CN-122029024-A - Method and system for forming liquid crystal polymer sheet

Abstract

The application provides a method and a system for forming a sheet made of a liquid crystal polymer, which can form a stable shape when the liquid crystal polymer is used as a raw material and the sheet is formed by using an extrusion forming die. A system for molding a sheet of a liquid crystal polymer according to an embodiment of the present application comprises an extrusion device (1) provided with a screw therein for heating and melting the liquid crystal polymer, and an extrusion die (2) for extruding the liquid crystal polymer heated and melted by the extrusion device (1) into a sheet shape, wherein a lip heater is embedded in a lip of the extrusion die (2). At this time, when the liquid crystal polymer sheet (100) is molded, the temperature difference between the lips of the extrusion molding die (2) is set to 5 ℃ or less.

Inventors

• KUSHISAKI YOSHIYUKI
• KAWAKAMI TAKAYUKI
• IMANISHI HIDEAKI

Assignees

• 株式会社日本制钢所

Dates

Publication Date

20260512

Application Date

20241003

Priority Date

20231017

Claims (16)

1. 1. A method for forming a sheet of liquid crystal polymer, comprising the steps of: a step (a) of conveying the liquid crystal polymer melted by heating by an extruder having a screw provided therein, and B, extruding the liquid crystal polymer obtained in the step a and melted by heating from a die for extrusion molding into a sheet shape, Wherein the temperature difference of the lip portions of the extrusion molding die is set to be within 5 ℃.
2. 2. The method for forming a liquid crystal polymer sheet according to claim 1, wherein, A lip heater embedded in the lip of the extrusion molding die, and the temperature of the lip is adjusted by the lip heater.
3. 3. The method for forming a liquid crystal polymer sheet according to claim 1, wherein, The lip heater is provided on both sides along a longitudinal direction of a slit which is an ejection port of the extrusion molding die.
4. 4. The method for forming a liquid crystal polymer sheet according to claim 1, wherein, The temperature difference is satisfied in a range in which the width of the slit in the central region with respect to the extrusion die is 90% or more.
5. 5. The method for forming a liquid crystal polymer sheet according to claim 1, wherein, In a connection pipe connecting the extrusion molding die from the extrusion device, the shear rate of the liquid crystal polymer is set to 10/sec or more.
6. 6. The method for forming a liquid crystal polymer sheet according to claim 1, wherein, The connecting pipe has a perforated plate, a gear pump, and a pipe elbow.
7. 7. The method for forming a liquid crystal polymer sheet according to claim 1, wherein, The step a is performed while exhausting the gas generated in the extrusion device to the outside.
8. 8. A method for forming a sheet of liquid crystal polymer, comprising the steps of: a step (a) of conveying the liquid crystal polymer melted by heating by an extruder having a screw provided therein, and B, extruding the liquid crystal polymer obtained in the step a and melted by heating from a die for extrusion molding into a sheet shape, In a pipe connecting the extrusion molding die from the extrusion device, the shearing speed of the liquid crystal polymer is set to be 10/sec or more.
9. 9. The method for forming a liquid crystal polymer sheet according to claim 8, wherein, The piping has a perforated plate, a gear pump, and a piping elbow.
10. 10. A system for forming a sheet of liquid crystal polymer, comprising: An extrusion device having a screw provided therein for heating and melting the liquid crystal polymer, and An extrusion molding die for extruding the liquid crystal polymer melted by heating by the extrusion device into a sheet, The lip of the extrusion die has a buried lip heater.
11. 11. The system for forming a liquid crystal polymer sheet according to claim 10, wherein, The lip heater is provided on both sides along a longitudinal direction of a slit which is an ejection port of the extrusion molding die.
12. 12. The system for forming a liquid crystal polymer sheet according to claim 10, wherein, The die for extrusion molding has a control unit that adjusts the temperature difference of the lip portion of the die for extrusion molding to within 5 ℃ by using the lip heater.
13. 13. The system for forming a liquid crystal polymer sheet according to claim 12, wherein, The control unit satisfies the temperature difference in a range in which a width of the slit in the central region with respect to the extrusion die is 90% or more.
14. 14. The system for forming a liquid crystal polymer sheet according to claim 10, wherein, A plurality of lip heaters are provided in a divided manner in the longitudinal direction of the slit of the lip.
15. 15. The system for forming a liquid crystal polymer sheet according to claim 10, wherein, The piping has a perforated plate, a gear pump, and a piping elbow.
16. 16. The system for forming a liquid crystal polymer sheet according to claim 10, wherein, The extrusion device has a gas discharge portion capable of discharging a decomposition gas generated by decomposing the liquid crystal polymer to the outside.

Description

Method and system for forming liquid crystal polymer sheet Technical Field The present invention relates to a method and a system for molding a liquid crystal polymer sheet. Background As a method for molding a resin sheet, a method is known in which a resin sheet is produced by melting pellets as a raw material by an extruder and extruding the obtained molten resin into a sheet form from an extrusion molding die (T die) (for example, refer to patent document 1 (japanese patent application laid-open No. 2018-36535). In this case, when a liquid crystal polymer is selected as a material of the resin sheet, when the resin sheet made of the liquid crystal polymer is to be molded, it is necessary to determine molding conditions of the resin sheet in consideration of temperature control, fluidity in piping, and the like, due to the specificity of the polymer characteristics. That is, the liquid crystal polymer has a characteristic that a viscosity change is large due to a temperature change of a molding temperature. In addition, since the extrusion molding die (T die) for molding a resin into a sheet shape has a slit shape in which the resin discharge port is long in the lateral direction, the temperature difference around the lip of the extrusion molding die tends to be relatively large. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2018-36535 Disclosure of Invention Problems to be solved by the invention Here, when the temperature difference around the lip portion becomes large, the amount of shrinkage of the liquid crystal polymer discharged from the extrusion molding die becomes uneven, or the thickness of the sheet becomes uneven, and a liquid crystal polymer sheet having a stable shape may not be obtained. Accordingly, an object of the present invention is to provide a molding method and a molding system for a liquid crystal polymer sheet, which can form a stable shape when a liquid crystal polymer is used as a raw material and the sheet is molded using an extrusion molding die. Other problems and novel features will become apparent from the description and drawings of the specification. Means for solving the technical problems According to one embodiment, a method for molding a resin sheet made of a liquid crystal polymer includes a step of conveying a liquid crystal polymer melted by heating by an extrusion device having a screw provided therein, and a step of extruding the melted liquid crystal polymer into a sheet form from an extrusion die. At this time, the temperature difference of the lip portion of the extrusion molding die was set to 5 ℃. Effects of the invention According to one embodiment, a method and a system for molding a liquid crystal polymer sheet, which can obtain a liquid crystal polymer sheet having a stable shape even when the liquid crystal polymer is molded into a sheet shape, can be provided. Drawings Fig. 1 is a schematic diagram showing a schematic configuration of a system for molding a liquid crystal polymer sheet according to embodiment 1. Fig. 2 is a schematic diagram illustrating a schematic configuration of an extrusion device used in a system for molding a liquid crystal polymer sheet according to embodiment 1. Fig. 3 is a schematic diagram illustrating the structure of an extrusion molding die used in the system for molding a liquid crystal polymer sheet according to embodiment 1. Fig. 4 is a schematic diagram (front view and bottom view) illustrating the structure of an extrusion molding die used in the system for molding a liquid crystal polymer sheet according to embodiment 1. Fig. 5 is a schematic diagram illustrating a schematic configuration of an extrusion molding die used in a molding system for a liquid crystal polymer sheet according to modification 1. Fig. 6 is a schematic diagram illustrating a schematic configuration of an extrusion device used in a system for molding a liquid crystal polymer sheet according to modification 2. Fig. 7 is a schematic diagram (front view and bottom view) illustrating the schematic configuration of an extrusion molding die used in a molding system for a liquid crystal polymer sheet according to modification 3. FIG. 8 is a graph showing (a) temperature dependence and (b) shear rate dependence of a liquid crystal polymer. Detailed Description An embodiment will be described in detail below with reference to the drawings. In all the drawings referred to for the purpose of describing the embodiments, the same reference numerals are given to the same or substantially the same functional components and the like. In addition, the description of the components and the like described once is not repeated in principle. < Prior study item > First, before explaining the present embodiment, characteristics of an extrusion-molded liquid crystal polymer will be explained. The extrusion molding uses an extruder equipped with a screw, heats and melts a raw material resin, kneads the raw material