
operator activates the control system to start the dispensing
process, the dispensing head moves along the curved path (again, in
a movement that travels along a path offset from and corresponding
to the opening, without divergence from the path), depositing the
amount of foam agent needed to provide the panel's foam in finished
form, after which the top platen returns top side member 34d into
position in the panel shell, thereby once again enclosing volume
42. The side platens then are pulled and pushed toward each other
by a series of lock arms and hydraulic pistons, to resist the
pressure of the now-expanding foam. In a further embodiment, where
the inner facer of the panel's generally planar central portion is
separate from respective portions of the inner facer that form the
curved parts of the inner facer, an independently pivotable central
portion of the press platen secures the top part of the generally
planar central portion of inner facer 191 and bends the top part
away from the remainder of the panel shell, as shown with regard to
portion 190 in FIG. 11, to thereby create an opening between
interior volume 192 and exterior area 193.
[0090] Modifications and variations to the particular embodiments
of present invention may be practiced by those of ordinary skill in
the art, without departing from the spirit and scope of the present
invention, which is more particularly set forth in the appended
claims. In addition, it should be understood that aspects of the
various embodiments may be interchanged both in whole or in part.
Furthermore, those of ordinary skill in the art will appreciate
that the foregoing description is by way of example only, and is
not intended to be limitative of the invention so further described
in such appended claims.
* * * * *