JP5409463B2 - Production method and production apparatus for polyolefin resin film for agriculture - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an agricultural polyolefin resin film manufacturing method and manufacturing apparatus, and more specifically, an agricultural polyolefin resin film manufacturing method in which an aqueous antifogging agent is applied to a film obtained by inflation molding. And a manufacturing apparatus.

  One method for producing an extruded film by heating and melting a film material is inflation molding. And the corona discharge process is performed in order to apply | coat an aqueous | water-based antifogging processing agent, after modifying the surface of the film manufactured using inflation molding. Such a conventional technique is known as a method for producing an antifogging film described in Patent Document 1, for example.

JP 2001-226504 A

  However, the conventional techniques as described above have the following problems. That is, when the blow ratio, which is the ratio between the diameter of the die and the diameter of the cylindrical film, is relatively large in inflation molding, when the molded cylindrical film is flattened and sent to the next process, the longitudinal direction of the flat film Or, fine wrinkles tend to occur in an oblique direction.

  And the flat film in which the fine wrinkles produced on the surface may contact with the electrode which produces a corona discharge, and a surface may be damaged when performing a corona discharge process. In addition, since a flat film having fine wrinkles on the surface cannot be subjected to a uniform corona discharge treatment, there is a possibility that a product with partial adhesion failure may be manufactured.

  This invention is an invention made in view of the said subject, and when manufacturing the polyolefin resin film for agriculture which apply | coated the aqueous | water-based antifogging processing agent, the poor adhesiveness of an aqueous processing agent can be eliminated reliably. It aims at providing the manufacturing method and manufacturing apparatus of the polyolefin resin film for agriculture.

In order to achieve the above object, the present invention has the following characteristics.
1st invention is the manufacturing method of the polyolefin resin film for agriculture which apply | coats an aqueous | water-based antifogging processing agent to the outer surface of the cylindrical film manufactured by inflation shaping | molding, and forms an antifogging coating film, Comprising: A flat film manufacturing process for flattening a manufactured cylindrical film with a pinch roll to manufacture a flat film, a film temperature control process for heat-treating both surfaces of the flat film with at least two hot water rolls, and the film temperature control process A tension applying step for applying tension in the width direction to the flat film heat-treated in step, and a corona discharge processing step for performing corona discharge treatment on both surfaces of the flat film applied with tension in the tension applying step. An antifogging coating film forming step in which an aqueous antifogging treatment agent is applied to both surfaces of the flat film subjected to the corona discharge treatment and dried Equipped with a.

  2nd invention is invention which is dependent on the said 1st invention, Comprising: In a film temperature control process, it heat-processes with the warm water roll which lets warm water of 40 to 80 degreeC pass inside.

  A third invention is an invention subordinate to the first invention, wherein the aqueous antifogging treatment agent is an aqueous paint mainly composed of a thermoplastic emulsion and a hydrophilic colloidal inorganic compound.

  4th invention is the manufacturing apparatus of the polyolefin-type resin film for agriculture which apply | coats an aqueous | water-based antifogging processing agent to the outer surface of the cylindrical film manufactured by inflation molding, and forms an antifogging coating film, Comprising: Flattened film manufacturing means for flattening the manufactured cylindrical film with a pinch roll to manufacture a flat film, film temperature control means for heat treating both surfaces of the flat film with at least two heating rolls, and heat treatment with the film temperature control means The applied flat film was subjected to corona discharge treatment, tension applying means for applying tension in the width direction, corona discharge treatment means for corona discharge treatment on both surfaces of the flat film tensioned by the tension applying means, An antifogging coating film forming means for applying an aqueous antifogging treatment agent to both surfaces of the flat film and drying it is provided.

  According to the present invention, when manufacturing an agricultural polyolefin resin film coated with an aqueous antifogging treatment agent, a film production apparatus and a film production method capable of reliably eliminating the poor adhesion of the aqueous treatment agent. Can be provided.

The figure which shows an example of a structure of the film manufacturing apparatus which concerns on this invention

(First embodiment)
FIG. 1 is a diagram showing a configuration of a film manufacturing apparatus 1 according to the first embodiment of the present invention. The film manufacturing apparatus 1 according to the present embodiment includes an inflation molding unit 101, a first roll 102, a dancer roll 103, a foreign matter detection unit 104, a film temperature control unit 105, a flat expander roll 106, and a first The corona discharge processing unit 107 and the second corona discharge processing unit 108 are provided.

  The inflation molding unit 101 forms a two-layer flat film 201 by molding a film material heated and melted. More specifically, the inflation molding unit 101 first extrudes a melted film material 101b from an extruder (not shown) through an annular die 101a in a cylindrical shape. Next, the inflation molding unit 101 expands the film material 101b so as to increase its diameter by blowing compressed air into the cylindrical shape while cooling the extruded film material 101b using a blower (not shown). Let Then, the inflation molding unit 101 flattens the diametrically expanded cylindrical film material 101b with a pair of guides 101c and 101d, and a pair of flat film 201 with a pair of pinch rolls 101e and 101f. Is generated.

  The 1st roll 102 is a typical conveyance roll, Comprising: The flat film 201 produced | generated by the inflation shaping | molding part 101 is conveyed to the dancer roll 103 provided in the back | latter stage.

  The dancer roll 103 is typically configured such that the support force of the support portions that support both ends thereof can be adjusted by an air cylinder, and adjusts the tension applied to the flat film 201 conveyed by the film manufacturing apparatus 1. The dancer roll 103 detects the tension applied to the flat film 201 by a sensor (not shown), and controls the air pressure inside the air cylinder based on the detected tension to adjust the supporting force thereof, thereby applying the tension applied to the flat film 201. Control to the required tension. The dancer roll 103 conveys the flat film 201 conveyed from the first roll 102 to the foreign matter detection unit 104 provided in the subsequent stage while controlling the tension.

  The foreign matter detection unit 104 includes a second roll 104a and a foreign matter detector 104b. The 2nd roll 104a is a typical conveyance roll, Comprising: The flat film 201 conveyed from the dancer roll 103 is conveyed to the film temperature control part 105 provided in the back | latter stage. The foreign object detector 104b is mainly composed of a plate-like member having at least the same width as the flat film 201 and a predetermined height and thickness. The foreign object detector 104b is rotatably installed at a support point P provided at the upper portion so that the lower end is positioned at a predetermined installation height from the surface of the flat film 201 fed out by the second roll 104a. The

  The foreign object detector 104b installed so as to be rotatable is pressed by the foreign object conveyed together with the flat film 201 when the foreign object adheres to the surface of the flat film 201 conveyed along with the rotation of the second roll 104a. Then, it rotates around the support point P. The foreign object detection unit 104 detects a rotation angle when the foreign object detector 104b rotates, for example, with a rotation angle sensor such as a rotary encoder, and the detected rotation angle exceeds a predetermined angle threshold value. Sometimes it is determined that a foreign object has been detected.

  The first corona discharge processing unit 107 is configured to separate a later-described first corona discharge electrode 107a from the surface of the flat film 201 when the foreign object detection unit 104 determines that a foreign object is detected. Thereby, the film manufacturing apparatus 1 which concerns on this embodiment can prevent that the foreign material detected by the foreign material detection part 104 contacts with the 1st corona discharge electrode 107a, and is damaged.

  The film temperature control unit 105 heats the flat film 201 conveyed from the second roll 104a at a predetermined temperature to cause thermal contraction in the width direction and conveys the flat film 201 to the flat expander roll 106 provided in the subsequent stage. More specifically, the film temperature control unit 105 according to this embodiment includes a first hot water roll 105a and a second hot water roll 105b. Each of the 1st warm water roll 105a and the 2nd warm water roll 105b maintains the contact surface with the flat film 201 at the predetermined contact temperature by letting warm water flow through the water channel provided inside. It is a roll that can.

  Here, in this embodiment, the 1st warm water roll 105a is installed so that it may contact | abut on the surface of the flat film 201, and the 2nd flat film 201 conveyed from the 2nd roll 104a was provided in the back | latter stage. It is conveyed to the hot water roll 105b. Moreover, the 2nd warm water roll 105b is installed so that it may contact | abut on the back surface of the flat film 201, and conveys the flat film 201 conveyed from the 1st warm water roll 105a to the flat expander roll 106 provided in the back | latter stage. Thus, the film temperature control part 105 which concerns on this embodiment performs the heat processing which heats the 2 layer flat film 201 from the both surfaces with the above-mentioned contact temperature with the 1st warm water roll 105a and the 2nd warm water roll 105b. .

  The flat expander roll 106 is typically a cylindrical roll, and is a conventionally known roll in which rubber bands that can expand and contract along the width direction of the surface are arranged at equal intervals along the circumferential direction. It is. The flat expander roll 106 is configured such that a rubber band disposed on the surface repeats expansion and contraction in the width direction every rotation of the roll. The flat expander roll 106 receives the flat film 201 conveyed from the film temperature control unit 105 when the rubber band is contracted in the width direction, and the rubber band extends in the width direction relatively. It is installed so that it can be sent to the first corona discharge processing unit 107 provided in the subsequent stage. Therefore, the flat film 201 conveyed from the film temperature controller 105 is tensioned by the rubber band extending in the width direction by the flat expander roll 106, and the first corona discharge provided in the subsequent stage after the wrinkles are removed. It will be conveyed to the processing unit 107.

  The first corona discharge treatment unit 107 performs corona discharge treatment on the surface of the flat film 201 conveyed from the flat expander roll 106 to modify the surface. More specifically, the first corona discharge treatment unit 107 includes a first corona discharge electrode 107a and a first corona discharge roll 107b. The first corona discharge electrode 107a is an electrode for generating corona discharge. The 1st corona discharge roll 107b conveys the flat film 201 conveyed from the flat expander roll 106 to the 2nd corona discharge roll 108b provided in the back | latter stage.

  The first corona discharge treatment unit 107 applies a high voltage at a high frequency between the first corona discharge electrode 107a and the first corona discharge roll 107b to cause corona discharge. The first corona discharge treatment unit 107 improves the wettability of the surface by passing the surface of the flat film 201 through the corona discharge using the first corona discharge roll 107b.

  The second corona discharge treatment unit 108 performs corona discharge treatment on the back surface of the flat film 201 conveyed from the first corona treatment roll 107b to modify the back surface. More specifically, the second corona discharge treatment unit 108 includes a second corona discharge electrode 108a and a second corona discharge roll 108b. The second corona discharge electrode 108a is an electrode for generating corona discharge. The second corona discharge roll 108b conveys the flat film 201 conveyed from the first corona discharge roll 107b to the subsequent stage.

  Similarly to the first corona discharge treatment unit 107, the second corona discharge treatment unit 108 applies a high frequency high voltage between the second corona discharge electrode 108a and the second corona discharge roll 108b. Cause corona discharge. The second corona discharge treatment section 108 improves the wettability of the back surface by passing the back surface of the flat film 201 through the corona discharge using the second corona discharge roll 108b.

  The above is description of schematic structure of the film manufacturing apparatus 1 which concerns on this embodiment. Next, the film processing steps in the film manufacturing apparatus 1 according to this embodiment will be described along the flow.

  In the film manufacturing apparatus 1 according to the present embodiment, first, the flat film 201 is generated from the film material 101b heated and melted by the inflation molding unit 101 (molding process), and the first roll 102 is used as the dancer roll 103. The tension is adjusted by carrying (tension adjusting step), and the foreign matter detecting unit 104 detects whether or not foreign matter is attached to the flat film 201 conveyed from the dancer roll 103 (foreign matter detecting step). And in the film manufacturing apparatus 1 which concerns on this embodiment, after letting the flat film 201 pass to a foreign material detection process, it conveys and heat-processes to the film temperature control part 105 (film temperature control process), and heat-processed the flat film 201. The flat expander roll 106 applies tension in the width direction (tension applying process), and the first corona discharge processing unit 107 and the second corona discharge processing unit 108 perform corona discharge processing on both surfaces (corona discharge processing process). . In the film temperature control step, the surface of the flat film 201 is heated by the first hot water roll 105a (first heating step), and then the back surface of the flat film 201 is heated by the second hot water roll 105b (first step). 2), both surfaces of the flat film 201 are heat-treated.

  The above is description of the film manufacturing apparatus 1 which concerns on 1st Embodiment. According to the film manufacturing apparatus 1 according to the first embodiment, the flat film 201 in which wrinkles or distortion has occurred by forming with a forming method of forming the film material 101b heated and melted, such as inflation molding, It passes through a film temperature control process and a tension | tensile_strength provision process. Therefore, according to the film manufacturing apparatus 1 according to the present embodiment, wrinkles or distortion can be eliminated, and the surface of the flat film 201 can be prevented from being damaged by the first corona discharge electrode 107a.

  The flat film 201 that has passed through the second corona discharge treatment unit 108 according to the first embodiment passes through an impregnation tank or a coating apparatus to apply an aqueous antifogging treatment agent, and then an excess treatment agent. It is made into a product through an anti-fogging coating film forming step of scraping and drying with a bar coater or the like. According to the film manufacturing apparatus 1 according to the first embodiment, as described above, the surface of the flat film 201 can be uniformly subjected to corona discharge treatment to modify the surface. It is also possible to prevent poor adhesion of the antifogging treatment agent.

  Moreover, the flat film 201 manufactured with the film manufacturing apparatus 1 which concerns on 1st Embodiment is good also as a product with a two-layer flat film, and cuts and opens any one edge part, and is a one-layer film After that, it may be a product.

  In addition, when the inflation molding unit 101 manufactures the flat film 201, the pinch roll 101e, and the pinch roll 101e are expanded after expanding the diameter of the film material 101b extruded into a cylindrical shape so as to obtain a necessary width as a product. A two-layer flat film 201 in which the cylindrical shape is flattened along the diametrical direction is manufactured by pulling along a pair of guides 101c and 101d sandwiched between 101f. Therefore, when the inflation molding part 101 expands the diameter of the film material 101b extruded into a cylindrical shape by expanding, the ratio of the diameter when extruded from the annular die 101a to the cylindrical shape and the diameter after expansion, that is, The flat film 201 must be manufactured by preliminarily setting the blow ratio so as to obtain a necessary width as a product and expanding the film material 101b. Here, the blow ratio in the inflation molding portion 101 according to the first embodiment may be an arbitrary blow ratio, but when it is a blow ratio of 2 or more, it occurs in the flat film 201 produced by expansion. Distortion or wrinkles is particularly increased. That is, according to the film manufacturing apparatus 1 according to the first embodiment, a particularly large effect can be obtained when the blow ratio is 2 or more.

  Moreover, although the width | variety of the film which can be manufactured with the film manufacturing apparatus 1 which concerns on 1st Embodiment is arbitrary, as mentioned above, it cuts either one edge part of the flat film 201 of 2 layers, and is 4-10 meters. Products of width can be obtained. In this case, in each process mentioned above, the flat film of the width | variety of 2-5 meters of the half should just be processed.

  Moreover, in the film manufacturing apparatus 1 which concerns on 1st Embodiment, the film temperature control part 105 demonstrated as an example the case where it consists of two warm water rolls, the 1st warm water roll 105a and the 2nd warm water roll 105b. However, in the film manufacturing apparatus according to another embodiment, the number of hot water rolls constituting the film temperature control unit 105 may be three or more. For example, when the conveyance speed of the flat film 201 is relatively high, the flat film 201 can be effectively heated by increasing the number of hot water rolls.

  Further, the temperature of the hot water that is passed through the first hot water roll 105a and the second hot water roll 105b according to the first embodiment may be any temperature as long as the flat film 201 can be subjected to appropriate heat shrinkage. However, as an example, a temperature of 40 ° C to 80 ° C, and a more preferable example is a temperature of 50 ° C to 70 ° C.

  In addition, in the foreign matter detection unit 104, the installation height from the surface of the flat film 201 to the lower end of the foreign matter detector 104b may be an arbitrary height depending on the size of the assumed foreign matter. In order to detect a foreign object having a size of 1 mm or more, it may be 1 mm.

  Moreover, the film which can be manufactured with the film manufacturing apparatus which concerns on this invention includes the polyolefin resin film for agriculture which consists of an olefin resin as an example. More specifically, a multilayer made of a compound such as a low density polyethylene resin, a linear low density polyethylene resin, an ethylene-vinyl acetate copolymer, and an ethylene-α olefin copolymer produced by using a high pressure method. A film can be manufactured with the film manufacturing apparatus which concerns on this invention.

  In addition, as the above-mentioned aqueous antifogging treatment agent, an emulsion of a thermoplastic resin such as an acrylic resin, a urethane resin, and an ethylene-vinyl acetate copolymer, and a hydrophilic colloidal inorganic compound such as colloidal silica and colloidal alumina Water-based paints mainly composed of These resins and inorganic compounds may be used alone or in combination of two or more, and it is preferable to add a small amount of a silicone surfactant to further improve the wettability.

  Moreover, as a coating device which apply | coats the water-based antifogging processing agent mentioned above to the flat film 201, the various coating device using a well-known technique can be utilized. As a more specific example, a dip coater, a gravure coater, a comma coater, or the like can be used. When a dip coater is used as a coating device, if a Mayer bar is additionally used, the film pressure when applying the aqueous antifogging treatment agent to the flat film 21 can be finely adjusted, and maintenance of the coating device can be performed. Since it becomes easy, it is more preferable.

  ADVANTAGE OF THE INVENTION According to this invention, the film manufacturing method and film manufacturing apparatus which do not produce a defect in an external appearance can be provided, For example, it can utilize for the manufacturing method of a polyolefin resin film for agriculture, a manufacturing apparatus, etc.

DESCRIPTION OF SYMBOLS 1 Film manufacturing apparatus 101 Inflation shaping | molding part 101a Annular die 101b Film material 101c Guide 101d Guide 101e Pinch roll 101f Pinch roll 102 1st roll 103 Dancer roll 104 Foreign substance detection part 104a 2nd roll 104b Foreign substance detector 105 Film temperature control part 105a First hot water roll 105b Second hot water roll 106 Flat expander roll 107 First corona discharge treatment unit 107a First corona discharge electrode 107b First corona discharge roll 108 Second corona discharge treatment unit 108a Second Corona discharge electrode 108b Second corona discharge roll

Claims (4)

A method for producing an agricultural polyolefin-based resin film in which an aqueous antifogging treatment agent is applied to the outer surface of a tubular film produced by inflation molding to form an antifogging coating film,
A flat film production process for producing a flat film by flattening a tubular film produced by inflation molding with a pinch roll;
A film temperature control step of heat treating both surfaces of the flat film with at least two hot water rolls;
A tension application step for applying tension in the width direction to the flat film heat-treated in the film temperature control step,
A corona discharge treatment step for corona discharge treatment on both surfaces of the flat film applied with tension in the tension application step;
A method for producing an agricultural polyolefin-based resin film, comprising: an antifogging coating film forming step in which an aqueous antifogging treatment agent is applied to both surfaces of the flat film subjected to the corona discharge treatment and dried.   The said film temperature control process is a manufacturing method of the polyolefin-type resin film for agriculture of Claim 1 which performs the said heat processing with the hot water roll which lets warm water of 40 to 80 degreeC pass inside.   2. The method for producing an agricultural polyolefin-based resin film according to claim 1, wherein the aqueous antifogging treatment agent is an aqueous paint mainly composed of a thermoplastic resin emulsion and a hydrophilic colloidal inorganic compound. An apparatus for producing an agricultural polyolefin-based resin film for applying an aqueous antifogging treatment agent to the outer surface of a tubular film produced by inflation molding to form an antifogging coating film,
A flat film manufacturing means for manufacturing a flat film by flattening a cylindrical film manufactured by inflation molding with a pinch roll,
Film temperature control means for heat treating both surfaces of the flat film with at least two heating rolls;
Tension applying means for applying tension in the width direction to the flat film heat-treated by the film temperature control means,
Corona discharge treatment means for performing corona discharge treatment on both surfaces of the flat film applied with tension by the tension applying means;
An apparatus for producing an agricultural polyolefin-based resin film, comprising: an anti-fogging coating film forming means for applying an aqueous anti-fogging treatment agent to both surfaces of the flat film subjected to the corona discharge treatment and drying it.

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