JP2017217800A - Lamination apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lamination apparatus capable of suppressing an interface unstable phenomenon by suppressing shearing stress or extension stress applied onto the interface of a laminate at a joining time.SOLUTION: In a lamination apparatus, a high quality lamination sheet can be produced stably by removing an interface unstable phenomenon by specifying surface roughness on a joining wall surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminating apparatus.

  A technique that has been remarkably developed in recent years as a method for reducing the cost and increasing the function of a film is a laminated film in which a plurality of types of sheet materials are laminated. By laminating sheet materials having different physical properties, this laminated film can add a new function that was not found in each single sheet material.

  Generally, a plurality of types (especially two types) of sheet materials (typically, molten resin, etc.) are guided in the downstream direction and merged with each other, and a plurality of types at the position where the channels merge. There is known a laminating apparatus including a joining portion that forms a laminated body in which the sheet materials are laminated. And a laminated body is discharged as it is or through a nozzle | cap | die, and post-processes, such as extending | stretching, are given as it is, and it becomes a laminated film.

  Here, in order to laminate | stack the sheet | seat material from which a physical property differs, in the laminated | multilayer film, the defect phenomenon which was not seen by the single layer may generate | occur | produce. One typical failure phenomenon is interfacial instability. This phenomenon is that wavy irregularities occur at the interface of the laminated sheet materials, resulting in poor appearance and uneven thickness. There are various forms of this phenomenon, ranging from those occurring on the entire film to those occurring only on a part thereof, and those that cause unevenness in thickness depending on the strength. Here, since the range in which this phenomenon is judged as defective differs depending on the required function of each film, it cannot be generally said that the appearance and thickness unevenness is defective. As a main cause of this phenomenon, shear stress and elongation stress applied to the interface of the laminated body at the time of merging are known.

  Until now, several methods for suppressing this interface instability phenomenon have been proposed. For example, Patent Document 1 discloses a method of widening a slit toward a confluence to suppress an interface instability phenomenon. FIG. 6 is a cross-sectional view of the vicinity of the merging point in the feed block of Patent Document 1. As shown in FIG. 6, the basic configuration of the feed block of Patent Document 1 is slits 11 and 12 through which resin materials A and B flow, a widening portion 91 that gradually widens the slit 11 toward the junction 13, the slit 11, It consists of a merge point 13 where 12 merge. In the steady state, that is, the interface position of the laminated body sufficiently downstream from the merging point is mainly determined by the flow rate and viscosity of each resin material. For this reason, if the interface position of the laminate in the steady state and the position of the merging point are different, one resin material moves the interface position while pressing the other resin material after merging. In Patent Document 1, it is assumed that an interface instability phenomenon occurs when this pressing force is applied to the interface of the laminate. Therefore, the technique of Patent Document 1 widens the slit 11 at the confluence 13 at the widening portion 91 according to the flow rate and viscosity of each resin material, and merges so that the interface position is the same as the steady state. The pressing force applied to the interface of the laminate is reduced, and the interface instability phenomenon can be suppressed.

JP 2006-142714 A

  However, since the technique of Patent Document 1 does not consider the shear stress and the extension stress applied to the interface of the laminated body at the time of joining, the interface instability phenomenon due to the shear stress and the extension stress may not be suppressed.

  The objective of this invention is providing the lamination apparatus which suppresses an interface instability phenomenon by suppressing the shear stress and elongation stress which are applied to the interface of a laminated body at the time of merge.

A laminating apparatus that achieves the above object includes a plurality of flow paths that guide a plurality of types of sheet materials in the downstream direction and merge with each other, and a laminate in which a plurality of types of sheet materials are stacked at a position where the flow paths merge. A joining portion to be formed,
A configuration in which a surface roughness Ra of the merging wall surface in the vicinity of the merging point satisfies 2 um or more and 10 um or less when an inner wall surface that merges at an acute angle among the inner wall surfaces of the plurality of flow paths is a merging wall surface. It is.

  Next, the meaning of each term in the present invention will be described.

  “Sheet material” refers to a material constituting the laminate. Examples of sheet materials include polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene, alicyclic polyolefin resins, polyamide resins such as nylon 6 and nylon 66, aramid resins, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, Polybutyl succinate, polyester resin such as polyethylene-2,6-naphthalate, polycarbonate resin, polyarylate resin, polyacetal resin, polyphenylene sulfide resin, tetrafluoroethylene resin, trifluorinated ethylene resin, trifluorinated ethylene chloride resin, Fluoropolymers such as tetrafluoroethylene-6fluoropropylene copolymer / vinylidene fluoride resin, acrylic resin, methacrylic resin, polyacetal resin , Polyglycolic acid resins, polylactic acid resins, and the like can be used as the fluidized, such as by melt or dissolved in a solvent. Further, these thermoplastic resins may be homo resins, copolymerized or blends of two or more. Also, in each thermoplastic resin, various additives such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, thickeners, thermal stabilizers, lubricants, infrared absorbers, ultraviolet absorbers. An agent, a dopant for adjusting the refractive index, and the like may be added. Moreover, as a sheet material which comprises a laminated body, it is preferable to select and use 2-10 types from the above.

  “Laminate” refers to a sheet material having a multilayer structure in which a plurality of types of sheet materials are laminated as a plurality of layers from when extruded from an extruder until it is discharged.

  “Laminating apparatus” refers to an apparatus for laminating a plurality of types of sheet materials to form a laminated body.

  “Multiple channels” refers to a plurality of channels that guide a plurality of types of sheet materials in the downstream direction and merge with each other in the laminating apparatus.

  “Merging point” refers to a point where a plurality of flow paths merge in the stacking apparatus. The vicinity of the merging point is a range from the merging point to the upstream 10 mm position.

  “Merging part” refers to a part of the laminating apparatus that forms a laminated body downstream of the merging point.

  The “merging wall surface” refers to an inner wall surface that merges at an acute angle among the inner wall surfaces of the plurality of flow paths in the laminating apparatus. For example, in the case of five layers, four merging points are formed by eight merging wall surfaces of five flow paths.

  “Surface roughness Ra” means the average of the arithmetic average roughness of the merging wall surface measured at 10 mm intervals in the sheet width direction at a position 5 mm upstream from the merging point in accordance with JIS B0601: 2013.

  The “heating mechanism” refers to a mechanism that heats the merged wall surface in the laminating apparatus. As a heating method, a heater, heating medium heating, or the like may be used.

  “Contact angle” means DM-501 manufactured by Kyowa Interface Science Co., Ltd. under a temperature of 22 ° C. and a humidity of 35%. Using the droplet method, the position 5 mm upstream from the merging point is 10 mm apart in the sheet width direction. It means the average contact angle of the measured confluence wall with water.

  In the laminating apparatus of the present invention, there is no interface instability phenomenon, and a high-quality laminated sheet can be manufactured stably.

The schematic diagram which shows the flow of the sheet | seat material in the vicinity of a confluence | merging point in the cross section perpendicular | vertical to a sheet | seat width direction in the lamination apparatus of this invention. The perspective view which displayed only the internal space which the sheet | seat material etc. of a lamination | stacking apparatus can pass. In the conventional lamination apparatus, the schematic diagram which shows the flow of the sheet | seat material in the vicinity of a confluence | merging point in the cross section perpendicular | vertical to a sheet | seat width direction. Sectional drawing perpendicular | vertical to the sheet | seat width direction of the vicinity of a confluence | merging point explaining the lamination apparatus of this invention which has a heating mechanism. Sectional drawing perpendicular | vertical to the sheet | seat width direction of the vicinity of a merge point explaining the angle which two merge wall surfaces make in the lamination apparatus of this invention. Sectional drawing perpendicular | vertical to the sheet | seat width direction of the vicinity of a confluence | merging point in the feed block of patent document 1. FIG.

  The present invention will be described in detail below, but the present invention is not limited to the embodiments including the following examples.

  1 to 5 are all diagrams of a laminating apparatus. 1, 4 and 5 show the laminating apparatus of the present invention, FIG. 3 shows the conventional laminating apparatus, and FIG. 2 shows the present invention and the conventional laminating apparatus. Note that members having the same application and function in the laminating apparatus of the present invention and the conventional laminating apparatus may have the same reference numerals.

  First, a conventional laminating apparatus will be described. FIG. 2 is a schematic perspective view of the laminating apparatus, FIG. 3 is a schematic cross-sectional view of the conventional laminating apparatus perpendicular to the sheet width direction in the vicinity of the junction 13, and the arrow line represents the flow velocity vector of the sheet material. As shown in FIG. 2, in the laminating apparatus, the sheet materials A and B are guided in the downstream direction through the flow paths 11 and 12, merged at the merge point 13, and the laminated body is formed at the merge portion 14. As shown in FIG. 3, since the sheet material adheres to a general smooth flow path wall surface, the flow rates on the wall surfaces of the sheet materials A and B are zero in the flow paths 11 and 12. Shear stress caused by the difference in flow velocity from the wall surface is applied to the interface of the laminate at the time of merging. Further, the elongation stress caused by the rapid acceleration of the flow velocity that was zero at the junction 13 is also applied to the interface of the laminate. These shear stress and elongation stress cause interface instability.

Next, the laminating apparatus of the present invention will be described. FIG. 1 is a schematic cross-sectional view perpendicular to the sheet width direction in the vicinity of the merge point 13 of the laminating apparatus of the present invention. As shown in FIG. 1, in the laminating apparatus of the present invention, the surface roughness of the merging wall surfaces 21 and 22, which are the inner wall surfaces that merge at an acute angle, of the inner wall surfaces of the flow paths 11 and 12 is determined at the merging point 13. By roughening in the vicinity of the sheet material, the sheet materials A and B slip, and the flow velocity is not zero. Therefore, the flow rate difference is reduced and the shear stress is also reduced. Moreover, the acceleration of the flow velocity from the junction 13 is also reduced, and the elongation stress is also reduced. Therefore, the interface instability phenomenon caused by these shear stress and elongation stress can be suppressed. As a result of extensive studies by the present inventors, the surface roughness Ra of the merging wall surfaces 21 and 22 in the vicinity of the merging point 13 is set to 2 μm or more and 10 μm or less, so that the interface instability phenomenon is suppressed and high quality lamination is performed. It was found that the sheet can be obtained stably. When the surface roughness Ra is less than 2 um, slippage on the wall surface does not occur so much and shear stress and elongation stress do not become small, so that the interface instability phenomenon cannot be suppressed. The lower limit of the surface roughness Ra is preferably 4 μm or more. Further, when the surface roughness Ra is larger than 10 μm, the sheet material is caught on the unevenness of the wall surface, and the flow velocity unevenness is generated, thereby causing an interface instability phenomenon. The upper limit of the surface roughness Ra is preferably 8 μm or less. In the present invention, “near the merging point” refers to a range from the merging point to the upstream 10 mm position. The minimum range in which the surface roughness Ra should be 2 μm or more and 10 μm or less varies depending on the size of the laminating apparatus, but the range from the junction to the upstream 10 mm position is that the surface roughness Ra is 2 μm or more and 10 μm or less. The laminating apparatus of the invention preferably has a heating mechanism 31 that heats the merging wall surfaces 21 and 22. FIG. 4 shows a laminating apparatus of the present invention having a heating mechanism. As shown in FIG. 4, it is preferable to heat the merging wall surfaces 21 and 22 by the heating mechanism 31 because the temperature of the merging wall surfaces 21 and 22 rises and slippage on the wall surface of the sheet material is more likely to occur.

  In the laminating apparatus of the present invention, the angle 41 (acute angle) formed by the merging wall surfaces 21 and 22 is preferably 60 degrees or less. FIG. 5 shows a laminating apparatus of the present invention. When the angle 41 is 60 degrees or less, the sheet material collides at the junction 13 in a state of being nearly parallel, so that the stress applied to the interface is larger in the ratio of shear stress and elongation stress than the normal stress. The effect of suppressing the interface instability phenomenon is sufficiently exhibited, which is preferable.

  In the laminating apparatus of the present invention, the contact angle between the merging wall surfaces 21 and 22 is preferably 80 degrees or less. When the contact angle is 80 degrees or less, it is preferable that the sheet material easily slips at the merged wall surfaces 21 and 22, and the effect of suppressing the interface instability phenomenon according to the present invention is sufficiently exhibited.

  In the laminating apparatus according to the present invention, it is preferable that the merging wall surfaces 21 and 22 are subjected to surface treatment. When the surface treatment is performed, the sheet material is easily slipped on the merged wall surfaces 21 and 22, and the effect of suppressing the interface instability phenomenon according to the present invention is sufficiently exhibited, which is preferable. Examples of the surface treatment include, but are not limited to, electroplating, electroless plating, chemical conversion treatment, anodizing treatment, hot dipping, thermal spraying, and vapor deposition.

  Typical applications of the film produced by the laminating apparatus of the present invention are general optical, general industrial, adhesive tape, display, backlight reflector, touch panel, window pasting, capacitor, battery separator, solar cell, Although it is for mold release and a ribbon, it is not restricted to these.

[Example 1]
The result of actually manufacturing and evaluating a laminated film using the laminating apparatus of the present invention will be described. A specific manufacturing method is as follows.
(1) Sheet material: Sheet material A; polyethylene terephthalate (PET) resin (thermoplastic resin F20S manufactured by Toray Industries, Inc.), sheet material B: cyclohexanedimethanol copolymerized PET (thermoplastic resin PETG6763 manufactured by Eastman)
(2) Preparation: Each sheet material was dried and then supplied to an extruder.
(3) Extrusion: The extruder was set at 280 ° C., and after passing through a gear pump and a filter, each sheet material was supplied to the laminating apparatus. The flow rate of the sheet material A was 100 kg / h, and the flow rate of the sheet material B was 20 kg / h.
(4) Laminating apparatus: The two flow paths upstream from the merging point both have a sheet width direction dimension of 100 mm and a sheet thickness direction dimension of 20 mm. The merging wall surface has a surface roughness Ra = 2.4 μm, a contact angle of 85 degrees, and the angle formed by the two merging wall surfaces is 70 degrees. The flow path downstream from the merging point has a sheet width direction dimension of 100 mm and a sheet thickness direction dimension of 40 mm.
(5) Discharge: On a casting drum on which a laminated body formed by a laminating apparatus is supplied to a T die (500 mm width) and extruded into a sheet shape, and then the surface temperature is maintained at 25 ° C. by applying electrostatic force (DC voltage 8 kV) Then, it was quickly cooled and solidified.
(6) Appearance evaluation: The appearance of the obtained laminated film was visually confirmed, and the presence or absence of an interface instability phenomenon was examined.
(7) Thickness unevenness evaluation: When the interface instability phenomenon is remarkable, the thickness unevenness occurs in the film. Therefore, the value obtained by subtracting the minimum value from the maximum value of the film thickness at the points divided into 10 approximately equally in the width direction of the film and dividing by the average value was used as the evaluation standard of the interface instability phenomenon.
As a result, the interface instability phenomenon could not be visually confirmed, and the thickness unevenness was 12%.

[Example 2]
A multilayer film was produced in the same manner as in Example 1 except that the surface roughness of the merged wall surface was changed to Ra = 9.5 um. As a result, the interface instability phenomenon could not be visually confirmed, and the thickness unevenness was 13%.

[Example 3]
A multilayer film was produced in the same manner as in Example 1 except that the surface roughness of the merged wall surface was changed to Ra = 4.3 μm. As a result, the interface instability phenomenon could not be visually confirmed, and the thickness unevenness was 8%.

[Example 4]
A multilayer film was produced in the same manner as in Example 1 except that the surface roughness of the merged wall surface was changed to Ra = 7.8 um. As a result, the interface instability phenomenon was not visually confirmed, and the thickness unevenness was 9%.

[Example 5]
A laminated film was produced in the same manner as in Example 1 except that a cartridge heater (φ6, 150 W) was installed as a heating mechanism inside the confluence wall surface and the temperature was adjusted to 290 ° C. As a result, the interface instability phenomenon could not be visually confirmed, and the thickness unevenness was 5%.

[Example 6]
A laminated film was produced in the same manner as in Example 1 except that the angle between the joining wall surfaces was changed to 50 degrees. As a result, the interface instability phenomenon could not be visually confirmed, and the thickness unevenness was 6%.

[Example 7]
A laminated film was produced in the same manner as in Example 1 except that the contact angle of the merging wall surface was changed to 75 degrees. As a result, the interface instability phenomenon could not be visually confirmed, and the thickness unevenness was 4%.

[Comparative Example 1]
A multilayer film was produced in the same manner as in Example 1 except that the surface roughness of the merged wall surface was changed to Ra = 1.3 um. As a result, the interface instability phenomenon could be clearly confirmed visually and the thickness unevenness was 19%.

[Comparative Example 2]
A multilayer film was produced in the same manner as in Example 1 except that the surface roughness of the merged wall surface was changed to Ra = 12.6 um. As a result, the interface instability phenomenon could be clearly confirmed visually, and the thickness unevenness was 23%.

[Evaluation results]
In Examples 1 to 4 where the surface roughness Ra of the merging wall surface satisfies 2 μm or more and 10 μm or less, the interface instability phenomenon could not be confirmed, and the thickness variation was as small as 13% or less. By increasing the surface roughness of the confluence wall surface, the shear stress and the elongation stress were reduced, the interface instability phenomenon was suppressed, and a high-quality laminated sheet could be stably obtained. In particular, Examples 3 and 4 satisfying 4 μm or more and 8 μm or less where the surface roughness Ra of the merged wall surface is a preferable range were very good results with thickness spots of 8% and 9%, respectively.

  In Example 5 in which the heating mechanism was installed inside the merged wall surface, the thickness unevenness was 5%, which was further reduced as compared with Examples 1 to 4.

  In Example 6 in which the angle between the joining wall surfaces was 60 degrees or less, the thickness unevenness was 6%, which was further reduced as compared with Examples 1 to 4.

  In Example 7, in which the contact angle of the merged wall surface was 80 degrees or less, the thickness unevenness was 4%, which was further reduced as compared with Examples 1-4.

  In Comparative Example 1 where the surface roughness Ra of the merging wall surface was less than 2 μm, the interface instability phenomenon could be clearly confirmed visually, and the thickness unevenness was as large as 19%. It is considered that the instability phenomenon of the interface occurred because the slip on the wall surface does not occur so much and the shear stress and elongation stress do not become small.

  In Comparative Example 2 in which the surface roughness Ra of the merged wall surface was larger than 10 μm, the interface instability phenomenon could be clearly confirmed visually, and the thickness unevenness was as large as 23%. It is considered that the instability phenomenon of the interface occurred due to the sheet material caught on the irregularities of the wall surface and uneven flow velocity.

  According to the present invention, by defining the surface roughness of the merging wall surface, there is no interface instability phenomenon, and a high-quality laminated sheet can be manufactured stably.

11: A flow path through which the sheet material A flows 12: A flow path through which the sheet material B flows 13: A merge point where the sheet materials A and B merge 14: A merge part which forms a laminate 21: A merge point of the flow path 11 is formed Junction wall surface 22: Junction wall surface 31 forming the junction of the flow path 12: Heating mechanism 41: Angle 91 of the junction wall surfaces 21 and 22 91: Widened portion

Claims (4)

A plurality of flow paths that guide a plurality of types of sheet materials in the downstream direction and merge with each other; and a merge portion that forms a laminate in which a plurality of types of sheet materials are stacked at the position where the flow paths merge. ,
Lamination having a surface roughness Ra of 2 μm or more and 10 μm or less in the vicinity of the junction when an inner wall that merges at an acute angle among the inner walls of each of the plurality of flow paths is defined as a merge wall. apparatus.   The laminating apparatus according to claim 1, further comprising a heating mechanism that heats the merging wall surface.   The lamination apparatus according to claim 1 or 2, wherein an angle (acute angle) formed by the merging wall surfaces is 60 degrees or less.   The lamination apparatus according to any one of claims 1 to 3, wherein a contact angle of the merging wall surface is 80 degrees or less.

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