Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1083Z01
The present invention relates to an auto ceiling panel
with an improved sound-absorbing effect and its manufacturing
method.
The conventional auto ceiling panel is a four-layer
structure of a metal lath with a vinyl chloride sheet-attached
polyethylene foam and another polyethylene foam pasted on both
sides thereof, but the polyethylene foam has isolated air bubbles
and accordingly with poor permeability, its effect of absorbing
the sound is dubious.
The present invention provides an auto ceiling panel
with an improved sound-absorbing effect comprising a polyethylene
foam on the auto interior side which has been bored with numerous
small holes; a polyethylene foam on the ceiling side to be pasted
to said polyethylene foam which has been bored with numerous large
holes; and a metal lath sandwiched between said auto interior
side polyethylene foam and said ceiling side polyethylene foam.
The auto ceiling panel of this invention does not spoil
the auto interior look.
In another aspect, the invention provides a method for
making an auto ceiling panel which comprises a step of boring
numerous small holes in a polyethylene foam and boring numerous
large holes in another polyethylene foam; a step of giving an
embossed pattern to only the small-holed polyethylene foam before
or after its boring; a step of thermally fusing together said
embossed, small-holed polyethylene foam and said large-holed
polyethylene foam with a metal lath sandwiched between them;
and a step of molding a laminated product thus obtained to a
specific profile of auto ceiling in a cold press-molding machine.
Figure 1 is a sectional view of an auto ceiling panel
according to the present invention.
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Figure 2 ls ~n oblique view of thc auto ceiling panel
in Fig. 1.
Figure 3 is a front elevation view of a punching machine
to be used for manufacturing the auto ceiling panel in Fig. 1.
Figure 4 is a front elevation view of an embossing
machine to be used for manufacturing the auto ceiling panel in
Fig. 1.
Figure 5 is a front elevation view of a laminating
machine to be used for manufacturing the auto ceiling panel in
Fig. 1.
Figure 6 is a front elevation view of a molding machine
to be used for manufacturing the auto ceiling panel in Fig. 1.
In the auto ceiling panel according to the present
invention a polyethylene foam with small holes is fused to
another polyethylene foam with large holes, with a metal lath
sandwiched between them; therefore with through-holes secured at
least in the large-hole part, the sound-absorbing effect can be
improved.
One embodiment of the present invention is to be
described referring to the drawings.
In Figs. 1 and 2, the polyethylene foams 2, 3 are
laminated with an interlayer of the metal lath 1. The specific
gravities of them are 0.02 - 0.1 and they are respectively bored
with numerous holes. The hole 4 in the polyethylene foam 2
which constitutes the auto interior is a small one with its dia-
meter 0.1 - 2.0 mm, while the hole 5 of the polyethylene foam 3
which constitutes the lining of the auto ceiling is a large one
with its diameter 2.0 - 5.0 mm.
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Thus in this panel which represents a pasted combination
of the polyethylene foam 3 with large holes S and the polyethyl-
ene foam 2 with small holes 4, the holes are more likely to
become through-ones than in the case of small-holed polyethylene
foams being pasted together; at least it is certain that the holes
become invariably through-ones where a small hole 4 overlaps a
large hole 5.
ext the manufacturing method of such an auto ceiling
panel is to be described.
At first, as indicated in Fig. 3, the polyethylene foams
2 and 3 are prepared respectively by boring small holes 4 of 0.1 -
- 2 mm diameter in a polyethylene sheet of 0.02 - 0.1 specific
gravity and boring large holes 5 of 2.0 - 5.0 mm diameter in
another polyethylene sheet, by means of a punching machine 6.
Boring is done before pasting together the foams.
Therefore the metal lath 1 to be sandwiched does not obstruct
the work.
Next, as indicated in Fig. 4, the polyethylene foam 2
with small holes 4 having a diameter 0.1 - 2.0 mm is heated by
.,
a heater 7 and then sent to an embossing roll 8, where it is
` given an embossed pattern 9.
The polyethylene foam 3 is not submitted to such an em-
bossing. Embossed pattern given by the embossing roll 8 looks
aesthetic. When the look is spoiled by small holes 4, it may
be improved by application of a permeable leather.
Next, as indicated in Fig. 5, the polyethylene foam 2
which has been embossed and made permeable by boring and the
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' polyethylene foam 3 with large holes 5 are respectively heated
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by a heater 10; and after sandwiching a metal lath 1 therewith,
they are fused together by a roll. Thus a ceiling panel mater-
ial with through holes as illustrated in Fig. 1 is yielded.
The panel material with this structure, characterized by rigidity
and soundproofness, makes a highly acoustical ceiling panel.
Next, the panel material is cut to a specified size and
then is press-molded to a specific profile by a cold press-
molding machine shown in Fig. 6. The press-molding machine is
equipped with a movable top-mold 13 which is capable of going
up and down against a stationary bottom mold 12, a male member
14 for wrinkle prevention and a female member 15. The panel
material is laid with its side to be embossed up. The top mold
13 together with the anti-wrinkle male member 14 is lowered to
squeeze the fringe of the panel material between the male and
female members 14, 15. Thus the panel material is molded to a
specific profile by the top 13 and the bottom mold 12 with a
wrinkle formation prevented.
; In this ceiling panel at least where the small hole 4
and the large hole 5 overlap each other, perfectly through holes
are constituted giving high permeability to the panel, and
- ; accordingly a high acoustical effect of it.
The following benefits accrue from the auto ceiling -~
panel and its manufacturing method according to the present
invention:
ii (a~ Since the panel is such a structure that a polyethylene
`~ foam with small holes on the auto interior side is pasted to
l another polyethylene foam with large holes on the ceiling lining
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108320~
side, the sound-absorbing effect is remarkably better than in
the conventional panel.
(b) The small holes are so fine as not to spoil the interior
appearance and so many as to give a sufficiently good effect
of absorbing the sound; besides an embossed pattern is given to
the surface; and accordingly an aesthetic effect is also assured.
(c) Sandwiching of metal lath facilitates thermal usion of
polyethylene foams with small holes and with large holes.
(d) Since the interlayer between polyethylene foams is only a
metal lath, through holes are little obstructed and a ceiling
panel with as many through holes as to assure the acoustical
effect can be manufactured.
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