JPS6117943B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoforming device for thermoforming a fiber aggregate mixed with heat-fusible fibers into a nonwoven fabric.

Conventionally, in this type of thermoforming apparatus, as shown in FIGS. 1A and 1B, which are cross-sectional views of the main parts, a plurality of stavers 3, 3, etc. are appropriately installed between endless chains 2, 2 stretched on both left and right sides. A conveying device 5 is constructed by horizontally hanging the stavers 3, 3, etc. on the stavers 3, 3, etc., and attaching an endless conveying belt 4 made of a wire mesh or the like to the conveying belt 4. While transporting the fiber aggregate 1, hot air (for example, 120 to 150°C) is passed from the slit nozzles 6a, 6a, . . . of the hot air supply chamber 6 to the hot air suction chamber 7.
The material is heated and molded. However, the conventional thermoforming apparatus had a low production capacity because it required a processing speed of 30 m/min or less. because,
Forced lubrication is required to run the endless chains 2, 2 at a speed of 30 m/min in a high temperature atmosphere. This is because it is not possible to run the endless chains 2, 2 at more than 30 m/min, as there is no suitable solution to avoid contamination.

Therefore, although not shown in the drawings, it is conceivable to use a conveyance device in which an endless conveyance belt made of synthetic resin filament fabric is stretched between reversing rolls without using auxiliary means such as chains. However, in order to stably run the endless conveyance belt at a high speed of 30 m/min or more, it is necessary to use a meandering adjustment device that swings a reversing roll or the like. However, running an endless conveyor belt in a high temperature atmosphere while adjusting the meandering with such a meandering adjustment device causes large elongation strain on both sides of the endless conveyor belt in a short period of time, making it difficult to adjust the meandering. This becomes difficult and it is impossible to obtain a smooth conveying surface suitable for conveying the fiber aggregate, so that it cannot be used for a long period of time and is unsuitable as a thermoforming apparatus.

The present invention has achieved a 120m/
The object of the present invention is to provide a thermoforming device for producing nonwoven fabrics that can achieve a processing speed of min.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a thermoforming apparatus for producing a nonwoven fabric according to the present invention (hereinafter referred to as the apparatus of the present invention) will be described based on embodiments shown in the drawings. FIG. 2 is a partial sectional view on the right side with the middle omitted, showing an embodiment of the apparatus of the present invention, and numeral 11 in the figure is a conveying device. The conveying device 11 includes a reversing roll 12 on the entrance side and a driving reversing drum 1 on the exit side.
An endless conveyor belt 14 is stretched between the rollers 3 and 3, and guide rolls 16, 16...
is installed. The conveyor belt 14 is made of a synthetic resin filament fabric connected in an endless manner, for example, the filament material is polyester, the vertical filament diameter and the horizontal filament diameter are
Planet (trade name) manufactured by Nippon Filcon Co., Ltd., which has a diameter of 0.4 mm and a weight of 0.45 Kg/m ² , is used. The reversing roll 12 is provided with take-ups 15 and 15 equipped with compression coil springs so as to apply an appropriate tension (for example, 30 to 40 kg/m) to the conveying belt 14.
It is pivoted on. The driving reversing drum 13 is
The cylindrical part 13a has air permeability, and the opening 13c of the side plate 13b and the suction port of a cooling fan (not shown) are brought close to each other, and the air on the outer periphery of the cylindrical part 13a is sucked into the drum to form a heat-formed product. It is configured to cool the nonwoven fabric 1'. Further, inside the drive reversing drum 13, there is a seal plate 13d for improving the sealing performance of the area A where the non-woven fabric 1' is not covered, and a passing wind velocity distribution of the cooling air in the area C where the non-woven fabric 1' is covered. A perforated rectifying plate 13f for making the flow uniform across the width is pivotally supported on the drum shaft 13e. As shown in FIGS. 3 and 4, the conveyance belt 14 has a guided protrusion 17 on one longitudinal edge of the non-conveyance side.
a, 17a... are appropriately pitched along the longitudinal direction.
(for example, P=30 to 50 mm).
The guided protrusion 17a is formed by sewing a reinforcing cloth 18 onto the edge of the conveying belt 14, and then attaching a hook 17 with a protrusion to the reinforcing cloth 18. A guide wall b for preventing meandering is formed at a suitable position in the endless passage B through which the guided projection 17a passes. The meandering prevention guide wall b is preferably formed at the reversing roll 12, the driving reversing drum 13, the guide rolls 16, 16, . . . and the entrance/exit portion of the heating device 20. is an annular groove 1 for the reversing roll 12, driving reversing drum 13, and guide rolls 16, 16...
2a and 16a (the grooves of the drive reversing drum 13 are omitted from the illustration) are respectively recessed, and the heating device 20
At the entrance/exit portion of the guide block 19, a groove 19a of a guide block 19 having an appropriate length is formed to match the endless passage B. In the figure, reference numeral 31 denotes a back-up roller, which is the guided projection 17a.
This is to prevent the groove from jumping out of the groove 19a.

As shown in FIG. 2, a heating chamber 21, 21, . A device 20 is provided. Each heating chamber 21 has, as shown in FIG.
The hot air suction chamber 2 is vertically divided into a hot air supply chamber 22 formed above the conveying surface of the conveying belt 14 and a hot air suction chamber 23 formed on the non-conveying surface of the conveying belt 14.
The discharge port 23a opened at 3 is connected to the suction port 24a of the circulation fan 24 via a damper 25, and the pressure chamber 24b of the circulation fan 24 and the supply port 22e of the hot air supply chamber 22 are connected via a heat exchanger 26. The conveyor belt 14 is connected so that hot air at a predetermined temperature passes through the conveyor belt 14 from above to below. The hot air supply chamber 22 has a hot air discharge area 22b covering almost the entire surface facing the conveyance surface of the conveyance belt 14, and has a hot air inlet area 22c above the hot air discharge area 22b.
There are two rectifying partition walls 27 between the rectifying gap 22 and
d (for example, H ₁ =50 to 150 mm). The rectifying partition wall 27 has a perforated plate 27a having a perforated area approximately the same as the hot air discharge area 22b, which is arranged approximately parallel to the conveyance belt 14, and has air permeability so as to cover the entire perforated area. The fiber assembly layer 27b is placed on a perforated plate 27a. The fiber assembly layer 27b is made of one or more layers of nonwoven fabric made of heat-resistant fibers such as polyester fibers. The fiber assembly layer 27b
The thickness and passing resistance are appropriately selected depending on the thickness of the fiber aggregate 1 and the hot air speed. For example, when the thickness of one sheet is 15 mm, the passing air speed is 0.5 to 1.7 m/
Three layers of nonwoven fabric having an air flow resistance of 0.6 to 2.00 mm water column when expressed as sec are used in the upper layer, and one layer is used in the lower layer. Seal plates 22f, 22 forming both sides of the hot air discharge area 22b
f has its lower end hanging down to a position approaching the conveyance belt 14, and is configured to prevent cold air from outside of the hot air supply chamber 22 from leaking into the hot air suction chamber 23 via the conveyance belt 14. . In the hot air suction chamber 23, a hot air suction area 23b is formed at a position opposite to the hot air discharge area 22b via the conveyance belt 14, and between the hot air suction area 23b and a lower hot air discharge area 23c. A rectifying partition wall 28 is disposed with a rectifying gap 23d (for example, H ₂ =50 to 150 mm) between the conveyor belt 14 and the conveyor belt 14 . The rectifying partition wall 28 has a hot air suction area 23b.
A perforated plate 28a having a porous area of approximately the same area as the perforated plate 28a.
are arranged approximately parallel to the conveyance belt 14, and a fiber assembly layer 2 having air permeability covers the entire porous area.
8b is placed on a perforated plate 28a. The fiber aggregate layer 28b is similar to the fiber aggregate layer 27.
Similarly to b, it is made of one or more layers of nonwoven fabric made of heat-resistant fibers such as polyester fibers. a frame 23e on both sides with sealing properties forming a hot air suction area 23b of the hot air suction chamber 23;
Longitudinal guide rails 29, 29 for guiding the conveyance belt 14 are arranged above the conveyance belt 14, and a sixth
As shown in the figure, guide rails 30 having a V-shaped plane are arranged at appropriate pitches on the connecting frames 23f, which are provided at appropriate pitches (for example, 1000 mm pitches) so as to cross the hot air suction area 23b. . Note that when the conveyance belt 14 is stretched over a short distance, the guide rail 29 is not required, and when the width of the conveyance belt 14 is short, the guide rail 30 is not required. On the operation side of the hot air suction chamber 23,
An inspection door 23g is provided for replacing or inspecting the fiber assembly layer 28b. The heating chamber 21
An inspection door 21a (see FIG. 2) is provided on the operation side of the controller. 31 in Fig. 2 is the heating chamber 21
This is an interference chamber for preventing the inconvenience of the nonwoven fabric 1' flying up from the conveyor belt 14 due to the hot air leaking from the outlet of the chamber. is connected to the hot air suction chamber 23 by piping.

Next, the effects of the device of the present invention will be explained. As the driving reversing drum 13 is driven, the conveying belt 14 is moved.
The guided protrusions 17a, 17a... run stably without meandering while being guided by the meandering prevention guide wall b. The circulating air generated by the rotation of the circulation fan 24 is heated to a predetermined temperature (for example, 120 to 150° C.) while passing through the heat exchanger 26 and is then sent to the hot air supply chamber 22.
The hot air is supplied to the hot air inflow region 22c. The hot air supplied to the hot air inlet chamber 22c is rectified while passing through the upper rectifying partition wall 27, the rectifying gap 22b, and the lower rectifying partition wall 27, and is then rectified into the hot air discharge area 2.
2b to uniform wind speed distribution (e.g. 0.5 to 1.7 m/
Fiber aggregate 1 on the conveyor belt 14 as hot air of
is discharged to. The discharged hot air passes through the fiber aggregate 1 and the conveying belt 14 and is sucked into the hot air suction area 23b of the hot air suction chamber 23 in a uniform air velocity distribution state. Even if the negative pressure distribution in the hot air discharge area 23c is uneven, the hot air suction area 23
This is because the suction negative pressure distribution of b becomes uniform.

The inventor conducted an experiment under the following conditions and obtained the following results.

[Experimental conditions]

(1) Fiber aggregate Blend ratio Heat-adhesive fibers made of polypropylene, etc.…50% Heat-resistant fibers made of polyester, etc.…50% Fabric weight…20g/m ^2- layer structure…2 layers cross-overlapping Width dimension…2400mm (2) Heating chamber Composition: 3 rooms with each room length 2400mm (3) Hot air speed and temperature 1st room...135℃ at 1.5m/sec 2nd room...135℃ at 1.5m/sec 3rd room...1.5m/sec (4) Cooling conditions Driving reversing drum diameter...1000mmφ Cold air passing speed...2.0m/sec (5) Processing speed 60~120m/min [Experimental results] The obtained nonwoven fabric was heated and melted uniformly throughout. There was no striped pattern that occurs during non-uniform heating.

As detailed above, the apparatus of the present invention has the following excellent effects.

Guided protrusions are protruded at appropriate pitches from the longitudinal edge of the non-conveying surface of the conveying body, and the guided protrusions travel while being guided by a guide wall for preventing meandering, so that the conveyance belt can move from low speeds without meandering. Stable running can be maintained up to high speeds, and production capacity can be improved.

Since the conveying body is composed of a synthetic resin filament woven fabric, the thermal conductivity of the conveying belt and the fiber aggregate are almost the same, and a nonwoven fabric with almost the same texture on the front and back surfaces can be obtained. I can do it.

A plurality of rectifying partition walls are arranged with a rectifying gap in the hot air supply chamber, and at least one rectifying partition wall is arranged with a rectifying gap in the hot air suction chamber. The velocity distribution of the hot air passing through the assembly becomes uniform over the whole, and a nonwoven fabric with stable quality and no uneven heat fusion can be obtained.

In the conventional slit nozzle method, when the hot air blown onto the fiber aggregate diffuses, local negative pressure is generated on the fiber aggregate, causing the fiber aggregate to be locally lifted from the conveying belt. The disadvantage was that the nonwoven fabric was distorted. However, in the present invention, the hot air passing through the fiber aggregate passes through the entire fiber aggregate from the non-conveyance side to the conveyance side at a uniform speed, so that the fiber aggregate is locally separated from the conveyance zone. It is possible to obtain a nonwoven fabric with stable quality and no local distortion.

[Brief explanation of the drawing]

FIG. 1A is a front sectional view of the main part of a conventional thermoforming apparatus, FIG. 1B is a right sectional view of the main part of the same as above, and FIGS. For example, Fig. 2 is a right side view in cross section with the middle omitted, Fig. 3 is an enlarged perspective view of the inlet of the conveyance device, Fig. 4 is an enlarged view cut along the - line of the same as above, and Fig. 5 is the same as Fig. 2. 6 is an enlarged cross-sectional perspective view showing the arrangement of the rectifying partition wall. 14... Conveyance belt, 17a... Guided protrusion, B...
... Endless passage, b... Guide wall for meandering prevention, 22... Hot air supply chamber, 22b... Hot air discharge area, 22c... Hot air inflow area, 22d... Rectification gap, 23... Hot air suction chamber, 23b ... Hot air suction area, 23c hot air discharge area, 27, 28... Partition wall for rectification.

Claims (1)

[Claims] 1. While conveying a fiber aggregate mixed with heat-fusible fibers in an endless conveyor belt having air permeability, hot air is passed from the surface of the fiber aggregate to the non-conveying side of the conveyor belt. In the thermoforming device for heating and molding the fiber aggregate to form a nonwoven fabric, the conveyance belt is made of a synthetic resin filament woven fabric, and guided protrusions are arranged at appropriate pitches on the longitudinal edge of the non-conveyance side. 1. A thermoforming apparatus for producing a nonwoven fabric, characterized in that a guide wall for preventing meandering is provided at a suitable position in an endless passageway through which the guided protrusion passes. 2. While conveying the fiber aggregate mixed with heat-fusible fibers in an endless conveyor belt having air permeability, hot air is passed from the surface of the fiber aggregate to the non-conveying side of the conveyor belt, and the fiber aggregate is In a thermoforming device for thermoforming a nonwoven fabric into a nonwoven fabric, the conveyance belt is made of a woven synthetic resin filament, and guided protrusions are provided at appropriate pitches on the longitudinal side edge of the non-conveyance surface. A guide wall for preventing meandering is provided at a suitable position in the endless passage through which the guided protrusion passes, and a hot air supply chamber is provided outside the conveying surface of the conveying belt, and the hot air supply chamber is formed on substantially the entire surface facing the conveying surface as a hot air discharge area. A plurality of rectifying partition walls are provided between the hot air inflow area and the hot air discharge area formed in the hot air supply chamber and are made of a fiber aggregate layer having air permeability and have substantially the same planar shape as the hot air discharge area. The hot air is arranged with a rectification gap between the opposing partition walls for rectification, and a hot air suction area is formed on the outside of the non-conveyance surface of the conveyance zone at a position opposite to the hot air discharge area via the conveyance zone. A suction chamber is provided, and between a hot air discharge area formed in the hot air suction chamber and a hot air suction area, there is provided a rectifying partition wall made of a fiber aggregate layer having air permeability and having a substantially same planar shape as the hot air suction area. at least 1
1. A thermoforming apparatus for producing a nonwoven fabric, characterized in that a plurality of sheets are arranged with a rectifying gap between them and the conveyance belt.