JP2002113729A - Resin sheet manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin sheet manufacturing apparatus enhancing production efficiency by preventing the neckdown of a resin sheet in a casting or stretching process. SOLUTION: In a casting apparatus for extruding a molten resin in a sheetlike form from a cap 1 and bringing the extrudate into contact with a cooling rotary body 2 to cool and solidify the same, slip-resistant means 4 for suppressing the slip of the resin sheet in its lateral direction are respectively provided to the surfaces of both end parts of the cooling rotary body 2 in its axial direction. In an apparatus for stretching the resin sheet S between rotary bodies 20 and 21 having different surface speeds, the slip-resistant means 4 suppressing the slip of the resin sheet in its lateral direction are provided to the surfaces of both ends in the axial direction of at least the rotary body 21 having a high surface speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a resin sheet, and more particularly, to an apparatus for manufacturing a resin sheet for efficiently producing a resin sheet by preventing neck-down during a process.

[0002]

2. Description of the Related Art In a resin sheet casting process,
The molten resin is extruded from a die into a sheet, and the molten resin is brought into contact with the surface of a casting drum to be cooled and solidified. As described above, when the molten resin sheet is cooled and solidified by the casting drum, there is a phenomenon in which the width of the resin sheet is narrowed and a neck-down occurs. This phenomenon tends to increase as the resin sheet extruded from the base is pulled, that is, as the draft ratio (base lip gap / film thickness) increases.

[0003] This neck-down not only reduces the width of the sheet as a product, but also increases the thickness of the end portion, so that the trimming rate of the end portion increases the fringe rate and reduces production efficiency. There was a problem. Furthermore, the higher the speed, the more the air is caught between the resin sheet and the casting drum, the lower the gripping force, and the greater the neck down, which is an obstacle to improving the productivity by increasing the speed.

In the step of stretching the resin sheet after casting, the resin sheet is stretched by moving the resin sheet between rolls having a surface speed difference. In this stretching step, an accompanying airflow is involved between the resin sheet and the roll, and the resin sheet floats on the roll,
There is a phenomenon that causes a neck down,
In some cases, the same problem as in the above-described casting occurs.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin sheet manufacturing apparatus which solves the above-mentioned conventional problems and improves production efficiency by preventing necking of the resin sheet in a casting step or a stretching step. Is to provide.

[0006]

According to the present invention, there is provided an apparatus for manufacturing a resin sheet, wherein a molten resin is extruded into a sheet form from a die, and is brought into contact with a cooling rotary member to be cooled and solidified. It is characterized in that slip resistance means against the slip in the width direction of the resin sheet are provided on the surfaces of both ends in the axial direction of the rotating body.

As described above, in the casting process, slip resistance means against slippage of the resin sheet are provided on the surfaces of both ends in the axial direction of the cooling rotator, so that necking of the molten resin sheet can be prevented.

In another resin sheet manufacturing apparatus according to the present invention, at least the surface speed is high in the resin sheet manufacturing apparatus in which the resin sheet is moved between rotating bodies having different surface speeds and is stretched by the surface speed difference. A sliding resistance means against sliding in the width direction of the resin sheet is provided on the surface of both ends in the axial direction of the rotating body on the side.

As described above, in the stretching step, slip resistance means against slip of the resin sheet is provided at least on the surfaces of both ends in the axial direction of the rotating body having the higher surface speed, thereby preventing necking of the resin sheet. Can be.

[0010]

1 and 2 show a case where the apparatus for manufacturing a resin sheet of the present invention is applied to a casting process.

Reference numeral 1 denotes a die having a slit-shaped discharge port, from which the molten resin is extruded as a resin sheet S. The molten resin sheet S is cooled and solidified by coming into contact with the surface of the casting drum 2 (cooling rotator), and is sent to the next step via the guide roller 3. Here, a casting belt can be used as the cooling rotary member instead of the casting drum.

At both ends in the axial direction of the casting drum 2, there are provided slip resistance means 4 and 4 having a plurality of rows of projections or depressions wound on the surface in the circumferential direction. The slip resistance means 4 provides slip resistance so that the molten resin sheet S does not shrink in the width direction with respect to slip in the width direction, thereby preventing neck-down.

The protrusions constituting the slip resistance means 4 are formed by winding the metal wires 4a in plural rows around the outer peripheral surface of the casting drum 2 as shown in FIG. 3, and have a square cross section as shown in FIG. The stepped projections 4b or the stepped projections 4c whose cross sections are arc-shaped as shown in FIG. 5 are machined so as to be arranged in a plurality of rows, or not shown, but a number of independent projections are arranged in a multirow. Can be exemplified. Among these projections, those having a configuration in which the metal wire 4a is wound are particularly preferable because the casting drum can be easily processed and the slip resistance is large.

The width w and the height h of the projection are the same as those of the projection 4b.
In the case of those formed by machining (such as grinding) as in FIGS. 4A and 4C, the respective ranges are preferably in the range of 0.05 to 3 mm. The width w and the height h of the projection are not always the same, and may be different from each other, such as a rectangle or an ellipse. When the projection is formed by winding the metal wire 4a, the diameter d is 0.05 to 3 m.
Those using a metal wire in the range of m are preferred.

If each of the width w and the height h or the diameter d is less than 0.05 mm, the sliding resistance against the resin sheet becomes insufficient, and it becomes difficult to obtain a sufficient gripping force. On the other hand, if it is larger than 3 mm, the resin sheet does not come into contact with the surface of the casting drum and easily bites in the air, so that the sliding resistance is also reduced.

The spacing p between the projections is 0.1 to 3 in the case of the projections 4b and 4c formed by machining.
The range of 0 mm is preferable, and 3-10 m is more preferable.
m. When the interval p is less than 0.1 mm, the resin film is less likely to contact the casting drum surface, and the slip resistance is reduced. Also, 30mm
If it is larger than this, the number of edges of the protrusions engaging with the surface of the resin sheet is reduced, so that the slip resistance is reduced as described above. The interval p in the case of the convex portion around which the metal wire 4a is wound is 0.
It is good to make it into the range of 30 mm, more preferably 3 to 10 mm. Since the metal wires 4a have a circular cross section, slip resistance can be generated even when the metal wires 4a are wound so that they are in close contact with each other and the interval p is set to 0 mm.

In the case where the slip resistance means 4 is formed of a concave portion, as shown in FIG. 6, grooves 4d are machined in a plurality of rows on the outer periphery of the casting drum 2, or as shown in FIG. An example is one in which the independent recesses 4e are machined so as to be arranged in multiple rows. The cross-sectional shape of the groove or the depression is not particularly limited, and may be any of a V-shape, a quadrangle, and a round shape.

These recesses 4d and 4e have a width w of 0.1 to
It is preferable that the range is 30 mm and the depth k is in the range of 0.05 to 3 mm. The interval p between the arrays is 0.05 to 3
The range of mm is preferred. If you fall outside these ranges,
For the same reason as the case of the convex portion, it becomes impossible to sufficiently obtain the slip resistance with respect to the resin sheet.

When the above-described projections or depressions are arranged in a plurality of rows on the outer periphery of the casting drum, a large number of these projections or depressions may be arranged in parallel with each other. A book or several books may be wound continuously in a spiral. Further, the arrangement direction of the convex portions and the concave portions may be parallel (0 °) to the direction orthogonal to the axis of the casting drum, or may be -2.
It may be inclined in the range of 0 ° to + 20 °.

However, when the arrangement direction of the projections and the depressions is inclined, as shown in FIG. 1, the arrangement direction of the projections and the depressions is in the direction of the drum axis with respect to the rotation direction (arrow direction) of the casting drum. It is preferable to incline toward the center. That is, the arrangement direction of the convex portions or concave portions provided at both ends may be inclined toward each other inward (to form a V-shape) with respect to the drum rotation direction.
By thus arranging the convex portions or concave portions in an inclined manner,
Since the frictional force is applied so as to widen the resin sheet S outward in the width direction, the effect of preventing neck down can be further enhanced.

The width L (see FIG. 1) for bringing the end of the resin sheet S into contact with the slip resistance means 4 is not particularly limited, but is preferably within 100 mm, more preferably in the range of 20 to 50 mm. Good to do. With such a range, neck down can be effectively prevented.

FIGS. 8 and 9 show a case where the apparatus for manufacturing a resin sheet according to the present invention is applied to a stretching step.

The stretching step is provided following the casting step. The stretching device 10 is composed of a number of roll groups, and a preheating roll group 11, a stretching roll group 12, and a cooling roll group 13 are sequentially provided in a carry-in section and a carry-out section in the transfer direction of the resin sheet S in this order. Stretching roll group 12
Is designed to stretch between the first roll 20 and the second roll 21, and the surface speed of the second roll 21 is set to a draw ratio relative to the surface speed of the first roll 20. It is designed to rotate faster by the amount corresponding to. Subsequent third and subsequent rolls 22, 23, 24
Are rotating at the same surface speed as the second roll 21.

The second roll 21 is provided with resistance means 4 and 4 in which a plurality of rows of convex portions or concave portions are respectively provided on the surfaces of both ends in the axial direction in the circumferential direction, as in the case of the casting roll described above. Have been. The slip resistance means 4,
4 is the first roll 20 to the second roll 21
For the resin sheet S that is stretched while being stretched,
In order to provide a sliding resistance that widens outward in the width direction, it acts to prevent neck down.

The convex portions or concave portions constituting the slip resistance means 4 on the stretching roll may be the same as those illustrated in FIGS. 3 to 7 and the like provided on the casting roll described above. The range of the width and height of the portion and the interval between the convex portions, or the range of the width and depth of the concave portion and the range of the interval between the concave portions may be the same as in the case of the above-described casting roll.

[0026]

Example 1 and Comparative Example 1 The structure shown in FIG. 1 was used, the slit width of the die was 300 mm, and the outer diameter of the casting drum / the axial length of the outer peripheral surface was 30.
0 mm / 400 mm is a common condition, and the wire diameter d is 0.2 mm at both ends of the casting drum.
A 2 mm stainless wire is spirally wound so that the interval p is 5 mm and the inclination angle θ with respect to the direction perpendicular to the drum axis is 0.32 °, and the width L at which the resin film contacts the wire row is 40 mm. Casting apparatus (Example 1) and a casting apparatus that does not wind such a stainless steel wire (Comparative Example 1).
And two were made.

Using these two types of casting devices, the polypropylene resin was extruded at a temperature of 210 ° C. and the temperature of the casting drum was set at 30 ° C., and the film forming speed was changed to 15 to 25 m / min. The change in the film width when the film was made was measured, and the occurrence of neck-down was examined. Table 1 shows the results.

As is clear from Table 1, in Example 1, the film width was maintained at a constant width of 244 mm at all levels.
However, in Comparative Example 1, the film width was reduced as the film forming speed was increased, resulting in a significant neck down. In particular, width fluctuation occurred at 25 m / min.

[0029]

[Table 1]

Example 2 and Comparative Example 2 A roll group having an outer diameter of 200 mm was formed into a structure shown in FIG. 8, the draw ratio (surface speed ratio of the draw roll 21 to the draw roll 20) was 3.7 times, 85 ℃ -1
10 ° C., the temperature of the stretching rolls 20 and 21 is 110 ° C., the temperature of the cooling roll group is 30 ° C., and the exit speed of the stretching roll group is 1
A common condition is that the speed is 20 m / min. A stainless steel wire having a wire diameter d of 0.22 mm is provided at both ends of the stretching roll 21 at an interval p of 5 mm and an inclination angle θ with respect to a direction perpendicular to the drum axis is 0. It is spirally wound so as to be 48 ° (inclined toward the center of the roll width with respect to the rotation direction), and the width L at which the resin film comes into contact with this wire row is 40 m.
m and a stretching device (Comparative Example 2) in which such a stainless steel wire is not wound were manufactured.

Using these two types of stretching devices, the width 111
3.7 mm polyester film with a thickness of 8 mm and a thickness of 70 μm
The state of neck-down when stretching longitudinally twice was measured.
As a result, in the apparatus of Example 2, the film width after stretching was 1
020 mm, whereas the device of Comparative Example 2 was 97 mm.
2 mm, and the neck was greatly reduced.

[0032]

As described above, according to the present invention, in the casting step of the resin sheet, slip resistance means against slipping of the resin sheet are provided on the surfaces of both ends in the axial direction of the cooling rotator. The neck down of the sheet can be prevented, and in the stretching step, slip resistance means against slipping of the resin sheet is provided at least on the surface of both ends in the axial direction of the rotating body having a higher surface speed, so that the resin sheet Neck down can be prevented, and production efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a resin sheet manufacturing apparatus of the present invention.

FIG. 2 is a side view of the apparatus of FIG.

FIG. 3 is an explanatory view showing a cross section of a main part of a slip resistance means used in the device of the present invention.

FIG. 4 is an explanatory view showing a cross section of a main part of another embodiment of the slip resistance means used in the device of the present invention.

FIG. 5 is an explanatory view showing a cross section of a main part of still another embodiment of the slip resistance means used in the device of the present invention.

FIG. 6 is an explanatory view showing a cross section of a main part of still another embodiment of the slip resistance means used in the device of the present invention.

FIG. 7 is a front view illustrating a rotating body used in the apparatus of the present invention.

FIG. 8 is a schematic side view showing another example of the resin sheet manufacturing apparatus of the present invention.

FIG. 9 is a plan view showing a main part of the device of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cap 2 Casting drum (rotating body for cooling) 4 Slip resistance means 4a Metal wire (projection) 4b, 4c Step projection (projection) 4d Groove (recess) 4e Depression (recess) 12 Stretching roll group 20, 21 Stretching Roll (rotating body)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65H 27/00 B65H 27/00 B // B29L 7:00 B29L 7:00 (72) Inventor Shintaro Kugeta 3F103 AA03 BA34 3F104 AA03 CA00 JB02 JB04 JD11 4F205 AA11 AG01 AG23 GA07 GB02 GC02 GE07 GF01 GN24 GN28 GW21 4F207 AM32 KA01 KA1-1F AM32 QA03 QC02 QG01 QG18 QM05

Claims (11)

[Claims] 1. A resin sheet manufacturing apparatus in which a molten resin is extruded into a sheet form from a die and is brought into contact with a cooling rotary body to be cooled and solidified. An apparatus for manufacturing a resin sheet provided with slip resistance means against slip in the width direction. 2. A resin sheet manufacturing apparatus in which a resin sheet is moved between rotating bodies having different surface velocities and stretched by the difference in the surface velocities. An apparatus for manufacturing a resin sheet provided with slip resistance means for sliding in the width direction of the resin sheet. 3. The resin sheet manufacturing apparatus according to claim 1, wherein the slip resistance means is a convex or a concave arranged in a circumferential direction of the rotating body. 4. The resin sheet according to claim 3, wherein the projections are formed in a plurality of rows in the circumferential direction of the rotating body by machining, and the width and height of the projections are 0.05 to 3 mm. Manufacturing equipment. 5. An arrangement interval of the convex portions is 0.1 to 30 mm.
The resin sheet manufacturing apparatus according to claim 4, wherein: 6. The resin sheet manufacturing apparatus according to claim 3, wherein the protrusion is formed by winding a metal wire having a diameter of 0.05 to 3 mm a plurality of times in a circumferential direction of the rotating body. 7. A winding interval of the metal wire is 0 to 30 m.
The resin sheet manufacturing apparatus according to claim 6, wherein m is m. 8. The recesses are formed in a plurality of rows in the circumferential direction of the rotating body by machining, and the width of the recesses is 0.1 to 10.
The resin sheet manufacturing apparatus according to claim 3, wherein the thickness is 30 mm and the depth is 0.05 to 3 mm. 9. The arrangement interval of the concave portions is 0.05 to 3 mm.
The resin sheet manufacturing apparatus according to claim 8, wherein 10. The resin sheet manufacturing apparatus according to claim 3, wherein an arrangement direction of the protrusions or the recesses is inclined toward a center of a rotation body axial direction with respect to a rotation direction of the rotation body. 11. A method for producing a resin sheet using the apparatus according to claim 1. Description: