U.S. patent application number 13/427759 was filed with the patent office on 2012-10-11 for cold lamination with radiation.
This patent application is currently assigned to Lisa Draxlmaier GmbH. Invention is credited to Wolfgang Fischer, Robert Magunia, Stephanie Reisinger.
Application Number | 20120258288 13/427759 |
Document ID | / |
Family ID | 45954334 |
Filed Date | 2012-10-11 |
United States Patent
Application |
20120258288 |
Kind Code |
A1 |
Fischer; Wolfgang ; et
al. |
October 11, 2012 |
COLD LAMINATION WITH RADIATION
Abstract
A process for laminating a material layer to a support
including: providing the support, applying the material layer to
the support, a heat-activatable adhesive being applied to s side of
the material layer facing the dimensionally stable support and/or
to the side of the dimensionally stable support facing the material
layer, pressing the flexible material layer and the dimensionally
stable support together by means of a lower dimensionally stable
mold half and an upper dimensionally stable mold half, irradiating
the mold halves, the support and the material layer with
electromagnetic radiation, in particular with microwave radiation,
high-frequency radiation or induction radiation, whereby the
adhesive is activated directly or indirectly.
Inventors: |
Fischer; Wolfgang;
(Neufahrn, DE) ; Reisinger; Stephanie; (Landshut,
DE) ; Magunia; Robert; (Geisenhausen, DE) |
Assignee: |
Lisa Draxlmaier GmbH
Vilsbiburg
DE
|
Family ID: |
45954334 |
Appl. No.: |
13/427759 |
Filed: |
March 22, 2012 |
Current U.S.
Class: |
428/174 ;
156/273.7; 156/380.9; 977/734 |
Current CPC
Class: |
B29C 63/0065 20130101;
B32B 2310/0806 20130101; B29C 65/1425 20130101; B29C 65/4885
20130101; B32B 2605/003 20130101; B29C 65/3612 20130101; B29C
65/3684 20130101; B29C 65/4835 20130101; B29C 65/487 20130101; B29C
63/0073 20130101; B32B 37/12 20130101; B29C 65/1483 20130101; B29C
65/4845 20130101; B32B 37/08 20130101; B29C 65/488 20130101; B29C
66/81267 20130101; B29C 65/3696 20130101; Y10T 428/24628 20150115;
B29K 2507/04 20130101; B29C 65/1412 20130101; B29K 2105/167
20130101; B32B 37/06 20130101; B29C 63/04 20130101; B29C 66/301
20130101; B29C 66/8322 20130101; B29C 66/723 20130101; B29C 65/1435
20130101 |
Class at
Publication: |
428/174 ;
156/273.7; 156/380.9; 977/734 |
International
Class: |
B32B 37/06 20060101
B32B037/06; B32B 3/26 20060101 B32B003/26; B32B 37/12 20060101
B32B037/12 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 22, 2011 |
DE |
10 2011 005 901.6 |
Claims
1. A process for the lamination of a flexible material layer to a
dimensionally stable support, comprising: providing the
dimensionally stable support; applying the flexible material layer
to the dimensionally stable support, a heat-activatable adhesive
being applied to at least a side of the material layer facing the
dimensionally stable support and/or to a side of the dimensionally
stable support facing the material layer; pressing the flexible
material layer and the dimensionally stable support together by
means of a lower dimensionally stable tool half and an upper
dimensionally stable tool half; and irradiating the lower and upper
tool halves, the support, and the material layer with
electromagnetic radiation, wherein the adhesive is activated.
2. The process according to claim 1, wherein the support has a
three-dimensional contour surface.
3. The process according to claim 1, wherein irradiating with
electromagnetic radiation comprises irradiating with any one of
microwave radiation, high-frequency radiation, or induction
radiation.
4. The process according to claim 1, wherein a surface of at least
one of the lower tool half, upper tool half, material layer, or
support is at least partially coated with a layer containing
graphene-like materials.
5. The process according to claim 1 wherein at least a section of
at least one of the upper tool half, lower tool half, material
layer, or support contains in sections graphene-like materials.
6. The process according to claim 1, wherein the adhesive contains
graphene-like materials.
7. The process according to claim 1, wherein at least a section of
at least one of the upper tool half or lower tool half is
transparent for the radiation.
8. The process according to claim 1, wherein the material layer
comprises a decorative layer.
9. The process according to claim 1, wherein the material layer
comprises a spacer layer.
10. The process according to claim 1, wherein the material layer is
formed at least partly of fibers, wherein the fibers are coated
with a layer containing graphene-like materials.
11. The process according to claim 1, further comprising cooling
the adhesive.
12. The process according to claim 11, wherein cooling the adhesive
comprises providing cooling channels in the upper tool half filled
with a coolant that is not excited by the radiation.
13. The process according to claim 1, wherein the irradiation with
the electromagnetic radiation lasts less than 5 seconds.
14. The process according to claim 1, wherein the lower tool half
and the upper tool half are not moved apart until the activated
adhesive has cooled.
15. The process according to claim 1, wherein at least one of the
duration and/or level of the energy input by the radiation is set
by the type of activation of the adhesive and the amount of
graphene-like materials used.
16. An apparatus for laminating a flexible material layer to a
dimensionally stable support, comprising: a lower tool half,
holding the dimensionally stable support, and an upper tool half
wherein at least a section of the lower tool half and/or of the
upper tool half is transparent for the electromagnetic radiation
and an electromagnetic radiator.
17. The apparatus according to claim 16 wherein the support has a
three-dimensional surface contour.
18. The apparatus according to claim 16, wherein a surface of at
least one of the upper tool half, lower tool half, material layer,
or support is coated with a layer containing graphene-like
materials.
19. The apparatus according to claim 16, wherein at least a section
of at least one of the lower mold tool, upper tool half, material
layer, or support contains graphene-like materials.
20. The apparatus according to claim 16, wherein at least a section
of at least one of the upper tool half or lower tool half is
transparent for the radiation.
21. The apparatus according to claim 16, wherein the upper tool
half comprises cooling channels filled with a coolant, wherein the
coolant is not excited by the radiation.
22. A method for laminating a material layer to a support, the
method comprising: providing the support; pressing the material
layer and the support together with a pressing tool; and
irradiating at least one of the support, the material layer, the
tool and heat-activatable adhesive between the material layer and
the support, thereby activating the adhesive.
23. A press laminated workpiece produced by the process according
to claim 1.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Foreign priority benefits are claimed under 35 U.S.C.
.sctn.119(a)-(d) of German application number 10 2011 005 901.6,
filed Mar. 22, 2011, which is hereby incorporated by reference
herein.
BACKGROUND
[0002] 1. Field
[0003] Aspects relate to a process for producing structural
elements which are used in the interior of a motor vehicle (e.g.,
trim parts for the doors, instrument panels, steering wheels,
central consoles, etc.). In particular, aspects relate to a process
for the cold lamination of a material layer to one side of a
support. In addition, aspects relate to a tool for carrying out the
process and to a product produced by the process.
[0004] 2. Discussion of Related Art
[0005] A process for producing a structural element for the
interior of a motor vehicle such as an instrument panel includes
joining two components (e.g., a material layer joined with a
support) by press lamination. One phase of the press laminating
process is activating the adhesive (which has already flashed off
at standard temperature). The adhesive can be in the form of an
aqueous dispersion, for example, and can be applied to the one or
both of the components before they are joined. The material layer
can be a decorative composite with or without spacer fabrics.
[0006] The components are joined and subsequently placed into a
press laminating tool and compressed between two mold halves. Once
a certain pressure is obtained, heat from the laminating tool is
transferred from the tool to the components and, from there, into
the adhesive between the components. The heat activates and
crosslinks the adhesive so that it develops its adhesive and
bonding properties.
[0007] A disadvantage of the described press laminating process is
that the material layer/decorative substrate material is a poor
conductor of heat and hinders the heat transfer into the adhesive
joint. This results in longer process times (for example several
minutes per joining process) as well as a higher required energy
input. This is because, in the process outlined here, the energy
input for activating the adhesive must take place starting from the
tool and transfer through the entire structural element (the joined
components).
[0008] Document DE 10 2007 001 132 A1 is known prior art. This
specification relates to a vehicle seat which has a seat component
with a seat heater, the seat heater having carbon nanotubes as
ohmic resistance. In order to heat the seat heater, a current path
is provided between electrical contacts.
[0009] Document DE 20 2008 010 669 U1 relates to a vacuum
lamination process in which a heating medium effects activation of
the adhesive. Heat can additionally be introduced by radiation (IR
radiation, high-frequency, microwave).
[0010] DE 10 2006 055 474 A1 relates to a process for the coating
of surfaces. In this known process, film systems can be joined to
an object with the aid of a NIR-curable adhesive by passing
electromagnetic radiation in the wavelength range .lamda. 750 to
950 nm through pigmented films. The film system is provided with an
adhesive layer on one side of a film substrate layer. The object to
which the film system is to be bonded can optionally also be
provided with an adhesive layer. Coating can also be effected by
back-injection of the film. To that end, the film is preferably
deep drawn in a deep-drawing tool, and plastics composition is
injected onto the back of the substrate layer. Curing of the
radiation-curable adhesive layer takes place according to the
invention by irradiating the adhesive layer with NIR radiation
through the film layer and/or through the substrate layer.
[0011] However, the process described in DE 10 2006 055 474 A1 is
suitable only in the joining of structural elements which are used
in the exterior field and accordingly do not have increased
requirements in respect of surface quality as does an interior trim
part. Explicit mention is made here of wings, (exterior) door
trims, bumpers, spoilers, skirts and exterior minors. Furthermore,
the process of DE 10 2006 055 474 A1 does not relate to a press
lamination process.
SUMMARY
[0012] In order to shorten the cycle times as much as possible,
after activation of the adhesive, the structural element is
demolded while it is still in the warm state, although in one
embodiment, cold demolding can be used in order to avoid restoring
forces. In one embodiment, therefore, the structural element is
cooled while it is still in the press laminating tool and
appropriate pressure is still applied to the components. However,
for economic reasons, it is necessary to find a balance between the
quality of the structural component and as short a cycle time as
possible. In one embodiment, a process for laminating a material
layer to a support includes providing the support, applying the
material layer to the support, wherein a heat-activatable adhesive
is applied to at least a side of the material layer facing the
support or to a side of the support facing the material layer. The
process includes pressing the material layer and the support
together by means of a lower tool half and an upper tool half and
irradiating the lower and upper mold halves, the support, and the
material layer with electromagnetic radiation to activate the
adhesive.
[0013] The present invention relates further to an apparatus with
which the process according to the invention can be carried out. In
one embodiment, an apparatus for laminating a material layer to a
support includes a lower tool half holding the support, an upper
tool half, and an electromagnetic radiator. The lower tool half or
upper tool half, or both, may have a section that is transparent
for the electromagnetic radiation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings are not intended to be drawn to
scale. In the drawing, each identical or nearly identical component
that is illustrated in various figures is represented by a like
numeral. For purposes of clarity, not every component may be
labeled in every drawing. Various embodiments of the invention will
now be described, by way of example, with reference to the
accompanying drawing, in which:
[0015] FIG. 1 is a schematic view of a press laminating tool
according to one embodiment; and
[0016] FIG. 2 is an enlarged view of a section of the press
lamination tool of FIG. 1 including a tool shell, a material layer,
and a support.
DETAILED DESCRIPTION
[0017] In one illustrative embodiment, a process may be implemented
in order to solve the problems mentioned above by providing a tool
which can reduce the cycle time in the production of press
laminated structural elements as compared with the prior art.
[0018] Aspects of the invention are directed to activating the
adhesive and subsequent drying, not by direct or indirect heat
input via the tool, but by means of electromagnetic radiation which
passes through the press laminating tool (e.g., microwave
radiation, high-frequency radiation, or by means of induction).
[0019] In another embodiment, the cycle time may be shortened
substantially. Moreover, during the activation process, excessive
heat on a decorative surface component may be avoided, preventing
disadvantageous effects, such as shiny spots, dents, or even
burning.
[0020] In a further embodiment, a process may suppress the
occurrence of temperature-induced restoring forces in the
decoration because the decoration itself may not be heated. As a
result, adhesion defects resulting in an edgefold region and in
concave regions of a structural element may be avoided. In another
embodiment, the demolding process may take place in the cold state
and as a result the demolding process may be very gentle for the
joined components.
[0021] In another embodiment, a process may include direct
activation of an adhesive resulting in a uniform temperature
distribution in the adhesive joints and considerably reducing
energy consumption.
[0022] According to a further embodiment, a process may include
indirect activation of an adhesive by coating a section of one of
the tool halves that faces a material layer and/or a support with a
layer containing graphene-like materials (e.g., fullerenes, carbon
nanotubes, and graphene). Alternatively, a section of the support
or the material layer on a side facing the support may be coated
with a layer containing graphene-like materials. Furthermore, a
section of one of the tool halves, the support, or material layer
may contain graphene-like materials. As a result, rather than heat
the tool halves, radiation may directly heat the section coated
with or containing graphene-like materials, which in turn may
indirectly activate the adhesive.
[0023] In a further embodiment, a process may include direct
activation of the adhesive by including graphene-like materials in
the adhesive itself. As a result, the adhesive may be activated
directly because the graphene-like materials already present in the
adhesive may be excited by the applied radiation.
[0024] In another embodiment, a section of the upper tool half
and/or of the lower tool half may be transparent for the radiation
such that the radiation may pass through the tool half without
exciting and heating the tool half.
[0025] The material layer may be a flexible material layer. The
material layer may be a decorative layer (e.g., leather, imitation
leather, foils, textile, etc.) and/or a spacer layer (haptic layer)
(e.g., spacer fabrics, nonwovens, gel cushions, foams, in
particular gap-filling foams). The material layer can be
multi-layered. According to one embodiment, when using textiles or
a spacer fabric with nonwovens, it may be preferable to coat fibers
of the material layer with a layer containing graphene-like
materials. As a result, radiation may excite the layer containing
graphene-like materials to directly and indirectly activate the
adhesive.
[0026] In one embodiment, a process may include a cooling step
after the adhesive is activated. The upper or lower tool half may
have cooling channels filled with a coolant that is not excited by
the radiation. As a result, the cycle time may be shortened further
since when the process is complete, the workpiece may be removed in
a cooled state from the laminating tool. In this embodiment, it may
be preferable to wait until the activated adhesive has cooled
before the lower tool half and the upper tool half are moved
apart.
[0027] According to a further embodiment, the duration and/or level
of the energy input by the radiation are set on the basis of the
type of activation of the adhesive and the amount of graphene-like
materials used. In this manner, the process can be used in a
variable manner for a very wide variety of workpieces to be joined,
and at the same time the advantages already mentioned can be
achieved.
[0028] Turning now to the figures, aspects and embodiments of the
present invention are described below purely by way of example with
reference to a press lamination process and a press laminating
tool.
[0029] FIG. 1 shows a press laminating tool 1 including a lower
tool half 2 and an upper tool half 3. The lower tool half 2 may be
configured to receive and hold a support 4. Alternatively, the
upper tool half 3 may be configured to receive a support 4. The
support may be rigid or semi-rigid or otherwise dimensionally
stable and may have a three-dimensional or two-dimensional surface
contour. The lower tool half 2 and/or the upper tool half 3 may be
cooled. The upper tool half 3 may include a tool shell 5, which may
be dimensionally stable. Alternatively the lower tool half 2 may
include a tool shell 5. The tool shell 5 may be rigid and may have
a shaping contour 6. Between the shaping contour 6, the tool shell
5, and a surface 2a of the lower tool half 2 there may be a press
gap in which, in the operating state, the components to be joined
(e.g., a dimensionally stable support and a flexible material
layer) are located. In one embodiment, cooling channels 7 may be
included in the tool shell 5 through which a coolant can flow, as
show in FIG. 1. Alternatively, cooling channels may be located in
other areas of the upper or lower tool halves.
[0030] In one embodiment, the upper tool half 3 may include an
electromagnetic radiator 8, which may emit radiation (e.g.,
microwave radiation, high-frequency radiation, induction radiation,
infrared radiation, etc.). The direction of the radiation is
indicated in FIG. 1 with the reference symbol S. Alternatively, an
electromagnetic radiator 8 may be included in the lower tool half.
It has been shown that the adhesive may be directly activated by
different processes (optionally in combination), the activation
being effected by microwave radiation, high-frequency radiation or
inductively.
[0031] The electromagnetic radiator 8 may be, according to one
embodiment, a continuous microwave furnace. The radiation emitted
by the electromagnetic radiator may pass through non-absorbing
materials of the lower and/or upper tool halves 2, 3, because they
may be made of materials that are not excited by the radiation
passing through them (e.g., plastics material, glass, ceramic,
etc.).
[0032] The radiation may also pass through the component parts to
be joined (e.g., the support, decoration/composite of plastics
materials) and accordingly reach unhindered the adhesive between
the components. In an embodiment, the energy of the electromagnetic
radiation may be absorbed by water still contained in the adhesive
(generally from 5 to 40 wt. %), resulting in selective heating of
the adhesive in the adhesive joints. In this embodiment, the
activation and drying operation may take only a few seconds. During
this time, pressure may continue to be applied in the press
laminating tool 1.
[0033] In another embodiment, the apparatus shown in FIG. 1 may
include an edgefolding slider 9 for edgefolding a portion of the
material layer 4a (shown in FIG. 2) that may project beyond the
support 4 in an edge region of the support 4.
[0034] In a further embodiment, there may be a radiator 10 located
near the edgefolding slider 9 to directly subject the edge region
of the support to energy.
[0035] To activate the adhesive, graphene-like materials (e.g.,
carbon nanotubes (CNTs), fullerenes, and graphene or derivatives
thereof) may be used. Accordingly, the activation of the
graphene-like materials by different variants may be used in such a
manner that the adhesive or the adhesive joint may be ultimately
activated.
Further embodiments of the invention are mentioned below purely by
way of example only (optionally in combination):
Example A
[0036] In one embodiment, a section of the lower and/or upper tool
half 2, 3 may be coated on a part-facing side with a layer
containing graphene-like materials. The layer containing
graphene-like materials may be a plastic material containing CNTs.
The CNTs may also be incorporated into a section of one of the tool
halve 2, 3 that faces the components to be joined. Radiation may be
applied by the radiator 8 through one of the tool halves to
activate the CNT-containing layer (heat the layer). Starting
therefrom, the heat input takes place through the components to be
joined to the adhesive. The adhesive is in turn activated by the
heat input and accordingly develops its adhesive action.
[0037] In this embodiment, the transfer of heat through one of the
tool halves, as known in the prior art in press lamination
processes, is avoided. The CNT-containing layer may also be
directly applied to a surface of the tool half so that direct
heating can be achieved.
Example B
[0038] In another embodiment, at least a section of the support
(positioned in FIG. 1 on the lower tool half 2), may contain CNTs.
As a result, heat may transfer from the support to directly
activate the adhesive.
Example C
[0039] In a further embodiment, the adhesive itself may contain
CNTs. As a result, the CNTs may be excited by the radiation energy
introduced directly at the point where activation of the adhesive
may also take place. This results in particularly low energy
consumption without dissipation losses, and a correspondingly short
activation and cooling time.
Example D
[0040] In another embodiment, a decorative underside, which is
remote from the upper tool half 3 and faces the adhesive, may be
coated with a CNT-containing primer or with a corresponding
preparation. In the laminating operation, the CNT-containing layer
may heated by the radiation emitted by the radiator 8, and as a
result transfer heat to activate the adhesive.
Example E
[0041] In an alternative embodiment, fibers of the spacer fabric
may be coated with a CNT-containing primer or with a corresponding
preparation, or they may contain CNTs themselves. In the laminating
operation, the CNT-containing layer may heated by the radiation
emitted by the radiator 8, and as a result transfer heat to
activate the adhesive, such as describe in Example D.
[0042] In the above-mentioned Examples, which may be used in
combination with one another, the adhesive may be activated by
means of electromagnetic radiation. This gives rise to the
following advantages:
[0043] In an embodiment in which a surface of a tool half is coated
with CNTs (Example A), the tool surface is heated, and indirect
activation of the adhesive thereby takes place. Indirect heating of
the adhesive is also achieved when the support is provided with
CNTs, as mentioned in Example B. The same is true of embodiments in
which the spacer fabric or the decorative layer is heated and the
adhesive is thereby activated (Examples D and E).
[0044] The process according to aspects of the invention has the
advantage of uniform activation and heating of the components to be
joined. In addition, a reduction in the cycle time and a reduction
in the energy consumption may be obtained, and the tool costs may
be reduced. Because the energy input may take place directly,
rather than by heating the lower or upper tool halves themselves,
the energy losses may be smaller and excessive heat on a decorative
surface, which later is located on the outer side in the vehicle,
may be avoided. As a result, the quality of the decorative surface
may not be impaired by the joining process, and temperature-induced
restoring forces, which can otherwise occur in the material of the
decorative layer, may be avoided.
* * * * *