Information
-
Patent Grant
-
6524434
-
Patent Number
6,524,434
-
Date Filed
Monday, September 25, 200023 years ago
-
Date Issued
Tuesday, February 25, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 493 193
- 493 190
- 493 267
- 053 451
- 156 218
- 156 292
- 156 3084
- 156 3801
- 156 5831
- 156 544
-
International Classifications
-
Abstract
A tube-forming apparatus in a bag-forming, filling, and sealing machine has a longitudinal seam heat-sealing device for connecting edge regions of the packing material belt that are placed against each other inside surface to inside surface. In order to achieve a sufficient sealing temperature in a short time, a heating body that is embodied in a lamella-like fashion protrudes like a tongue between the edge regions. In order to aid the heating body, similar heating bodies rest against the outside of the edge regions. The heating bodies have a U-shaped electric resistance wire with elongated legs which is embedded in a longitudinally folded casing made of a thin, temperature-proof woven cloth.
Description
PRIOR ART
The invention is based on a tube-forming apparatus in a bag-forming, filling, and sealing machine. In known tube-forming apparatuses of this type, the superposed edge regions of the packing material band are heated by heating belts, jaws, or rollers resting against their outsides, wherein the heat transmitted penetrates through the outer layer into the inner layer. By virtue of the fact that in order to transmit heat into the inner layer, the outer layer must also be heated, a high heating capacity is required on the one hand and a long heating time is required on the other. This is particularly disadvantageous in relatively thick, multi-layer packing materials. For this case, endless heating belts must have a reasonably large contact section, which is accompanied by the disadvantage that the returning part of the belt cools and therefore experiences heat stresses or must also be unnecessarily heated. Heating rollers are not considered since the necessary heat quantity cannot be transmitted in the narrow contact area.
ADVANTAGES OF THE INVENTION
The tube-forming apparatus according to the invention has the advantage that with direct transmission of the heat to the inside of the edge regions of the packing material band to be sealed, the heating capacity of the heating body is low and therefore the contact area is relatively small. If the outside of the edge regions of the packing material belt is also heated, this produces a particularly short structural length of the longitudinal seam sealing device.
BRIEF DESCRIPTION OF THE DRAWING
An exemplary embodiment of the invention is shown in the drawing and will be described in detail below.
FIG. 1
is a simplified front view of a tube-forming apparatus in a bag-forming, filling, and sealing machine,
FIG. 2
is a cross section through a heat-sealing device of the tube-forming apparatus according to
FIG. 1
, and
FIG. 3
is a side view of a heating body of the heat-sealing device.
DESCRIPTION OF THE EXEMPLARY EMBODIMENT
A bag-forming, filling, and sealing machine has a forming device
10
in which an incoming flat packing material belt
1
is formed into a tube
2
and its two edge regions
3
,
4
protruding from the tube
2
are guided against each other inside to inside and are heat sealed to each other.
A forming tube
11
and a forming shoulder
12
that encompasses the forming tube with an annular gap are used to form the tube
2
; the flat packing material belt
1
slides over the forming tube and forming shoulder and when it enters the annular gap around the forming tube
11
, it is formed into the tube
2
.
The two edge regions
3
,
4
, which are placed against each other and belong to a packing material belt
1
, having a heat-sealable inner layer, when passing through a longitudinal seam heat-sealing device
15
associated with the forming tube
11
, are heated to the melting temperature of the inner layer and are then pressed together by a pair of press rollers
16
so that the two inner layers of the edge regions
3
,
4
melt together in the heated region or at least undergo a firm adhesion.
The longitudinal seam sealing device
15
has a heating body
20
in the form of a thin lamella, which protrudes like a tongue between the two edge regions
3
,
4
of the packing material belt
1
that are guided against each other. The heating body
20
has an electric resistance wire
18
bent into a U-shape, with two closely adjacent elongated legs
22
,
23
. The two legs
22
,
23
are embedded in a casing
24
, which is comprised of a longitudinally folded strip
25
made of a thin woven cloth of a heat-resistant, low friction material such as Teflon fiberglass. In the folded strip
25
, the two legs
22
,
23
of the resistance wire
21
are disposed close to the fold
26
, which extends close to and parallel to the forming tube
11
when the heating body
20
is completely installed. The superposed layers of the casing
24
, which are glued to each other by means of a temperature-proof adhesive, are mounted between two support strips
27
,
28
which are held together by means of nuts
30
and bolts
29
which are also used to mount the longitudinal seam sealing device
15
. The two ends of the resistance wire
21
protruding from the casing
24
are connected by means of connecting clamps
31
,
32
to conductors
33
,
34
that lead to a power source. Preferably, the power source, not shown, is a transformer with a voltage of 4 to 12 volts and a current intensity of 6 to 12 amps. During operation of the device, the electrical output is adjusted and regulated so that the inside of the two edge regions
3
,
4
of the continuously advanced tube
2
or of the packing material belt
1
touch the outside of the lamella-like heating body
20
, are heated to melting temperature before they leave the heating body
20
, are pressed together by the pressing rollers
16
, and are cooled so that a definite melting or adhesion of the longitudinal seam is produced.
In order to accelerate the heating of the edge regions
3
,
4
of the packing material belt
1
, which is necessary for a high yield of the bag-forming, filling, and sealing machine, in the embodiment according to
FIG. 2
, two similar heating bodies
36
,
37
are also disposed, which touch the outside of the edge regions
3
,
4
of the packing material belt
1
. These two heating bodies
36
,
37
are disposed on both sides of the first heating body
20
and are attached along with it in the support strips
27
,
28
. Their wall regions covering the resistance wire
21
close to the fold
26
rest against an elastic insert
38
,
39
in the support strips
27
,
28
. Like the main heating body
20
, the additional heating bodies
36
,
37
are connected to a power source that can be regulated. They heat the edge regions
3
,
4
of the packing material belt
1
with an output that is adjusted so that a temperature is achieved in the outer layer of the edge regions
3
,
4
of the packing material belt so that a rapid heating of the inner layer is encouraged.
Preferably, the heating bodies
20
;
36
,
37
are mounted in the support strips
27
,
28
so that the arc-shaped bottom of the resistance wire
21
of the two heating bodies
36
,
37
contacting the outside rests against the inlet end and the arc-shaped bottom of the resistance wire
21
of the inner heating body
20
rests against the outlet of the longitudinal seam sealing device
15
. The arc-shaped bottom
41
of the resistance wire
21
of the inner heating body
20
can also be uncovered by the casing
24
, as indicated with dot-and-dash lines in FIG.
3
.
The foregoing relates to a preferred exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.
Claims
- 1. A tube-forming apparatus in a bag-forming, fifting, and sealing machine, comprising a device in which a packing material belt (1) with a heat-sealing layer on an inside is formed into a tube (2), wherein edge regions (3, 4) of the packing material belt (1) are placed inside to inside, having a longitudinal seam heat-sealing device (15) with a heating body (20) that has an electrical resistance wire (21) and heats the edge regions (3, 4) of the continuously advanced packing material belt (1), and a pressing device (16), said pressing device presses the heated edge regions (3, 4) together and cools them, the resistance wire (21) of the heating body (20) is disposed in a U shape with closely adjoining legs (22, 23) between two thin, heat-resistance strips (24) that have a low coefficient of friction, and that the heating body (20) is associated with the tube-forming apparatus (10) in such a way that the edge regions (3, 4) of the packing material band (1) to be sealed against one another rest in a sliding fashion with their insides against the heating body (20) that protrudes between them during the advancing motion of the packing material belt (1).
- 2. The tube-forming apparatus according to claim 1, in which a heating body (36, 37) having an electrical resistance wire (21) is disposed on each of the two sides of the heating body (20) and that these heating bodies (36, 37) each touch an outside surface of an edge region (3, 4) of the packing material belt (1).
- 3. The tube-forming apparatus according to claim 1, in which the resistance wire (21) of the heating body (20) is embedded in a longitudinally folded arc made of a thin, temperature-proof woven cloth.
- 4. The tube-forming apparatus according to claim 2, in which the resistance wire (21) of each of the heating bodies (20; 36, 37) is embedded in a longitudinally folded arc made of a thin, temperature-proof woven cloth.
- 5. A tube-forming apparatus according to claim 1, in which the heating body (20) is attached between two support strips (27, 28).
- 6. A tube-forming apparatus according to claim 2, in which the heating bodies (20; 36, 37) are attached between two support strips (27, 28).
- 7. A tube-forming apparatus according to claim 3, in which the heating body (20) is attached between two support strips (27, 28).
- 8. A tube-forming apparatus according to claim 4, in which the heating bodies (20; 36, 37) are attached between two support strips (27, 28).
Priority Claims (1)
Number |
Date |
Country |
Kind |
197 43 158 |
Sep 1997 |
DE |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/DE98/02439 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO99/16609 |
4/8/1999 |
WO |
A |
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
2563278 |
Rummel et al. |
Aug 1951 |
A |
2953976 |
Hahn |
Sep 1960 |
A |
3303629 |
Tobin |
Feb 1967 |
A |
5794406 |
Reichental et al. |
Aug 1998 |
A |
Foreign Referenced Citations (8)
Number |
Date |
Country |
12 15 351 |
Apr 1964 |
DE |
1 914 960 |
Oct 1969 |
DE |
76 04 204 |
Feb 1976 |
DE |
1 265 312 |
Oct 1961 |
FR |
2.092.298 |
Jan 1971 |
FR |
2 356 493 |
Jan 1978 |
FR |
754936 |
Aug 1956 |
GB |
882740 |
Nov 1961 |
GB |