JP4639491B2 - Sheet extrusion die - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to sheet over preparative extrusion die.
[0002]
[Prior art]
Conventionally, sheets such as polyester, polypropylene, polyamide, and polycarbonate films are generally manufactured by a process as shown in FIG.
[0003]
In FIG. 4, the molten material is extruded from the extruder 1, after which the discharge amount is made constant by the gear pump 2, foreign matter is removed through the filter 3, and the base width direction perpendicular to the direction in which the sheet is discharged from the base 4. (A direction perpendicular to the plane of the paper. Hereinafter, it may be simply referred to as a width direction) and discharged to form a sheet, and then the sheet 10 is solidified and formed by the cooling roll 5 and then subjected to a process such as stretching by the stretching device 6. The winder 7 winds up. FIG. 4 illustrates one process as a stretching apparatus. However, a stretching method by sequential biaxial stretching or the like, which includes a longitudinal stretching process of stretching in the sheet conveying direction and a lateral stretching process of stretching in the sheet width direction. Is also commonly used. The thickness profile in the width direction of the sheet is measured with the thickness meter 8 and, in order to manufacture a product level sheet, the thickness controller 9 calculates the difference between the current thickness profile measurement value and the target value, and becomes the target value. As shown in FIG.
[0004]
FIG. 5 shows a general structure of the base. The base usually has a manifold part 11 that widens the molten material flowing through the filter in the width direction, and a tip part including a pair of lips 13 that form a narrow slit 12 between the manifold part 11 and a side plate 14. It is configured. Since the thickness profile in the width direction of the sheet can be arbitrarily determined by manipulating the slit shape and temperature of the leading end, it is often used to adjust the thickness of the sheet. The slit can be formed by a method in which a plurality of adjusting bolts 15 arranged along the base width direction are rotated on the lip at the tip portion to adjust the push-pull (hereinafter referred to as a manual method), or a cartridge type heater 16 is provided on the bolt or a sleeve. A method (hereinafter referred to as a thermal expansion method) is often employed in which a bolt is heated by covering a type of heater, and the gap shape is deformed by expanding and contracting the bolt by thermal expansion of the bolt. Depending on how the slit shape is determined, the thickness unevenness of the sheet can be within 1%. Generally, the base body is heated by inserting a plurality of cartridge heaters 17 in the base width direction and heating the base body by covering the outer peripheral surface of the base with a cast heater (not shown).
[0005]
Normally, when adjusting the sheet thickness profile during sheet manufacture, both the manual and thermal expansion methods operate the bolts on the lip to widen or narrow the slit gap so that the sheet at that position can be adjusted. Adjust the thickness.
[0006]
For convenience of the following explanation, the following terms are defined.
[0007]
“Pushing the lip”: Push the screw of the bolt provided at the tip of the lip in the manual type, expand the bolt in the case of the thermal expansion type, and deform the lip in the direction of narrowing the slit gap to make the sheet Reduce the thickness of
[0008]
“Pull the lip”: Pull the bolt screw provided at the tip of the lip in the manual type, or stop the bolt expansion in the case of the thermal expansion type. Increase the thickness of the sheet.
[0009]
“Nipple point of lip deformation”: Neutral point of pushing and pulling of the lip, with no residual stress or distortion in the lip.
[0010]
To adjust the thickness of the sheet, the lip must be pushed and pulled with an accuracy of several μm, and a high level of adjustment capability is required. As described above, in the case of the thermal expansion type, the bolt attached to the tip of the lip is expanded by heat, and the lip is pushed and pulled to adjust the thickness. This method is widely and generally used for manufacturing sheets as the most convenient and highly accurate method for adjusting the thickness. Similarly, manual adjustment of the thickness is generally performed, but in the case of manual, there is screw backlash, and in order to adjust the thickness of the sheet with high accuracy, a very advanced human being can adjust the thickness. Skill is required. In recent years, since the demand for thickness accuracy of sheet products has become very high, it is substantially difficult to adjust the thickness by a manual method. Therefore, it is most preferable to adjust the thickness of the sheet by a thermal expansion method. In the thermal expansion type, in order to make effective use of the thermal expansion of the bolt, there is no rattling of the mounting.
[0011]
In order to adjust the thickness of the sheet by the thermal expansion method, it is necessary to take the following procedure. That is, in order to adjust the thickness of the sheet, it is necessary to push and pull the lip. Therefore, in order to realize this by a thermal expansion type, the bolt is thermally expanded in advance and the lip is pushed. Therefore, the lip can be pulled by the amount that the lip is pushed. The stroke of the lip push / pull realized in this manner is the range in which the bolt expands from room temperature to the highest heating temperature. In general, the pressing is performed until the intermediate temperature between room temperature and the maximum heating temperature.
[0012]
Conventionally, in the manufacture of a sheet, it has been possible to sufficiently adjust the thickness of the sheet product portion by the adjustment method as described above. However, it has been difficult to adjust the thickness only by the thermal expansion method at the end in the width direction of the sheet. When the sheet is successively biaxially stretched, etc., the sheet end is formed thicker than the center of the sheet in order to prevent the sheet from meandering in the longitudinal stretching process and to form a gripping portion with a clip in the lateral stretching process. There is a need. However, in the thermal expansion type, the lip cannot normally be pulled beyond the neutral point of the lip deformation, so the difference in thickness between the sheet product part and the end part can be adjusted only by the amount by which the lip has been pushed in advance. A sufficient range of adjustable thickness could not be obtained. That is, since the deformation of the lip cannot be thicker than the thickness of the sheet edge at the neutral point, when the thickness of the sheet edge is adjusted only by the thermal expansion method, there is a problem of meandering or clip slippage. It was. Therefore, in actuality, the thickness adjustment of the sheet edge portion has to rely on manual adjustment. However, as described above, it is difficult to adjust the thickness with high accuracy by manual adjustment, and as a result, problems such as clip dislocation may occur.
[0013]
As an example of pushing and pulling the lip from the neutral point, the following structure is disclosed in Japanese Utility Model Laid-Open No. 1-89118. In other words, a piezoelectric element is attached to a bolt attached to a lip without generating residual stress, distortion, etc. by attaching the piezoelectric element in the direction in which the lip is pressed and in the direction in which the lip is pulled. However, the above publication does not show how to adjust the thickness at the end in the width direction of the sheet. In addition, the piezoelectric element has insufficient heat resistance, and often malfunctions at about 150 ° C. For this reason, a cooling device is indispensable to use as a base for extruding a molten material having a high temperature of about 300 ° C. When the cooling device is in the sheet product section, the apparatus becomes large and the thickness is adjusted with a fine pitch in the width direction. It is difficult to make it practical enough at the present time.
[0014]
As described above, the thickness adjustment of the center portion of the sheet is simple and easy to use, but it is difficult to operate in the direction of pulling from the neutral point of the lip deformation at the end portion. Manufacture had to take some alternatives, such as relying on manual adjustment.
[0015]
[Problems to be solved by the invention]
An object of the present invention, in manufacturing the sheet, the thickness adjustment of the seat easily and effectively is to provide a row cormorants press-molded die. Especially also provide sufficient thickness adjustment range in the thickness adjustment of the sheet edge is to provide a problem of such I押 out forming die on steps such as a clip out.
[0016]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have reached the present invention described below. Sheet over preparative extrusion die of the present invention, the following constitution.
[0018]
That is, the first lip whose tip portion is deformable, the second lip paired with the first lip, and the tip portions of the first and second lips form a slit. The fixing member for fixing the first and second lips and the tip of the lip at least at both ends in the width direction of the first lip are also reduced so that the gap between the slits is enlarged from the neutral point of deformation. And a first lip tip portion deforming means using an inflatable member , wherein the first lip tip portion deforming means places the tip end portion of the first lip between the slits. It has the 1st expansible member which has expansibility in the direction which contracts, and the 2nd expansible member which has expansibility in the direction in which the gap of the slit expands .
[0019]
Furthermore, an inflatable member that can deform the tip of the lip at the widthwise end of the second lip so as to expand or contract the gap of the slit from the neutral point of deformation is utilized. The second lip tip portion deforming means can also be provided.
[0021]
Furthermore, the expandable member is characterized in that it expands due to thermal expansion of the member.
[0022]
The first lip whose tip is deformable, the second lip paired with the first lip, and the tip of the first and second lips form a slit. A fixing member for fixing the first lip and the second lip; and a lip tip portion deforming means for deforming the tip portion of the first lip so that a gap between the slits is changed. A push-pull block located on the opposite side of the slit of the first lip tip, a base portion provided between the tip of the first lip and the push-pull block, and the first lip A structure including a first inflatable member coupled to the tip portion of the lip and the push-pull block, and a second inflatable member coupled to the base portion and the push-pull block, respectively.
[0023]
Furthermore, the first and second expandable members at the first lip tip are expanded by thermal expansion of the members.
[0024]
Moreover, the cooling means of the said lip front-end | tip part deformation | transformation means can be provided, and the said lip front-end | tip part deformation | transformation means can be provided in the edge part of a nozzle | cap | die width direction.
[0025]
Further, the push-pull block portion is made of a heat insulating material.
[0026]
Here, the term “expandable member” refers to a member that expands in a single direction by applying energy such as heat or electricity, but may expand or contract in a negative direction. That is, when energy is applied when no energy is applied, only one of expansion and contraction is deformed as viewed from the beginning. Here, the act of applying another type of energy that cancels the effect of the application of energy for expansion, such as supplying cold air to the member that expands by application of heat energy, is the application of energy in the above sense. I do not consider. The inflatable member may be a metal material. If there is no problem such as heat resistance, a member in which a piezoelectric material is laminated, a member using a magnetostrictive material, or the like may be used.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a sheet manufacturing method and a sheet extrusion die according to the present invention will be described with reference to the drawings. However, the present invention is not limited to these.
[0028]
FIG. 1 is a cross-sectional view at the end in the base width direction for producing the sheet of the present invention. This sectional view shows the end of the base of the present invention with the same cut as the AA sectional view of FIG. In FIG. 1, 13 is a first and second lip, and 18 is a bolt for fastening each lip. Reference numeral 11 denotes a manifold that widens the resin in the width direction. The manifold is formed into a sheet shape by 12 slits and extrudes the sheet. Reference numeral 15 denotes a bolt for pushing and pulling the tip of the lip, and a cartridge heater 16 for heating and cooling the bolt to push and pull the lip is provided. The structure in which these are assembled constitutes the second lip tip portion deformation means 26. Reference numeral 19 denotes a base portion provided on the lip, and 20 denotes a push-pull block. The lip pushing direction adjusting bolt (first inflatable member) 21 passes through the base portion 19 from the lip tip and is coupled to the push / pull block 20. In the penetrating portion, the base portion 19 does not prevent the lip pushing direction adjusting bolt 21 from expanding. The lip pulling direction adjusting bolt (second inflatable member) 22 is coupled between the push-pull block 20 and the base portion 19. The adjustment bolts 21 and 22 are internally equipped with a cartridge heater. The portion surrounded by the two-dot chain line in FIG. 1 (first lip tip deforming means 25) is the portion that best represents the present invention.
[0029]
The lip is pushed and pulled from the neutral point as follows. That is, when pushing the lip, the cartridge heater inserted in the lip pushing direction adjusting bolt 21 is heated to expand the bolt. The pushing direction adjusting bolt 21 is supported by the rigidity of the pushing and pulling block 20 and the lip drawing direction adjusting bolt 22 and pushes the lip tip. When pulling the lip, the lip pulling direction adjusting bolt 22 is heated. The pull-direction bolt 22 is supported by the rigidity of the base portion 19 and moves the push-pull block 22 in the direction of pulling the lip. The tip of the lip receives a force in the pulling direction via the bolt 21 in the pushing direction.
[0030]
The adjustment bolt in the lip pulling direction is a cylindrical type, and the push direction bolt 21 may be put therein. However, in order to make a finer thickness adjustment by reducing the interval between adjacent bolts in the base width direction, the push direction It is preferable to arrange a pulling direction bolt above and below the bolt. One pulling direction bolt may be used, but when there is only one pushing direction bolt, it is preferable to provide two or more in order to prevent tilting in the vertical direction. Conversely, one pulling direction bolt may be provided, and two pushing direction bolts may be provided so as to sandwich the bolt.
[0031]
In order to efficiently push and pull the lip tip, the rigidity of each part is preferably as follows. That is, it is preferable that the rigidity is set such that base portion> pull direction adjusting bolt, push / pull block> push direction adjusting bolt, and pull direction adjusting bolt> push direction adjusting bolt.
[0032]
The material of each push / pull adjustment bolt may be the same as or different from the base. General structural steel, stainless steel, and the like can be used, but it is more preferable to use heat-resistant steel because it is a portion where high heat is applied. Depending on the conditions of the resin used, an aluminum alloy or a copper alloy may be used. Further, the expansion rate of the bolt may be changed between the pushing direction and the pulling direction according to the adjustment amount of the lip.
[0033]
The adjustment bolt may be heated by inserting a cartridge heater inside the bolt, or by covering the outer peripheral surface of the bolt with a sleeve heater or the like. Considering the cooling of the adjusting bolt and the arrangement space, it is more preferable to insert a heater inside.
[0034]
Since both the push direction adjusting bolt 21 and the pull direction adjusting bolt 22 are coupled to each other in the push / pull block, if thermal interference occurs at this portion, the sheet thickness adjusting accuracy deteriorates. Therefore, the push-pull block is preferably made of a heat insulating material. The entire block may be made of a heat insulating material such as ceramic, or a heat insulating material may be used for the bushing of the bolt coupling portion. Further, in order to prevent thermal interference due to radiation and convection between the pushing direction adjusting bolt and the pulling direction adjusting bolt, a heat insulating material may be provided between them. An example of this is shown in FIG. It is preferable to install the heat insulating member 23 as shown in FIG. As the heat insulating member, a ceramic material such as alumina or zirconia or a member using glass fiber is preferable.
[0035]
The adjusting bolt may be provided with a cooling means for efficiently lowering the temperature. Efficient cooling is preferable because the response speed of the adjusting bolt can be improved and the thickness can be adjusted quickly. An example of this is shown in FIG. It is convenient and preferable to provide the cooling means 24 as shown in FIG. 3 and use air cooling.
[0036]
Further, the configuration of the first lip tip portion deforming means 25 may be used for a portion for adjusting the thickness of the product portion of the sheet as shown in FIG.
[0037]
With the above configuration, by adjusting the thickness of the sheet, especially the thickness of the edge, the required amount of thickness can be achieved with high accuracy without relying on manual operation. Stable production can be performed without any problems.
[0038]
【Example】
When manufacturing sheets under conditions where polyethylene terephthalate is discharged at a discharge rate of 1000 kg / hour, with a setting of 1 m width and 1.50 mm gap, the gap profile is flat at room temperature and the deviation in the width direction is ± 10 μm We prepared a base that was maintained and assembled. When the base was connected to the filter and the extruder via the molten material pipe, a gasket was provided on the flange of the pipe, and the pipe and the base were connected at the flange portion. After the connection, a cartridge heater was inserted into the base, and heating of the base was started in this state. The temperature was set to 300 ° C., a thermocouple was provided at the tip of the lip of the base, and heating was performed until about 5 hours had passed after the temperature was saturated.
[0039]
As the configuration of the adjusting bolt, a material obtained by heat-treating SUS630 was used, and a pushing direction adjusting bolt having a diameter of 20 mm and a pulling direction adjusting bolt having a diameter of 30 mm were prepared. The adjustment bolt was heated by inserting a 100 V 100 W cartridge heater inside, and installing a glass wool insulation to prevent thermal interference between the adjustment bolts. The above-mentioned means for adjusting the pulling and pulling were installed in groups of 5 only at the end of the base, and the other product parts were provided only with a pushing direction adjusting bolt having a diameter of 20 mm.
[0040]
With the configuration as described above, before the molten material is discharged, the push direction adjustment bolt is heated to push the lip so that the gap between the product parts is about 1.30 mm, and the end part is pulled so that the gap is 1.70 mm. The direction adjustment bolt was heated to pull the lip. According to the die used in this example, the thickness of the product part of the die could be adjusted well in the range of 1.30 mm ± 90 μm by the push direction adjusting bolt. Further, at the end portion, it was possible to satisfactorily adjust the thickness in the range of about 0.5 mm to 2.7 mm by using the adjustment bolts for pushing and pulling.
[0041]
In this state, the molten resin was discharged, and a sheet was formed at a cooling roll rotational speed of 5 m / min. As a result, the sheet thickness of the product portion on the cooling roll was about 200 μm, and the end portion was about 1000 μm. Thereafter, the sheet was passed through a stretching process, stretched 4 times in the longitudinal direction and 3 times in the lateral direction, and winding was started. Here, the thickness of the product portion was corrected by using a push direction adjusting bolt with a gap of 1.30 mm as the center, and the end portion of the sheet end portion on the cooling roll was adjusted using an end portion adjusting means. The pulling direction adjusting bolt was operated to adjust the gap to about 1.90 mm so that the thickness was about 1400 μm. Adjustment was carried out by applying feedback control to the heater of the means for adjusting the base from the thickness data measured by the thickness gauge. The adjustment took about 15 minutes. Thereafter, the sheet was manufactured at an increased speed until the winding speed reached about 300 m / min. At this time, the sheet could be stably produced without causing meandering of the sheet or disconnection of the clip. In addition, since it was possible to prevent the tear due to the clip coming off, the loss at the start of sheet production could be greatly reduced.
[0042]
On the other hand, when adjusting the thickness of the sheet end with a base having only a push direction adjusting bolt under the same conditions as described above, assuming that the gap of the product portion is 1.30 mm, the thickness is 1.50 mm at the end. Since the gap cannot be opened as described above, it is impossible to adjust the thickness of the end itself. In addition, when adjusting the thickness with a manual adjustment bolt to compensate for the disadvantage, gap adjustment itself was possible, but in order to make a fine thickness adjustment by operating the adjustment bolt while looking at the thickness meter, The adjustment took about an hour. Also, the adjusted thickness profile is less accurate than in the case of the present invention, and the clip may be detached during the stretching process during the speed increase. Furthermore, the time required for the adjustment varies depending on the skill level of the operator, and in the case of a person with low skill, the adjustment may take 2 hours or more.
[0043]
【The invention's effect】
As described above, according to the present invention, when manufacturing a sheet, it is possible to easily and effectively adjust the thickness of the sheet, particularly the thickness at the end. In other words, the thickness of the sheet edge can be adjusted from the neutral point of the lip deformation by using the thermal expansion of the bolt, and the thickness of the end of the sheet can be adjusted to reduce process problems such as clip disengagement. Can do. As a result, there is no loss of raw materials, fixed costs, that is, costs such as labor costs and depreciation costs, and a great number of excellent points such as an increase in production capacity can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic view of Example 1 showing a base of the present invention.
FIG. 2 is a schematic view of Example 2 showing a base of the present invention.
FIG. 3 is a schematic view of Example 3 showing the die of the present invention.
FIG. 4 is a schematic view of a process for producing a general sheet.
FIG. 5 is a schematic view of a die for producing a general sheet.
FIG. 6 is a schematic view of Example 4 showing the die of the present invention.
[Explanation of symbols]
1: Extruder 2: Gear pump 3: Filter 4: Base 5: Cooling roll 6: Stretching process 7: Winder 8: Thickness gauge 9: Thickness controller 10: Sheet 11: Manifold part 12: Slit 13: Lip 14: Side plate 15: Adjustment bolt 16: Adjustment bolt heating heater 17: Base heating heater 18: Base fastening bolt 19: Base portion 20: Push-pull block 21: Push direction adjustment bolt (first inflatable member)
22: Pulling direction adjusting bolt (second inflatable member)
23: Thermal insulation member 24: Cooling means (cooling means for the lip tip deforming means)
25: First lip tip deforming means 26: Second lip tip deforming means

Claims (8)

A first lip having a deformable tip portion; a second lip paired with the first lip; and the first and second lips such that the tip portions of the first and second lips form a slit. The fixing member for fixing the second lip and the tip of the lip at least at both ends in the width direction of the first lip may be enlarged or reduced so that the gap of the slit increases from the neutral point of deformation. First lip tip deforming means using an inflatable member that can be deformed, and the first lip tip deforming means reduces the gap between the slits at the tip of the first lip. For sheet extrusion molding , comprising: a first inflatable member having an expandability in a direction to be expanded; and a second expandable member having an expandability in a direction in which the gap between the slits is expanded . Base. The second end utilizing the inflatable member that can deform the tip of the lip at the widthwise end of the second lip so that the gap between the slits is enlarged or reduced from the neutral point of deformation. 2. The sheet extrusion molding die according to claim 1 , comprising two lip tip portion deformation means. The base for sheet extrusion molding according to claim 1 or 2 , wherein the expansion member expands due to thermal expansion of the member. A first lip having a deformable tip portion; a second lip paired with the first lip; and the first and second lips such that the tip portions of the first and second lips form a slit. A fixing member for fixing the second lip; and a lip tip portion deforming means for deforming a tip portion of the first lip so that a gap between the slits is changed. A push-pull block located on the opposite side of the slit of the lip tip, a base portion of the first lip provided between the tip and the push-pull block, and the first lip A first inflatable member coupled to the tip portion and the push-pull block, respectively, and a second inflatable member respectively coupled to the base portion and the push-pull block. Sheet extrusion die. 5. The sheet extrusion molding die according to claim 4 , wherein the first and second inflatable members at the tip of the first lip are expanded by thermal expansion of the members. 6. The sheet extrusion die according to claim 5 , further comprising a cooling means for the lip tip deforming means. The base for extrusion molding of a sheet according to any one of claims 4 to 6 , wherein the lip tip portion deforming means is provided at least at an end in the base width direction. The base for extrusion molding of a sheet according to any one of claims 5 to 7 , wherein the push-pull block portion is made of a heat insulating material.

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