JP2000310594A - Method and apparatus for inspecting polymeric molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inspection method and apparatus capable of automatically inspecting the surface treated state, component and quality such as thickness or the like of a polymeric molded article over the entire surface thereof. SOLUTION: The unpolarized light emitted from a lamp 3 is linearly polarized in the specific direction by a polarization plate 4 provided in parallel to a film 2 to be incident on the film 2. The transmitted light from the film 2 is split into a P-polarized component and an S-polarized component by the beam splitter of a polarization camera and both components are respectively detected by CCD image sensors 8,9. A CPU 12a compares the signal value of the P- polarized component with the signal value of the S-polarized component to find a polarized component ratio R corresponding to an angle of rotation. Since the angle of rotation changes corresponding to find a surface treated state, the polarized component ratio R is compared with the standard value of the film to which proper surface treatment is applied to enable the inspection of the surface treated state of the film.

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 inspecting a polymer molded article used in a production line or the like.

[0002]

Generally, the surface of a polymer molded article, for example, a polymer film (for example, a polyester film) has hydrophobicity and is poor in printability and adhesiveness. Therefore, a method has been adopted in which a polymer film is subjected to a surface treatment such as a corona discharge treatment to oxidize the surface (generate a carbonyl group) to make the surface hydrophilic, followed by printing or bonding. I have.

[0003] This surface treatment is performed during the production of a polymer film. In other words, the produced strip-shaped polymer film passes between a dielectric roll and an electrode to which a high-frequency high voltage is applied for corona discharge treatment, and then is wound into a roll through an inspection process of this surface treatment. It is being taken. Conventionally, the inspection of the surface treatment has been performed by an inspector applying a chemical to the end of the polymer film wound in a roll shape and confirming the applied state.

However, in such an inspection method,
Since only the winding end of the rolled polymer film is inspected, it is difficult to detect even a portion of the wound polymer film that has not been subjected to surface treatment in the middle. In addition, this inspection work is very time-consuming.

[0005] Further, for example, in a production line for producing a plurality of types of polymer films, when the distribution of raw materials is incorrect at the time of the changeover, or when the thickness of the produced polymer film is uneven, Conventionally, only a part of the polymer film was inspected, so that it was difficult to perform sufficient quality control.

[0006] The present invention has been made in view of the above circumstances, and has as its object the surface treatment state, components, and the like of a polymer molded article.
It is an object of the present invention to provide a method and an apparatus for inspecting a polymer molded article capable of automatically inspecting the quality such as thickness and the entire surface thereof.

[0007]

In order to achieve the above object, a method for inspecting a polymer molded article according to claim 1 is to transmit polarized incident light to the polymer molded article and to obtain a P of the transmitted light. It is characterized in that the polarization component and the S polarization component are detected, and the quality of the polymer molded article is inspected by comparing the magnitudes of both polarization components.

According to this inspection method, the optical rotation of a polymer molded product having a predetermined quality (surface treatment state, components, purity, thickness, etc.) and a polymer molded product having a quality different from the predetermined quality are determined. By utilizing the difference, the quality of the polymer molded article can be inspected. That is, when the polarized incident light is transmitted through the polymer molded article, the transmitted light has a different rotation angle of the polarization plane depending on quality. Therefore, by detecting the P-polarized light component and the S-polarized light component of the transmitted light, and comparing the magnitudes of the two polarized light components in order to eliminate the influence due to the variation of the intensity of the incident light, the difference in the optical rotation is obtained. Can be detected correctly. In this case, it is possible to inspect whether or not the surface treatment is appropriately performed on the polymer molded article by utilizing the difference in the optical rotation depending on the surface treatment state (claim 2). This makes it possible to inspect the surface treatment more easily and more reliably than in the past.

Further, light from a light source is incident on a surface-treated polymer molded product, and a P-polarized component and an S-polarized component of the reflected light are detected, and the magnitudes of the two polarized components are compared. Thereby, it can be inspected whether the surface treatment is properly performed on the polymer molded article (claim 3).

According to this inspection method, when unpolarized incident light is incident on a surface-treated polymer molded article,
Using the difference in the polarization of reflected light between the part where the surface treatment is not properly performed and the part where the surface treatment is properly performed, it is possible to inspect whether the surface treatment is properly performed. . That is, the surface treatment state can be determined by comparing the P-polarized light component and the S-polarized light component included in the reflected light and detecting the ratio of both the polarized light components.

[0011] An inspection apparatus that embodies the method for inspecting a polymer molded article using the transmitted light includes a light projecting unit that polarizes light from a light source to make incident light on the polymer molded article, A P-polarized light receiving means for detecting a P-polarized component of the transmitted light from the polymer molded article, and an S-polarized light receiving means for detecting an S-polarized component of the transmitted light from the polymer molded article with respect to the incident light Determining means for comparing the P-polarized light component detected by the P-polarized light receiving means with the S-polarized light component detected by the S-polarized light receiving means to determine the quality of the polymer molded article; (Claim 4).

According to this structure, the light from the light source is given a predetermined polarization by the light projecting means, and the P-polarized light component detected by the P-polarized light receiving means by the determining means and the S-polarized light component detected by the S-polarized light receiving means. The quality of the polymer molded article can be automatically detected in a non-contact manner based on the result of comparison with the above.

In this case, it is preferable that the determining means is configured to determine whether the surface treatment is properly performed on the polymer molded article. According to this configuration,
A defective part of the surface treatment can be easily and reliably detected.

In addition, the inspection apparatus which embodies the method for inspecting a polymer molded article using the reflected light is a light projecting means for converting light from a light source into incident light on the surface-treated polymer molded article. And P-polarized light receiving means for detecting a P-polarized light component of the reflected light from the polymer molded article with respect to the incident light; and detecting an S-polarized light component of the reflected light from the polymer molded article with respect to the incident light. The S-polarized light receiving means and the P-polarized light component detected by the P-polarized light receiving means are compared with the S-polarized light component detected by the S-polarized light receiving means so that the polymer molded article is appropriately subjected to the surface treatment. It is preferable to provide a configuration including a determination unit that determines whether the operation is performed.

According to this structure, the light from the light source is incident on the polymer molded article in a non-polarized state by the light projecting means, and the P-polarized light component detected by the P-polarized light receiving means and the S-polarized light receiving means by the judging means. It is possible to automatically detect the surface treatment state based on the result of comparison with the detected S-polarized light component.

Further, in each of the above inspection devices, P
Preferably, the polarized light receiving means and the S polarized light receiving means are configured as a polarization camera capable of line scanning. According to this configuration, the quality of the surface treatment state and the like of the entire surface of the polymer molded article can be inspected at high speed by performing the line scanning of the polymer molded article by the polarization camera.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Hereinafter, a first embodiment (corresponding to claims 1, 2, 4, 5, and 7) of the present invention for performing a surface treatment inspection of a polymer film will be described. 1 and FIG. FIG. 1 schematically shows the entire configuration of the surface treatment inspection apparatus. The surface treatment inspection apparatus 1 shown in FIG. 1 is a transparent polymer film such as a polyester film 2 (hereinafter, referred to as a polymer molded product).
The film 2 is installed on a production line or the like, and inspects the surface treatment state after the produced film 2 is subjected to a surface treatment such as a corona discharge treatment. This corona discharge treatment is generally a treatment for making the surface of a polymer film having hydrophobicity hydrophilic to enhance printability and adhesiveness. The film 2 passes through the surface treatment / inspection apparatus 1 at a substantially constant speed, for example, in the direction of arrow A shown in FIG. 1, and is then wound up in a roll shape by a winder (not shown).

The surface treatment inspection apparatus 1 includes the film 2
Lamp 3 corresponding to the light projecting means
In addition, a polarizing plate 4 and a polarizing camera 5 are provided.
Then, unpolarized light emitted from a lamp 3 (corresponding to a light source in the present invention) provided so as to be capable of projecting light onto the film 2 has a specific polarization by a polarizing plate 4 provided in parallel with the film 2. After being turned into linearly polarized light, the light enters the film 2 as incident light.

The polarization camera 5 includes a lens 6, a polarization beam splitter 7, a CCD image sensor 8 as P-polarized light receiving means, a CCD image sensor 9 as S-polarized light receiving means, P
It comprises a polarization amplifier 10 and an S polarization amplifier 11. The transmitted light that has passed through the film 2 is condensed by the lens 6 and then passes through the polarization beam splitter 7, whereby a P polarization component (a linear polarization component parallel to the incident surface of the polarization beam splitter 7) and an S polarization component ( (A linearly polarized light component perpendicular to the plane of incidence of the polarizing beam splitter 7) and incident on CCD image sensors 8 and 9, respectively.
The output signals of the CCD image sensors 8 and 9 are passed through a P polarization amplifier 10 and an S polarization
Is output to

The judging device 12 (corresponding to the judging means in the present invention) is mainly composed of a microcomputer, and includes a CPU 12a, a ROM 12b, a RAM 12c,
P frame memory 12p, S frame memory 12
s, an input interface 12d, an output interface 12e, a keyboard 12f, a CRT 12g, and the like.

Next, the operation of the present embodiment will be described with reference to FIG. Non-polarized light from a lamp 3 (for example, a fluorescent tube or a halogen lamp) is converted into linearly polarized light by a polarizing plate 4 and continuously incident on the film 2. When this incident light passes through the transparent film 2 that has been subjected to the surface treatment, the polarization plane rotates due to the optical rotation of the film 2. Also, the linearly polarized light changes to elliptically polarized light. In this case, the rotation angle (optical rotation) of the polarization plane is different between the portion where the film 2 is appropriately subjected to the surface treatment and the portion where the surface treatment is not properly performed. This difference in optical rotation is
When the film 2 is subjected to a corona discharge treatment or the like, a part of the surface structure is replaced with a carbonyl group, and the structure as an optically anisotropic body on the surface of the film 2 is changed. Therefore, the surface treatment inspection apparatus 1 compares the optical rotation (and the degree of change to elliptically polarized light) with the film 2
By detecting the ratio between the P-polarized light component and the S-polarized light component contained in the transmitted light from the camera, the surface treatment state of the film 2 can be inspected.

On the basis of this inspection principle, the surface treatment inspection device 1 specifically performs the inspection of the surface treatment as follows. That is, the transmitted light from the film 2 is divided into a P-polarized component and an S-polarized component by the polarization beam splitter 7 in the polarization camera 5. The polarization camera 5 receives the P-polarized light component and the S-polarized light component by the CCD image sensors 8 and 9. And the CCD image sensors 8 and 9
The output signals of the pixels for imaging the line in the direction perpendicular to the traveling direction A of the film 2 are sequentially output to the P-polarization amplifier 1 respectively.
After amplification to a predetermined level by the 0 and S polarization amplifiers 11, the CPU 12a
Transfer to

The CPU 12a executes the processing shown in FIG. 2 in real time according to an inspection program stored in the ROM 12b in advance. That is, the signal value of the P-polarized light component and the signal value of the S-polarized light component at the same coordinate point on the line are input (steps S1 and S2), and the input signal value of the P-polarized light component and the signal value of the S-polarized light component are inputted. Are compared and the polarization component ratio R is obtained by calculation. Although the absolute value of the signal value of the P-polarized light component and the signal value of the S-polarized light component change due to the intensity of the incident light, etc., the polarization component ratio R corresponding to the optical rotation etc. Regardless of the size, the value depends on the surface treatment state of the film 2.

The ROM 12b stores the lower limit value NL and the upper limit value NH of the standard polarization component ratio R for the film 2 on which an appropriate surface treatment has been performed. CPU 12
a determines whether or not the polarization component ratio R obtained by the calculation is within an allowable range between the lower limit value NL and the upper limit value NH (step S4), and determines that the ratio is within the allowable range (Y).
In ES), it is determined in step S5 whether or not the inspection has been completed. Here, when the inspection end command is input from the keyboard 12f (YES), the inspection process is ended, and when the inspection end instruction is not input (NO), the process returns to step S1 to return to the next coordinate point. The same processing is repeated. On the other hand, if the CPU 12a determines that it is out of the allowable range in step S4 (NO), for example, a notification process using an alarm buzzer, an alarm lamp, or the like, a display of the polarization component ratio R and the occurrence time on the CRT 12g and a storage in the RAM 12c are performed. And the like (Step S6), and the process proceeds to Step S5.

The data stored in this abnormal processing can be used as product management data. For example, according to the number of occurrences of surface treatment abnormalities detected during the production of the rolled-up film 2, the film can be used. 2 can be ranked.

In the above inspection process, the CPU 12
a indicates the P-polarized light component signal value and the S-polarized light component signal value transferred from the polarization camera 5,
The polarization component ratio R is immediately obtained and inspected for each coordinate point without being stored in the frame memory 12s for p and S. However, the signal values of the P polarization component and the S polarization component for one line are stored in the P frame memory 12p and the S frame memory 12s, respectively, and then the signal values are sequentially read from the frame memories 12p and 12s. An inspection process may be performed.

As described above, according to the present embodiment,
Light having linear polarization is incident on the film 2 and the polarization component ratio R of the P-polarization component and the S-polarization component contained in the transmitted light.
Thus, the surface treatment state of the film 2 can be inspected. This makes it possible to automate the inspection of the surface treatment that has conventionally depended on manual labor. Further, since this inspection is performed in a non-contact manner, the film 2 as a product is not stained with a chemical or the like for the inspection.

In this case, the difference in the optical rotation (and the degree of change to elliptically polarized light) depending on the surface treatment state of the film 2 is P
Since the detection is performed based on the polarization component ratio R between the polarization component and the S polarization component, the influence of the intensity of the light incident on the film 2 and the like can be eliminated, and only the defective portion of the surface treatment can be reliably detected. In addition, since the belt-shaped film 2 is line-scanned and the CPU 12a performs the inspection in real time, the entire surface of the film 2 can be inspected, and a defective portion having a small area can be reliably detected.

Further, the optical rotation of the transmitted light varies depending on the quality of the film 2 other than the above-mentioned surface treatment state, for example, the film thickness, the composition, the purity (the degree of mixing of irregular substances) and the like. Therefore, the surface treatment inspection device 1 can detect a nonuniform portion of the film thickness, a portion mixed with impurities, and the like, in addition to a defective portion of the surface treatment. Further, in a production line for producing a plurality of types of polymer films, it is possible to immediately detect, for example, an erroneous distribution of raw materials when switching to a different type. By using the above-described product management data and the polarization component ratio R measured in real time, it is possible to easily and reliably perform quality control on various qualities that can be detected as a change in optical rotation.

(Second Embodiment) Next, a second embodiment of the present invention (corresponding to claims 3, 6, and 7) will be described with reference to FIG. FIG. 3 schematically shows the entire configuration of the surface treatment inspection apparatus. In FIG. 3, the surface treatment / inspection device 13 differs from the surface treatment / inspection device 1 described above in light emitting means. Lamp 3
And the polarizing camera 5 are provided on the same side (the right side in FIG. 3) of the film 2 on which the surface treatment has been performed, and the unpolarized light (light having the same P-polarized component and S-polarized component) from the lamp 3
Are disposed so as to have a predetermined incident angle θ with respect to the film 2. The polarization camera 5 is provided so as to be able to detect reflected light having a predetermined reflection angle θ reflected by the film 2 with respect to the incident light.

According to the above configuration, the light reflected on the surface of the film 2 is polarized depending on the incident angle θ, the surface state of the film 2 and the like. Then, since the incident angle θ is constant, the magnitude of the polarized light (the degree of polarization) is determined depending on the surface treatment state of the film 2. Therefore, the surface treatment inspection device 13 detects the degree of polarization of the reflected light from the film 2 as the ratio of the P-polarized light component to the S-polarized light component included in the reflected light, so that the film 2 is appropriately subjected to the surface treatment. It can be checked whether or not there is.

The specific surface treatment inspection processing by the surface treatment inspection device 13 is the same as that of the surface treatment inspection device 1. In this case, the ROM 12b stores a standard polarization component ratio R for the film 2 on which an appropriate surface treatment has been performed.
Are stored as the lower limit value NL 'and the upper limit value NH'. Further, since the degree of polarization of the reflected light slightly changes depending on the wavelength, it is preferable to use a light source having a single wavelength as the lamp 3.

According to this embodiment, the same effect as that of the first embodiment can be obtained for detecting the surface treatment state. In addition, a non-transparent polymer film or a polymer film having low permeability can be inspected. Furthermore, it is preferable that the incident angle θ to the film 2 is set to a Brewster angle with respect to the film 2 that has not been subjected to the surface treatment or a Brewster angle with respect to the film 2 that has been appropriately subjected to the surface treatment. By setting this incident angle θ,
Since a large amount of polarized light appears in the reflected light on the surface of the film 2,
The polarization component ratio R of the reflected light increases, and the detection sensitivity increases. Therefore, it is easy to determine the difference in the surface treatment state, and a highly accurate inspection can be performed.

(Other Embodiments) The present invention is not limited to the embodiments described above and shown in the drawings, and the following expansions or modifications are possible. CPU
12a inspects the surface treatment state by comparing the polarization component ratio R with a standard value stored in advance in the ROM 12b. In this case, teaching is performed on the film 2 on which an appropriate surface treatment has been performed to determine the polarization component ratio R. An appropriate value may be obtained, and the appropriate value may be used instead of the standard value.

In the second embodiment, the incident angle and the reflection angle are set to the same angle θ, but may be set to different angles. Further, the polymer molded article is not limited to the polymer film, but may be similarly applied to any molded article that can transmit light (first embodiment) or reflect light (second embodiment). In addition, the present invention can be similarly applied to not only polyester but also polyethylene and polypropylene.

[0036]

As described above, according to the method and apparatus for inspecting a polymer molded article of the present invention, the transmitted light can be controlled in accordance with the surface treatment state, component, purity, thickness and the like of the polymer molded article. Since the quality of the polymer molded article is inspected for the appropriateness by utilizing the properties of different optical rotations, the inspection can be automated. In this case, by measuring the optical rotation using a polarization camera capable of line scanning, the entire surface of the polymer molded article can be inspected.

It is also possible to inspect whether the surface treatment of the polymer molded article is properly performed by utilizing the property that the degree of polarization of the reflected light varies depending on the surface treatment state of the polymer molded article. . In this case, it is possible to inspect a non-transparent polymer molded product.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of a surface treatment inspection apparatus according to a first embodiment of the present invention.

FIG. 2 is a flowchart of an inspection process.

FIG. 3 is a view corresponding to FIG. 1, showing a second embodiment of the present invention;

[Explanation of symbols]

In the drawings, reference numerals 1 and 13 denote surface treatment / inspection devices (inspection devices for polymer molded products), 3 denotes lamps (light sources and light emitting means), 4 denotes polarizing plates (light emitting means), and 8 denotes CCD image sensors (P-polarized light). Light receiving means), 9 is a CCD image sensor (S-polarized light receiving means), 12
Denotes a determination device (determination means).

Claims (7)

[Claims] 1. A polymer molded product by transmitting polarized incident light through a polymer molded product, detecting a P-polarized component and an S-polarized component of the transmitted light, and comparing the magnitudes of both polarized components. A method for inspecting a polymer molded article characterized by inspecting the quality of the article. 2. The method for inspecting a polymer molded article according to claim 1, further comprising inspecting whether the surface treatment is properly performed on the polymer molded article. 3. Light from a light source is incident on a surface-treated polymer molded product, and a P-polarized component and an S-polarized component of the reflected light are detected, and the magnitudes of both polarized components are compared. A method for inspecting whether or not the surface treatment is properly performed on the polymer molded article. 4. A light projecting means for polarizing light from a light source into incident light on a polymer molded article, and a P for detecting a P-polarized light component of transmitted light from the polymer molded article with respect to the incident light. Polarized light receiving means, s-polarized light receiving means for detecting an s-polarized light component of transmitted light from the polymer molded article with respect to the incident light, p-polarized light component detected by the p-polarized light receiving means, and the s-polarized light receiving means And a determination means for determining the quality of the polymer molded article by comparing the S-polarized component detected by the method. 5. The apparatus for inspecting a polymer molded article according to claim 4, wherein said determination means determines whether or not the polymer molded article has been properly surface-treated. 6. A light projecting means for using light from a light source as incident light on a surface-treated polymer molded article, and a P-polarized light component of reflected light from the polymer molded article with respect to the incident light. P-polarized light receiving means for detecting, S-polarized light receiving means for detecting an S-polarized component of the reflected light from the polymer molded article with respect to the incident light, P-polarized light component detected by the P-polarized light receiving means, and S Determination means for determining whether or not the surface treatment has been properly performed on the polymer molded article by comparing the S-polarized light component detected by the polarized light receiving means. Inspection equipment for polymer molded products. 7. The apparatus for inspecting a polymer molded product according to claim 4, wherein the P-polarized light receiving means and the S-polarized light receiving means are configured as a line-scanning polarization camera.