Note: Descriptions are shown in the official language in which they were submitted.
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A MOLDED PANEL HAVING A DECORATIVE FACING
TECHNICAL FIELD
The field of this invention relates to a
structured molded paneTfor use with automotive interi- -
ors and a process of making such a panel.
BACKGROUND OF THE DISCLOSURE
Automotive interiors have many interior panels
that form the interior door panels, floor panels, and
rear deck storage panels. The panels need to be struc-
turally sound and light weight while being expeditiously
made from readily accessible materials. Because of the
high volume of automotive vehicles being manufactured
each year, great efforts have been made to make the cars
from environmentally friendly materials. These environ-
mentally friendly materials are either recyclable, i.e.
they can be reused a second time, or may be made from
recycled materials, i.e. they are beiz~g used for a
second time.
Another source of materials that is considered
environmentally friendly is material that would other-
wise be waste. The salvaging of material that is
otherwise waste provides for a second chance for materi-
al that would otherwise be burned or deposited in
landfills. Natural materials are considered because of
their renewable natural fiber content. Flax is grown in
great quantities for its seed which is crushed to obtain
its desirable flaxseed oil. However, since the days
when synthetic materials and other cloth greatly re-
placed the dominant use of linen, the flax chaff and
stalks have found little use and often lie in the field
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as waste material. This situation is particularly acute
in North America where the flax is primarily grown for
the seed. Flax stalk is often burned since its oily
content repels water thereby inhibiting its quick
degradation back into the soil.
It has been known to incorporate flax or other
natural cellulose fibers in a composite material.
However, previous compositions that incorporated natural
fillers either did not have the structural integrity
within the dimensional thinness needed for molded
contoured automotive panels or could not be expeditious-
ly made to produce a consistent product having a cosmet-
ic or decorative facing. The process used to blend and
mold the fibers with the plastic resin required the
plastic resin to be in a melted or liquid state and
required mixing of the fibers with the liquid before the
resin sets. Furthermore, the fibers need to be chopped
because longer lengths of fibers tend to clog the nozzle
of extruders or injection molding machines resulting in
defective molding. However, the structural supporting
properties of the fibers are lessened and the stiffness
of the board may drop when shorter fibers are used.
Furthermore, the heat in previous molding
processes often ruined the temperature sensitive cosmet
is or decorative facing. Heat can destroy textured
surfaces as-well as any foam backings to the decorative
layers. On the other hand, the absence of heat above
room temperature prevents the proper joining of struc-
tural layers. Crazing also can appear in deformation
areas if the materials are overly cool during deforma-
tion.
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What is needed is an expeditious molding -
process that in a single molding step provides an
automotive interior structurally supportive panel having
a decorative facing and if desired can incorporate a
sound insulating layer and anchored fastener members.
SUMMARY OF THE DI&CLOSURE
In accordance with one aspect of the inven-
tion, a process for forming a panel for an automotive
interior includes the step of forming a mat of blended
material. The materialis made from a blend of thermo-
plastic fibers and natural fibers, preferably approx-
imately one-half polypropylene and one-half flax fibers
I5 by weight. The mat is made by a commercially available
machine that manufactures the mat from polypropylene and
flax fibers to a desired thickness. The mat is flexi-
ble, porous and preferably non-woven. The mat is placed
into a heating chamber with heated gaseous flow passing
through the mat to evenly heat the mat throughout--its
entire interior and exterior surfaces to at least the
melting temperature of the thermoplastic fibers. In the
case of polypropylene the mat is heated to approximately
200° C. The shape of the mat is retained by the natural
fibers.
A layer of cosmetic covering is placed in an
unheated mold between two mold halves with opposing
surfaces. The cosmetic covering may be an unformed
layer, a contoured preform, or sprayed directly on a
mold surface of one die. If sound insulation is de-
sired, a layer of sound insulating material is placed
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within or against the mat prior to the molding thereof.
If the sound insulating material is porous, it may be
stacked with the mat and heated-therewith.
In one embodiment, the cosmetic covering is
made .from vinyl material with a pre-attached foam
backing at its underside. If the underside of the
covering material is a material that is not compatible
and does not bond directly to the thermoplastic in the
mat, an intermediate scrim material is preattached
either directly to the vinyl or if present, the foam
back. The scrim is positioned to be interposed between
the covering layer and mat to bind at one side to the
backside of the covering material and at a second side
to the thermoplastic at the outer surface of the mat.
If the backside of the covering is compatible, the
cosmetic covering may directly bond to the mat without
any scrim. The heated mat is then placed in the mold
and the mold dies are promptly closed and pressed to
exert pressure on the layers of mat, sound insulating
material and the cosmetic covering.
When the mold is closed and pressure exerted,
the flax fibers compress together with the melted
thermoplastic within the mat. The thermoplastic materi-
al also makes contact with the cosmetic covering. The
mold is retained closed until the compressed layers in
the mold are cooled and the thermoplastic bonds the flax
fibers together and the cosmetic covering becomes bonded
to the mat. The mold dies.are then opened and the
completed molded panel is removed.
If the panel needs to be mounted to a support
or vehicle door via fastener members, the fastener
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members may be anchored into the panel during the
molding process without interfering with the integrity
or appearance of the cosmetic covering.
In an embodiment which incorporates a layer of -
sound- insulating material, it is preferable that the
opposing surfaces of the respective mold dies when in
the closed position have a varying distance therebe-
tween. The varying distance provides a finished sound
insulating panel with varying thickness. A substantial
part of the varying thickness is due to the change in
thickness of the sound insulating layer which also
provides a change in density of the sound insulating
layer. The sound insulating layer in one embodiment is
a layer of non-woven cotton. In another embodiment, the
sound insulating layer is a layer of Kaldex'" by DuPont
or a similar commercial product.
According to another aspect of the invention,
a laminated sound insulating panel for use in automotive
interiors includes a cosmetic covering layer bonded-to
a multi-layer mat of a blend of thermoplastic fibers and
natural fibers, preferably approximately one-half flax
fibers and one-half polypropylene fibers by weight. A
layer of non-woven sound insulating material is inter-
posed between a first and second layer of -the flax and
polypropylene mat. The insulating material preferably
is impregnated with a thermoplastic material that is
compatible or similar to the thermoplastic used in the
mat. In another embodiment the layer of sound insula-
tion may be a layer of blended thermoplastic fibers and
natural fibers with approximately 80% by weight being
natural-fibers.
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A fabric covered component may be interposed
between the decorative layer and the mat such that, after
forming the panel, the overlying portion of the decorative
layer is removed to reveal the fabric covered component as a
decorative addition to the panel.
In this fashion, the panel with the above-
described features is made in a single compression molding
step.
The invention may be summarized according to one
aspect as a process for forming a sound insulating panel for
an automotive interior characterized by the steps of;
forming a porous flexible mat of blended fibers using a
needling machine with 30-60o by weight of the fibers being a
thermoplastic material and the remaining 40-70% of the
fibers being a natural material; placing a layer of porous
sound insulating material in contact with said mat such that
said mat is in contact along a major surface thereof with
said sound insulating material; placing said mat and sound
insulating material into a heating chamber with heated
gaseous flow that passes through said mat and sound
insulating material to evenly heat said mat interior and
exterior surfaces to at least the melting temperature of the
thermoplastic material; placing a layer of moldable cosmetic
covering into a cavity of an unheated mold; removing said
mat and sound insulating material from said heating chamber
and placing said heated mat and sound insulating material
into said cavity of said unheated mold; molding said mat,
sound insulating material, and said cosmetic covering under
pressure between two mold dies having opposing surfaces
while said mat has a temperature from said heating chamber
of at least the melting temperature of the thermoplastic
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material; retaining said mat, sound insulating material, and
said covering in said mold until cooled and said
thermoplastic is resolidified to bond said natural fibers
together and said sound insulating material is adhered to
said mat and said cosmetic covering is bonded via the melted
and resolidified thermoplastic fibers to said mat; opening
said mold dies and removing the molded sound insulating
panel.
According to another aspect the invention provides
a laminated panel for use in automotive interiors
characterized by: a mat made from fibers with 30-60% by
weight of the fiber being a first thermoplastic material and
the remaining 40-70% of the fibers being a natural material;
a cosmetic layer connected to one side of the mat by the
application of pressure and heat via an intermediate scrim
layer; said scrim layer having fibers made of a second
thermoplastic fiber which is a different thermoplastic
material from that of the fibers of thermoplastic material
in the mat that comprises a compatible thermoplastic
material that can be bonded to the thermoplastic of that mat
and having a melting temperature at least as high as the
thermoplastic material in the mat.
According to another aspect the invention provides
a laminated sound insulating panel for use in automotive
interiors characterized by; a mat having a first layer
having a blend of 30-60o by weight of the fiber being a
first thermoplastic material and the remaining 40-700 of the
fibers being a natural material; a second layer having a
blend of flax fibers and thermoplastic fibers forming an
outer back layer; a layer of non-woven sound insulating
material adhered to said mat and interposed between said
first and second layers of said mat.
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According to another aspect the invention provides
a process for forming an automotive interior panel
characterized by; forming a porous flexible mat of 30-60% by
weight of the fiber being a first thermoplastic material and
the remaining 40-70% of the fibers being a natural material,
said thermoplastic material having a melting temperature;
placing said mat into a heating chamber with heated gaseous
flow that passes through said mat to evenly heat said mat
interior and exterior surfaces to at least the melting
temperature of said thermoplastic material; placing a layer
of unheated cosmetic moldable covering into a cavity of an
unheated mold; removing said mat from said heating chamber
and placing said heated mat into said cavity of said
unheated mold; molding said layers of mat and said cosmetic
moldable covering under pressure between two mold dies
having opposing surfaces before said mat substantially cools
from temperature caused by said heating chamber such that
said natural fibers and said cosmetic moldable covering
become bonded together via the melted thermoplastic fibers
when said mold dies are closed; retaining said compressed
layers in said mold until cooled and said thermoplastic
fibers resolidify; and opening said mold dies and removing
the formed panel.
According to another aspect the invention provides
a method for producing a laminated panel wherein a mat made
of fibers with 30-60% by weight of the fiber being a first
thermoplastic material and the remaining 40-70~ of the
fibers being a natural material has its thermoplastic fiber
content reinforced by the application of pressure and heat
and is connected on at least one side with a decorative
layer, said method characterized by: preheating the mat to a
temperature to at least the melting temperature of the
thermoplastic fibers of the mat; preattaching a scrim layer
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to a decorative layer having thermoplastic fibers which are
of a different material than that of the thermoplastic
fibers of the mat that comprises a compatible thermoplastic
material that can be bonded to the thermoplastic of that mat
and having a softening temperature of which is at least as
high as that of the thermoplastic fibers of the mat; placing
the decorative layer and a fleece layer into a mold; placing
said mat in said mold such that said scrim layer is
interposed between said mat and said decorative layer; and
subjecting said mold to a closing pressure in which the
reinforcement of the mat occurs as well as the bonding of
the decorative layer via the scrim layer to the mat.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference now is made to the accompanying drawings
in which:
Figure 1 is a schematic view illustrating one
embodiment according to the invention;
Figure 2 is a side elevational segmented view of
an open mold shown in Figure 1;
Figure 3 is a view similar to Figure 2
illustrating the mold dies moved to a closed position;
Figure 4 is a fragmentary segmented view of the
molded article removed from the mold shown in Figure 3;
Figure 5 is a view similar to Figure 4
illustrating an alternative embodiment;
Figure 6 is a top perspective view of an alternate
embodiment of the layer of flax with sound deadening
embossments;
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Figure 7 is a cross-sectional view taken along
line 7-7 shown in Figure 6;
Figure 8 is a side elevational segmented view of
another embodiment in accordance with the invention;
W0 96116804 PCTIUS95115551
Figure 9 isa view similar to Figure 2 illus-
trating another embodiment of the invention;
Figure 10 is a side elevational segmented view
of a molded article shown in Figure 9 after removal from
the mold;
Figure li is a plan view of the molded article
shown in Figure 10;
Figure 12 is an enlarged plan view of the
fastening member; and
Figure 13 is an enlarged cross-sectional view
taken along lines 13-13 shown in Figure 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to figure 1, a flexible needled
non-woven mat 10 is made on a commercially available
needling machine 12. The needling machine 12 builds the
mat 10 from a supply of polypropylene fibers 14 and a
supply of flax fibers 16 at 50% polypropylene and 50%
flax by weight. Variations from this preferred 50-50
ratio may be acceptable. The percentage-of flax may be
between 40-70% by weight depending on the particular
applications. The needl-ing machine 12 builds the mat 10
with multiple loosely inter-connected thin layers which
is quite porous to air flow. The needling machine 12 is
operated at room temperature with the polypropylene
being in the form of solid flexible fibers. A single
layer of mat i0 has a thickness of approximately one and
one-half inches and a mass of approximately 2000
grams/meter2. The wide range-between 100 grams/meter2 - _
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3000 grams/meter2 is foreseen depending on the particu-
lar application.
The mat l~ then transferred into a furnace
20. If desired and as described below, several layers
40 and 42 of mat 10 may be stacked upon each other.
Furthermore, a porous sound insulating material 42 may
be placed between the layers of mat 10. The layer 42
may be a pre-pressed non-woven recycled cotton fiber.
The furnace evenly heats the layers of mat 10 and any
sound insulating layer 42 to a temperature of approxi-
mately 200° C. To obtain even heating throughout the
mat interior, an air current is set up by a fan 22 which
draws air from a heat source 24 (electric or gas) and
passes the air through one or more layers of-the mat 10.
The heated air, by being drawn through the mat 10,
evenly heats the mat 10 throughout its interior.
Immediately after the layers of mat 10 are
heated to the proper 200° C temperature, the layers of
mat 10 and sound insulation 42 are transferred into an
unheated mold assembly 30. The time needed within
furnace 20 is 'dependent on mass of mat 10 and sound
insulation 42. For many applications thirty to fifty
seconds may be sufficient to adequatelyheat the layers
to 200°C.
The mold assembly has a die 32 and die 34.
One side of die 32 may be covered with an unheated
cosmetic covering 35 for example a thermal plastic
olefin (tpo). The mat 10 and material 42 are placed on
the back- side 36 of the tpo cosmetic covering to form
layers 40, 42 and 44. The front side 37 of the cosmetic
covering faces the contoured mold die surface 38.
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The mold assembly is closed, as shown in
figure 3, immediately after the layers 35, 40, 42 and 44
are correctly positioned therein. The heat from the mat
undergoing pressure from the mold assembly bonds the
5 flax fibers together with the polypropylene. In this
example, large opposing planar sections 46 and 48 of the
mold dies 32 and 34 are spaced farther apart than the
opposing contoured sections 50 and 52 of the mold dies
32 and 34. Mold die 32 may have its surface 38 embossed
10 to form a design or texture in the surface 37 of the tpo
layer-35.
The mold dies are at ambient temperature and
not heated by any source other than what heat the mats
10 transfers to the mold dies. A cooling mechanism (not
shown) dissipates excess heat from the mold. A minimal
pressure of 5 bars provides sufficient compressive force
to achieve part configuration within the mold.
The mold remains under pressure until the
polypropylene resolidifies which can, depending on the
application and thickness of the materials, range
between 30 and 140 seconds. The mold is then opened and
a finished panel 60 is formed, as shown in figures 3 and
4, with large planar sections 62 having a thicker cross-
section than contoured sections 64. The increased
thickness is primarily due to the increased thickness of --
layer 42 at the planar sections 62 due to the mold
shape.
An alternate embodiment is shown in figure 5.
In this panel 70, the tpo cosmetic covering 35 in figure
4 is replaced by a lamination of heat sensitive foam
backed vinyl material 71 with a vinyl decoration layer
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72, a foam baclting 73, and a heat barrier scrim 74. zt
is cama~on to receive vinyl layer 72 with Layers of foam
73 already affzxed together in a single lamination 71.
A heat barrier thin scrim mater5.a1 74 is prebonded to
5 the foa~u layer 73. The scr;~m material is a compatible
thermoplastic material that can bond to the polypropyl-
ene plastic in layer 40 0;~ mat z0 and the :polyester
material can be a suitable mater~,al far the scrim layer
74. The lamination 7i of scrim 74, foam 73, and vinyl
~.0 72 is unheated when placed in the mo7.d_ with a layer of
scrim 74 having a mass of approximate~.y l00
granss/metar2, it has been discovered that the scrim
layer 74 protects the soft foam Layer 73 and decorative
vinyl layer 72 from an unacceptably high heat transfer
Z5 from the mat 14 that wo'u1d otherwise damage the foam 73
and viny3 72. However, the scrim does soften under the
heat and securely bands to the layer 40 of mat 10.
dther sound insulation may he accomplished by
embossing the flax mat 10 as shown in figures 6. and 7
with embossments 82. In this embodiment, a vinyl.
laminated layer 71 inaZudes a vinyl Layer 7z and a layer
of scrim 74. ~,'he scrial 74 is bonded to the mat 7Ø The
die surface 80 of upper mold 34 may be appropriately
embossed to create embossments 82 ix1 the back surface 45
of mat to to inhibit the trans~aission of sound waves
laterally through the mat 10. The embossments 8z are
actually raised and create thicker arBas 84 in mat 10 as
shown in figure 7.
Another embodiment which provides a sound
insulating layer is illustrated in Figure 8. In this
embodiment as with other previously described embodi~
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ments, a scrim layer 74 is preattached to the vinyl
lamination 71. On the back surface 45 of mat IO lies -
another layer 90 of-p-aiypropylene fibers and flax fiber.
This layer 90 has by weight approximately 80% flax
fibers and approximately 20% polypropylene. The mat 10
and layer 90 are preheated to 200° and then placed in
the mold. The scrim 74 becomes bonded to the front
surface of mat 10. The layer 90 also becomes bonded to
mat 10. when released, the 20% polypropylene is an
insufficient amount to keep the flax totally compressed,
and the flax fibers in layer 90 rebound after being
released from the mold. The rebound lowers the density
of layer 90 which acts as a dampener of sound. The
layer 90 may be fabricated separately and laid with mat
10 before they enter furnace 20. Other sound insulation
material such as KaldexT"' material by DuPont may be used
for layer 90. However because Kaldex"" is nonporous, the
mat 10 is preheated first and then stacked together with
the Kaldex~" layer 90. The KaldexT" layer 90 may also be
separately preheated for greater flexibility during the
molding process.
Furthermore, the cosmetic surface may further
incorporate cushioned areas or inserts that are commonly
known for door panels. The process does not inhibit the
incorporation of these known cushioned inserts. As
shown in Figure 9, decorative fabric covered cushioned
insert 100 is interposed between the tpo layer 35 and
mat 10. The mold die 32 has an embossed spring loaded
cutting__.adge 102 which conforms to the shape of the
periphery 105 of the cushioned insert 100. The cutting
edge 102 tucks the tpo layer 35 into the mat 10 and cuts
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the piece of tpa 11o that overlies the cushion loo.
After the mold opens, tha tpo piece 110 is reaaoved to
expose th$ cushion 300 and its decorative fabric 301 as
shown in Figure 11. The cushion insert I00 as shown in
Figure 10 is raised with respect to the rest of the
panel 120. However, the panel 220 may be molded such
that the fabric covering 14~. ~.s coplanar or-. even re-
cessed with respect to the tpo section 35 of panel 120.
As also spawn in Figures 9 and 10, the process
s0 also provides for thg securement of one ar more fastener
members 110 to the panel during tha molding process
without the need far a separate step or other applied
adhesive. Each fastener member 110, as spasm in more
detail in figures 12 and 1~ has a plurality of rosettes
i5 112 w~.th distal point$d pxongs 116. A raised section
117 includes a threaded apexture therethrough 114'whiah
can be fastened tc a bolt. These types of fastener
members 110 are commercially availak~le.
During the molding process, the xa~.sad s$ction
20 217 is aligned with a recessed section 122 in mold paxt
34. The molds are closed with sufficient pressure to
cause each prong x.16 to deflect generally parallel with
' the p3ane of the panel while embedded in the mat 10.
After the mat 10 cools, the nOw generally parallel
25 prongs 1~.6 sre ewbedded and anchor the fastener member
27.0 tc the panel 120. Tha prongs 116 are embedded on3y
in matt l0 and do not interfere with the structure of
cosmetic appearance of vinyl layer 73. The prongs 116
remain concealed undex vinyl layex 71.
30 zn this fashion, an expeditious pxoaess forms
an automotive interior structural7.y self-supportive
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panel that incorporates material that may be recycled or
otherwise waste material. The panel may be, for exam-
ple, a back panel shelf or an interior door panel. The
panel may incorporate sound insulation and other con-
s structions that reduce an effect commonly referred to as
the drum effect. The expeditious process creates a
structurally supportive panel that may have an embossed
or textured cosmetic -surface as well- as cushioned
inserts.
Other variations and modifications are possi-
ble- without departing from the scope and spirit of the
present invention as defined by the appended claims.
