JP2000346800A - Method and apparatus for measuring coating ratio of thermoplastic resin coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the coating ratio of the thermoplastic resin coating film formed on the surface of the side wall part of a glass product in an inspection chamber on the spot in a relatively simple manner. SOLUTION: Ultraviolet rays 3 with a predetermined wavelength are allowed to be incident on the surface of a glass product 4 coated with a thermoplastic resin and the coating ratio of the thermoplastic resin coating film P on the glass product is measured on the basis of the quantity of the reflected light 6 from the surface of the coated glass product after passing through a P- polarizer 7. A coating ratio measuring apparatus is equipped with a light source part 1 having a beam splitter 2 allowing the ultraviolet rays 3 with the predetermined wavelength to be incident on the surface of the glass product 4, a first detector 5 for detecting the reflected light from the beam splitter 2, a light detection part having a second detector 9 detecting the scattered reflected light 6 reflected from the surface of the glass product and the P-polarizer 7 and an operator 11 for dividing the output value B from the second detector 9 by the output value A from the first detector 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the coverage of a thermoplastic resin film, and more particularly to a method of irradiating a glass product with ultraviolet rays to coat the thermoplastic resin film applied to the surface of the glass product. The present invention relates to a method and an apparatus for measuring a rate.

[0002]

2. Description of the Related Art A glass product, for example, a glass container such as a glass bottle is formed in a molding section of an IS machine or the like by a metal mold, and then tin oxide or titanium oxide is formed on the surface by a hot end coating process at an inlet side of an annealing furnace. After forming a hard inorganic thin film such as a thermoplastic resin such as a surfactant, a wax, or a thermoplastic resin such as polyethylene, a cold end coating process is performed at the outlet side of the annealing furnace. The cold end coating process is used to provide lubricity to the surface to prevent abrasion when glass containers hit each other while being conveyed by a conveyor or the like, and to prevent breakage (breaking) due to abrasion. It is.

As the organic film, a thermoplastic resin, particularly polyethylene (including a copolymer mainly composed of polyethylene), is preferably used from the viewpoint of low cost and good scratch resistance. However, if the number of sprays and the spray amount (per spray) are increased to increase the abrasion resistance and the area ratio covered with the polyethylene film is increased, the label will not be stuck with glue (usually starch glue). This is because polyethylene is non-polar and has no adhesiveness to the label paste.
Therefore, the polyethylene film is frame-treated (Japanese Unexamined Patent Publication No.
Special processing such as that described in Japanese Patent Application Laid-Open No. 9-57991) has been proposed, but such processing is costly and inefficient. Also, if a special adhesive is used instead of inexpensive glue, the sticking property of the label is improved, but the cost is increased. An organic film such as polyethylene has good adhesion to a tin oxide film layer or the like.

[0004] On the other hand, when the number of sprays and the spray amount are reduced and the area ratio covered with the polyethylene film is reduced, the scratch resistance is deteriorated and the container is easily broken. Therefore, it is desirable to manufacture a glass container partially formed with a polyethylene thin film having an appropriate thickness. This is because the portion without the polyethylene thin film adheres well to the label, and the portion with the polyethylene thin film has scratch resistance. For this purpose, it is desirable to measure the coverage of the polyethylene thin film on the surface of the glass container, particularly on the side wall surface, and feed back the result to the production site to manage the polyethylene thin film. However, up to now, there has been no known method and apparatus for measuring the coverage of a thin film of a thermoplastic resin such as polyethylene formed on a glass container relatively easily and accurately in an on-site inspection room or the like.

[0005]

SUMMARY OF THE INVENTION According to the present invention, it is possible to relatively easily measure the coverage of a glass product, particularly a thermoplastic resin film formed on the surface of a side wall portion of a glass container, in a field inspection room or the like.
It is another object of the present invention to provide a method capable of measuring with relatively high accuracy. The present invention further provides a device which can measure the coverage of a thermoplastic resin film formed on the surface of a glass product, especially a glass container, relatively easily and with relatively high accuracy in an on-site inspection room or the like. With the goal.

[0006]

According to the present invention, there is provided a method for measuring the coverage of a thermoplastic resin film on a glass article having a surface coated with a thermoplastic resin. Wherein ultraviolet light having a predetermined wavelength is incident on the surface, and the coverage of the thermoplastic resin film is measured based on the amount of reflected light from the surface (claim 1).

[0007] Cold end coating is usually performed by spraying an aqueous dispersion of a thermoplastic resin into a glass container at about 70 to 150 ° C. At this time, the surface of the glass container is wetted by the spray of the aqueous dispersion, but is condensed by the water repellency of the high-temperature glass surface, and a large number of elliptical islands having an extremely small area (see s in FIG. 2) and An aggregate (see s ′ in FIG. 2) is formed, and the island-shaped portions and the like are evaporated and then solidified by cooling to form a thermoplastic resin film (P in FIG. 2).
See). It has been confirmed by the present inventors by atomic force microscopy or the like that the islands and the like after solidification have a rough surface, that is, a rough surface, which is considered to be due to condensation.

[0008] Since ultraviolet light has a short wavelength, it is liable to be scattered and reflected by the convex portion of the thermoplastic resin film which is a rough surface. On the other hand, ultraviolet rays incident on a portion where the glass (inorganic thin film) not covered with the thermoplastic resin film is exposed are regularly reflected. Therefore, the amount of scattered reflected light is proportional to the area of the thermoplastic resin film. That is, the ratio between the amount of scattered reflected light from the glass product surface and the amount of incident light is substantially proportional to the coverage of the thermoplastic resin film. Therefore, the coverage of the thermoplastic resin film can be measured relatively easily and with relatively high accuracy based on the amount of light reflected from the glass product surface.

In the case of the first aspect of the present invention, it is preferable to measure the amount of reflected light after passing through the P polarizer (claim 2). The amount of scattered reflected light increases as the incident angle decreases, and the intensity varies depending on the polarization direction. The intensity of linearly polarized light parallel to the incident surface is the highest. Therefore, by measuring the P-polarized light that has passed through the P-polarizer, it is possible to efficiently measure the coverage of the thermoplastic resin film.

The apparatus for measuring the coverage of a thermoplastic resin film according to the present invention is an apparatus for measuring the coverage of a thermoplastic resin film on the surface of a glass product having a surface coated with a thermoplastic resin, the apparatus comprising: Is a light source unit having a beam splitter that causes ultraviolet light having a predetermined wavelength to enter the surface; a first detector that detects specularly reflected light from the beam splitter; and a second detector that detects scattered reflected light reflected from the surface.
And a light receiving unit having a P polarizer and a calculator for dividing an output value from the second detector by an output value from the first detector.

Since ultraviolet light having a predetermined wavelength is incident on the surface, the amount of scattered and reflected light can be increased. The first detector that detects the regular reflection light from the beam splitter of the light source unit can detect the light amount of the light source unit, that is, the light amount proportional to the incident light amount. Since the second detector for detecting the scattered reflected light reflected from the surface and the light receiving section including the P polarizer are provided, the second detector efficiently reflects the scattered reflected light from the thermoplastic resin film. Can be detected. Since an arithmetic unit for dividing the output value from the second detector by the output value from the first detector is provided, the output value from the second detector, that is, the amount of scattered and reflected light from the thermoplastic resin film is calculated. , By the output value from the first detector, the ratio of the output value from the second detector to the output value from the first detector, that is, the reflectance can be obtained. Based on the reflectance, the coverage of the thermoplastic resin film can be determined relatively easily and with relatively high accuracy.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1 showing the principle of the present invention, reference numeral 1 denotes a light source of ultraviolet light (preferably at a wavelength of 340 nm), 2 denotes a beam splitter, and a part of the ultraviolet light 3 from the light source 1 is: The light passes through the beam splitter 2 and is incident on the surface of the side wall 4 of the glass bottle at an incident angle θ. Ultraviolet light 3 specularly reflected by the beam splitter 2 is detected by an incident ultraviolet detector 5. A polyethylene thin film P is formed on the surface of the side wall 4 of the glass container by a spray method. As shown in FIG. 2, the thin film P is made up of discontinuous, elliptical islands s and an aggregate s ′ of islands s. FIG.
As shown in the figure, the height of the island-shaped portion s and the aggregate s' is usually about 0.01 to 0.5 [mu] m, and it is an uneven surface in the form of a continuous peak or a mountain range, that is, a rough surface. FIG. 6 shows an example of a topographic photograph of a part of the island s by an atomic force microscope, and the vertical axis on the right side is a height scale based on shading. In this case, the height of the island portion s is about 150 to 250 nm (0.15 to 0.25 μm).
It can be seen that the area is uneven in a mountain range.

Therefore, the polyethylene thin film P on the side wall 4
The ultraviolet light 3 incident at a relatively small incident angle θ is scattered to generate scattered reflected light 6. The diameter of the spot portion 3a on the side wall portion 4 of the incident ultraviolet light 3 is usually about 1 to 5 mm. The reflection angle δ formed by the center line of the scattered reflected light 6 and the normal line 10 is small, and is generally 30 degrees or less. Scattered reflected light 6
Pass through the P-polarizing plate 7 and enter the condenser 8. Concentrator 8
Is a truncated cone made of an aluminum plate, and the inner surface is mirror-finished to form a reflecting mirror 8a. Concentrator 8
Has a structure in which the diameter of the entrance is large and the diameter of the exit is small, and the scattered reflected light 6 entering the condenser 8 is condensed and detected by the scattered reflected light detector 9 as shown in FIG. You. The sum of the incident angle θ and the scattering reflection angle δ is preferably about 30 to 45 degrees.

The output signal A of the incident ultraviolet detector 5 and the output signal B of the scattered / reflected light detector 9 are input to a divider 11 where the division of B / A is performed. In this specification, B / A is referred to as the reflectance H of the scattered reflected light. The surface of the side wall portion 4 is divided into a portion covered with the polyethylene thin film P and irregularly reflected and a portion r where the uncoated smooth inorganic thin film is exposed (see FIG. 2). Therefore, the reflectance H
Is proportional to the coverage C of the polyethylene thin film P.

[0015]

FIG. 3 shows the apparatus used in the embodiment. FIG.
The same reference numerals denote the same parts. Reference numeral 12 denotes a light source lamp (for example, a xenon lamp). Light source lamp 12
The emitted light is converted into a parallel light flux by the collimator lens 13, and then becomes ultraviolet light 3 having a predetermined wavelength by the ultraviolet interference filter 14. Part of the ultraviolet light 3 is reflected by the beam splitter 2 and is incident on the incident ultraviolet detector 5.
Is detected by An output signal A from the incident ultraviolet detector 5 is input to a divider 11.

The ultraviolet light 3 transmitted through the beam splitter 2
A spot portion 3a (see FIG. 2; preferably having a diameter of 1 to
2mm). The incident angle θ is set as small as possible within a range of 45 degrees. Largest scattered reflected light 6
This is for obtaining the strength. In the case of the apparatus shown in FIG. 3, the scattering reflection angle δ is 0 degree. This is for obtaining the intensity of the scattered reflected light 6 as large as possible.

The scattered reflected light 6 is transmitted to a collimator lens 16
After being converted into a parallel light beam, the light passes through the P-polarizing plate 7 and becomes a polarized light parallel to the incident and projected surface. Is detected. The output signal B from the scattered and reflected light detector 9 is divided by the divider 1
1, the divider 11 divides B / A, and the reflectance H (%) is obtained.

The side wall 4 has a slight variation in the diameter of each glass container, a slight variation in the radius in the circumferential direction at the same position in the longitudinal direction, or a slight local unevenness even in a single container. is there. There is a similar variation in the length direction. Therefore, in order to increase the measurement accuracy, a mechanism that ensures that the spot 3a having a constant area is always positioned on the surface of the side wall 4, that is, the distance between the condenser lens 15 and the portion 4a where the spot 3a is connected is constant. It is desirable to provide a mechanism that becomes Next, this mechanism will be described.

As shown in FIGS. 3 and 4, the lower portion of the side wall portion 4 is supported by a driving roller 32 and a backup roller 34 having rubber rings 33 and 35 protruding slightly, respectively. I have. Drive roller 3
2 is intermittently rotated in the same direction by a stepping motor 31. At the same time, the side wall 4 is also intermittently rotated in the same direction. During the stop, the above measurement is performed, and the rotation is restarted, and the measurement is performed again at the next stop, so that the measurement is repeated.

The stepping motor 31 is mounted on a slide 36 having a horizontal upper surface and slidable along a support plate 37. Reference numeral 39 denotes a vertical screw screw rotatably mounted on the fixed base 38, and reference numeral 40 denotes a handle for rotating the screw screw 39. The support plate 37 is formed with a female screw to be screwed with the screw screw 39, and when the handle 40 is rotated, about 1 m per rotation.
It moves up and down with an accuracy of m. Slide 36
Has a slot 45 through which a screw screw 39 is passed, formed in the axial direction of the side wall portion 4, so that the slide 36 can slide in the axial direction of the side wall portion 4 along the support plate 37. ing. The slide 36 can be finely moved manually or electrically by a mechanism not shown.

As shown in FIG. 2, the spot portion 3a, that is, the portion 4a has a portion r where the glass surface (inorganic thin film) is exposed. The light incident on the portion r is specularly reflected to generate specularly reflected light 26. The specularly reflected light 26 passes through the condenser lens and the cylindrical lens 25 and enters the quadrant photodetector 27. The quadrant photodetector 27 includes four photodiode elements 27a, 27b, 27c, and 27d, and the output signals from the elements 27a, 27b, 27c, and 27d are added to an adder (not shown) or a differential amplifier. (Not shown) and the like.

The output signal 29 of the position detecting circuit 28 is input to a monitor (not shown) or a meter (not shown). The position detection circuit 28 outputs 0 when the spot 3a having a certain area is located on the surface of the side wall 4 and deviates from 0 when it is not located.
Which is input to the monitor or meter,
It is configured to be displayed.

Based on the displayed value, the handle 40 is rotated until the displayed value becomes 0, and the support plate 37 and thus the side wall portion 4 are moved up and down. Alternatively, the output signal 29 may be input to an electric mechanism (not shown) that moves the support plate 37 up and down, and the support plate 37 may be automatically moved up and down until the display value becomes zero.
After one round of measurement, the slide 36 and thus the side wall 4 are moved a predetermined distance, for example, 1 or 2 mm axially, and the same measurement is repeated. By repeating this operation, the reflectance H of almost the entire side wall 4 can be measured. However, it is usually sufficient to measure several representative portions. The output signal 41 from the divider 11 is input to a personal computer 42, and necessary data such as the reflectance for each measurement and the average value of the reflectance for each round measurement are displayed on a monitor. . Note that instead of the divider 11, an arithmetic unit having a division function may be used.

FIG. 5 shows the reflectance H measured by the above apparatus.
FIG. 4 is a diagram showing a relationship between (%) and a coverage C (%) of a polyethylene thin film P. However, three flat glass plates of 20 cm × 40 cm (temperature: 100 ° C.) were used as a base material of the polyethylene thin film P, and an aqueous dispersion of polyethylene was sprayed on each plate under different conditions. Then, the coverage C at a specific position was measured with a scanning laser microscope. At the same position, the ultraviolet ray 3 (wavelength 340n) of the apparatus of FIG.
m) is incident (spot diameter 1 mm) and the reflectance H (%)
Was measured. It can be seen that the reflectance H and the coverage C have a substantially linear relationship. Using the apparatus of FIG. 3 and the diagram of FIG. 5, the polyethylene thin film P on the surface of the side wall 4 of the glass container is used.
Was able to be determined.

[0025]

According to the present invention, the coverage of a glass product, particularly a thermoplastic resin thin film formed on the surface of the side wall of a glass container, can be measured relatively easily and with relatively high accuracy in an on-site inspection room or the like. It has the effect of being able to.

[Brief description of the drawings]

FIG. 1 is an explanatory drawing for illustrating the principle of the measuring method of the present invention.

FIG. 2 is an explanatory schematic view showing a state of a thermoplastic resin film formed on a surface of a glass product.

FIG. 3 is an explanatory front view of an example of the device of the present invention.

FIG. 4 is a side view of the apparatus of FIG. 3, as viewed from the line IV-IV.

5 is a diagram showing an example of the relationship between the reflectance measured using the apparatus of FIG. 3 and the coverage of a thermoplastic resin film.

FIG. 6 is a photograph substituted for a topographic drawing of an island by an atomic force microscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultraviolet light source (light source part) 2 Beam splitter (light source part) 3 Ultraviolet light 4 Side wall part of glass bottle (glass product) 5 Incident ultraviolet detector (first detector) 6 Scattered reflected light (reflected light) 7 P polarizing plate (P polarizer) 9 Scattered reflected light detector (second detector) 11 Divider (arithmetic unit) 12 Light source lamp (light source) 14 Ultraviolet interference filter (light source) P Polyethylene thin film (thermoplastic resin film) θ Angle of incidence

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ken Takenouchi 4-4-21 Nomidai, Kanazawa-ku, Yokohama, Kanagawa Prefecture D-407 F-term (reference) 2G059 AA05 BB10 CC12 EE02 EE05 FF01 HH03 JJ19 JJ22 KK03 MM14 NN05 4G059 AA01 FA14

Claims (3)

[Claims] 1. A method for measuring a coverage of a thermoplastic resin film on a surface of a glass product having a surface coated with a thermoplastic resin, wherein ultraviolet light having a predetermined wavelength is incident on the surface and reflected from the surface. Measuring the coverage of the thermoplastic resin film based on the amount of light,
Method for measuring coverage of thermoplastic resin film. 2. The method for measuring the coverage of a thermoplastic resin film according to claim 1, wherein the amount of reflected light is measured after passing through a P polarizer. 3. An apparatus for measuring the coverage of a thermoplastic resin film on a surface of a glass product having a surface coated with a thermoplastic resin, the apparatus comprising: a beam splitter for causing ultraviolet light having a predetermined wavelength to enter the surface. A first detector for detecting light reflected from the beam splitter; a second detector for detecting scattered reflected light reflected from the surface; a light receiving unit including a P polarizer; and a second light detector. An apparatus for measuring the coverage of a thermoplastic resin film, comprising an arithmetic unit for dividing an output value from a detector by an output value from a first detector.