Note: Descriptions are shown in the official language in which they were submitted.
CA 02310758 2002-08-12
DESCRIPTION
Sealing s3rstem with sealing profile and adhesive strip
The invention relates to a sealing system with a sealing prafile, which
sealing
profile is fixed onto a first adhesive layer of an adhesive strip which is
adhesive
on both sides, wherein a second adhesive layer disposed an the opposite side
of the adhesive strip is covered by a peelable first liner and which second
adhesive layer, after removal of the first liner, can be adhered to a
substrate to
be sealed.
In a known sealing system of this type the sealing profile and the adhesive
strip
io are produced separately. The adhesive strip is subsequently fixed by means
of
its first adhesive layer to the sealing profile in an additional working
process.
This is expensive in time and costs and limits the design of the sealing
profile.
The object of the invention is to form the sealing system more cost-
effectively
and achieve greater freedom in the formation of the sealing system.
is This object is achieved by a sealing system characterized in that the
sealing
profile is injection molded onto the first adhesive layer of the adhesive
strip in a
molding tool, said adhesive strip having been placed in the molding tool. The
sealing profile, being injection molded onto the first adhesive layer in the
molding tool, is permanently and consistently well connected to the adhesive
2o strip. The adhesive strip can also extend in each direction beyond the
sealing
profile. In this manner even difficult installation and sealing situations can
be
overcome. As a result of molding the seating profile in the molding tool the
sealing profile becomes a molded part of the highest dimensional accuracy and
dimensional stability, whereby three-dimensional formations can also be
2s produced from the outset without the subsequent need to deform the sealing
profile during installation and thereby place it under undesirable stresses.
The first adhesive layer consists of a hot-melt adhesive which is heated and
activated in the molding tool before the sealing profile is injection molded
onto
the layer activated in this manner.
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The first adhesive layer is covered by a second liner and the second liner is
removed from the first adhesive layer wherever the sealing profile is
injection
molded to the first adhesive layer so that a fixed and permanent connection of
the sealing profile to the adhesive strip is also produced.
The first adhesive layer consists of a pure acrylate adhesive or of a modified
acryiate adhesive which are especially suited to use in motor vehicle sealing
systems.
In between the first and the second adhesive layer is disposed a supporting
layer, said supporting layer being adhered to the fiwo adhesive layers and
which
io provides the adhesive strip with all desirable characteristics with regard
to the
application of the sealing system.
The supporting layer may be a foamed layer made of, for example, acrylates,
polyethylene or polyurethane if, for example, certain elastic; sealing
characteristics are to be achieved in the regions of the sealing system beyond
is the seating profile by means of the adhesive strip alone.
The supporting layer can be a supporting film which consists of, for example,
polyethylene, polypropylene, polyester, polyvinyl chloride or polyamide or of
a
laminated multi-layer film comprising a combination of these materials so that
the formation of the supporting layer can, for example, be especially thin
with
2o nevertheless suftacient strength.
The sealing profile can be an injection molded part made of a thermoplastic
elastomer or of a soft polyvinyl chloride so that the manufacturing
temperatures
in the molding tool can be comparatively low. This protects the adhesive
strip,
which has been placed in the molding tool, and nevertheless leads to the
2s desired secure connection of the sealing profile to the adhesive strip.
The sealing profile comprises an elastic sealing strip and a stiffening strip
made
of synthetic material, that at least one of these strips is injection molded
onto
the first adhesive layer of the adhesive strip which has been placed in the
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molding tool, and that the one strip is injection molded onto the other strip,
which other strip has been previously injection molded onto the first adhesive
layer and is located in the molding tool and, occasionally, is additionally
injection molded onto the first adhesive layer. In this way, the sealing
profile is
s constructed in the form of a combination or composite profile. In this
structure
the sealing strip undertakes the sealing function with respect to the
component
to be sealed, while the stiffening strip serves so to speak as reinforcement
of
the sealing strip for an optimum sealing effect of the sealing strip.
io Advantageously, the sealing strip consists of a thermoplastic elastomer or
of
soft polyvinyl chloride.
The materials for the stiffening strip are selected according to any one of
polyethylene, polypropylene, polyester, polyvinyl chloride, polyamide,
is polyphenylene ether or modified polyphenylene ether with regard
to the practical application. All these materials produce the
desired stiffening or reinforcement of the sealing strip and support
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and improve its sealing effect.
These and further features and advantages of the invention are explained
below with reference to the exemplified embodiments illustrated in the
s drawings. The drawings show:
Fig. 1 a schematic longitudinal section through a first embodiment of
the sealing system,
to Fig. 2 a schematic longitudinal section through a further embodiment of the
sealing system,
Fig. 3 a schematic longitudinal section through yet another different
embodiment of the sealing system, and
is
Figs. 4 to 6
in each case a schematic longitudinal section through further
embodiments of the sealing system, each with a sealing profile
comprising one sealing strip and a stiffening strip.
Fig. 1 shows a sealing system 1 with a sealing profile 2, which sealing
profile 2
has been injection molded onto a first adhesive layer 3 of an adhesive strip 4
in
a molding tool [not illustrated], said adhesive strip 4 being adhesive on both
sides.
2s
The first adhesive layer 3 is applied to a supporting layer 5, said supporting
layer 5 consisting in this case of an acrylate foam. Onto the opposite side of
the
supporting layer 5 is applied a second adhesive layer 6 which is covered with
a
peelable first liner 7.
For the purpose of producing the sealing system 1, the complete adhesive strip
4 including its liner 7 is placed into the molding tool. The first adhesive
layer 3,
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which consists of hot-melt adhesive, is thereupon heated by means of the
injection of sufficiently warm sealing profile mass until it is active. During
the subsequent cooling process, the hot-melt adhesive solidifies again and
produces the desired fixed bond between the first adhesive layer 3 and the
s sealing profile 2.
The sealing profile 2 can consist of, for example, a thermoplastic elastomer
or
of soft polyvinyl chloride.
As illustrated in Fig. 1, the sealing profile 2 need not be injection molded
onto
io the entire surface of the first adhesive layer 3. On the contrary, the
sealing
profile 2 can be injection molded only locally onto the first adhesive layer
3.
During cooling of the sealing system the hot-melt adhesive of the first
adhesive
sheet 3, which hot-melt adhesive is only activated in the region of the
injection
molding, then returns again to its passive state thus achieving the adhesive
is connection.
For the purpose of installing of the sealing system 1, as indicated in the top
right of Fig. 1, the first liner 7 is removed and the sealing system 1 is
adhered
with its second adhesive layer 6 onto a substrate 8 to be sealed, for example
a
2o vehicle bodywork sheet.
In all drawing figures, identical parts are provided with identical reference
numbers.
2s In Fig. 2 the first adhesive layer 3, which consists of hot-melt adhesive,
is
applied to the supporting layer 5 which is formed here as a supporting film.
This
supporting film can be formed relatively thinly while being sufficiently
strong. It
can, for example, consist of polyethylene, polypropylene, polyester, polyvinyl
chloride or polyamide or also of a laminated multi-layer film comprising
3o combinations of these materials.
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Towards the top, the layers 6 and 7 in Fig. 3 are for their part attached to
the
supporting layer 5 in accordance with Fig. 1.
There is also used in Fig. 3 a supporting layer 5, which is formed as this
type of
s supporting film. In this case, however, there is applied to the underside of
the
supporting layer 5 a continuously adhering first adhesive layer 3, said
adhesive
layer 3 being covered by a second liner 9. The second liner 9 is removed from
the first adhesive layer 3 wherever the sealing profile 2 is to be injection
molded
onto the first adhesive layer 3. In this manner the finished sealing system 1
in
1o accordance with Fig. 3 supports, where appropriate in a localized manner,
one
or more sealing profiles 2, while the first adhesive layer 3 also remains
covered
by portions of the second liner 9.
In the exemplified embodiments in accordance with Figs. 4 to 6 the adhesive
is strip 4 is formed at any one time in a suitable way corresponding to one of
Figs.
1 to 3 and said adhesive strip 4 is only schematically indicated in Figs. 4 to
6.
Each of Figs. 4 to 6 shows the first adhesive layer 3, onto each of which is
injection molded the sealing profile 2 in a molding tool which is also not
shown
here.
2o
In Fig. 4, sealing profile 2 comprises a stiffening strip 10 consisting of a
comparatively hard synthetic material. The stiffening strip 10 is injection
molded
in a first operation onto the first adhesive layer 3 in the molding tool. A
sealing
strip 12 consisting of a comparatively soft sealing material is subsequently
2s injection molded onto a free surface 11 of the stiffening strip 10. Along
the free
surface 11 in this last formation a fixed and permanent connection is produced
between the stiffening strip 10 and the sealing strip 12. The strength of this
connection can, according to requirements, be supported by means of a
coupling layer known per se between the stiffening strip 10 and the sealing
strip
30 12.
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The process in accordance with Fig. 5 was performed in the reverse sequence
to that in Fig. 4. Firstly therefore the sealing strip 12 was injection molded
onto
the first adhesive layer 3 in the molding tool. In a following operating step
the
stiffening strip 10 was injection molded onto a free surface 13 of the sealing
s strip 12 in the molding tool.
In the exemplified embodiment according to Fig. 6, in a similar manner to Fig.
4,
the stiffening strip 10 was firstly injection molded onto the first adhesive
layer 3.
In a following operating step the sealing strip 12 was then injection molded
both
1o onto a free surface 14 of the stiffening strip 10 and also onto base
surfaces 15
and 16 on the first adhesive layer 3 in the molding tool. In this manner the
sealing profile retains a universal elasticity beyond the first adhesive layer
3,
while within the sealing strip 12 the stiffening strip 10 provides the desired
stiffening of the entire sealing profile 2.
