JP5332181B2 - Packaging defect inspection equipment for packaging products with thin film - Google Patents

Description

  The present invention relates to a method and apparatus for detecting defective packaging of a product in which an article is hermetically packaged with a thin film. More particularly, the present invention relates to a method and apparatus for easily detecting packaging defects such as perforations that occur during shrink packaging of cup-shaped containers and the like.

  As one of packaging forms such as cup noodles and cup soups, shrink packaging using a heat-shrinkable synthetic film is known. In order not to impair the design of the cup-shaped container, a colorless and transparent thin film is generally used. In addition, as with the shrink wrapping, other articles may be wrapped with a thin film in order to prevent foreign matters from being mixed or tampered with.

  This shrink wrapping accommodates articles before wrapping by a heat shrink film having a number of pinholes on the sheet surface, and heat is applied to these to cause shrinkage according to the characteristics of the heat shrink film and is taken into the package. Air is exhausted from pinholes formed in the film, so that the film is brought into close contact with the surface of the article.

  However, in such a packaging process, there is a case where the position of the article accommodated in the film before heat shrinkage is shifted, or the film is torn at the time of heat shrinkage due to overheating, so that the package product is perforated. Conventionally, whether or not there is such a packaging defect has been inspected by visual inspection of a product carried out from the heating device, or inspected by image processing by photographing the packaging state with an image sensor. However, the visual inspection has a problem that it takes a lot of manpower, and the inspection by the image sensor has a disadvantage that it is difficult to find a packaging defect of the transparent film.

  As a method for solving this problem, a shrink film is obtained by irradiating an article packaged by a shrink film with a test pattern with an ultraviolet light emitting fluorescent ink and reading the test pattern emitted by the irradiation of the ultraviolet light. Has disclosed a method for determining whether or not an article is normally packaged (see, for example, Patent Document 1).

  On the other hand, in order to detect a packaging failure in the folded part of a stick product such as gum or candy, compressed air is jetted in the direction in which the flap of the folded part of the product opens, and the flap peeled off by this air is photoelectrically detected. A method of detecting with a sensor has been reported (see, for example, Patent Document 2).

JP 2006-143231 A JP-A-6-99951

  However, the method disclosed in Patent Document 1 requires a system for coating a film with a special paint and further irradiating a special illumination, which increases the cost. Further, in the method of Patent Document 2, it is not always possible to detect the perforation of the film generated on the surface of the packaged product, and it is necessary to detect it by temporarily stopping the conveyance of the product.

The present invention has been made to solve such a problem, and provides a method and an apparatus for simply and efficiently detecting a packaging defect of a packaged product in which an article is sealed with a thin film. That is, the detection device for defective packaging according to the present invention includes a conveyor that conveys the packaged product along a guide that suppresses vibration of the packaged product, and an angle of 90 to 45 degrees with respect to the product surface parallel to the conveyance direction. And at least one air nozzle for injecting compressed air onto the surface of the packaged product, and a sensor for detecting a film swollen above a predetermined height from the surface of the packaged product by the compressed air injected from the air nozzle; Here, when the compressed air jetted from the air nozzle has a hole in the film, it enters the inside of the film through the hole, and the film is moved from the packaging surface to a predetermined height. It is characterized by inflating more than this. The inspection apparatus may further include a discharge unit that discharges the defective product from the conveyor based on a defect detection signal of the sensor.

  In a preferred embodiment of the inspection apparatus according to the present invention, the air nozzle includes an air nozzle having a flat air jet port with a widened tip.

  In another embodiment, the sensor is an area regression laser sensor arranged on the left and right of the conveyor, and the light path of the sensor intersects with the spread in the width direction of the air ejected from the air nozzle. It is preferable.

  The thin film is a film having a thickness of 15 to 100 μm and may or may not be heat shrinkable. Further, it may be a transparent or colored thin film.

  In a preferred embodiment of the inspection apparatus of the present invention, the packaged product has a cup shape, and the body of the cup-shaped container is sandwiched by a belt conveyor together with guides that support the four ends of the top and bottom surfaces of the cup. It conveys, The said air nozzle injects air from the upper part and the lower part of the said cup-shaped container, It is characterized by the above-mentioned. More preferably, the thin film is a shrink film, and the perforation of the film generated on the top and bottom surfaces of the cup is detected.

  In a further different embodiment of the inspection apparatus of the present invention, the sensor is a contact sensor that detects by contacting with a film swollen above a predetermined height from the surface of the packaged product by compressed air injected from the air nozzle. And an image processing device for detecting the bulge of the film.

  The inspection apparatus of the present invention can easily and reliably inspect a hole opened in a packaging bag sealed with a thin film. By detecting a film swelled by compressed air with a photoelectric sensor, it is possible to inspect regardless of the size, shape, position and number of holes. Further, it is possible to inspect the perforation during the conveyance without temporarily stopping the conveyance of the product.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a typical inspection device for inspecting the top surface and bottom surface perforations (about 3 mm to 40 mm) of the shrink film applied to the entire surface of the cup-shaped container (1). In FIG. 1, a cup-like container (1) conveyed in a state of being inverted from a packaging line (not shown) is sandwiched between four guides (4) that support the top and bottom edges, and both sides Are conveyed by being sandwiched between belt conveyors (5), thereby opening the top and bottom surfaces of the cup-shaped container. Compressed air is blown from the air nozzle (2) onto the opened top and bottom surfaces. When the film has a hole, air enters inside and the film swells, and the swell is detected by the photoelectric sensor (6). Based on this detection signal, the discharge timing sensor (9) detects that the defective product has been transported to a predetermined position, and the defective product is automatically discharged by the air injected from the discharge air nozzle (8). Is done. Therefore, this inspection method can be performed while the product is being transported, and there is no need to temporarily stop the transport for the inspection.

Here, the guide (4) and the belt conveyor (5) are not particularly limited as long as they can convey the packaged cup-shaped container without vibrating, and the arrangement and shape thereof can be changed as appropriate. When inspecting only the top or bottom surface of the cup, a normal belt conveyor or roller conveyor may be used. A mechanical method such as a lever type may be used for the defective product discharge portion described above.

  The air nozzle (2) described above has various shapes such as a radial air nozzle (2a) (see FIG. 2) for injecting radial air and a wide air nozzle (2b) (see FIG. 3) for injecting linear air. However, it is preferable to use an air nozzle (wide air nozzle) that has a widened tip and has a flat air outlet. Since the position, size, number, and shape of the film perforations that occur on the top and bottom of the cup cannot be specified, it is possible to detect what kind of perforations at any location. is there. For example, as shown in FIG. 2, the hole opened near the center of the container is inflated as shown in the figure by the air injected from the radial air nozzle (2a), and this can be detected by the sensor (6). . By appropriately adjusting the position of the sensor (6), it is possible to detect a film swollen more than a predetermined height from the cup surface. Usually, it is less than 10 mm from the cup surface.

On the other hand, in order to detect perforations generated in the peripheral part of the container, it is effective to use a wide air nozzle (2b) as shown in FIG. Only one type of these nozzles may be used, or a plurality of types may be used in combination. Further, it is preferable that the compressed air is injected from a direction substantially perpendicular to the product surface. Specifically, plus or minus 45 degrees from the vertical, i.e., in the range of an angle of 90-45 degrees with respect to the product surface. The pressure of the compressed air can be appropriately adjusted in consideration of the size of the nozzle and the distance from the product surface. For example, the pressure of the compressed air is 0.4 MPa, and the distance from the top or bottom surface of the cup is 10 mm or more. It is preferable to set to. By appropriately dividing the areas to be inspected on the top and bottom surfaces of the cup-shaped container and arranging a predetermined air nozzle for each area, it is possible to inflate regardless of where there is a hole.

  FIG. 4 is a perspective view showing an inspection apparatus according to another embodiment of the present invention. Air nozzles are installed at three locations on the upper part of the transport line to inspect the perforations in predetermined areas on the cup bottom. For example, the radial air nozzle (2a) is installed so as to inject air to the center part of the cup bottom surface, and the wide tip air nozzles (2b to 2e) are injected to the peripheral part of the cup bottom surface. In FIG. 4, it is preferable that the light path of the photoelectric sensor (6) intersects with the spread in the width direction of the wide air nozzle at a predetermined angle. This is because if the spread in the width direction of the air jetted from the wide air nozzle and the light path of the sensor overlap, the swelling of the film cannot be detected efficiently.

  The sensor for detecting the swelling of the film is not particularly limited, such as a photoelectric sensor, a contact sensor, and an image processing device, but in order to detect a transparent thin film, an area transmission type, an area regression type, a small spot reflection type, Various photoelectric sensors such as an area reflection type are preferable. Among these, in order to detect a transparent thin film, an area regression type laser sensor is particularly preferable. FIG. 5 is a schematic diagram showing a preferable positional relationship between the arrangement (detection area) of the area regression laser sensors (6a, 6b) and the wide air nozzle. As shown in FIG. 5, when the light path of the sensor intersects with the width of the wide air nozzle in the width direction, the film bulge can be detected efficiently. The preferred angle of intersection may be in the range of about 45 degrees to about 90 degrees.

  FIG. 6 is a schematic diagram showing the arrangement of air nozzles on the top or bottom of the cup in a particularly preferred embodiment of the present invention. The perforation of the film at the center of the top or bottom of the cup is inflated by the radial air nozzle (2a), and the perforation of the film generated in the four areas around the cup is made using the wide air nozzles (2b to 2e). Can be inflated.

  Moreover, the detection apparatus of this invention is not limited to the packaging by a heat shrink film, what is called a shrink film. For example, a thin film that does not shrink by heat is used for packaging gum, candy, tobacco, etc., and the detection device of the present invention can be used for such packaging defects.

  The inspection device for defective packaging according to the present invention can be used in a manufacturing process for articles that need to prevent foreign matters from being mixed and tampered with, and is useful not only in the food manufacturing industry but also in many industrial fields.

It is a perspective view which shows the typical test | inspection apparatus of this invention. It is a schematic diagram which shows the perforation detection method by the radial type air nozzle used with the test | inspection apparatus of this invention. It is a schematic diagram which shows the perforation detection method by the wide air nozzle used with the test | inspection apparatus of this invention. It is a perspective view which shows the test | inspection apparatus in other embodiment of this invention. It is a schematic diagram which shows arrangement | positioning of the wide air nozzle and area regression type laser sensor in the test | inspection apparatus of this invention. It is a schematic diagram which shows arrangement | positioning of the air nozzle on the cup top surface or bottom face in preferable embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cup-shaped container 2 Air nozzle 2a Radiation type air nozzle 2b, 2c, 2d, 2e Wide air nozzle 3 Air supply source 4 Guide 5 Belt conveyor 6 Photoelectric sensor 6a, 6b Area regression type laser sensor 7 Shrink film 8 Air nozzle for discharge 9 Discharge timing sensor

Claims (8)

An apparatus for detecting defective packaging of a packaged product in which an article is sealed with a thin film,
A conveyor for conveying the packaged product along a guide for suppressing vibration of the packaged product;
At least one air nozzle that injects compressed air onto the surface of the packaged product at an angle of 90 to 45 degrees with respect to the product surface parallel to the transport direction;
A sensor for detecting a film swollen above a predetermined height from the surface of the packaged product by compressed air sprayed from the air nozzle;
With
Here, when the compressed air jetted from the air nozzle has a hole in the film, the film enters the film through the hole and swells the film to a predetermined height or more from the packaging surface. That
An apparatus for detecting defective packaging.   The detection device according to claim 1, further comprising a discharge unit that discharges the defective product from a conveyor based on a defect detection signal of the sensor.   The detection device according to claim 1, wherein the air nozzle includes an air nozzle having a flat air jet port with a wide end. The sensor is an area regression laser sensor arranged on the left and right of the conveyor, and the light path of the sensor intersects with the spread in the width direction of the air ejected from the air nozzle. Item 4. The detection device according to Item 3 .   The detection device according to claim 1, wherein the thin film is a film having a thickness of 15 to 100 μm.   The packaged product has a cup shape, and conveys the body of the cup container sandwiched by a belt conveyor together with guides that support the top and bottom surfaces of the cup, and the air nozzle is located above the cup container. 6. The detection device according to claim 1, wherein air is jetted from a lower portion.   The detection device according to claim 6, wherein the thin film is a shrink film and detects perforation of the film formed on a top surface and a bottom surface of the cup.   The sensor is a contact sensor that detects when the compressed air blown from the air nozzle comes into contact with a film swollen above a predetermined height from the surface of the packaged product, and an image processing device that detects swelling of the film. The detection device according to claim 1.

Images