JP3660085B2 - T-die with deckle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a T-die with deckle (hereinafter abbreviated as T-die) connected to the lower end of an extruder for extrusion of a sheet-like article.
[0002]
[Prior art]
For example, in an extruder for extruding a sheet-like article such as a film, a flat plate having a uniform width and thickness is obtained by connecting a T die to the lower end and extruding molten resin through the T die. A shaped molded product is obtained. Examples of T-die structures are shown in FIGS. 7 and 8 are a front view and a sectional view of the T die, respectively, and FIG. 9 is an enlarged sectional view of the end portion of the T die.
In the figure, reference numeral 1 denotes a die body, and the die body 1 is composed of a pair of front and rear members extending in the width direction of the sheet-like article, and a space called a resin flow path 2 is interposed between these members. Is formed. As shown in FIG. 8, the resin flow path 2 hangs down in parallel from the upper manifold portion 2 a having an approximately circular cross section when viewed from the end and the upper manifold portion 2 a so that the thickness in the front-rear direction is the same, It is composed of a slit-like land portion 2 b that opens at the lower end of the die body 1. A resin injection port 3 communicating with the resin flow channel 2 is formed above the resin flow channel 2.
[0004]
Reference numeral 4 denotes a pair of front and rear lip portions respectively projecting from the lower end of the die body 1 toward the center portion in the thickness direction of the land portion 2b. A slit-like space (lip land) 5 is formed. Here, the lower part of the die body 1 is formed in a wedge shape having a predetermined angle downward, and the lip part 4 is formed along the wall surface 1a of the lower part of the die body 1 forming the wedge shape on the sliding surface 4a. And slidably supported up and down. As a result, it is possible to adjust the distance in the front-rear direction of the lip land 5 (that is, the thickness of the molded product) by the vertical movement of the lip portion 4 along each wall surface 1a. Furthermore, a portion of the lip portion 4 that forms the lip land 5 is a hanging surface 4b that hangs parallel to the land portion 2b.
[0005]
Reference numeral 6 denotes a pair of left and right side plates that closes both ends of the die body 1 and the lip portion 4. In the resin flow path 2, a pair of deckles 7 extend along the longitudinal direction of the resin flow path 2 from both ends. Are slidably inserted. The deckle 7 has substantially the same cross section as the resin flow path 2 and extends through the through holes 6a formed in the side plate 6 to both ends of the die body 1, as shown in FIG. The die body 1 protrudes left and right from both ends.
[0006]
Further, as shown in FIG. 9, openings 8 having a predetermined depth are formed in the upper end portion of the deckle 7 from both end sides of the T die along the longitudinal direction of the deckle 7. Sliding screws 9 are inserted from both ends of the T die. These sliding screws 9 pass through a Dickel fixing plate 10 that supports the Dickel 7 from the base end side, and are screwed to a moving nut 11 provided outside the Dickel fixing plate 10. Then, the deckle 7 can slide in the resin flow path 2 by the rotation of the moving nut 11. On the other hand, reference numeral 12 denotes a support bar that supports the deckle fixing plate 10 through the bearing 13 so as to be movable along the longitudinal direction of the deckle 7.
[0007]
In the production of the molded product, the molten resin is supplied from the resin injection port 3 into the resin flow path 2 by the extruder and pushed out from the lip land 5, and as a result, according to the distance in the front-rear direction of the lip land 5. A sheet-like molded product having a uniform thickness and a uniform width according to the distance between the tips of the pair of deckles 7 is formed. Further, by changing the width of the lip land 5 and the distance between the tips of the pair of deckles 7 as necessary, molded articles having different thicknesses and widths can be obtained using the same die body 1.
[0008]
[Problems to be solved by the invention]
By the way, in the case of the conventional T-die, the deckle 7 penetrates through the through-hole 6a through a gap having a predetermined width, and the molten resin that has flowed into the gap from the inside of the die body 1 decreases its pressure and temperature. By predefining the length along the longitudinal direction of the side plate 6 and the dimensional tolerance of the gap so as to remain in the gap due to the viscosity increase accompanying the above, leakage of resin from the side plate 6 was prevented. .
[0009]
However, in order to keep the dimension crossing of the gap within a predetermined range, the through-hole 6a is required to have high dimensional accuracy. However, when processing a large member such as the side plate 6, the through-hole 6a can be formed with high dimensional accuracy. It was difficult to process. The present invention has been made in view of the above circumstances, and provides a T die that can easily increase the dimensional accuracy between the side plate 6 and the deckle 7 and reliably prevent resin leakage from both ends of the T die. That is the purpose.
[0010]
[Means for Solving the Problems]
The present invention comprises a pair of front and rear members extending in the width direction of a sheet-like molded product, a resin flow path that opens downward between these members, and a resin inlet that communicates with the resin flow path. And a pair of left and right deckles slidably inserted along the longitudinal direction of the die body from both ends of the die body into the resin flow path. A pair of left and right side plates are supported on both ends of the die body, and the deckle is diametrically inserted into the pair of left and right seal metal boxes supported on the outside of the side plates. sealing metal covering from a direction outward are detachably supported, the sealing metal is, radially outward by the disposed a screw in the seal metal box The seal metal is elastically deformable in the radial direction by changing the pressing amount of the screw, and the screw is placed on both sides with a slit opened below the seal metal box. It is characterized by being provided .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. In addition, about the part which has the structure similar to the said conventional T die, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
[0013]
1 to 3 show examples of the shape of the seal metal box 20 used in the T-die of the present invention. FIGS. 1 and 3 are views showing end faces 20a and 20b of the seal metal box 20, respectively. FIG. 3 is a side view of a seal metal box.
[0014]
The seal metal box 20 is an integrally molded product made of metal, and an opening 21 is formed in the center of the seal metal box 20 to communicate with the resin flow path 2 when the seal metal box 20 is installed on the outer end surface of the side plate 6. Has been. Here, the opening 21 is formed according to the shape and size of the seal metal so that the seal metal (described later) is closely inserted into the seal metal box 20 from the one end face 20b side of the seal metal box 20. Yes. Further, the other end face 20a side of the opening 21 is reduced in diameter according to the size of the deckle 7 to form a reduced diameter portion 21a, and the lower end of the opening 21 is a lip when fitted to the die body 1. A slit 22 communicating with the land 5 opens downward.
[0015]
On the other hand, reference numerals 23 and 23 a are screw holes for attaching the seal metal box 20 to the end face of the side plate 6 and pin holes for positioning the seal metal box 20 with respect to the side plate 6, and reference numeral 24 is supported in the opening 21. It is a screw hole for pressing the seal metal from the outside in the radial direction to cause elastic deformation. Here, the screw hole 24 extends from the side surface of the seal metal box 20 toward the center portion, and the tip thereof opens to the side surface of the opening 21 on one end surface 20 b side of the seal metal box 20.
[0016]
4 and 5 show examples of the shape of the seal metal 30 used in the T-die of the present invention. FIG. 4 is a view showing the end face of the seal metal 30 and FIG. 5 is a cross-sectional view of the seal metal 30. .
[0017]
The seal metal 30 is an integrally molded product made of metal, and at the center thereof, when the seal metal 30 is inserted into the opening 21 of the seal metal box 20, it communicates with the resin flow path 2, and the deckle 7 has a predetermined width. The opening 31 inserted through the gap is provided. Further, a slit 32 communicating with the lip land 5 and the slit 22 when opened in the seal metal box 20 is opened downward at the lower end of the opening 31.
[0018]
Here, the length (symbol L in FIG. 5) of the seal metal 30 along the longitudinal direction of the deckle 7 when the seal metal box 20 is inserted and the width of the gap are as described above from the resin flow path 2 when the molded product is molded. It is determined in advance that the molten resin that has flowed into the gap remains in the seal metal 30 due to an increase in viscosity accompanying a decrease in pressure and temperature.
[0019]
The conditions for determining the length L of the seal metal 30 along the longitudinal direction and the width of the gap include, for example, the pressure, temperature, and viscosity of the molten resin in the resin flow path 2 and the inside and outside of the T die. Temperature difference, the material of the deckle 7 and the seal metal 30, the processing accuracy of the deckle 7 and the seal metal 30, and the like.
[0020]
Next, the manufacture of a molded product using a T die having the seal metal box 20 and the seal metal 30 will be described with reference to FIG. First, the seal metal 30 is inserted into the opening 21 from the one end face 20b side of the seal metal box 20, and a screw (not shown) disposed in the screw hole 24 is inserted at the tip of the seal metal 30. Push in until it touches the side. As a result, the seal metal 30 is supported in the opening 21 while being pressed from the outside in the radial direction by the tip of the screw.
[0021]
Next, the seal metal box 20 is placed on the outside (left side in FIG. 6) of the side plate 6 provided at both ends of the die body 1 (not shown) so that one end face 20b faces the resin flow path 2 side. Each is attached and both ends of the die body 1 are closed. Further, the deckle 7 is inserted into the resin flow path 2 from the other end face 20a side of the seal metal box 20 through the reduced diameter portion 21a and the opening 31 to adjust the width of the molded product. In this state, the molten resin supplied into the resin flow path 2 is extruded to obtain a sheet-like molded product having a uniform thickness and a uniform width.
[0022]
Here, as described above, the length L of the seal metal 30 along the longitudinal direction of the deckle 7 when the seal metal box 20 is inserted and the width of the gap between the opening 31 and the deckle 7 are resin when molding a molded product. It is determined in advance that the molten resin that has flowed into the gap from the flow path 2 stays in the seal metal 30 due to an increase in viscosity accompanying a decrease in pressure and temperature. Therefore, when the molded product is manufactured, the molten resin in the resin flow path 2 stays in the seal metal 30, and as a result, leakage of the resin from both ends of the T die is prevented. In addition, this effect is achieved by providing a seal metal 30 on the outer side of the side plate 6 included in the normal T die so that the gap between the opening 31 and the deckle 7 is extremely narrow. This is the first effect obtained by covering from the outside in the radial direction.
[0023]
Furthermore, in the T-die according to the present invention, the portion having the opening 31 that requires particularly high dimensional accuracy in the seal metal box 20 is configured by a separate member called the seal metal 30, so that the opening 31 can be easily processed. It is possible to do it. Therefore, the width of the gap between the opening 31 and the deckle 7 can be easily maintained with high dimensional accuracy, and resin leakage from both ends of the T die can be prevented more reliably.
[0024]
Furthermore, the seal metal 30 is supported in the opening 21 while being pressed from the outside in the radial direction of the opening 21 by screws arranged in the screw holes 24 formed in the seal metal box 20. When the seal metal 30 is cleaned, the seal metal 30 can be easily removed by loosening the screws after removing the seal metal box 20 from the die body 1.
[0025]
Moreover, since the seal metal 30 can be elastically deformed in the radial direction by changing the position of the screw in the screw hole 24, the screw is further pushed into the screw hole 24, and the seal metal 30 by the screw is used. By increasing the pressing amount, the seal metal 30 is elastically deformed so that the opening 31 is narrowed, and the width of the gap between the opening 31 and the deckle 7 is adjusted accurately, or the opening 31 is placed around the deckle 7. It is also possible to prevent the molten resin from entering the gap by making contact. Further, since the screw hole 24 is opened on the side surface of the seal metal box 20, the above operation can be easily performed without removing the seal metal box 20 from the die body 1.
[0026]
When the molten resin has a sufficient viscosity, the sealing metal 30 having a constant gap between the opening 31 and the deckle 7 is not provided without the above-described diameter adjusting mechanism of the opening 31 by the screw hole 24. It is also possible to prevent leakage of resin from both ends of the T die.
[0027]
【The invention's effect】
As described above, according to the T-die of the present invention, the portion that requires high dimensional accuracy in the seal metal box is configured with a separate member called a seal metal, so that the dimensional accuracy between the seal metal and the deckle is easily increased. This makes it possible to reliably prevent resin leakage from both ends of the T die.
[Brief description of the drawings]
FIG. 1 is a front view along an arrow I showing an example of the shape of a seal metal box used in a T die according to the present invention.
FIG. 2 is a side view along an arrow II showing an example of the shape of a seal metal box used in a T die according to the present invention.
FIG. 3 is a front view along an arrow III showing an example of the shape of a seal metal box used for the T-die according to the present invention.
FIG. 4 is a front view along an arrow IV showing an example of the shape of a seal metal according to the present invention.
FIG. 5 is a longitudinal sectional view taken along line VV showing an example of the shape of the seal metal according to the present invention.
FIG. 6 is an enlarged sectional view of an end portion of a T die according to the present invention.
FIG. 7 is a side view of the conventional T-die along arrow VII.
FIG. 8 is a sectional view taken along line VIII-VIII of a conventional T die.
FIG. 9 is an enlarged sectional view of an end portion of a conventional T die.
[Explanation of symbols]
1 Die body 2 Resin flow path 3 Resin inlet 6 Side plate 7 Dickel 20 Seal metal box 30 Seal metal

Claims (1)

A die main body comprising a pair of front and rear members extending in the width direction of a sheet-like molded product, and having a resin flow path opening downward between these members and a resin injection port communicating with the resin flow path And a T-die with a deckle comprising a pair of left and right deckles slidably inserted along the longitudinal direction of the die body into the resin flow path from both ends of the die body,
A pair of left and right side plates are respectively supported at both ends of the die body, and the deckles are moved radially outward in the pair of left and right seal metal boxes respectively supported by the outsides of the side plates. The seal metal covering from the side is supported detachably ,
The seal metal is pressed from outside in the radial direction by a screw disposed in the seal metal box, and the seal metal is elastically deformable in the radial direction by changing the pressing amount of the screw. And
The T-die with deckle, wherein the screw is provided on both sides with a slit opened below the seal metal box .

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