JP3743989B2 - Calendar roll shape control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a calender roll shape control device in a calender device for rolling a thermoplastic resin molding material into a film or sheet.
[0002]
[Prior art]
To roll a thermoplastic resin molding material into a film or sheet (hereinafter simply referred to as a film) having a uniform thickness in the width direction in a multistage calender device (hereinafter simply referred to as a calendar) for molding plastics or rubber. The most important factor is the gap between the calendar rolls. In order to adjust the gap, a gap adjusting mechanism that moves the roll axis in parallel is used.
[0003]
However, when the molding material passes through the gap between the two rolls, each roll bends due to an evenly distributed load caused by the rolling reaction force, so that the vicinity of the center portion of the film tends to be thick. That is, the cross section of the film has a drum shape as schematically shown in FIG.
[0004]
In order to correct the drum shape, a cross mechanism that crosses the rolls is used. This cross mechanism arbitrarily crosses the axis of at least one roll with respect to the other axis in two rolls adjacent to each other in parallel (roll cross).
When roll crossing is performed, the distance between the rolls is small near the center and increases toward the end, so that the cross section of the rolled film has a drum shape as schematically shown in FIG. . That is, there is an effect of correcting the drum-shaped cross section of FIG.
[0005]
However, if this cross mechanism cannot sufficiently correct the drum-shaped cross section due to the above-described bending, a bending mechanism that applies a moment load to both ends of two rolls adjacent to each other in parallel is used. In this case, the rolled film has a drum-shaped cross section as schematically shown in FIG. 4C, and has an effect of further correcting the drum-shaped cross section.
[0006]
Apart from the above, there is a phenomenon called roll heat crown due to thermal expansion of the outer diameter of the roll during rolling. This is a phenomenon that due to heat received from the molding material during rolling, the heat of the end of the roll is easier to dissipate from the vicinity of the center of the roll, and the vicinity of the center of the two adjacent rolls swells outward. As a result, the cross section of the rolled film has a drum shape as schematically shown in FIG.
[0007]
As described above, the shape control in the sheet width direction of the calendar uses a rolling mechanism, a bending mechanism, and a cross mechanism individually or in combination as required for each roll to prevent a rolling failure phenomenon.
[0008]
[Problems to be solved by the invention]
When the influence on the sheet width shape due to the behavior of the rolls according to each function is combined, even if the width direction sheet thickness after rolling is adjusted to be the same, the secondary, depending on the characteristics of each adjusting mechanism, etc. By combining the cubic and quartic curves, uncorrected portions that cannot be corrected are generated in the vicinity of both ends of the roll as schematically shown in FIG. This phenomenon is also called Oxbow (cow back) because of its cross-sectional shape. If the uncorrectable numerical value is ΔY and the product plate width of the film is L, ΔY is maximized at a distance X from the end. This distance X is about 15% of the product plate width L. When this uncorrectable error thickness ΔY is within the required value of the product (for example, 5 μm), there is no problem even if it is ignored in practice. However, when the required value is exceeded, conventionally, the uncorrectable plate width range must be cut as a defective portion, the quality is deteriorated, and the production is greatly damaged.
[0009]
The present invention has been developed to solve such problems. That is, an object of the present invention is to provide a calender roll shape control device capable of forming a film while suppressing the Oxbow phenomenon, thereby further improving the plate thickness accuracy in the plate width direction. is there.
[0010]
[Means for Solving the Problems]
According to the present invention, a reduction mechanism that applies a reduction force to the calendar roll, a bending mechanism that applies a moment load to both ends of two calendar rolls whose axes are adjacent to each other in parallel, and an axis that is adjacent to each other in parallel. A film-like member is provided with a rolling failure phenomenon correcting mechanism comprising a roll cloth mechanism that causes at least one roll axis to intersect the other axis center in two calender rolls, and rolling a molding material of a thermoplastic resin In addition to the rolling failure phenomenon correcting mechanism , the calender is formed in contact with the last roll sandwiching the last bank of the calender roll or the roll before the last roll, and between the last roll and the previous roll. in a position substantially perpendicular to the pressing direction of the molding material, the width of the molding material that can not be corrected by the rolling failure phenomena correction mechanism The unmodified portion occurring toward both ends with a horizontal bending apparatus to grant only the pressing force in the axial center portion of the roll so as to correct the shape control of the calender roll is provided, characterized in that. Also, a plate thickness detector that detects the plate thickness in the plate width direction of the film-like member rolled and sent from the calendar roll at a downstream position of the calendar, and the plate thickness in the plate width direction is predicted from the detection value of the plate thickness detector An arithmetic device that calculates, a command device that outputs an operation signal based on a pressing force that is calculated and applied by the arithmetic device, and a hydraulic servo valve that operates by the output from the command device to control the pressing force of the horizontal bending device And further.
[0011]
According to the above configuration of the present invention, the plate thickness detector that detects the plate thickness in the plate width direction of the film-like member rolled and sent from the calendar roll at the downstream position of the calendar, and the plate from the detection value of the plate thickness detector An arithmetic device that predicts and calculates the plate thickness in the width direction, a command device that outputs an operation signal based on a pressing force that is calculated and applied by the arithmetic device, and a pressing force of the horizontal bending device that is operated by an output from the command device A hydraulic servo valve for controlling the final roll, and a final roll sandwiching a final bank of calendar rolls or a roll immediately before the final roll, which is arranged in contact with the roll of the molding material between the final roll and the previous roll. at the crossed, the horizontal bending devices for applying only pressure in the axial direction center portion of the roll so as to correct the unmodified portion occurring in the width direction both end portions of the molding material that can not be corrected by rolling failure phenomena correction mechanism Therefore, this horizontal bending device can apply a pressing force to the roll to change the roll crown arbitrarily, so that the thickness of the sheet can be increased by correcting the roll crown in response to the Oxbow phenomenon that occurs during molding. High film can be produced efficiently.
[0012]
According to a preferred embodiment of the present invention, the horizontal bending device includes a pressing roll in which the vicinity of both ends of the roll for applying a pressing force is divided and placed in contact, and a pressure rubber is wound around the outer surface of the core metal. And a hydraulic cylinder for applying a pressing force to the pressing roll. With this configuration, the pressing rolls that correct the roll crown by coming into contact with both end portions of the calendar roll where the Oxbow phenomenon occurs can be quickly and appropriately corrected. In addition, since the outer surface of the pressing roll is made of a pressure-resistant rubber (for example, coated with Teflon or the like), it is possible to prevent the discoloration problem in which the gloss generated by the contact between the metal rolls is transferred to the film and the product is defective.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.
[0014]
1 to 3 show an embodiment of a calendar roll shape control apparatus according to the present invention. FIG. 1 is an overall configuration diagram of a calendar roll shape control apparatus 1 according to the present invention. As shown in this figure, a calendar roll shape control device 1 of the present invention includes a calendar 2, a horizontal bending device 3, a plate thickness detector 4, a calculation device 5, a command device 6, and a hydraulic servo valve 7.
[0015]
The calendar 2 includes multi-stage rolls (six in this figure) R1 to R6 for rolling the thermoplastic resin molding material 8 that has been heated and kneaded and carried in the previous step. Each roll is attached to the calendar body 9 so that the end of each roll shaft can be freely rotated via a shaft box (not shown). Further, between the two adjacent rolls, resin retaining banks (five locations in the figure) B1 to B5 are formed. Further, each roll is provided with a reduction mechanism, a bending mechanism and a cross mechanism (which are referred to as “rolling failure phenomenon correction mechanism” in the present invention) not shown in accordance with the required shape of the film in the plate width direction . .
[0016]
Further, in FIG. 1, the horizontal bending device 3 includes a final roll R6 (position indicated by a solid line in the figure) adjacent to the final bank B5 or a roll R5 immediately before the final roll (in a virtual line in the figure). The rolling direction of the winding portion of the final roll R6 that winds and rolls the molding material 8 that is placed in contact with the bank B5 and is in contact with the display position (the rolling direction of the molding material between the final roll and the previous roll). It is installed in the support material 10 so that a pressing force can be applied to the roll R6 at a position orthogonal to.
[0017]
A plate thickness detector 4 for detecting the plate thickness in the plate width direction of the film 14 is installed at a position downstream of the cooling roll device 13. An example of the plate thickness detector 4 is a β-ray thickness gauge. The plate thickness detector 4 detects the plate thickness of the film 14 in the plate width direction, and the detected value is input to the arithmetic unit 5 that predicts and calculates the plate thickness in the plate width direction. Next, a command device 6 that outputs an operation command based on the pressure data calculated by the arithmetic device 5 is provided. Further, a hydraulic servo valve 7 is provided, and the hydraulic servo valve 7 receives an operation signal output from the command device 6 and supplies pressure oil for controlling the pressing force of the horizontal bending device 3 or It comes to discharge. The hydraulic servo valve 7 is connected to a hydraulic pump P as a hydraulic power source and a drain tank T, respectively.
[0018]
Since such a device is provided, the plate thickness detector 4 downstream of the calendar detects the plate thickness distribution of the film 14 in the plate width direction, and the detection result is horizontally output from the arithmetic unit 5 through the hydraulic servo valve 7. A predetermined pressing force is applied to the roll of R6 (or R5) by the bending device 3, and the Oxbow phenomenon generated in the molding material can be corrected by arbitrarily changing the roll crown.
[0019]
FIG. 2 is a view taken along the line AA of FIG. 1 and shows a state in which a pressing force is applied to both ends of the rolling roll by a horizontal bending device of the pressing roll. In FIG. 2, the form of the horizontal bending apparatus 3 will be described in more detail. The horizontal bending device 3 includes a cylinder body 20, a piston 21, and a piston rod 22 having a pressing roll 23 attached to the piston 21. A detection rod 24 for detecting the movement position of the pressing roll 23 and a position detection sensor 25 are provided on the piston 21 opposite to the pressing roll 23. The cylinder body 20 is installed on a support member 10 attached to a calendar body 9 fixed to the floor 15. Piping ports 26 and 27 that are piped to the hydraulic servo valve 7 are provided on each side surface of the cylinder body 20. The position detection sensation 25 described above constantly detects the movement position of the pressing roll 23 and feeds it back to the arithmetic unit 5.
[0020]
Therefore, a predetermined pressing force can be applied to the pressing roll 23 based on the fed back data to arbitrarily change the roll crown of R6 (or R5), and the Oxbow phenomenon can be reduced quickly and reliably.
[0021]
FIG. 3 is a cross-sectional view taken along the line BB in FIG. 2 and shows a cross section of the pressing roll 23. The pressing roll 23 includes a metallic core 28 having a predetermined width W, a pressure rubber 29 having a predetermined thickness wound around the outer periphery of the core 28, and R6 (or R5) of a rolling roll of the pressure rubber 29. The surface in contact with Teflon is made of a coating portion 30 of Teflon or fluorine. Therefore, since the pressure roller 29 is coated with Teflon or the like on the surface of the pressure roll 23, the gloss caused by the contact between the metal rolls is transferred to the film and becomes a product discoloration problem when the metal roll is used. Can be prevented.
[0022]
The present invention is not limited to the above-described embodiment, and four or five rolls or the like, and the pressing roll may be three or one set depending on the film shape, and various changes can be made without departing from the gist of the present invention. Of course.
[0023]
【The invention's effect】
As described above, the calendar roll shape control device of the present invention is arranged in contact with the final roll sandwiching the final bank of the calendar roll or the roll immediately before the final roll, and molding between the final roll and the previous roll. Horizontal that applies a pressing force only to the central portion in the axial direction of the roll so as to correct the uncorrected portions that occur at both ends in the width direction of the molding material that cannot be corrected by the rolling failure phenomenon correction mechanism at a position that is substantially perpendicular to the rolling direction of the material. Since a bending device and a feedback control device for the plate thickness in the plate width direction of the film are provided, the roll crown can be arbitrarily changed, and a flat and uniform film can be efficiently produced. Further, productivity is improved. In addition, since the surface of the pressing roll is coated with Teflon, gloss transfer to the film can be prevented, and the problem of discoloration that is regarded as a product defect can also be prevented.
[0024]
Therefore, the calender roll shape control device of the present invention can form a film while suppressing the Oxbow phenomenon, thereby providing excellent effects such as further increasing the plate thickness accuracy in the plate width direction. Have.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an embodiment of a calendar roll shape control device according to the present invention.
FIG. 2 is a view taken in the direction of arrows AA in FIG.
3 is a cross-sectional view taken along the line BB in FIG.
FIG. 4 is a schematic view showing a cross-sectional shape of a film generated when various rolling is performed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Calendar roll shape control apparatus 2 Calendar 3 Horizontal bending apparatus 4 Plate thickness detector 5 Arithmetic apparatus 6 Commander 7 Hydraulic servo valve 8 Molding material 9 Calendar main body 10 Support material 11 Take-off roll apparatus 12 Embossing unit 13 Cooling roll Device 14 Film 15 Floor 20 Cylinder body 21 Piston 22 Piston rod 23 Press roll 24 Detection rod 25 Position detection sensor 26 Piping port 27 Piping port 28 Core metal 29 Pressure resistant rubber 30 Coating portion R1 to R6 Calendar roll B1 to B5 Bank H Thickness L Product width X Distance ΔY Uncorrectable value P Hydraulic pump T Tank

Claims (3)

A reduction mechanism that applies a reduction force to the calendar roll, a bending mechanism that applies a moment load to both ends of two calendar rolls whose axes are adjacent to each other in parallel, and two calendar rolls whose axes are adjacent to each other in parallel In a calendar for forming a film-like member by rolling a molding material of a thermoplastic resin , comprising a rolling failure phenomenon correcting mechanism consisting of a roll cross mechanism that intersects at least the axis of one roll with the other axis .
Aside from the rolling failure phenomenon correcting mechanism, the rolling direction of the molding material between the final roll and the previous roll, which is arranged in contact with the final roll sandwiching the final bank of the calendar roll or the roll immediately before the final roll, A horizontal bending device that applies a pressing force only to the central portion in the axial direction of the roll so as to correct uncorrected portions occurring at both ends in the width direction of the molding material that cannot be corrected by the rolling failure phenomenon correcting mechanism at substantially perpendicular positions. It was,
A shape control device for a calendar roll.   A sheet thickness detector that detects the sheet thickness in the sheet width direction of the film-like member rolled and sent from the calendar roll at a downstream position of the calendar, and predicts the sheet thickness in the sheet width direction from the detection value of the sheet thickness detector. An arithmetic device, a command device that outputs an operation signal based on a pressing force calculated and applied by the arithmetic device, a hydraulic servo valve that operates with an output from the command device to control the pressing force of the horizontal bending device, The shape control device for a calendar roll according to claim 1, further comprising:   The horizontal bending device includes a press roll in which the vicinity of both ends of a roll for applying a pressing force is divided and arranged, and an elastic member is wound around the outer surface of the core metal, and a liquid for applying the pressing force to the pressing roll. The shape control device for a calender roll according to claim 1, comprising a pressure cylinder.

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