Note: Descriptions are shown in the official language in which they were submitted.
CA 02477368 2011-03-25
Extruded Window and Door Multi-Composite Frames and
Method
BACKGROUND
It is known that wooden frames can be equipped [encased in part] with weather
resistant surfaces by running the wooden components through a special extruder
which places a weather resistant rigid polyvinylchloride shell on selected
surfaces of
the wood. An example of the latter is Andersen 400 series patio door which has
an
outer polyvinylchoride skin which is bonded to the exterior faces of the
wooden
components in an extruder of a special design which allows a wooden component
to
pass through the extruder when the skin or shell is applied to selected
surfaces of the
wooden component. With this described process, sometimes the shell or skin
does not
adhere well to the wood or delaminates later. Moreover considerable milling of
the
wooden components in such frames is required, increasing the overall costs.
Also
problems result form insect or rot infestation of the wood and/or warp age
when the
frame is in place in use since the vinyl shell or skin does not increase
stability of the
wood component or provide complete encasement.
In contrast the novel patio doorframe of this invention is made of frame
members, which are fully extruded members, employing multiple extruders. As a
result of the novel extrusion process each frame member has a constant cross
section,
like pipe, rod, tube, etc. but with several integral components, including a
rigid plastic
shell for the exterior or weather faces of the frame member, a core element of
polylvinylchloride/wood floor foam with channels formed therein for door
components and integral flexible plastic sealing strips incorporated in the
channels.
Three or more extruders are employed in fabricating the novel frame member and
coordinated to achieve a single extruded product.
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SUMMARY OF THE INVENTION
Certain exemplary embodiments can provide an extrusion process for forming
window and door frame members comprising the steps of: a. extruding a foamed
selected profile of polyvinylchloride and wood flour with at least one channel
therein,
said profile having reduced dimension where a protective shell is desired; b.
co-
extruding a plastic shell of polyvinylchloride on said profile where the
reduced
dimension are provided to form a protective shell thereat; c. passing said co-
extrusion
and plastic shell through a calibration die; d. heating the co-extrusion from
the
calibration die at selected locations where weather stripping is desired; e.
passing said
co-extrusion through a final extrusion die where weather stripping elements
are
extruded at said heated locations whereby an integrated multi-component frame
member is formed; and f. cooling the extrusion from the final extrusion die.
An extruded frame member for windows and doors having surfaces exposed to
weather elements includes an integrated three element extrusion of a constant
cross
section having a core element with at least one channel formed therein, soft
sealing
strips integrated within said channel and a protective plastic shell formed on
selected
exterior surfaces of said core element extruded as an integral unit. On the
surfaces of the
core element not protected by the plastic shell wood patterns can be embossed
for
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aesthetic reasons and core element is formed of materials which can be painted
or'
stained so that frame member can be co-ordinated with the decor or of a room
where
the frame is installed.
Within the purview of this invention, the manufacturing method of this
invention also includes the steps of extruding a foamed selected profile of
polylvinylchloride and wood flour with at least one channel therein and
reduced
dimension where a protective shell is desired, co-extruding a plastic shell of
polylvinylchloride on the profile where the reduced dimension are provided in
profile
to form a protective shell, passing the co-extrusion through a calibration
die, heating
the co-extrusion form the calibration die at selected locations where weather
stripping
is desired, passing said co extrusion through a final extrusion die where
weather
stripping elements are extruded at the heated location and cooling the
extrusion form
the final extrusion die where weather stripping elements are extruded at the
heated
location and cooling the extrusion form the final extrusion die.
DESCRIPTION OF THE DRAWINGS
Fig. 1 is a cross section of a novel vertical frame member according to this
invention for one side of a sliding glass doorframe;
Fig. 2 is a cross section of a novel vertical frame member according to this
invention for the side of a sliding glass doorframe opposite frame member
shown in
Fig. 1;
Fig.3 is a cross section of a novel bottom frame member for a sliding glass
doorframe;
Fig.4 is a cross section of a novel top frame member for a sliding glass
doorframe; and
Fig.5 is a broken apart sliding glass doorframe make of the several profiles
described in Fig.l through 4.
DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
Different cross-sectional profiles, as illustrated in Fig. 1 through 4, are
used for
the vertical parts of the frames and the top and the bottom parts of the
doorframe,
which is easily done by changing dies in the extruders. ' Moreover, these
profiles can
change to accommodate swinging double patio doors or sliding patio doors, as
elected,
without departing form the concept of the invention.
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Frame members constructed according to this invention have a plastic shell on
their exterior or weather surfaces of any color selected before the members
are
extruded, such as white, sandstone, dark brown or any other color obtainable
with
pigments compatible with polyvinylchloride. In addition the core element can
include
wood graining on its exposed surfaces and has channels for the door components
formed therein without milling the core component. Also these channels include
integrated plastic sealing strips for a door, when extruded.
The core element is formed a wood flour laced polyvinylchloride foam
extrusion, such as described the composition described in U.S. Letters Patent
6,380,272 issued to Chen. The plastic shell is weather resistant
polyvinylchloride and
the plastic sealing strips are a soft polyvinylchloride. Also the core
element, being an
extruded part, can take advantage of hollow core-designs which lessen its
weight
without sacrificing strength and can include wood graining on the exposed
surfaces
which are not cover with the shell. Moreover the exposed surfaces of the core
element
can be painted or stained to coordinate with the interior of a room where a
patio
doorframe is installed. Colors such as country white, Spanish oak, dark
mahogany, or
any other suitable color can be used to provide an initial color to the core
element.
By incorporating integral plastic sealing strips in the channels of the core
element, considerable labor savings are had and the uniform extruded members -
avoid
waste due to wood imperfections that occur when wood components are used.
Further
the extruded frame members of uniform cross section are not subject to insect
infestation, rot, warp age nor peeling of the shell form the extruded foam
core
element.
Using the co-extrusion process of this invention, it is possible to achieve a
uniform shell on the exterior or weather surfaces of the frame members plus
the
channels therein for the door components and also plastic surfaces where wear
is
likely to occur.
The core element is formed of a powered PVC, wood flour, thermal stabilizers,
inorganic foaming aids, organic foaming agents, inorganic foaming agents,
processing
aids, modifiers, lubricants, fillers and pigments. Typically these components,
in
powered form, are fed to the thermal mixer in the desired quantities by the
metering
devices as described in U.S. Letters Patent 6,380,272. Thereafter the mixture
is
extruded.
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Suitable polyvinylchloride [PVC] powers are those sold by Formosa Plastics
Corporation as S-60 and S-65. As to the wood flour it can be derived form
hardwood
wastes, will preferably have a fiber length below 0.6 mm and a fiber diameter
is
between 0.04 to 0.6 mm along with an aspect ratio between 2 to 6. Such wood
flour is
sold by JRS as CB-120 as well as other entities. Thermal stabilizers are
selected form
organic and/or inorganic thermal stabilizer in powder form which are used to
prevent
the thermal degradation of PVC resin, typically organic tin carboxylate,
organic tin
mercaptide and barium/zinc stabilizer are preferred. Inorganic foaming aids
are
selected form magnesium oxide and zinc oxide, which are employed to increase
the
volume of gas form the organic and inorganic foaming agents. For organic
foaming
agents selections can be made form azodicarbonamide, benzene-sulfohydrazide
and
diphenylene oxide-4, 4'-disulfohydrazide which act as blowing agents to
provide gas
for the foamed product. The inorganic foaming agent, which also acts as
product, can
be blowing agents to provide gas for the foamed product, can be sodium
bicarbonate.
To enhance the gelatinization of the mixed powders, methyl methacrylate
copolymer
and high molecular weight acrylic polymers can be used as processing aids.
Modifiers are employed for the purpose of increasing the strength of the
plastic
component in the composite and typically are selected form ethylene-vinyl
acetate,
acrylate/methyl methacrylate graft polymer and chlorinated polyethylene.
Likewise it
is also helpful to use external lubricants such as polyethylene wax and
paraffin wax,
which are employed to reduce friction during the extrusion process. Fatty
acids, fatty
alcohols and fatty acid esters are employed for the purposes of increasing the
gelatinization of the powders during the extrusion step.
While not necessary fillers can be selected form calcium carbonate or
precipitated calcium carbonate can be used and pigments such as titanium
dioxide,
iron oxide and carbon black can be employed.
Extrusion machines having a twin-screw extruder, such as the extruder model
CM-65 built by Cincinnate further process the core mixture by shearing and
heating it
until it is gradually gelatinized as its is forced by the extruder into the
adapter, then
into the extrusion die and finally through the calibration die that controls
the
cross-sectional profile of the foamed core element of the novel frame member.
To construct the novel frame members, two additional extruders employed.
Each is connected to the extruder for the core element ahead of the
calibration die.
One extruder contains weather resistant polyvinylchloride and extruders the
shell,
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which forms the outer or exterior surfaces of the novel frame members. This
shell
extrusion marries with extruded core element in the machine. Suitable
polyvinylchloride for the shell are those conventionally used for coated
window and
doorframes now on the market.
The third extruder is likewise connected to the extruder for the core element
and provides the soft plastic weather stripping elements in the channels
formed in the
core element during extrusion. At the time the strips are applied the channels
in the
core element have been formed and strips are located in the channels where
desired as
the core element the shell as desired. This is accomplished after the shell-
coated
profile leaves the calibration die. At this time the profile and is still hot
and additional
heat is applied to the profile where the strips are to be place for weather
stripping,
either is the core element or the shell. Thereafter the profile passes through
a final die
where the soft polyvinylchloride is extruded in the desired locations. For the
soft
plastic weather stripping a soft polyvinylchloride such as EPDM purchased form
Kupoaoch Chemical Limited can be employed.
After the shell is married to the core element the extrusion passes through
the
calibration die controlling it final dimensions. As indicated above this
profile is heated
where the soft polyvinylchloride weather stripping is to locate and passes
through the
final die. After the three-element co-extrusion leaves the final calibration
die passing
the extrusion through a cooling tank cools it. Before cooling occurs a wood
grain
surface can be applied to the desired surfaces of the core element in the
three-element
co-extrusion by rollers having a reserves grain pattern on theirs surfaces.
Once the three-element extrusion cools the continuous extrusion can be cut
into
appropriate lengths for forming a frame for a sliding or swing a patio
doorframe, such
as illustrated in Fig.4.
Figures 1 and 2 illustrate several profiles employed in frame members for
constructing a frame for a sliding glass patio door. The cross section in Fig.
1 is that
of vertical frame member 20 for the fixed portion of the sliding glass door.
In this
cross section, the polyvinylchioride protective shell 21 is deployed on the
surfaces of
the frame member that will be exposed to the weather when a doorframe with
this
frame member 20 is installed in. a building or home. The
polyvinylchloride/wood
flour core element 22, which is co-extruded with the protective shell 21, has
a channel
23 for the frame of the fixed door of a sliding glass door. As the core
element 22 is
extruded with the protective shell 21 a third co-extrusion is carried out
which places a
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soft polyvinylchloride sealing strip 24 in the channel 23 so that when the
fixed door of
the sliding glass door is installed these strips 24 will form a weather seal
against a
face of this fixed door.
The polyvinylchloride/wood flour extrusion forming the core element 22
readily accepts paint and stains. Thus the exposed surfaces 25, 26 and 27 of
the core
element 22 can be painted to coordinate with the color scheme of the interior
room,
which the sliding door services. In the past frames using polyvinylchloride on
all the
surfaces of the frame were limited to color used by the manufacturer. Since
materials
used for the core element 22 are structurally sound, the frame member can have
void
coring 28, 29 and 30 to lighten the member and affect a cost savings in
materials.
In Fig. 2, a cross section of the vertical frame member 40 is illustrated,
which is
used on the opposite side of the door relative to frame member 20. It is
constructed
with a protective shell 41 on exterior surfaces of its core element 42 of
polyvinylchloride/wood flour. The core element has a door channel 43 formed
therein
during the co-extrusion process described and a soft plastic sealing strip 44
in
integrated in this channel 43. This sealing strip 44 is of softer vinyl than
that used for
the protective shell and is co-extruded with the protective shell 41. Like the
other
frame 20, the surfaces of the core element 42 making up the three component
co-extrusion, readily accepts paints and/or stains allowing its interior
surfaces 45, 46
and 47 to be painted or stained to coordinate with the room decor which the
sliding
glass door services.
Since the core element 42 has adequate strength for making a doorframe, it has
coring voids 48, 49 and, 50 to reduce the weight and make the frame member
more
economical to produce.
A further advantage is achieved with the fully extruded three component
doorframe members, and that is providing weather stripping gloves 51 which are
formed during the extrusion processes eliminating the necessity of milling the
several
frame members, with the accompanying cost savings.
Viewing Fig. 1 and 2 it can be readily appreciated that differing profiles can
be
made by changing the dies in the three coordinated extruding machines,
according
this invention. Moreover, the composition of the core element in the several
frame
members is such that it can be worked with standard wood working tools, such
as
saws and drills and also be nailed to the supporting building structures when
a frame
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constructed of this member is installed in a building.
The bottom profile of the frame can be seen in the cross section illustrated
in
Fig. 3, and it can be this bottom frame member 60 is composed mostly of the
same
weather resistant polyvinylchloride 61 that is used for the shell on the other
frame
members. It has a small core element 62, which is extruded with the
polyvinylchloride
that allows the inside surfaces of the bottom frame member 60 to be stained or
painted
as previously described. The top 63 of this frame member 60 includes a
doorpost 64
with a knob 65 at its top, which accepts a metal cap (not known) on which the
rollers
for the sliding glass door ride. The bottom of the glass door is grooved so
that the
doorpost 64 will be received in the groove. If desired doorpost 64 can include
sealing
strips 66 and 67 which are formed of a soft polyvinylchloride and extruded
simultaneously with the parts of the frame member. When used these sealing
strips 66
and 67 prevent air drafts form passing under the sliding glass door. Also on
the top of
the bottom frame member grooves 68 and 69 are formed for receiving finishing
strips
(not known) that merely snap into these grooves. At the end of this frame
member a
toe piece 70, shown in phantom, can be secured in the grooves 71 and 72
provided for
this purpose. Typically the toe piece 70 is an aluminum extrusion.
Fig. 4 shows the cross section of the top frame member 80. Like the vertical
frames members, it includes a core element 81 formed of polyvinylchloride and
wood
flour, a weather resistant plastic shell 82 on the portions of the core
element 81 that
will be exposed to weather conditions along with an integrated weather seal
strip 83
which is formed of a soft plyvinylchloride. As previously described the
individually
identified components are extruded together in a single extrusion. In the top
frame
member 80 there are two door channels 84 and 85 formed during the extrusion
process with door channel having the protective plastic shell channel. In the
channel
grooves 86 and 87 are provided for weather stripping (not known) for sides of
a
sliding glass door that moves back and forth through this channel. These
weather
stripping grooves 86 and 87 allow the weather stripping in channel 85 to be
replaced
if needed. Like the vertical frame members, coring voids 88, 89 and 90 are
employed
to reduce the cost of the materials without a loss of strength.
Once the several frame members are extruded they are fabricated into a frame
for a patio door by cutting them to length and assembling them in a
rectangular frame
as illustrated in Fig. 5. As can be seen in Fig. 5 the frame 100 is composed
of vertical
frame member 20 and vertical frame member 40 along with the bottom frame
member
60 and the top frame member 80 shown in a building wall 101 illustrated in
phantom.
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Further the frame members can be employed in both right hand opening doors and
left
hand opening doors by merely reversing the vertical frame members, top to
bottom.
Like the vertical frame components the surfaces 91, 92 and 93 which are
exposed
inside the room when the frame is installed can be painted or stained to
accommodate
the room decor.
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