U.S. patent application number 14/093617 was filed with the patent office on 2014-03-27 for lineally adjustable molds, molding methods, and products therefrom.
This patent application is currently assigned to Andersen Corporation. The applicant listed for this patent is Andersen Corporation. Invention is credited to Kathleen Barton, Jim Eggert, Troy Rubenzer, Matt Sedivy, Dale Thompson, David J. Weiss.
Application Number | 20140086673 14/093617 |
Document ID | / |
Family ID | 44258770 |
Filed Date | 2014-03-27 |
United States Patent
Application |
20140086673 |
Kind Code |
A1 |
Rubenzer; Troy ; et
al. |
March 27, 2014 |
Lineally Adjustable Molds, Molding Methods, And Products
Therefrom
Abstract
A mold for producing a variety of fenestration members having
different predetermined lengths is disclosed. Generally, the mold
has a first lineal mold part that has an extended length and a
second lineal mold part also having an extended length. The mold
may also have mold end parts that are adapted to form end features
of the fenestration member. In use, the first lineal mold part and
the second lineal mold part fit together to define a profile. The
first and second mold end parts can be positioned in a range of
positions to define the lengths of a variety of different molded
fenestration members.
Inventors: |
Rubenzer; Troy; (Hudson,
WI) ; Eggert; Jim; (Woodbury, MN) ; Thompson;
Dale; (West Saint Paul, MN) ; Barton; Kathleen;
(Birchwood, MN) ; Weiss; David J.; (Stillwater,
MN) ; Sedivy; Matt; (Osceola, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Andersen Corporation |
Bayport |
MN |
US |
|
|
Assignee: |
Andersen Corporation
Bayport
MN
|
Family ID: |
44258770 |
Appl. No.: |
14/093617 |
Filed: |
December 2, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12971135 |
Dec 17, 2010 |
8597017 |
|
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14093617 |
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61287869 |
Dec 18, 2009 |
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Current U.S.
Class: |
403/288 ;
264/219; 403/266; 403/375 |
Current CPC
Class: |
Y10T 403/52 20150115;
F16B 11/006 20130101; Y10T 403/70 20150115; B29L 2031/005 20130101;
Y10T 403/473 20150115; Y10T 403/47 20150115; Y10T 403/471 20150115;
Y10T 428/24777 20150115; B29C 37/00 20130101; Y10T 403/7073
20150115; F16B 17/00 20130101; B29C 33/308 20130101 |
Class at
Publication: |
403/288 ;
264/219; 403/375; 403/266 |
International
Class: |
F16B 17/00 20060101
F16B017/00; F16B 11/00 20060101 F16B011/00; B29C 37/00 20060101
B29C037/00 |
Claims
1. A method for molding a variety of fenestration members having
different predetermined lengths comprising the steps of: providing
a mold comprising: a first lineal profile mold part having an
extended length; a second lineal profile mold part having an
extended length; a first mold end part adapted to form a first end
feature of the member, and a second mold end part adapted to form a
second end feature of the member, wherein the first lineal profile
mold part and the second lineal mold part fit together to define a
lineal profile, and at least one of the first mold end part and the
second mold end part can be positioned in a range of positions
along the first lineal mold part and the second lineal mold part to
define the lengths of a variety of molded fenestration members;
assembling the mold parts into a closed mold defining a molded
shape; filling the mold with a reaction injection molding material;
allowing the molding material to at least partially cure; and
opening the mold and removing the molded member.
2. The method of claim 1 further comprising the step of removing
mold end parts from the molded member.
3. The method of claim 1 wherein the reaction injection molding
material further comprises a foaming agent.
4. The method of claim 1 further comprising the step of painting
selected portions of the mold parts prior to assembly.
5. The method of claim 1 comprising the further step of using the
molded member as an end part in a mold and molding an additional
portion onto the molded member to form a second molded member.
6. The method of claim 1 comprising the steps of cutting the molded
member into two parts and using the two parts as end parts in a
mold for forming a molded member.
7. The method of claim 1 further comprising the steps of molding a
second member; assembling the two molded members with lineal mold
parts, using the two molded members as mold end parts, and; molding
a third member comprising the two previously molded members along
with a newly molded lineal portion joining the two previously
molded members.
8. A joint between a first member and a second member, wherein: the
first member comprises a first mitered portion, a mortise portion,
and at least one of a sidewall portion and a sidewall receiving
portion; the second member comprises a second mitered portion, a
tenon portion, and at least one of a sidewall portion and a
sidewall receiving portion, wherein: the sidewall portions are
adapted to fit over the sidewall receiving portions to provide the
appearance of a mortise and tenon joint, and wherein the tenon
portion fits into the mortise portion.
9. The joint of claim 8 further comprising an injection port and
flow channel for injection of sealant or adhesive material into the
joint.
10. The joint of claim 9 further comprising an internal reservoir
for receiving injected material.
11. The joint of claim 8 further comprising a resilient gasket
material between the first member and the second member.
12. The joint of claim 8 wherein the mortise portion and the tenon
portion are located on the first mitered portion and the second
mitered portion respectively.
13. The joint of claim 8, wherein the first member comprises one
sidewall portion and wherein the second member comprises one
sidewall receiving portion.
14. The joint of claim 13 wherein the lineal portion of at least
one of the joints extends to a second joint.
15. The joint of claim 8 wherein the first member comprises one
sidewall receiving portion and the second member comprises one
sidewall portion.
16. The joint of claim 8 wherein at least one of the first member
and the second member further comprises a lineal portion.
17. The joint of claim 8 wherein at least one member comprises a
reaction injection molding material.
18. A lineal member comprising a first end feature and a second end
feature, wherein the member is produced by a molding process.
19. The member of claim 18 wherein the molding process is a
reaction injection molding process.
20. The member of claim 18 wherein at least one of the end features
of a first member is adapted to engage a second member to form a
joint.
21. The member of claim 20 wherein the second member is also a
lineal member.
22. The member of claim 18 wherein at least one of the end features
serves a decorative function.
23. The member of claim 18 wherein the member is a cornice.
24. The member of claim 18 wherein the member is a stile or rail of
a window sash.
25. The member of claim 18 wherein the member is a stile or rail of
a window frame and sill.
26. The member of claim 18 wherein the member is a stile or rail of
a door panel.
27. The member of claim 18 wherein the member is a part of a door
frame.
28. The member of claim 18 wherein the member is part of a door
threshold.
29. A collection of at least two molded lineal members of differing
lengths, wherein each member comprises a first end feature and a
second end feature, and wherein all members in the collection are
produced in the same adjustable mold.
30. The collection of claim 29 wherein at least one of the first
and second end features of a first member in the collection is
adapted to engage an end feature of a second member in the
collection to form a joint.
31. The collection of claim 30 wherein the second member is also
contained in the collection.
32. The collection of claim 29 wherein at least one of the first
and second end features serves a decorative function.
33. The collection of claim 29 wherein all of the first end
features are the same and all of the second end features are the
same.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 12/971,135, filed Dec. 17, 2010, which applications claims
the benefit of U.S. Provisional Patent Application No. 61/287,869,
filed Dec. 18, 2009, which are incorporated herein by reference in
their entirety.
TECHNICAL FIELD
[0002] This disclosure relates generally to molds for producing
lineal fenestration members having different predetermined
lengths.
BACKGROUND
[0003] A longstanding concern in the window industry is that water
may accumulate in the lower part of the window and leak into the
house or other structure. Of particular concern is the potential
for water to leak into the rough opening and into the wall of the
structure, where it could go undetected and decay could occur.
While sealing of the joints between the various parts of the window
has proven beneficial, failures can still occur, due, for example,
to shifting of the building structure that may deform the window
and open sealed joints, and potential deterioration of the sealant
material itself. A more reliable approach would be to eliminate or
improve the joints between members where water could accumulate and
leaks could occur. It is to the provision of a mold and molding
method that addresses the above and additional needs that this
disclosure is directed.
SUMMARY
[0004] The entire contents of U.S. provisional patent application
61/287,869, to which priority is claimed above, is hereby
incorporated by reference.
[0005] A lineally adjustable mold is disclosed for molding lineal
members, such as those used in fenestration units and other
structures, having various lengths in a reaction injection molding
(RIM) process. The mold comprises at least one lineal part having
an extended length and at least one end piece that can be located
at a continuous range of selected positions along the lineal part
to produce lineal members in a range of different lengths. In one
embodiment, the end pieces of the mold are adapted for molding end
configurations for the lineals that enable two or more lineals to
be fitted together in an end-to-end manner to form an assembly for
a fenestration unit. In other embodiments, such as cornices, the
end pieces of the mold form a decorative configuration at least at
one end of the member. The end pieces of the mold can be removable
mold parts that are removed from the molded part after curing of
the RIM material, or, in alternative embodiments, the end pieces
can be preformed fenestration components that become part of the
molded member after curing of the molding material. The preformed
end parts can include resilient material on selected surfaces that
act as gaskets for sealing joints between members.
[0006] Moveable end parts can be manually positioned and held in
place by suitable holding devices, or can be positioned by powered
mechanisms. Powered positioning mechanisms can be manually
controlled or can be controlled by a programmable controller
having, for example, a user interface that allows the operator to
enter final product specifications to obtain a molded product of a
desired length, thereby creating a programmable mold.
[0007] As used herein, the term lineal member will refer in one
instance to a member that extends along an axis and that has a
constant cross sectional profile in planes perpendicular to the
axis along a substantial portion of that axis. Members that are
otherwise lineal but that have end portions not constant along the
axis, as might be needed for coupling with other members, for
example, will still be referred to as lineal members or
substantially lineal members. The axis of a lineal member may be a
straight line, a curved line, or a segmented line. Segmented lines
are combinations of straight lines that meet at non-zero angles, or
combinations of straight lines and curved lines. As used herein,
the term extended length will refer to a length greater than the
length of the longest member that a lineally adjustable mold is
expected to produce. More generally, a lineal member may refer to
any part of a window or door unit other than the glass, including,
for instance, frames, sashes, sills, grilles, headers, molding,
trim, and the like.
[0008] Members may also be lineal in more than one direction. For
example, the bevel edged panels that fill the openings between the
stiles and rails of many doors have a substantially constant cross
section in both the horizontal and vertical directions.
[0009] Also disclosed are joint structures for joining fenestration
members that take particular advantage of the ability of RIM to
repeatedly reproduce complex structures having a high level of
precision. Such joint structures may include mitered portions
combined with mortise and tenon portions in a manner that enhances
joint strength, joint appearance and joint sealing. It will be
appreciated that simple mortise and tenon joints and simple miter
joints also can be molded. Similarly, other types of joints, such
as butt joints and saddle joints, both well known in the joinery
art, also may be produced.
[0010] Precisely fitted joints of the type disclosed herein are
particularly well adapted to structures that can be sold in
disassembled, or knocked down, form, and assembled by a purchaser
at the point of use. Such items include bookcases, storage shelves,
product display structures, and other structures that might be used
in the home, business, or elsewhere. The precision with which the
joints can be molded and the ability to produce joints of greater
complexity in order to achieve greater strength and rigidity can be
very advantageous for such products. In addition, the ability to
produce a variety of sizes and configurations by the use of
adjustable molds is also a great advantage for cost effective
production of whole product lines of such items in the form of
modular systems. Additionally, the precision and robustness of the
joints may be advantageous in situations wherein a structure needs
to be assembled, disassembled, and reassembled multiple times.
[0011] It will also be recognized that decorative members such as
cornices for trimming above windows and doors are often needed in a
variety of lengths, but with the same cross-sectional profile.
Lineally adjustable molds are therefore well suited for this
application. Similarly, door thresholds and window sills are often
needed in different lengths, for different widths of doors and
windows, so that the lineally adjustable molds are useful for this
application as well.
[0012] The invention will be better appreciated and understood upon
review of the detailed description presented below in conjunction
with the accompanying drawing figures, which are briefly described
as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is an exploded perspective view of a mold system for
molding lineal members according aspects of the invention.
[0014] FIG. 2 is another exploded perspective view of the mold
system of FIG. 1 showing a lineal member produced with the
mold.
[0015] FIG. 3 is an exploded perspective view of the ends of a pair
of lineal members formed according to the invention.
[0016] FIG. 4 is a perspective view of the ends shown in FIG. 3
joined together to form a strong load bearing joint.
[0017] FIG. 5 is an exploded perspective view illustrating
formation of a lineal by injection molding a lineal member onto a
pre-formed end part according to the disclosure.
[0018] FIG. 6 is an exploded perspective view of the ends
components of a pair of lineal members illustrating molding of
resilient sealing surfaces as a part of the RIM molding methods of
this disclosure.
[0019] FIG. 7 illustrates lineal members made with segmented molds
according to the disclosure to produce window frames of virtually
any size.
[0020] FIGS. 8-10 illustrate another molding technique according to
the present disclosure for use in forming a unitary lineal member
of virtually any desired length using the same mold and a two step
molding methodology.
[0021] FIG. 11 illustrates a door having a lower panel, or kick
plate, having beveled edges.
[0022] FIG. 12 is a more detailed view of the lower panel shown in
FIG. 11.
[0023] FIG. 13 illustrates a molded threshold produced according to
the present invention.
[0024] FIG. 14 illustrates end pieces used in an alternative method
of producing a threshold according to the present invention.
[0025] FIGS. 15-16 illustrate a conventional double hung window
with transition stops between the upper sash and the lower
sash.
[0026] FIG. 17 illustrates a lineally adjustable mold for molding
in an intermediate stop in a molded-in channel.
[0027] FIG. 18 illustrates a lineally adjustable mold for molding
more than one member at a time.
[0028] FIG. 19 illustrates a sill for a double hung window that is
produced by the RIM process.
DETAILED DESCRIPTION
[0029] The mold portrayed in FIGS. 1 and 2 functions as a lineally
adjustable mold according to aspects of the present invention. Mold
10 comprises first extended length lineal profile part 12, second
extended length lineal profile part 14, first end mold part 16, and
second end mold part 18, which fit together to define an internal
mold cavity for molding lineal member 20 of a fenestration unit,
shown in FIG. 2. The types of end features that can be molded into
the member are not particularly limited, and alternative end
features, such as those that serve a structural, connecting, or
purely decorative function, may be produced, merely by substituting
different end parts 16 and 18.
[0030] It will be appreciated that while lineal profile mold parts
12 and 14 are each shown as single parts, they may also be made up
of two or more components bolted or otherwise fastened together to
form a modular mold system. In alternative embodiments, parts 12
and 14 may be made up of two or more components placed end to end,
optionally having different cross sectional profiles, so as to
produce a lineal member having a first cross sectional profile
along a first longitudinal portion and a second profile along a
second longitudinal port, and, in still other embodiments, other
cross sectional profiles along other longitudinal portions. In
still other embodiments, lineal mold parts 12 and 14 may be made up
of lineal components placed side by side and bolted or otherwise
fastened together. By providing a variety of different lineal
components, which can be assembled in different combinations, a
greater variety of cross sectional profiles can be created with
fewer mold parts.
[0031] Molds can be made from a variety of materials, depending
upon the type of member being molded, and it is possible to use
different materials for different mold parts. Referring to FIG. 1,
lineal mold parts 12 and 14 can be made of aluminum or other metal,
to achieve durability and dimensional stability, particularly if it
is important to maintain a high level of straightness over an
extended length. If curved lineal members are to be produced,
elastomeric or other flexible materials may be used to make lineal
mold parts that can be bent into curves prior to use. It may be
useful to provide fixturing to hold the bent lineal mold parts in
specified curved shapes. End parts 16 and 18 can also be made of a
metal, such as aluminum, although other materials may also be used.
In particular, since the temperatures produced by reaction of the
molding materials during cure is well below the melting point of
many thermoplastic materials, polymeric materials can be used as
end parts. Materials that are particularly useful are those with
low surface energy, such as high density polyethylene (HDPE),
polyacetals (DELRIN.RTM.) and fluoropolymers (TEFLON.RTM.), in that
they reduce the need for a liquid mold release to allow them to be
removed from the molded member after curing. This reduces the risk
of poor adhesion of paint and adhesives due to residual mold
release remaining on the molded member after removal from the
mold.
[0032] In building a mold, methods of fabricating the parts making
up the mold can be chosen according to the materials being used.
Metal parts, such as straight lineal parts 12 and 14, can be made
by machining from aluminum or other metal bar stock. If larger
quantities of a particular mold part are needed, it may be
convenient to extrude a suitable material and cut it to length.
Flexible lineal mold parts can be made by molding or extruding
rubber or other flexible or elastomeric material. If a member
having the desired shape already exists, and the task is to
duplicate it, the original member may be used as a pattern to cast
an impression, which can then be used as a mold for molding
additional mold parts. End parts for a lineal mold can be made by
machining or molding, as well. It has also been found that some wax
materials having a melting point suitably high to withstand RIM
molding temperatures can be used as materials for mold parts.
[0033] Referring to FIG. 1, a method for using mold 10 to mold
lineal members is first to install end parts 16 and 18 onto first
lineal mold part 12 at predetermined positions, as determined by
the desired length of the lineal member being molded. The mold is
then closed by clamping lineal mold part 14 over end portions 16
and 18 and lineal mold part 12, thereby forming an internal mold
cavity. The length of the lineal member to be molded is typically
determined by the position of end part 18, with end part 16 being
fixed for all lengths produced. This need not be the case, however,
as both end parts can be moved to suitable positions along lineal
mold part 12 to define a predetermined length therebetween. In
other embodiments, for example, when the mold is segmented, the
lengths of both segments may need to be adjusted relative to the
corner where the two segments join. Similarly, when the mold
combines a straight portion and a curved portion, the relative
lengths of the two portions can be adjusted by moving both end
parts to appropriate positions. End parts 16 and 18 can be held in
place by suitable stops or other holding devices. The holding
devices may be manually operated or power operated. Power operated
holding devices may be further operated by programmable
controllers. Clamping of lineal parts 12 and 14 can be achieved by
hydraulic, mechanical, or other suitable clamps. Heavy duty bar
clamps of the type used in woodworking have been found useful.
[0034] Lineally adjustable molds may incorporate features that
provide useful departures from strict lineality at selected
intermediate points along a lineal member. For example, features
can be molded into vertical members of double hung window frames
that avoid the need to attach separate parts that complicate
assembly and risk producing leaks. FIG. 15 illustrates conventional
double hung window 150 having upper sash 152 and lower sash 154.
The sashes are held in a frame having vertical side members, or
jambs, 153 and 155, in which the sashes can slide vertically for
opening and closing. Sashes 152 and 155 hold glazing units 151 and
157, which can be single sheets of glass, but preferably are double
pane insulated glazing units, which are well known and commercially
available from a variety of sources. In opening window 150, sash
152 can slide downward, and sash 154 can slide upward. Since both
sashes are moveable, sealing between them has proven to be
challenging.
[0035] Referring to FIG. 16, one way of sealing the gap between
sashes 152 and 154 is to provide flexible sealing member 169, which
is fixedly attached to lower rail 168 of sash 152. Sealing member
169 may be a resilient fin or tubular component, or other known
material of the type that may be effective in providing a sealing
function. When the sashes 152 and 154 are in the closed position,
sealing member 169 deforms to seal against upper rail 158 of sash
154. While sealing member 169 is effective in sealing between rails
158 and 168, it has been found less effective in sealing gaps
beyond the sides of the sashes, adjacent to vertical members 153
and 155, in the areas of rails 158 and 168. This problem has been
remedied by providing transition stops 167, attached to vertical
members 153 and 155, and which extend inwardly from vertical
members 153 and 155, and are positioned to enable the ends of
sealing member 169 to press upward against them, thereby providing
a seal. Transition stops 167 can be provided as, for example,
resilient foam components attached to vertical members 153 and 155.
Attaching stops 167 to vertical members 153 and 155 can be made
difficult, however, by the need for locating them precisely and
attaching them without drilling holes that might require additional
sealing or the risk of leakage. Lineally adjustable molds can be
adapted, however, to provide integrally molded-in transition stops.
Integrally molded-in transition stops can be used alone to provide
a surface against which sealing member 169 seals, or may provide a
fastening function for another component, such as a foam seal, to
be attached thereto.
[0036] Referring to FIG. 17, lineal profile mold part 170, not
shown in full length, for molding a member containing longitudinal
channels, is shown. Ribs 171a, 171b, and 173 extend into mold
cavity 174 to provide molded-in channels in the molded member. If
it is desired to provide a molded-in stop in one of the channels,
gap 176 can be provided. The location of gap 176 can be adjusted by
locating the end pieces, not shown, of the mold, at the desired
distance from gap 176. In an alternative embodiment, ribs 171a and
171b can be separate parts, slidable along lineal profile part 170,
to enable the size and location of gap 176 to be adjusted. This
general mold design can be used to provide stops such as stop 169,
when used in a suitable mold, as well as other integrally molded
intermediate features in lineal members.
[0037] Other intermediate features also may be provided by adding
inserts at intermediate locations in lineal profile mold parts.
Such inserts may be removable, in a manner similar to removable end
pieces, after curing of the molding material, or may become part of
the molded member itself. Permanently molded-in inserts may be of a
standard type of the sort commonly found in molded RIM parts, or
may be special purpose inserts produced for particular
applications.
[0038] The molding process is performed by injecting molding
material into the internal cavity of the closed mold through an
injection port (not shown). The injection port may be located
proximate one end of the mold, though other locations may be useful
in particular applications. One method of injecting the molding
material is to tilt the mold so that one end is higher than the
other, and inject the molding material at the lower end to fill the
internal cavity progressively, thereby reducing the likelihood of
trapped air causing defects in the resulting lineal member.
[0039] Venting to allow air removal from the mold during injection
can be provided in a manner conventional to known RIM processes.
For example, a small hole can be placed in an inconspicuous
location at the top end of the mold.
[0040] Useful molding materials are those sometimes used in
reaction injection molding (RIM) processes that comprise a blend of
reactive monomeric fluid components that can be mixed just prior to
injections, injected into the mold, and allowed to react within the
mold to form a solid polymeric lineal member. Useful RIM components
may include a first component comprising isocyanate chemical
groups, and a second component, such as a polyol, comprising
hydroxyl groups, which react to form a polyurethane polymer.
Additionally, foaming agents have been found useful, to produce a
lineal member that is lighter in weight, with lower thermal
conductivity, and an improved ability to accept and retain
fasteners such as screws. One suitable reactive system for use as a
molding material is Baydur 665, from Bayer Material Science. Other
reaction injection polymer or non-polymer materials also may be
selected depending upon application specific requirements. Baydur
665 has been found to have a suitable reaction time and has the
additional advantage that the cured product is a structural
foam.
[0041] The reactive molding material may also include particulate
fillers of the type typically used in RIM applications to improve
the mechanical and other properties of the cured product and to
reduce material cost. Such fillers include talc, calcium carbonate,
fly ash, Wollastonite, and other inorganic materials. In some
embodiments, organic fillers such as rice hulls, for example, may
be used. A particularly useful filler has been found to be NYGLOS 8
Wollastonite, available from Nyco of Willsboro, N.Y., which is
added to the Baydur 665 system in an amount of approximately 5% to
40% and more preferably about 20% of the overall composition. While
it was thought that higher loadings of Wollastonite might further
improve the mechanical properties of the cured product, it also was
found that higher loadings increased the viscosity of the molding
material prior to cure to such an extent that processing became
difficult. It will be appreciated that this limitation is specific
to Wollastonite and to Baydur 665, and that this specific
limitation may not apply to other fillers and reactive molding
material systems. Because fillers typically contain moisture, it
was found useful to add the filler to the polyol part of the Baydur
665 rather than to the isocyanate part, prior to mixing of the
isocyanate and polyol, since isocyanate reacts strongly with water,
and such a reaction could interfere with the desired reaction
between the isocyanate and the polyol.
[0042] As is well known in the art, the adhesive nature of some
reaction injection molding materials can create a tendency for
molded parts to adhere to the molds, thereby complicating
de-molding. A variety of mold release agents are commercially
available, with the choice depending on a variety of factors, in
particular, whether the molded part is to be painted after removal
from the mold. A mold release that was found useful was Chem-Trend
Pura 11166, available from Chem-Trend, 1445 West McPherson Park
Drive, P.O. Box 860, Howell, Mich., 48844-0860. Pura 11166 was
effective in releasing parts from the mold, did not cause damage to
the mold or excessive buildup of residual material in the mold
after repeated moldings, did not cause inconvenient extension of
the molding cycle, and allowed the molded parts to be painted after
molding. As would be recognized by one skilled in the art, other
molding situations might call for different mold release agents.
For example, in-mold painting, a well recognized operation in the
RIM industry, may call for a different mold release, one perhaps
formulated specifically for that purpose.
[0043] Various types of injection systems or injection guns for
injecting the molding material into the mold are commercially
available. For example, RIM injection systems available from High
Tech Engineering of Grand Rapids, Mich. have been found to perform
well the metering and mixing functions, as well as the injection
function. It may be desirable that the reactive components of the
molding material be metered and mixed in the proper quantities for
a desired lineal member just before injection into the internal
cavity of the mold. As is conventional practice in RIM, it is
useful to run the mixed injection material through an aftermixer,
or peanut mixer, just prior to injection into the mold, to reduce
any turbulence caused by the first mixing process and provide a
more laminar flow into the mold. Alternatively, the components may
be mixed prior to injection into the mold with the injection gun.
The volume of molding material to be injected depends, of course,
on the volume of the internal cavity of the mold, and account
should be taken of the possible expansion of the reactive
components of the molding material as it cures within the mold.
[0044] It is useful to provide flow channels in the mold to
circulate a temperature controlling fluid such as oil, water, or a
water and ethylene glycol blend, or other like fluid, through the
body of the mold. In addition, it is further useful to provide one
or more thermocouples or other temperature sensing devices in the
body of the mold for sensing the mold temperature and providing
feedback to the fluid heating and cooling system for maintaining
the mold temperature within predetermined limits during the molding
process. In the present case, wherein Baydur 665 is the molding
material, and a water ethylene glycol blend is the fluid, the mold
is first heated, at the beginning of injection, to a temperature
that allows the injected material to form a solid skin at the mold
surface, while providing a foamed structure in the bulk of the
molded part. Since the reaction of the molding material is
exothermic, the fluid temperature is then lowered, in response to
the rising mold temperature, as indicated by the temperature
sensor, to maintain the mold temperature in a range that produces a
satisfactory foam structure and surface quality.
[0045] Bayer recommends a mold temperature of 140.degree. F. to
160.degree. F. (60.degree. C. to 70.degree. C.) for Baydur 665. A
temperature of 130.degree. F. (54.degree. C.) was found, in one of
the molds used in the present invention, to produce satisfactory
results. Since in this particular case, the temperature sensor was
a slight distance away from the surface contacting the molding
material, it was estimated that the actual mold surface temperature
was slightly higher, due to the heat generated by the reaction of
the molding material, and was therefore near to the range
recommended by Bayer. It was found that allowing the measured mold
temperature to fall far below 130.degree. F. produced a
deterioration in the surface quality of the molded part, while
allowing the measured mold temperature to rise far above
130.degree. F. produced a non-uniform internal foam structure in
the part. It will be appreciated that while the mold temperature
control system described herein was found to produce satisfactory
results, other mold temperature control systems, particularly those
conventional to the RIM industry, may produce equally satisfactory
results, and are also considered enabling to the present
invention.
[0046] Once the mold has been closed and clamped, and the molding
material injected, the mold is held clamped until the curing
reaction has produced at least partial and perhaps complete
solidification. The mold is then opened by separating the lineal
mold parts, and the molded lineal member, possibly with the end
mold parts still attached, is removed. Depending on the design of
the molded member, the end parts may then be removed from the
molded member by, for example, pulling them from the ends of the
molded lineal member to leave ends shaped by the shape of the end
parts. Other conventional de-molding techniques, such as providing
knockout pins and injecting compressed air, may also be used. It
will be understood that the exact sequence, direction, and method
of opening the mold and removing the molded member from the mold
will depend upon the specific shape of the molded member and the
configuration of the end parts of the mold. After removal from the
mold, the molded lineal member may be trimmed or cleaned as
necessary to remove any flash or other imperfections prior to use,
in a manner conventional to other RIM processes.
[0047] The present method of producing lineal members for
fenestration units is particularly useful in producing lineal
members for fenestration units that are to be joined to other
lineal members because complex joint configurations can be
consistently reproduced to an exceptionally high level of
precision. For instance, referring to FIG. 3, a complex joint
between two lineal members having only two parts, namely the lineal
members themselves, is illustrated. In FIG. 3, lineal members 32
and 34, (only the end portions of which are shown) may, for
example, be a rail and stile for a window sash, with the window
glass unit fitting into channel 325. It will be understood that the
sash formed by members 32 and 34 is simplified, for the sake of
clarity, and that the cross sectional profiles of alternative
window sashes can be significantly more complex, without
complicating the molding process and without departing from the
scope of the invention.
[0048] The joint between lineal members 32 and 34 is a compound
joint, in that it combines features of mitered joints with those of
mortise and tenon joints. Mitered surface 322 of member 32 mate
with a similar mitered surface 319 of member 34. Tenon 326 of
member 32 fits into a mating mortise, not visible, in the end of
member 34. Surface 330 of member 34 fits against edge 328 of wall
323, thereby forming a joint having the external appearance of a
mortise and tenon joint. Similarly, surface 329 of member 34 fits
against edge 327 of wall 321, thereby forming a joint having the
external appearance of a mortise and tenon joint. Because the joint
between members 32 and 34 involves multiple surfaces that engage at
different angles, thereby supporting loads in a variety of
directions, and because molding of the joint enables a high level
of precision to be consistently achieved, members 32 and 34 fit
tightly together, in a rigid manner. Referring to FIG. 4, the final
fastening can be provided, for example, by a single screw 40, or by
screw 42, or both, positioned as shown or otherwise positioned. The
primary function of screws 40 and 42 is to hold the lineal members
32 and 34 in the engaged position, so as to enable the various
closely engaged and precisely fitting joint interfaces to perform
the primary load bearing functions of a window sash. In alternative
embodiments, fasteners other than screws, for example eccentric cam
type fasteners, or snap fit fasteners may be used, if found to be
suitable. In some embodiments, an adhesive may be used as a
fastener. Moreover, the specific positioning of the fasteners is
not particularly limited, because the resulting lineal members are
solid rather than hollow without screw bosses with which the screws
must be aligned. This has been found to produce a particularly
strong load bearing joint. It is further contemplated that adhesive
bonding may be useful in some instances.
[0049] In the joining of lineal members of fenestration units, it
often is required that joints between members not only provide a
required level of structural strength and rigidity, but that they
also seal against penetration of air and water. Because of the high
structural strength and rigidity of the joint illustrated in FIG.
3, structural adhesive bonding at the joint is not required.
Therefore, any sealants used for leak prevention need only serve
the sealing function, and are not required to provide structural
strength, although the sealants may aid in holding the joined
members in their positions for optimum mechanical engagement. This
simplifies the choice of sealants, in that compromises between
structural strength and sealing ability become less critical.
Additionally, the performance of sealants can be improved by
providing them in layers of precisely controlled thicknesses. The
ability of RIM to create joints having precisely controlled
interfacial spacing in selected areas, by molding in precisely
dimensioned spacers, is therefore useful in providing improved
sealing of joints. Sealants can be applied to members prior to
assembly, or injected through appropriately placed injection ports
after assembly. In FIG. 3, recessed area 324 is provided to receive
excess sealant that may have been applied, either by
pre-application or by injection, so as to avoid forcing it out
through visible portions of the joint. Alternative configurations
for recessed area 324 or other excess sealant reservoirs may also
be used, depending on the specific manner in which sealant is
applied or injected and the particular areas that need to be
sealed.
[0050] Referring to FIG. 5, lineal 50 is produced by molding lineal
member 54 onto preformed end part 52 according to the disclosure.
In this embodiment, end part 52 is placed in a first location of
one mold part, clamped in place along with the remaining parts of
the mold, and the resulting mold cavity, within which the end part
52 is located, is filled with molding material. Upon curing and
removal from the mold, end part 52 becomes an integral part of
lineal 50. It will be understood that while end 55 of member 50 is
portrayed as a simple flat end, for simplicity, it too can have an
end part similar to end part 52. A second lineal can be made by
molding a lineal member onto end part 56. Optionally, it may be
useful to provide end parts with protrusions or other features such
as protrusion 58 to enhance the coupling between the molding
material and the end part. End parts 52 and 56 can be produced by
any suitable means, such as injection molding. Reaction injection
molding of parts 52 and 56 may be most convenient, in order to
achieve material compatibility between the end parts and the molded
portions. Also, since the end parts are the same for many member
configurations, the same end part tooling can be used for many
member configurations.
[0051] In the embodiment illustrated in FIG. 6, an additional
feature has been incorporated into an end part 62. Portions 621 and
622 are covered with a layer of resilient material that acts as a
gasket for sealing the joint between end parts 62 and 66 tightly
against water and air penetration. A fastener such as screw 640 can
be used to pull end part 66 into secure engagement with end part
62. The thickness and mechanical properties of layers 621 and 622
are chosen to enable sealing contact to be made with part 66, while
allowing surfaces 629 and 630 to engage with edges 627 and 628,
respectively, to form a rigid structural joint. End part 62 can be
produced by overmolding a resilient material onto part 62. When
part 62 is produced by RIM, layers 621 and 622 can be provided as a
single insert in the mold, prior to injection of the RIM resin
material. While the mating and sealing surfaces are illustrated in
FIG. 6 in simplified form for clarity, it will be understood that
these surfaces may be significantly more complex in shape and
profile. Further, the placement and configuration of the layer of
resilient sealing material will be designed to function with the
particular profile to seal leakage paths that might exist to
prevent water penetration. Even so, the resilient sealing material
still can be an insert placed in the mold before the RIM of the
lineal member onto which the sealing surfaces are to be formed.
[0052] It will be recognized that molded-in inserts, of the type
traditionally used in conventional RIM, can also be used in the
present work. For example, referring again to FIG. 6, a threaded
insert made of metal or other material could be molded into member
66 to receive screw 640. Similarly, hole 631 could be provided by a
molded-in insert made of metal or other material. Other commonly
used inserts include stiffening members and hollow or foam members
for reducing material costs.
[0053] It has been found that the uncured or partially cured RIM
molding materials in the Baydur 665 resin system exhibit a strong
affinity for surfaces formed by previously cured RIM molding
materials of the same or similar composition. This affinity is
manifested in strong adhesion between the surfaces of a previously
molded and cured RIM components and uncured RIM resin that comes in
contact with the previously cured surfaces before curing. This
affinity can be utilized to build up larger members by molding new
portions onto previously molded and cured members.
[0054] Referring to FIG. 8, which depicts one technique according
to the disclosure, first RIM molded component 80 is produced by
molding in a mold having lineal mold part 82 and end parts 84 and
86. It will be understood that lineal mold part 82 may actually be
made up of two lineal mold parts or clamshell halves that can be
separated for removal of molded component 80, as disclosed above.
It will further be understood that end part 84 may be removed from
the mold with member 80 and then removed from component 80 as a
second mold removal step.
[0055] Referring to FIG. 9, once component member 80 is molded and
removed from the mold, end part 86 can be removed from lineal mold
part 82 and the molded member 80 can be inserted into the internal
cavity of the mold to a predetermined location (at 91 in FIG. 9),
determined by the desired length of the final molded part. The
location 91 is virtually infinitely variable along the length of
the mold cavity so that a completed lineal member of virtually any
desired length can be molded. A second portion 90 of the lineal
member is then formed within the unfilled portion of the internal
cavity by a second injection of reactive molding material. Because
of the affinity of the uncured reactive molding material for cured
resin surfaces of the pre-molded lineal member 80, a unitary
integrally formed lineal member, shown in FIG. 10, having a
precisely predetermined length is produced using only a single
fixed mold. While the joint between the first portion and the
second portion of member 100 is shown, for illustrative purposes,
as line 91 in FIG. 10, it has been found that the actual joint
between first portion 80 and second portion 90 is far less visible
than portrayed in FIG. 10, and may often be made substantially
invisible by a minor finishing operation such as sanding or flash
removal.
[0056] In yet another embodiment, illustrated in FIG. 7, L-shaped
segmented members 72 and 74 are fitted together to form a
rectangular fenestration frame 70. Members 72 and 74 are produced
using a segmented mold in a RIM molding process as described having
end part positions adjustable to define dimensions L and W. In this
embodiment, end joints 73 and 75, which may be preformed or formed
as part of their respective lineal members, are adapted to allow
members 72 and 74 to be produced by the same mold. Thus, the same
mold can be used to produce segmented members of virtually any
dimensions for use in fanning rectangular frames of virtually any
desired size, limited only, of course, by the size of the mold. The
same is true of other shaped frames as well such as, for instance,
segmented members that when joined form hexagonal frames, arched
frames, or round frames. In any of these cases, the dimensions of
the segments are selectable to form a finished frame of desired
size and shape.
[0057] It is also possible for members to be lineal in more than
one direction. Referring to FIGS. 11 and 12, lower panel, or kick
plate, 116, in door 110, has a substantially constant cross section
in both the horizontal ("h") and vertical ("w") directions. There
are therefore two possible mold configurations, one adjustable in
the horizontal direction, to vary dimension w to accommodate doors
of differing widths, and the alternative mold adjustable in the
vertical direction h to accommodate doors of differing heights.
[0058] FIG. 13 illustrates threshold member 130 having a lineal
bottom span defined by surfaces 131, 132, and 133, and upright end
portions 134 and 136. In this embodiment, upright end portions 134
and 136 include tenon portions 135 and 137 for engaging stiles
having hollow portions that receive tenon portions 135 and 137. The
stiles may, for example, be hollow extrusions or pultrusions having
outside profiles dimensioned to form a smooth joint when fitted
against surfaces 138 and 139. Upright end portions 134 and 136
serve to locate surfaces 138 and 139 at an elevated level so as to
reduce the exposure to water that might leak into the stiles and
then into the house, or cause deterioration of the joints between
the stiles and tenons 135 and 137. The stiles may be held in place
with mechanical fasteners such as screws, or may be adhesively
attached to threshold member 130. Surfaces 131, 132, and 133 may be
covered by an abrasion resistant material, such as aluminum, and
may further include features for receiving weather-stripping or
other useful components.
[0059] One method of molding threshold member 130 is first to mold
a complete threshold member for the smallest anticipated door
width. For wider doors, the molded threshold is cut at an
intermediate location between upright end portions 134 and 136. The
cut pieces are then placed in a lineal mold at a distance that
provides the desired threshold length. The resulting mold cavity is
then filled with RIM material and the RIM material is allowed to
cure, after which the completed threshold is removed from the
mold.
[0060] Alternatively, referring to FIG. 14, the end pieces 142 and
144 can be molded separately. Horizontal portions 143 and 145 are
then placed in a lineal mold with surfaces 146 and 149 (not
visible) defining the ends of the mold cavity. The cavity is filled
with RIM material, which forms an almost seamless bond with
surfaces 146 and 149. The RIM material is allowed to cure, the mold
is opened, and the finished threshold is removed.
[0061] In alternative embodiments, the intermediate portion onto
which end pieces 142 and 144 are molded need not be lineal, but
could contain non-lineal portions.
[0062] Referring to FIG. 19, a window sill with a reduced number of
joints is portrayed. Adjustable mold RIM is particularly well
suited to producing window sills of this type. Window sill 190 is
molded as a single part, thereby moving the joint between the sill
and the stiles to interface 193, which can be placed at any desired
height, thereby eliminating leakage at low points where water is
likely to accumulate and leak into the building structure.
Additionally, the sill may include leaked water collection features
such as trough 195. While not shown in FIG. 19, trough 195 may be
provided with molded-in drainage channels, possibly in the form of
inserts, to drain any leaked water to a harmless location, such as
the exterior of the building wall.
[0063] Other features can also be molded into sill 190. Locating
and connecting bosses 197 and 198 can be provided for connection to
the vertical members, or stiles, of the window frame. Rib 199 can
be provided as an extension of a vertical guide member for guiding
a vertically sliding sash. The stiles can be made of any suitable
material, but could be made using adjustable mold RIM. An advantage
of using RIM would be that mortises for receiving bosses 198 and
199 could be molded into the ends of the stiles. It may be useful
to mold metal corner stiffening inserts into the ends of the
threshold 190.
[0064] Lineally adjustable RIM molds are particularly useful for
producing window sills, due to the great number of different widths
in which windows must be provided. The adjustable molding
techniques described herein are well adapted for producing a range
of different sill lengths. For example, a short sill can be molded,
cut at its midpoint, the cut ends placed in an adjustable mold, at
the desired spacing, the open portion of the mold covered with a
second portion of the mold, and the middle portion molded in. The
length of the second, or covering, portion of the mold is
sufficient to cover the open portion of the mold, but short enough
to allow for length adjustment. Alternatively, the end pieces could
be moldered separately and placed in an adjustable mold, at the
desired spacing, and the middle portion molded in as before.
[0065] Lineally adjustable molds are also well suited for producing
trim pieces such as cornices, for fitting over the tops of doors
and windows. Cornices can be produced directly in a mold of
sufficient length, or can be produced in a shorter mold, cut at
some intermediate point, and the two resulting parts used as end
pieces in a further molding step. Presumably, this sequence of
steps could be repeated to produce even longer cornices. Since
cornices do not typically support heavy loads, material cost and
weight can be reduced by use of hollow or foam inserts, in a manner
conventional to RIM.
[0066] In yet another embodiment, illustrated in FIG. 18, a single
mold can be adapted to produce more than one member. This feature
is particularly useful when it is desired to produce multiple parts
of precisely the same length, as might be needed, for example, in a
window frame made up of mating parts that fit together to form a
rectangle, a polygon, or other structural configuration. More
particularly, since the joints produced by molding in lineally
adjustable molds can be made to a high degree of precision, with
tighter fits than may be commonly found in, for example,
conventionally produced fenestration members, the need for overall
precision, not only in the joints but in the length of the parts,
is increased. Thus, all of the parts must fit together properly,
without the flexibility found in less precise, more loosely fitting
joints.
[0067] Referring to FIG. 18, lineal profile part 180, shown in
shortened form, contains lineal mold cavity portions 182 and 184,
which may further contain profile features shown generically as
lineal features 183 and 185. Coupled end pieces 186 and 188 can be
inserted to distances suitable for producing members of the desired
length. By coupling the end pieces, errors leading to differences
in length can be reduced. Errors in locating the end 186 and 188
will only produce errors in the overall size of the assembled
structure, not in the uniformity of the group of members produced
by the mold. It will be understood that while lineal mold profile
part 180 only provides for molding two members at a time, such
molds are not so limited, and it may be desirable to mold all of
the members making up a structure in a single mold, whether that
structure is to be made up of two, three, four, or more
members.
[0068] It will be recognized that the RIM molding process, as
disclosed herein, may include additional, known, capabilities of
RIM, such as in-mold painting and molding in of inserts. These and
other features, aspects, and capabilities are possible and may be
implemented by those of skill in the art without departing from the
spirit and scope of the invention disclosed herein.
* * * * *