JPH0450893B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for width-splicing synthetic resin films such as agricultural vinyl chloride films. More specifically, the present invention relates to a width joint processing method that eliminates defects caused by unwelded parts when using a width joint processed product. "Conventional Technology" In recent years, farmers cultivating useful plants have widely adopted methods of promoting or suppressing cultivation of useful plants in greenhouses for the purpose of improving profitability. The covering materials for this house include vinyl chloride resin film, polyethylene film, and ethylene film.
Vinyl acetate copolymer film, polyester film, polycarbonate film, glass, etc. are used. Among them, vinyl chloride resin film is superior to other synthetic resin films in light transmittance, heat retention, mechanical strength, durability, workability, house adhesion, economic efficiency, etc. Therefore, it is the most used. This vinyl chloride resin film is usually manufactured by calender processing or extrusion processing, but there are limitations in terms of the size of the processing machines used in these processing methods, and wide synthetic resin films cannot be manufactured. The maximum width of normally manufactured film is
It is 4.6m. On the other hand, in recent years houses have become larger,
Houses are required to have a width of 5.4 to 12 meters or more. For this reason, synthetic resin films are usually joined by two to four sheets, and the bonding methods used include high-frequency welding using a high-frequency sewing machine or high-frequency welder, other heat welding, ultrasonic welding, etc. . However, from the viewpoint of processing efficiency, strength of the bonded surface, and quality of finish, high-frequency welding is most often performed using a high-frequency sewing machine. Conventionally, in width splicing of synthetic resin films, the overlapping portion of the two film ends is sandwiched between a pair of roller-type electrodes of a high-frequency sewing machine and welded using high frequency. Because welding is carried out by making the width of the overlapping part extremely large, there is an unwelded part left at the end of each film, and when this is used in an agricultural greenhouse, there may be water droplets or dust in that part. There were problems such as stagnation. In addition, as an improvement method, there is a method in which the width of the roller-type electrode is made wider than the overlapped part of the films to weld without leaving any unwelded parts, but sparks are generated at the edges of the roller-type electrode and the film is Due to the single layer structure, there were problems such as perforation and poor strength at the end of the welded part. ``Problems to be Solved by the Invention'' The present invention is a high-frequency welding process for synthetic resin films that does not cause stagnation of water droplets or dust in the unwelded parts of the overlapping welded parts of the films, and does not reduce the strength of the welded parts. As a result of intensive research into the method, we discovered that the above-mentioned problems could be solved by setting the width of the upper electrode roller and lower electrode roller of the high-frequency welding machine and the overlapping width of the ends of the synthetic resin film within specific ranges. This has led to the completion of the present invention. That is, an object of the present invention is to provide a method for splicing synthetic resin films, which prevents water droplets and dust from stagnation in the unwelded portions of the welded parts and which has excellent welding strength. "Means for Solving the Problems" The gist of the present invention is to provide a method for width-splicing synthetic resin films using a high-frequency welding machine, the upper (lower) electrode roller of the high-frequency welding machine The width is 15 to 40 mm, and the width of the lower (upper) electrode roller is 110% or more of the width of the upper (lower) electrode roller, and the overlapping width of the edges of the synthetic resin film to be welded is the width of the upper (lower) electrode roller. The present invention relates to a method for processing synthetic resin film width seams, which is characterized in that the width seaming is made 105 to 125% of the width of the synthetic resin film. The present invention will be explained in detail. First, the configuration of the present invention will be explained based on the drawings.
The figure is an explanatory front view of the vicinity of the roller electrode when width-splicing synthetic resin films is performed using a high-frequency welding machine, and this figure shows one mode in which the width of the lower roller electrode is larger than that of the upper electrode. shows. In the figure, 2 is an upper roller electrode whose rotation axis is 1, and 3 is a lower roller electrode whose rotation axis is 1'. They are inserted in an overlapping state with an overlapping width. While maintaining this state, the films 4, 4' are gradually moved toward the front (or behind) in the figure, and by applying a high frequency between both electrodes, the films 4, 4' are moved to the overlapped portion. The part corresponding to the width of the narrower electrode (the upper electrode in this figure) is continuously welded.
Width joints are processed. Examples of the synthetic resin film used in the method of the present invention include many synthetic resin films such as soft vinyl chloride film, vinylidene chloride film, and polyvinyl alcohol film, as well as laminated films of these films. The raw material of synthetic resin film, such as soft vinyl chloride film that can be used as agricultural film, is
The main components are vinyl chloride resin and plasticizer, and other subcomponents such as heat stabilizers, surfactants, ultraviolet absorbers, lubricants, weather resistance aids, color inhibitors, pigments, etc. are mixed using normal mixing techniques, such as ribbons. It is added and mixed using a mixer such as a blender or a Henschel mixer, then kneaded using a kneading machine such as a Banbury mixer or a mill roll, and then formed into a 30 to 200 μ thick product using a calender molding method or an extrusion molding method such as T-die casting or inflation. The film is then wound up using a winder. The film is
It is a rolled product with a width of approximately 50 to 460 cm and a length of 100 to 3000 m. If the thickness of the film is less than 30 μm, the strength of the film itself is insufficient, which is undesirable. If it is thicker than 200 μm, it is inconvenient for film forming operations and subsequent handling (including width splicing operations and house expansion operations). In addition, if the film width is less than 100 cm, the number of width seams will increase, which is undesirable, and if the film width is greater than 460 cm, storage, transportation, etc.
It becomes difficult to handle. If the length of the original fabric is less than 50 m rolls, there will be troublesome work such as transporting (carrying) the original fabric every time the original fabric is changed, setting it on the feed table, and aligning the welded part during width splicing work. Since width joint work cannot be performed, the operation rate of the welding machine will be reduced. Also, the length of the original fabric is
If the roll is larger than 1500 m, it will be too heavy and will be inconvenient to store, transport, and handle. Therefore, width splicing is performed using original fabrics of appropriate width and length, taking into account the size of the workplace, the type of processing machine, and workability. The high-frequency welding machine used in the method of the present invention has an upper or lower electrode roller width of 15 to 40 mm, and correspondingly, the lower or upper electrode roller width must be at least 110% of the upper or lower electrode roller width. . For example, if the upper electrode roller width is less than 15 mm, the overlap width of the film in the part to be welded must be narrow because the roller width is narrow, and it is technically recommended to weld at 105 to 125% of the upper electrode roller width. If this becomes difficult and the adhesive force per unit width of the welding part needs to be set higher depending on the application, it is necessary to set the high frequency current passing between the upper and lower roller electrodes to be large, and the overlapped part of the film during welding will be If it comes off in a meandering manner, sparks are likely to occur, and the strength of the welded end end is likely to be weakened due to the holes. Furthermore, if the width of the upper electrode roller exceeds 40 mm, the width of the welded part will be large, making it difficult to spread it onto the house, and the part that receives high frequency will have a negative effect on anti-fogging properties, which can easily cause problems with transparency. . Therefore, in practical terms, the width of the upper electrode roller should be 20~
Preferably it is 30mm. The lower electrode roller width is the upper electrode roller width.
If it is less than 110%, the edges of both electrodes will approach each other,
Sparks are likely to occur, and problems such as part of the welded part melting and creating holes are likely to occur. Practically speaking, the width of the lower electrode roller is preferably 115% or more of the width of the upper electrode roller. In the method of the present invention, the width of the end films to be overlapped for welding is equal to the width of the upper electrode roller.
It is necessary to be between 105 and 125%. If it is less than 105%, the upper electrode roller tends to come off from the overlapping part of the film during welding, causing sparks at the part where it comes off, causing holes, and weakening the strength of the edges of the welded part. There is a big concern that the house will break when it is expanded or used. Moreover, if it exceeds 125%, the width of the unwelded area becomes wider, and water droplets and dust accumulate in that area during use, making it impossible to solve the drawbacks of the conventional method. "Effects of the Invention" According to the method of the present invention, the width of one roller of a pair of roller electrodes of a high frequency welding machine is 15 to 40 mm.
and the width of the other roller is smaller than the width of one roller.
By setting the width to 110% or more, the overlapping width of the ends of the synthetic resin films to be welded is made slightly wider than that of one roller electrode, which prevents sparks during high-frequency welding and strengthens the width between the films. It can be spliced, and there is very little unwelded area in the overlapping parts of the film.
The spliced film does not collect dust and has excellent dust resistance. In addition, since the welding width is wide enough to provide welding strength, it is possible to apply a considerable amount of tension when, for example, extending the weld to a house, preventing wrinkles from forming and preventing pinholes, etc. There will be no breakage, etc. The method of the present invention is a welding processing method that prevents defects in film performance due to large amounts of unwelded parts that occur in currently widely practiced methods, such as deterioration of antifogging and dustproof properties in agricultural films. It has high utility value in a wide range of fields such as gardening and greenhouse horticulture. "Examples" Next, the method of the present invention will be explained in detail based on Examples, but the present invention is not limited to the following examples unless the gist thereof is exceeded. Example 1 A high-frequency sewing machine adhesive processing machine (manufactured by Nippon Koshuha Co., Ltd., model KL-1000) that allows the upper roller electrode and lower roller electrode to be replaced was equipped with an upper roller electrode width of 25 mm and a lower roller electrode width of 30 mm (upper roller electrode width of 30 mm). Equipped with upper and lower roller electrodes (120% of the roller electrode width), a 0.1 mm thick raw PVC agricultural film wound around two cores was set on each roll support, and the end of the film was Overlap width is 27
mm (108% of the upper roller electrode),
Roller electrode rotation speed 8m/min, voltage 100V,
Width joint welding was performed under the condition of a matching index of 40. I was able to weld it without any trouble. Example 2 Instead of the upper and lower roller electrodes used in Example 1, an upper roller electrode width of 30 mm and a lower roller electrode width of 30 mm were used.
Change to 45mm (150% of the upper roller electrode width),
Width joint welding was carried out in the same manner as in Example 1, except that the overlapping width of the films was changed to 33 mm (110% of the upper roller electrode width). I was able to weld it without any trouble. Comparative Example 1 The same upper and lower roller electrodes as in Example 1 were used, and width splicing was performed in the same manner as in Example 1, except that the overlap width at the film end was changed to 25 mm (100% of the upper roller electrode width). . Sparks were generated at the ends of the upper and lower roller electrodes, and numerous holes were created at the ends of the stacked films. Comparative Example 2 Width joint welding was performed in the same manner as in Example 1, except that the same upper and lower roller electrodes as in Example 1 were used, and the overlap width at the film end was changed to 35 mm (140% of the upper roller electrode width). Summer. I was able to weld it without any trouble. Comparative Example 3 Instead of the upper and lower roller electrodes used in Example 1, the upper roller electrode width was changed to 10 mm, the lower roller electrode width was 15 mm (150% of the upper roller electrode width),
The overlapping width of the film ends was changed to 12 mm (120% of the upper roller electrode width), and width joint welding was performed under the conditions of a roller electrode rotation speed of 8 m/min, a voltage of 130 V, and a matching index of 60. The end of the film meandered and sparks were generated in the area outside the overlapping area, resulting in numerous holes. Comparative Example 4 Instead of the upper and lower roller electrodes used in Example 1, the upper roller electrode width was changed to 45 mm, the lower roller electrode width was 50 mm (111% of the upper roller electrode width),
Example 1 except that the width of the overlapped portion of the film end was changed to 48 mm (107% of the width of the upper roller electrode)
Width joint welding was performed in the same manner as above. I was able to weld it without any problems. Comparative Example 5 Among the upper and lower roller electrodes used in Example 1,
Width joint welding was carried out in the same manner as in Example 1, except that the lower roller electrode width was changed to 25 mm (100% of the upper roller electrode width). Sparks were generated continuously, making welding difficult. Comparative Example 6 Using the same upper and lower roller electrodes as in Comparative Example 3, the overlapping width of the film edges was adjusted to the usual 30 mm.
Width joint welding processing was performed in the same manner as in Comparative Example 3, except that the width was changed to (300% of the upper roller electrode width). I was able to weld it without any problems. The various properties of the above width joint welded products (excluding the welded product of Comparative Example 5) were evaluated using the following test methods and are shown in Table 1. 1 Adhesive Part Strength Test Method Using a dumbbell for measuring tensile cutting load shown in JIS-K6732, four test pieces were prepared so that the welded part was in the center of the test piece. This test piece is 200mm/
The tensile cutting load was measured using a chopper with a pulling speed of min. The average value of the bond strength of the four pieces is shown. 2 Anti-fogging durability test method A single-roof type house with a frontage of 2.0 m and a depth of 10 m and a roof slope angle of 30 degrees (the length of the film on the slope is 231
cm) was expanded in October 1959 so that the welded part was horizontal at 1/3 from the bottom of the roof surface. (When expanded, the upper film of the welded part was placed above the roof surface.) Evaporated water tends to stagnate in the welded part after cooling, so the antifogging agent contained in the film is easily extracted. The adhesion phenomenon of water droplets was observed from the welded part upward every three months. Anti-fogging durability was evaluated based on the length of the dripped portion. The smaller the value, the less the antifogging agent is extracted and the longer the antifogging durability is. 3 Dust-proofing test method A house similar to 2 was expanded in December 1959 so that the welded part was horizontal to the center of the roof surface. (When expanded, the lower film of the welded part was placed on top of the roof surface.) Samples were taken every four months to include the welded part, and total light was transmitted using a spectrophotometer (Hitachi Model 323). The rate was measured.
The higher the value, the better the dustproof material. 4. House extensibility When a house similar to 2 was expanded so that the welded part was horizontal to the center of the roof surface, the state of wrinkles and sagging was visually evaluated. Evaluation criteria ○ No wrinkles or sagging × Wrinkles or sagging [Table]

[Brief explanation of the drawing]

The figure is a front explanatory view of the vicinity of an electrode roller of a high-frequency welding machine when width joining processing is performed according to the present invention. In the figure, reference numerals 1 and 1' indicate the rotating shaft of the electrode, 2 an upper roller electrode, 3 a lower roller electrode, 4 and 4' a welded film, and 5 a stand on which the film is placed.

Claims (1)

[Claims] 1. A method for width-splicing synthetic resin films using a high-frequency welding machine, wherein the width of the upper (lower) electrode roller of the high-frequency welding machine is 15 to 40 mm, and the lower (upper) ) The width of the electrode roller is 110% or more of the width of the upper (lower) electrode roller, and the overlapping width of the ends of the synthetic resin film to be welded is 105 to 125% of the width of the upper (lower) electrode roller. Synthetic resin film width joint processing method.