JPS6017341B2 - Surface treatment method for synthetic resin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects the degree of surface treatment over the entire length of a continuous synthetic resin film while running it, optimizes subsequent processing, and detects the degree of surface treatment of a continuous synthetic resin film over its entire length. The present invention relates to a surface treatment method that attempts to reprocess unsuitable portions that exist during the process.

By the way, synthetic resin films have been widely used for packaging in recent years.

For packaging, the film is processed into a bag shape or used as a single sheet, and furthermore, the film is coated with an adhesive on one side and used as an adhesive tape. In this manner, before the film is used, it is pre-printed with a product name, design, etc., or coated with an adhesive or the like.

However, in these processes, there are types of films that are difficult to adhere to, such as the printing ink used in the printing process or the adhesive used in the coating process.

For example, polyethylene, polypropylene, etc. belong to the category of materials that do not adhere well to printing inks, adhesives, etc. this is,
This is thought to be due to the fact that these resins have few polar groups in their chemical structure and have a high degree of crystallinity. Some other resins also have difficulty adhering to inks, adhesives, etc. for reasons based on other factors. However, polyethylene ethylene and the like are particularly suitable as packaging materials because they are inexpensive and have relatively high strength.

Therefore, these resins are used as packaging materials, while the adhesion with inks and adhesives can be improved by, for example, improving the inks themselves.
Alternatively, it is generally improved by special treatment of the film surface. The present invention relates to a technique of improving adhesion with ink, etc. through surface treatment, and whether or not this surface treatment provides appropriate compatibility with printing ink and adhesive over the entire length of the film. This method attempts to optimize the surface treatment by detecting parentheses and using the parentheses detection signal.

Examples of the above-mentioned surface treatment methods include the following.

1 Corona treatment 2 Flame treatment 3 Steam treatment 4 Chromic acid treatment 5 Sand treatment There are various other treatment methods, but these surface treatments cause physical and chemical changes in the film surface layer, causing printing ink and adhesive The compatibility with agents etc. is improved.

There is currently no clear explanation as to why the affinity improves. For example, in the case of corona treatment, it is said that this may be due to the formation of carbonyl groups or to a change in the physical shape of the surface. Here, the above-mentioned corona treatment is intended to cause physicochemical changes on the film surface by applying corona discharge generated by high voltage to the film surface, but the voltage may become unstable or The above treatment may not be carried out uniformly over the entire length of the film due to twisting of the discharge electrode. Even in other processing methods, uniform processing may not be achieved for some reason. In this way, ink will not adhere to areas where the degree of treatment has not reached a certain level, and even if it does, it will easily peel off, so it is necessary to detect such areas as defective areas or remove them. Must be.

Alternatively, the entire winding roll of film must be recognized as defective. There are various methods for detecting this defective part as follows. 1 Peeling test (method such as printing on the treated surface and pasting adhesive tape on it and then peeling it off to see the remaining ink) 2 Leakage test (applying liquid to the treated surface and calculating the surface tension from how it spreads) 3. Dyeing test (method of attaching a dye solution to the treated surface and checking the degree of treatment based on how dyed it is) However, all of the above test methods are done manually. On the other hand, the film is generally continuously formed and surface treated as seen in the inflation method, extrusion molding method, etc., and then wound up into a roll at the end. This is done by only partially cutting off the ends.

That is, the suitability of the surface treatment for the entire length of the roll is determined based on the results of a partial inspection, which is extremely inconvenient.

Furthermore, even if the extraction inspection were to be carried out over the entire length, this would require an extremely large amount of time and effort and would be impractical.

The present invention has been made in view of the above points, and it dyes the entire width of the film or the slit piece over the entire length of the film, and optically detects the dyeing density over the entire length. The objective is to inspect the degree of surface treatment over the entire length, and then go one step further and use the signals obtained from this inspection to optimize the surface treatment of the film.

Furthermore, if the above surface treatment is excessive, so-called blocking development occurs in which the film surfaces are attracted to each other, but the present invention can also detect excessively treated areas that can cause such development. .

Embodiments of the present invention will be described below based on the drawings. In FIGS. 1 and 2, 10 is a continuous synthetic resin film that is subjected to surface treatment, and 12 is a surface-treated film.

Here, the film 1 is a polyolefin or other synthetic resin film that does not have good affinity with adhesives such as printing inks and adhesives, and its form is a single leaf or a flat tube.

The unprocessed film 10 may be directly fed from a blown film extruder or an extrusion molding machine, or it may be discharged from such a forming machine in the form of a roll and then further processed and fed to another processing machine, such as a stretching machine. come. The untreated film 10 has now been corona treated.

In the figure, 14 is a high voltage electrode, 16 is an insulated roller, 1
8 is a high voltage generator, and the film is partially wound around the insulating roller 6 by a roller 20, and is exposed to corona discharge 22 while running. In the illustrated example, the surface treatment is performed only on the upper surface, but if another pair of high voltage electrodes 24 and an insulating roller 26 are placed side by side as shown in the third figure, the lower surface will also be surface treated. Flame treatments other than corona treatment are also performed at this stage.

The surface-treated film 12 is then passed through the inspection device 2.
8.

Here, the surface-treated film 12 has different running modes depending on its form, use, etc.

Next, let's classify the aspects. {1) If the film is a single leaf or a flat tube and the edge along the running direction must not be slit, ■ The film is a single leaf or flat tube and the edge along the running direction must not be slit. In the case of {1' above, this is especially required when flat tubes are used as the bag material, and in such cases the film is fed as is to the inspection device. Ru.

In the case of (2) above, this is a measure to be taken, for example, when the uneven thickness at the edge of the blown film is removed to obtain two monofilaments, or when the entire monofilament film must not be dyed.

In this case, the film is separated into a main body 32 and a slit piece 34 by a separation roller while one or both of the whole green parts are slit by a slit blade 30. The main body is wound up as a roll 36, while the slit piece 34 is Sent to 28th. Here, when the film 12 is a single sheet,
The slit piece 34 is sent as is to the inspection device 28,
If it is a tube, it is sent to the inspection device 28 through a process as shown in the fourth figure.

That is, in FIG. 4, 38 is a guide member, 4 vertical guide rollers, 42 is a turn bar, and 44 is a horizontal guide roller. The guide member 38 expands the V-shaped bent edge 34 and has a cone shape. Since the tube has a configuration as shown in FIG.
8, the vertical loaf 40 further expands the folds, the turn bar 42 further removes the creases, and finally the horizontal guide loaf 44 brings the state similar to that shown in FIGS. 1 and 2 to the inspection device 28. leading to.

The unslit film 12 or the film 34 which has become a slit piece is then dyed in an inspection device 28 as shown in FIG. 6, the excess dye solution is removed, and a certain amount of light is transmitted.

These steps are performed continuously while the film is running. In FIG. 6, the inspection device 28 includes a dyeing device 46, a cleaning device 48, a cleaning liquid removing device 50, a light source 52, and a light receiving element 54 arranged in sequence along the travel path of the film 34, and further includes A meter 56 is included to display the signal from element 54. The above devices are preferably housed in a single box 58, and the film enters through a slit 60 provided at one end of the box and exits through a slit 62 at the other end.

The dyeing device 46 includes a tank 66 for storing the dye liquid 64, a guide roller 68 for passing the film through the tank, and a squeezing roller 70 for removing the dye liquid adhering to the film.

A heating device 72 and a heating temperature detection device 74 are provided inside the tank or outside the tank as necessary. This dyeing device 46 uses a dipping method, but instead, a spray method may be used to inject the dye liquid toward the film, or it may be applied to the film using a roll. The treated surface of the film 34 is dyed in this dyeing apparatus so that the dyeing density changes depending on the degree of the surface treatment.

The cleaning device 48 removes excess dye liquid 64 that has adhered in the previous step to prevent problems from occurring in the subsequent light irradiation step, and includes a guide roller 76 that bends and runs the film in an approximately V-shape. , a cleaning tank 78 that covers the film running path around the guide roller, and a cleaning liquid supply pipe 80 and discharge pipe 8 provided above and below this cleaning tank, respectively.
2.

The film exiting the squeeze roller 70 passes through the guide roller 76.
It travels through the cleaning tank 78 while coming into contact with the water, and is washed by a cleaning liquid such as water flowing from the main supply pipe 80 toward the discharge pipe 82 along the way.

At this time, since the flow direction of the cleaning solution and the running direction of the film are opposite, the more the film advances, the more it comes into contact with new cleaning solution, and in the end, the excess dye solution is almost completely removed and the film is placed in the cleaning tank. It will come out from within 78.
A cleaning liquid removing device 5 is provided at a location where the film exits the cleaning tank 78 and is composed of a pair of moisture absorbing rollers 84 such as cotton rolls.

In addition, if necessary, a nip roll 8 may be installed in front of this roller 84.
6 is provided. The cleaning liquid is also squeezed out by the nip rollers 86, and the squeezed liquid falls, so a discharge pipe 88 for this purpose is provided at the bottom of the box. The cleaning liquid removing device 50 may be a dryer that blows hot air toward the film. The light source 52 and the light receiving element 54 are placed facing each other with a film in between.

The light receiving element 54 is a selenium photocell, a photoelectron emitting element, or the like, and a condenser lens 90 and a full filter 92 are provided on the optical axis from the light source toward this element. The light emitted from the light source 52 is converted into parallel light by a condensing lens 90, and then passed through a filter 9.
2, the light is turned into monochromatic light having a peak at a light wavelength of 610 m, for example, and then transmitted through the film 34 and sent to the light receiving element 5.
4. Although this example is a light transmission method, a reflection method may also be used in which a light source and a light receiving element are both placed on the processing surface and the amount of reflected light is detected. The output from the light receiving element 54 is displayed in analog or digital form by a meter 56.

Here, when dyeing the entire surface-treated surface of the film 12 without slitting it as in [1] above, the inspection device is placed in the film running path so that the entire width of the film runs within the inspection device 28 shown in FIG. The amount of transmitted light is measured at a desired location, for example at the center or both sides.

Further, when the film 12 is slit as in '2) above, the inspection device is installed within the travel path of the slit piece 34 as shown in FIGS. 1 and 2.

In this case, the inspection device 28 may be installed on the travel path of both slit pieces. Inspecting two slit pieces has the following advantages: That is, the high voltage electrode 14
The distance between the film and the insulating roll 16 may increase in the width direction of the film, and therefore the degree of surface treatment differs in the width direction of the film. However, if the slit pieces on both sides are inspected, such defects can be detected based on the difference in the amount of transmitted light, and the problem of the electrodes can be corrected and the degree of processing can be made uniform. Furthermore, when the film is made into a slit piece and the film 34 is discharged in the state shown in FIG. 4, different measures are taken depending on whether it is single-sided or double-sided processing.

That is, in the case of single-sided processing, the amount of transmitted light can be detected with a single spot light 94 as shown in FIG. 7 using a pair of light sources and a light receiving element. However, in the case of double-sided processing, since the slit piece 34 is discharged with both treated surfaces facing upward, it is better to irradiate the spot lights 94 and 96 in parallel as shown in FIG. 8. For this reason, irradiation light is generated as shown in FIG.

In the figure, 98 is a half mirror, and 100' is a reflecting mirror, and the light emitted from the single light source 52 is split into two optical paths by the half mirror 98, one of which passes through one of the slit pieces 34, and the other The reflecting mirror 100' transmits light through the other slit piece, and then the respective photoelectric elements 54, 102
It is reached. Meters 56 and 104 are connected to the photoelectric elements 54 and 102, respectively, and the amount of transmitted light is measured separately. The meters 56, 104 are ammeters,
It consists of a voltmeter or similar instrument, but
It is also possible to take out a part of the electrical signal from the light-receiving element that reaches this meter and send it to a recorder 106 as shown in the first figure and record it on recording paper in analog or digital form.

Also, as shown in Figure 1, a part of the above-mentioned extracted signal is taped.
It is possible to send the tape to the printer 108 and insert the tape into the location corresponding to the defective surface treatment, so that the location can be immediately identified after the inspection is completed.

A known tape inserter 108 can be used, and a colored adhesive tape or the like can be locked to the defective part of the slit piece 34 or the undyed film part 32 corresponding to the defective part by the above signal. become.

Further, an alarm device such as a buzzer can be connected together with the above-mentioned filter, recorder, tape inserter, etc. or alone.

Further, the above signal is fed back to the original surface treatment section. An example of these block diagrams is shown in FIG. In the figure, 54 is a selenium photovoltaic cell, and the electrical signal from this cell passes through a W converter and reaches a filter 56 and a comparator.

A comparator sets a voltage and extracts a signal corresponding to the defective surface treatment, and the resulting output from the amplifier activates an alarm device and a tape inserter. Further, the signal from the selenium photovoltaic cell 54 passes through the IV converter to the control circuit, and is fed back as a manipulated variable to the high voltage generator 18 of the surface treatment section. On the other hand, the output can also be used as shown in FIGS. 10 and 11.

In FIG. 10, the latter surface-treated section has the same configuration as the first surface-treated section, but it is provided within the running path of the main body of the film other than the slit pieces, and is located between the first surface-treated section and the other surface-treated section. A film travel path between the surface treatment section and the film travel path is set so that the film travel path between the first surface treatment section and the light irradiation position is approximately the same length. Therefore, the film is subjected to appropriate surface treatment over its entire length. In Fig. 11, the output signal from the Se photocell becomes a feedback voltage and is fed back to the original surface treatment section, while also being sent to the controller of another surface treatment section that performs reprocessing to compensate for insufficient processing. ing. This method cannot be adopted if the film must not be slit.

However, if the other surface treatment section is provided at a position where the film reaches after the light irradiation, and the manipulated variable is controlled by delaying from the time of light irradiation until the time when the film reaches the other surface treatment section, Regardless of the slit processing, reprocessing is possible.

In this case, the delay circuit may be provided within the controller shown in FIG. FIG. 12 shows an embodiment in which the surface treatment method of the present invention is applied when producing two strips of film by slitting a film sent from a blown film extruder or the like.

Here, output signals corresponding to the upper film and the lower film are generated from the inspection device and sent to the front and rear high voltage generators, respectively.

As a result, the film discharged as a take-up roll is subjected to appropriate surface treatment over its entire length. next,
The relationship between the amount of surface treatment, amount of dyeing, and light transmittance of the film will be described.

FIG. 14 shows the relationship between the light transmittance of the dyed film and the amount of corona treatment.

Here, the plate current is a current flowing through the plate of the vacuum tube type corona treatment device, and the higher the current value, the greater the amount of discharge and the greater the amount of surface treatment. In addition, the dye solution is 0.5% of the enemy sicBlue7 (c.1.42595) as a dye in water.
A transparent additive-free polyethylene film with a thickness of 70 mm was dyed by the dip method at 50 mm for 2 seconds using a product dispersed in a weight percent.

Staining was carried out on three films with different amounts of surface treatment, after which each film was irradiated with monochromatic light with a spot diameter of 100 feet, and the amount of transmitted light was measured using an Se photocell.
As is clear from this table, as the plate current increases, that is, as the amount of surface treatment increases, the staining concentration also increases, and it can be seen that there is a proportional relationship between the degree of treatment and the staining concentration of the treated surface. The above staining degree is shown in Figures 15 and 16.
As is clear from the figure and FIG. 17, it also changes depending on the dyeing temperature and the type of dye solution.

Here, the same films and dyes as in FIG. 14 are used.

Figure 15 shows how to add BasicBI female 7 to water as a dye solution.
．． The graph shows the measurement results of the amount of transmitted light when the temperature of the dye solution was variously changed using a 5% by weight dispersed dye solution.

From this table, it can be seen that as the dyeing temperature becomes higher, the difference in dyeing density depending on the degree of surface treatment becomes larger.
Figure 16 shows the European standard in a solvent of 20% ethanol and 80% water.
It shows the measurement results obtained when dyeing was carried out at varying temperatures using a dye solution in which 0.5% by weight of icBlue7 was dispersed.

In this case, the result is relatively similar to that shown in FIG.
Figure 17 shows 0.5 of mother sicBlue7 in ethanol.
It shows the measurement results obtained when dyeing was carried out in the same manner using a dye solution dispersed in weight percent.

In this case, it can be seen that the dyeing density is stable even if the temperature during dyeing changes.

From the above measurement results, when dyeing is carried out using the above-mentioned measuring device, it is possible to perform good inspections even when using a dye prepared by dispersing the dye in water or using a dye liquid dispersed in ethanol. It is obvious that when using a dye solution in which a dye is dispersed in water, a heating device 72 as shown in FIG. maintained at temperature.

In addition, the dyes mentioned above are not dyed by causing a chemical reaction with the film substrate, but dyes are selected that dye by chemically reacting only with the treated side of the film, and the amount of dyeing varies depending on the degree of treatment. Selected.

According to experiments conducted by the present inventors, triallylmethane dyes meet these requirements well, and in particular, Bas.
icBI female 7 (c.1.42595) was found to be superior. As described above, the slit piece 34 that has been inspected is wound up and rolled as shown in FIGS. 1 and 6.
The film 12 which is used as a roll 110 and is not slit is similarly wound up and stored.

Such a roll is unraveled and subjected to comparative inspection for overall density unevenness, and portions of the film corresponding to poor surface treatment areas with low density are cut out. Alternatively, surface treatment is performed again. This operation is required in the first illustrated embodiment. The same thing is done with recording paper by the recording device 106. Further, in this operation, since the defective portion is indicated on the film body 32 by the tape inserter 108 or the like, it can be easily removed before printing or applying an adhesive.

Furthermore, according to the embodiments of FIGS. 10 and 12 of the present invention, inspection is performed during the film running process, and various film manufacturing machines such as blown film extrusion equipment, stretching equipment, extrusion molding equipment, extrusion coaters, etc. The degree of surface treatment can be inspected in-line while the film that is continuously discharged from the processing machine is being surface treated.

At the same time, the entire length of the film can be subjected to appropriate surface treatment before being discharged.

[Brief explanation of the drawing]

FIG. 1 is a side view of a film surface treatment device according to the present invention;
FIG. 2 is a plan view thereof. FIG. 3 is a side view of the double-sided processing apparatus. FIG. 4 is a plan view of the V-shaped slit piece folding device. FIG. 5 is a sectional view taken along the line V-V of the film in FIG. 4. 6th
The figure is a vertical sectional view of a device for detecting the degree of surface treatment. 7th
The figure is a partially cutaway plan view of a folded V-shaped slit treated on one side, and FIG. 8 is a partially cutaway plan view of a piece treated on both sides. FIG. 9 is a diagram showing the principle of the light transmission amount measuring device. FIGS. 10 and 12 are explanatory diagrams of other embodiments of the present invention. FIG. 11 is a block diagram applied to the embodiment of FIG. 12. FIG. 13 is an example of a block diagram for processing electrical signals. FIG. 14 is a graph showing the relationship between the amount of transmitted light and the degree of surface treatment.
FIGS. 15, 16, and 17 are graphs showing the relationship between the amount of transmitted light, the degree of surface treatment, and the dyeing temperature. 12・
...Surface treatment film, 28...Detection device, 30...Slit blade, 32...Film body, 34
... Slit piece, 36 ... Roll, 38 ... Guide member, 42 ... Turn bar, 46 ...
...Dyeing device, 48...Cleaning device, 50...
-Cleaning liquid removal device, 52...Light source, 54...
... Light receiving element, 56 ... Meter, 64 ...
... Dye liquid, 108 ... Tape inserter, 11
0...Roll, 106...Recorder. , Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 7 Fig. 8 Fig. 6 Fig. 9 Fig. 10 Fig. 11 Fig. 13 Fig. 14 Fig. 15 Fig. 12 Fig. 16 Figure 17

Claims (1)

[Claims] 1. While surface-treating a traveling continuous synthetic resin film, part or all of the treated surface is dyed with a dye solution, then the excess dye solution is removed, and the resulting halo is dyed with a dye solution. A surface treatment method characterized by irradiating a portion, converting the amount of transmitted light or reflected light into an electrical signal, and obtaining a manipulated variable from the electrical signal to control the processing amount of a surface treating section. 2. The surface treatment method according to claim 1, wherein the film is a single film, and the entire surface of one or both surfaces of the film is subjected to surface treatment. 3. The surface treatment method according to claim 1, wherein the film is a flat tube, and the entire surface of one or both surfaces of the film is subjected to surface treatment. 4. The surface treatment method according to claim 1, 2 or 3, wherein the entire surface treatment area is dyed. 5. The surface treatment method according to claim 1, 2 or 3, wherein only the slit pieces produced by slitting the central part or the edge along the running direction of the film are dyed. 6. The surface treatment method according to claim 5, wherein a single slit piece produced by slitting one edge of the film along the running direction is dyed. 7. The surface treatment method according to claim 5, wherein two slit pieces produced by slitting both edges of the film in the running direction are dyed. 8. The dyeing is carried out with a dye solution in which the dye is dispersed in water,
The surface treatment method according to claim 1, wherein the surface treatment method is carried out by heating the dye solution. 9. The surface treatment method according to claim 1, wherein the dyeing is carried out at room temperature using a dye solution in which a dye is dispersed in a solvent other than water. 10. The surface treatment method according to claim 1, wherein the original surface treatment section is controlled using the manipulated variable. 11. The surface treatment method according to claim 1, wherein another surface treatment section that performs reprocessing is controlled using the manipulated variable. 12 The other surface-treated section is provided in a running path of the film other than the slit piece, and the film running path between the first surface-treated section and the other surface-treated section is set in the same direction as the first surface-treated section. 12. The surface treatment method according to claim 5, 6, 7 or 11, wherein the length is set to be the same as the film travel path between the irradiation position of the light and the irradiation position of the light. 13. The other surface treatment section is provided at a position where the film reaches after the light irradiation, and the manipulated variable is controlled by delaying from the time of the light irradiation until the time when the film reaches the other surface treatment section. The surface treatment method according to scope 4 or 11. 14. The other surface treatment section is provided in the travel path of the film main body that the film main body reaches after the light irradiation to the slit piece, and the operation amount is changed from the time when the film main body irradiates the slit piece with light. The surface treatment method according to claim 5, 6, 7, or 11, wherein the control is delayed until reaching the other surface treatment section.