JP3679816B2 - Belt cast film forming apparatus and belt for belt cast film forming apparatus - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a belt cast film forming apparatus and a belt for a belt cast film forming apparatus that can be used in a melt film forming method for thermoplastic resins such as polypropylene and polyester.
[0002]
[Prior art]
A conventional method for forming a molten resin film is mainly a method in which a molten resin discharged in a belt shape is brought into contact with a cast drum that is cooled from the inside by cooling and solidified.
The conventional film forming apparatus proposed in Japanese Patent Application Laid-Open No. 62-284719 has the same technical content as that shown in FIG. 6, and the molten resin 2 discharged from the base 1 in a band shape has a smooth surface. A pair of metal endless belts 4 and 4 'are pressed from both sides to be cooled and solidified to improve transparency. In FIG. 6, 6, 6 ', 7, 7', 8, 8 'are cooling rolls, respectively.
[0003]
[Problems to be solved by the invention]
However, in the conventional belt cast film forming apparatus, both end portions of the driving roll and the driven roll on which the endless belt is hung are not subjected to taper processing or R processing, and both end portions of the endless belt are also subjected to R processing. As a result, both ends of the endless belt contacted the driving roll and the driven roll, and stress concentrated on the end of the belt, causing cracks in the belt, resulting in a decrease in the life of the endless belt.
In the case of an endless belt used for belt casting film formation, it also serves as power transmission, so it has excellent toughness, high hardness, and excellent workability while maintaining film film and sheet quality. Further, fatigue strength and life are required. On the other hand, there has been a drawback that the surface of the belt or the ears are easily damaged due to rubbing between the resin contracting when the resin contracts, or foreign matters hitting the belt due to carelessness of the operator.
In the present invention, the end of the driving roll, the driven roll and the endless belt is subjected to R processing and the like, and the endless belt used for belt casting film formation is increased in toughness and hardness so that the conventional problems can be solved. An object of the present invention is to provide a membrane device and a belt for a belt cast membrane forming device.
[0004]
[Means for Solving the Problems]
Therefore, the present invention provides a belt-cast film forming apparatus that cools and solidifies a molten resin discharged in a band shape from a base while being sandwiched between a pair of metal endless belts having a smooth surface, and a driving roll for applying the endless belt; Both ends of the driven roll are subjected to taper processing or R processing, and both end portions of the endless belt are positioned at the taper processing or R processing portion of both ends of the drive roll and the driven roll. To do.
Further, the present invention provides a belt cast film forming apparatus that cools and solidifies a molten resin discharged in a band shape from a base while being sandwiched between a pair of smooth metal endless belts stretched between a driving roll and a driven roll. The endless belt has both ends used for taper processing or R processing on both ends of the drive roll and driven roll, and R processing is applied to both ends of the endless belt. Austenitic stainless steel SUS301, 303, 304, 316 or precipitation hardened stainless steel SUS630 is used, and the surface roughness of the endless belt surface is a mirror finish of 0.8 s or less. As a means for this.
The present invention performs the physical vapor deposition (PVD) coating TiN or TiC, or TiCN on the endless belt surface, are those formed by the surface hardness of the endless belt than Hv 2000, also the abrasive grains of fine ceramics endless belt surface The surface hardness of the endless belt is changed to HV500 to 550, and the endless belt surface is subjected to chrome plating, and the surface hardness of the endless belt is changed to HV600 to 900. It is a means for solving the problem.
[0005]
[Action]
In the present invention, the material of the endless belt is austenitic stainless steel SUS301, 303, 304, 316 or precipitation hardening stainless steel SUS630, and the surface roughness of the endless belt surface is a mirror finish of 0.8 s or less. The surface of the sheet is not rusted, and the surface of the transferred sheet can be molded neatly.
Since both ends of the endless belt are rounded, and both ends of the drive roll and driven roll are tapered or rounded so that both ends of the endless belt do not contact the drive roll and driven roll. Concentrated stress on the end portion is alleviated, cracks are less likely to occur in the belt, and the life of the belt can be extended.
[0006]
Also on the surface of the endless belt and physical vapor deposition (PVD) coating of TiN or TiC, or TiCN, or the surface hardness of the endless belt than Hv 2000, or by shot peening abrasive grains of fine ceramics endless belt surface, endless The surface hardness of the belt is HV500 to 550, or the endless belt surface is chrome-plated, and the surface hardness of the endless belt is HV600 to 900. In addition, it is possible to effectively prevent the belt from being damaged by things such as an operator's carelessness and the like being hit by the belt, and the life of the belt can be greatly extended.
[0007]
【Example】
1 and 2 show the first and second embodiments of the present invention, and FIGS. 3 to 5 show parts common to the first and second embodiments. .
First, the first embodiment of FIG. 1 will be described. In FIG. 1, the same parts as those of the conventional FIG. 6 will be described using the same reference numerals. In FIG. 1, 1 is a die, 2 is a molten resin, 4, 4 'is a metal endless belt, and its surface is physically vapor deposited (PVD) coated with TiN, TiC or TiCN, and the endless belt 4, The surface hardness of 4 'is HV2000 or higher, or the surface hardness of the endless belt 4, 4' is HV500-550 by shot peening abrasive grains such as fine ceramics on the surface of the endless belt 4, 4 '. Alternatively, the surface of the endless belts 4, 4 ′ is chrome plated so that the surface hardness of the endless belts 4, 4 ′ is HV 600-900. 3, 3 'are heating rolls as driven rolls, 5, 5' are infrared heaters, 7, 7 'are cooling rolls as drive rolls, 11 are motors, 12, 12' are bevel gears, and 13 and 13 'are Pinion gear.
[0008]
Next, the operation will be described. The molten resin 2 is discharged from the base 1 and is engaged between the heating rolls 3 and 3 'at the upper ends of the endless belts 4 and 4', and is sandwiched between the pressing parts between the endless belts 4 and 4 '. It is attached, cooled and solidified and sent out. The endless belts 4 and 4 'are respectively hung between the cooling rolls 7 and 7' rotating through the bevel gears 12 and 12 'and the pinion gears 13 and 13' and the heating rolls 3 and 3 'by driving the motor 11, respectively. While rotating in the direction opposite to the direction of the arrow, the molten resin pinching portion by the endless belts 4 and 4 'below the heating rolls 3 and 3' is pinched by cooling rolls 6 and 6 'from both ends to be cooled.
[0009]
Further, the surface of the endless belts 4 and 4 'is formed by physical vapor deposition (PVD) coating of TiN or TiC or TiCN, or shot peening or chrome plating of abrasive grains such as fine ceramics. ′ Has a high surface hardness. As a result, even if the endless belt 4 or 4 ′ rubs against the resin that contracts when the resin shrinks, or the endless belt 4 or 4 ′ is hit by an operator's carelessness, the endless belt 4 , 4 'can be effectively prevented from being damaged, and the life of the endless belts 4, 4' can be greatly extended.
[0010]
FIG. 2 shows a second embodiment of the present invention. The difference from FIG. 1 is that cooling rolls 9 and 9 'are provided above and below the cooling rolls 6 and 6' of FIG. 'Is a point in which a water tank 14 that can pass from between the upper cooling rolls 9 to the bottom is provided, and water 15 flows out from the belt passing portion of the slit 10 at the bottom and each of the endless belts 4 and 4'. This is a point formed by cooling the opposite surface of the contact surface with the resin. By the cooling by the water tank 14, the endless belts 4, 4 'are cooled extremely effectively.
[0011]
Next, FIGS. 3 to 5 show portions common to the first and second embodiments in a state in which the surface treatment of the endless belts 4 and 4 ′ is removed. In the belt cast film forming apparatus, the surface-treated endless belts 4, 4 'have a thickness of 0.2 to 2.0 mm, a width of 500 to 2500 mm, and the endless belts 4, 4' are made of austenitic stainless steel. SUS301, 303, 304, 316 or precipitation hardening stainless steel SUS630 is used, and the surface roughness of the surface of the endless belts 4, 4 ′ is a mirror finish of 0.8 s or less.
Accordingly, the diameter of the heating rolls 3, 3 'and cooling rolls 7, 7' can be reduced without increasing the fatigue level of the endless belts 4, 4 'resulting from repeated bending, thereby reducing the size of the entire apparatus. In addition, the surface of the endless belts 4 and 4 ′ is not rusted, and the surface of the sheet to be transferred can be formed beautifully.
[0012]
Also, as shown in FIG. 3, at both ends of a pair of smooth metal endless belts 4 and 4 'stretched between the driving rolls and driven rolls of the heating rolls 3 and 3' and the cooling rolls 7 and 7 '. The endless belts 4 and 4 'subjected to further R processing 16 are further driven so that the both ends of the endless belts 4 and 4' are not brought into contact with the heating rolls 3 and 3 'of the driving rolls and the driven rolls and the cooling rolls 7 and 7'. Both ends of the roll and driven roll are subjected to taper processing 17 having an arbitrary angle shown in FIG. 4A or R processing 18 shown in FIG. 4B, and the heating rolls 3 and 3 ′ and the cooling rolls 7 and 7 are applied. As shown in FIG. 5, the endless belts 4 and 4 'subjected to the R processing 16 have both ends of the heating rolls 3 and 3 and the cooling rolls 7 and 7' in the state where the endless belts 4 and 4 'are hung. Taper machining 17 or R processing Located in 18 parts, it is to avoid contact with the roll. As a result, the concentrated stress on the end portions of the endless belts 4 and 4 is alleviated and cracks are hardly formed in the endless belts 4 and 4 ', so that the life of the endless belts 4 and 4' can be significantly extended.
[0013]
【The invention's effect】
As described above in detail, the present invention applies R processing to both end portions of the endless belt, and tapers or R processing to both end portions of the drive roll and the driven roll so that both end portions of the endless belt are both ends of the drive roll and the driven roll. Since both end portions of the endless belt are not in contact with the driving roll and the driven roll, the concentrated stress on the belt end portion is alleviated, and the belt is difficult to crack. The life of the belt can be extended.
The endless belt surface is TiN or TiC, or by physical vapor deposition (PVD) coating TiCN, or the surface hardness of the endless belt than Hv 2000, or by shot peening abrasive grains of fine ceramics endless belt surface, an endless belt The surface hardness of the belt is HV500 to 550, or the endless belt surface is chrome plated so that the surface hardness of the endless belt is HV600 to 900. Even if the belt hits an object due to such carelessness, it is possible to effectively prevent the belt from being scratched and to greatly extend the life of the belt.
Further, the material of the endless belt is austenitic stainless steel SUS301, 303, 304, 316 or precipitation hardening stainless steel SUS630, and the surface roughness of the endless belt surface is a mirror finish of 0.8 s or less. The surface of the sheet to be transferred can be neatly formed.
[Brief description of the drawings]
FIG. 1 is a side view of a belt cast film forming apparatus showing a first embodiment of the present invention.
FIG. 2 is a side view of a belt cast film forming apparatus showing a second embodiment of the present invention.
FIG. 3 is a cross-sectional front view of end portions of endless belts 4 and 4 ′ common to the first and second embodiments of the present invention.
FIG. 4 is a cutaway front view of a heating roll and a cooling roll end common to the first and second embodiments of the present invention.
5 is a cutaway front view of the heating roll and cooling roll of FIG. 4 with the belt of FIG.
FIG. 6 is a side view showing an example of a conventional film forming apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base 2 Molten resin 3, 3 'Heating roll 4, 4' Endless belt 5, 5 Infrared heater 6, 6 ', 7, 7', 9, 9 'Cooling roll 10 Slit 14 Water tank 15 Water 16, 18 R processing 17 Taper processing

Claims (7)

In a belt-cast film forming apparatus that cools and solidifies a molten resin discharged in a band shape from a base between a pair of smooth metal endless belts with a smooth surface, both ends of a drive roll and a follower roll on which the endless belt is hung A belt cast film forming apparatus, wherein taper processing or R processing is performed , and both end portions of the endless belt are positioned at taper processing or R processing portions at both ends of the drive roll and the driven roll . In a belt cast film forming apparatus that cools and solidifies a molten resin discharged in a band shape from a base with a pair of smooth metal endless belts stretched between a driving roll and a driven roll, both end portions of the endless belt A belt for a belt cast film forming apparatus, wherein the belt is formed in a taper process or an R process part provided on both ends of a drive roll and a driven roll, and an R process is applied to both end parts of the endless belt. The belt casting film apparatus belt according to claim 2, belt cast film apparatus belt, characterized in that the material of the endless belt and the austenitic stainless SUS301,303,304,316 or precipitation hardening stainless SUS630.   The belt for a belt cast film forming apparatus according to claim 2, wherein the surface roughness of the endless belt surface is a mirror finish of 0.8 s or less. 5. The belt for a belt cast film forming apparatus according to claim 2, wherein a physical vapor deposition (PVD) coating of TiN, TiC or TiCN is applied to the endless belt surface, and the surface hardness of the endless belt is set to HV2000 or more. Belt for belt cast film forming equipment. The belt casting film apparatus belt according to claim 2 to 4 wherein, subjected to the shot peening treatment using abrasive grains of fine ceramics endless belt surface, characterized in that the surface hardness of the endless belt HV500~550 Belt cast film forming equipment.   5. The belt for a film casting apparatus according to claim 2, wherein the endless belt surface is chrome-plated so that the surface hardness of the endless belt is HV600-900.

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