JP3132863U - Glue application status inspection device - Google Patents

Abstract

An object of the present invention is to provide an inspection means capable of automatically and rapidly detecting whether or not back glue is applied in a bookbinding process using PUR glue.
An apparatus for inspecting the application state of glue, comprising means for measuring the temperature of a book-coated part with a radiation thermometer. In particular, the inspection is continuously performed by measuring the temperature of a fixed radiation thermometer by transporting a book to which glue has been applied. In addition, a means for detecting the position of the front end and / or rear end of the book being transported, such as a light projecting light source and a light receiving sensor, is disposed in the vicinity of the radiation thermometer.
[Selection] Figure 2

Description

  The present invention relates to an inspection apparatus for inspecting whether or not glue is properly applied, and in particular, automatically and rapidly detecting whether or not back glue is applied in a bookbinding process using PUR glue. It is related with the inspection apparatus which can be performed.

  In recent years, moisture-curing PUR adhesive (PUR glue) has attracted attention as a glue used for bookbinding. This PUR paste is an abbreviation for a polyurethane-type reactive hot-melt adhesive. PUR glue is characterized by being cured by heating and melting and then reacting with moisture (humidity) in the air. With normal hot melt adhesives, they are heated and melted, then cooled and solidified and bonded, so even after bonding, the adhesion is lost at high temperatures, and the degree of solidification becomes high at low temperatures and the flexibility is lost. . On the other hand, the PUR glue has a characteristic that its hardness does not change after heating and melting and adhesion and curing, and it does not melt even when heated.

  This characteristic is considered to be due to the fact that the PUR glue reacts with moisture in the air or moisture of the object to be coated to form a three-dimensional crosslinked structure. Because of this characteristic, when the PUR paste is cured, it is difficult to cause softening at high temperatures and cracking at low temperatures, and it is difficult to dissolve in chemicals (solvents). Therefore, the strength of the bonded portion is high, the durability and chemical resistance are good, the heat resistance and the cold resistance are excellent, and it is extremely suitable as an adhesive for bookbinding.

The feature of bookbinding using PUR glue will be described more specifically.
(1) A strong book can be produced because of its strong adhesive performance and strong adhesive film.
(2) The strength of the PUR glue does not drop even if it is placed in a vehicle under hot weather in summer (adopted on maps, etc.). In addition, it should not become brittle in cold areas in winter (used in catalogs for products for cold areas).
(3) Since it is excellent in solvent resistance, it is difficult for the paste to deteriorate due to the ink solvent.
(4) Since the film is tough and the amount of glue applied can be reduced, the book is easy to open (wide openability).
(5) The book is less likely to fall apart during recycling of used paper, and it is easy to remove unnecessary materials, so it is excellent in recyclability.
Etc.

  The application method of back glue in bookbinding is roughly divided into a method of applying with a roll and a method of applying with a spray nozzle. Conventionally, the PUR paste is generally applied by a roll. However, PUR glue has the property of curing by reacting with moisture in the air, and it is inevitable that the glue contacts the air in the roll coating method. Therefore, in the roll coating method, a method of slowing the curing rate of the PUR glue is taken. As a result, there is a problem that it takes about 3 days to dry after binding. On the other hand, the nozzle application method has an advantage that complete sealing is easy, the curing rate of glue can be increased, and drying after binding can be completed in about one day.

  In order to cope with such problems of the roll coating method, the following Patent Document 1 states that “PUR glue is loaded into a sealed glue tank excluding a rotating glue roll part, and nitrogen gas is sequentially added to this glue tank. A bookbinding method in which the PUR glue is glued by the glue roll while feeding the sheet is disclosed.

JP 2001-347772 A

  In recent years, the number of cases in which the nozzle coating method is adopted is increasing due to the problems of the roll coating method in the PUR glue. In the nozzle application method, PUR glue sealed in a container is blown out from a slit nozzle and applied to the back of a book transported on the nozzle. However, in an application process in which a large number of books are continuously processed, an application failure may occur in which no glue is applied to a predetermined portion of the book.

  There are various causes for such poor coating. First of all, nozzle clogging can be mentioned. That is, since the tip of the nozzle is open to the atmosphere, the PUR glue is cured at the tip of the nozzle, causing nozzle clogging. Especially after the application device has been stopped for a while, there is a high risk of nozzle clogging.

  Also, when there is an air pocket inside the stored glue and this flows into the nozzle, poor coating occurs. Furthermore, control is usually performed so that glue flows out only when the book passes through the nozzle portion. That is, it is a control system that detects the position of the front end of the book being conveyed, applies back pressure to the nozzle only when the book passes, and allows glue to flow out. In such a system, even if the position detection sensor malfunctions, adhesive application failure occurs.

  In the process of continuously binding a large number of books, if some of the back glue is not properly applied, this not only becomes a defective product, but also disturbs the entire process and has a great impact on productivity. . Therefore, it is very important to provide a means for detecting whether or not the back paste is properly applied immediately after the back paste application step. Such detection is preferably a simple and practical means that can be detected automatically and at high speed without human power.

  Therefore, the present invention provides a simple and practical inspection means capable of automatically and rapidly detecting whether or not the back paste is properly applied to a predetermined part in the bookbinding process in which the PUR paste is applied by the nozzle. Is an issue.

  The inventors have conducted various studies on means for solving the above-described problems. First, a method for measuring the thickness of glue applied using a displacement sensor and determining the application range of the glue based on the change in thickness was examined. However, before the step of applying the glue, the back portion of the book is cut at the milling portion, and a fine pitch cut is made at the gully portion, so that the back of the book is considerably uneven. The thickness of the glue to be applied is usually about 0.4 mm, but the unevenness of the back surface often exceeds this, and therefore it was judged that it was difficult to determine the application status using a displacement sensor.

  Therefore, the inventors of the present invention pay attention to the fact that the PUR glue is a hot melt, and the temperature of only the application part is high immediately after application, and by measuring the temperature of the application part of the glue with a radiation thermometer, Knowing that it is possible to easily and reliably determine whether or not glue has been applied to the site without contact, the present invention has been completed.

  In other words, the glue application status inspection device of the present invention is an apparatus for inspecting whether or not glue is normally applied to a predetermined part of a book, and the part of the book to which the glue is applied is detected by a radiation thermometer. A means for measuring temperature is provided.

  The glue is preferably a polyurethane-type reactive hot melt adhesive (PUR glue).

  Since the PUR paste is applied by hot melt, there is a temperature difference of 50 ° C. or more between the portion where the paste is applied and the portion where the paste is not applied. Therefore, by measuring the portion to which the glue has been applied with a radiation thermometer, the presence or absence of the glue can be determined at high speed and reliably without contact.

  In this inspection apparatus, it is preferable to perform temperature measurement with the radiation thermometer during conveyance of the book to which the paste is applied.

  As a result, it is possible to continuously perform a large number of book inspections with the radiation thermometer fixed.

  Moreover, it is preferable that this inspection apparatus is provided with the position detection means which detects the position of the front-end | tip and / or back end of the book in conveyance in the vicinity of the said radiation thermometer.

  With this configuration, it is possible to check whether or not there is a book at the position measured by the radiation thermometer. In addition, by turning on and off the radiation thermometer at the positions of the leading and trailing ends of the book being transported, temperature measurement can be performed only within a necessary range.

  Further, the position detecting means may comprise a light source of detection light projected so as to intersect the conveyance direction on the book conveyance path, and a light receiving element for receiving the detection light.

  According to the present invention, it is possible to automatically and rapidly inspect whether or not the back paste is properly applied. This inspection method requires only a relatively low cost of equipment, is easy to operate, and is highly practical.

  First, it will be described at which stage of the bookbinding process the inspection according to the present invention is performed. FIG. 1 is a flowchart showing an example of a bookbinding process for simple binding. The book that has been collated cuts the back part in the milling process (S1), adjusts the back state in the gully process (S2), goes through the back glue application process (S3), the side glue application process (S4), After the cover is pasted (S5), three-way cutting (S6) is performed. The inspection according to the present invention is generally performed between the side glue applying step (S4) and the cover sheet attaching step (S5).

  FIG. 2 is a perspective view showing a configuration of an adhesive application state inspection apparatus according to an embodiment of the present invention. The figure also shows the nozzle application process. The PUR glue is stored in a container (not shown) and is heated by a heater to be in a hot melt state. This PUR glue is transported to the slit nozzle 2 via the pipe 3. The book 1 to be coated is sandwiched between clamps 4 and conveyed in a direction substantially perpendicular to the longitudinal direction of the slit nozzle 2. The height is adjusted so that the back of the book 1 is just in contact with the upper surface of the slit nozzle 2, and the position of the portion close to the back of the book 1 is limited by the guide plate 5 so as not to move sideways. This back glue application device is provided with an optical sensor 6 for detecting the passage time of the front end of the book 1, and the back pressure of the PUR glue storage tank is controlled based on this signal, so that a predetermined portion of the back of the book 1 is controlled. Only the PUR glue is applied.

  The inspection device according to the present invention includes a radiation thermometer 7 and a data processing device 8. The radiation thermometer 7 is arranged so as to measure the back portion of the book 1 from the lower side, and continuously detects the surface temperature of the back portion according to the flow of the book 1 being conveyed, The data is recorded in the data processing device 8 and displayed on a chart as necessary.

  Further, in the inspection apparatus of the present embodiment, a means for detecting the position of the front end and / or the rear end of the book being conveyed is provided in the vicinity of the radiation thermometer 7. This position detection means comprises a combination of a light projecting light source 9 and a light receiving sensor 10, and in this embodiment, one set upstream of the radiation thermometer 7, one set downstream, and a total of two sets of light projecting light source 9 and light receiving. The position of the leading and trailing ends of the book is detected by the combination with the sensor 10.

  The light projecting light source 9 is projected on the book transport path so that the light is substantially perpendicular to the book transport direction. Therefore, when the leading edge of the book crosses the projected light beam, the output of the light receiving sensor 10 decreases in a step shape, and when the trailing edge of the book passes through the projected light beam, the output of the light receiving sensor 10 is stepped. Therefore, the time at which the front and rear ends of the book pass through the position of the light beam can be detected with high accuracy.

  The type of the radiation thermometer used in the present invention is not particularly limited, but may be any one that can detect a temperature range from room temperature to about 100 ° C. with a certain degree of accuracy. The temperature of the hot melt of the PUR glue is usually about 110 ° C., and the temperature measurement by the radiation thermometer is performed within 10 seconds after the application. Therefore, the surface temperature of the portion to which the paste is applied is about 50 to 90 ° C.

  Further, the types of the light projecting light source 9 and the light receiving sensor 10 used in the present invention are not particularly limited. The wavelength of the light projecting light source 9 may be in the visible region, infrared region, ultraviolet region, or the like, and the light receiving sensor 10 only needs to generate an electric output proportional to the intensity of light of this wavelength.

  Since the output of the radiation thermometer as described above is usually obtained as an electric signal, data display, recording, and various data processing can be easily performed. A personal computer can be used as the data processing device 8. In the present embodiment, when a book to which no back glue is applied is detected by the data processing device 8, an alarm sounds and the alarm lamp blinks to alert the operator. .

  Hereinafter, in the present invention, when inspecting the presence or absence of application of back glue with a radiation thermometer, a position sensor for detecting the position of the leading and trailing ends of the book by the light projecting light source 9 and the light receiving sensor 10 is provided in the vicinity thereof. Will be described.

  The first reason for using this position sensor is to confirm whether there is a book at the position measured by the radiation thermometer. When books are conveyed continuously at a predetermined interval, it is possible to estimate the position where a book should be approximately even without a position sensor. However, immediately after the bookbinding line begins to move, it is not clear where the temperature measurement of the book's back began. Therefore, even if the radiation thermometer indicates room temperature, it cannot be determined whether there is no book or whether there is a book but no back glue is applied. Therefore, if the measurement with the radiation thermometer is performed after the passage of the book is confirmed by the position sensor, only when there is the book can be reliably extracted.

  The second reason for using the position sensor is to limit the temperature measurement range. The temperature measurement data is required only for the back glue application range. Of course, the temperature may always be measured while the bookbinding line is in operation. However, when temperature measurement is always performed, temperature data is excessively accumulated, which is not preferable.

  Therefore, in the present invention, a position sensor is used to detect the leading and trailing ends of the book, and based on this signal, the measurement by the radiation thermometer or the acquisition of temperature data is turned on / off.

  The contents of such on / off control will be described below with reference to the drawings. Fig.3 (a) is explanatory drawing of the cutting method of the top and bottom of a book. In the printing process, a plurality of pages are simultaneously printed on a large sheet, and a book is created by folding the pages. At the time of folding, the size (length W) of the paper 11 is set to be somewhat larger than the standard length L of the book, and the distance a from the front end side of the paper 11 and the distance from the rear end in cutting the top and bottom. Cut with a cutter at a distance of b. Usually, the length of a is about 10 to 50 mm, and the length of b is 3 mm. A pair of cutter blades 12 for cutting the top and bottom are provided, and the distance between them is set to be the same as the standard length L of the book. The range in which the back paste needs to be applied is the range L in FIG. 3A (the hatched area in the drawing), but it may be applied a little wider than this.

FIGS. 3B and 3C are diagrams showing the positional relationship between the temperature sensor (radiation thermometer 7) and the two position sensors (first light receiving sensor 10a and second light receiving sensor 10b).
In FIG.3 (b), the radiation thermometer 7 is arrange | positioned only the distance A downstream from the 1st light reception sensor 10a. A is the same as or slightly narrower than the width a of the cutting margin on the top side (downstream side) of the book. Then, when the front end of the book passes through the first light receiving sensor 10a, the switch of the radiation thermometer 7 is turned on.
On the other hand, as shown in FIG. 3C, the second light receiving sensor 10 b is arranged at a position upstream from the radiation thermometer 7 by a distance B. B is equal to or slightly narrower than the width b of the cutting margin on the ground side (upstream side) of the book. Then, when the rear end of the book passes through the second light receiving sensor 10b, the switch of the radiation thermometer 7 is turned off.

  Thereby, the temperature of only the part (application | coating range of back glue) except the cutting allowance of the top and bottom of a book can be measured with a radiation thermometer. Therefore, it is easy to determine whether or not back glue is applied, and it is not necessary to handle unnecessary temperature data, thereby simplifying data processing.

  In the present invention, only one downstream first light receiving sensor 10a may be used as the position sensor. In this case, when the front end of the book passes the first light receiving sensor 10a, the switch of the radiation thermometer 7 is turned on, and thereafter (the length L of the back paste application range) / (book transport speed v) If the control of turning off the switch of the radiation thermometer 7 is performed after the elapse of time, the same effect as that obtained when two position sensors are provided can be obtained.

  In the bookbinding process of applying PUR glue with a nozzle, the temperature of the back of a continuously conveyed book was measured using an inspection apparatus as shown in FIG. As shown in FIGS. 2 and 3, the position sensor is disposed about 30 mm away from the radiation thermometer on both the downstream and upstream sides with the radiation thermometer interposed therebetween.

  Radiation thermometer data was input to a personal computer and the temperature waveform was displayed on a recorder. An example of the result of temperature measurement is shown in FIG. As can be seen in the figure, the temperature of the part where the PUR glue is applied is 60 to 90 ° C., and it can be reliably inspected whether the back glue is applied by the method of the present invention. It was confirmed. The temperature of the PUR paste before application was about 110 ° C., the time until temperature measurement after application was 5 to 10 seconds, and the temperature drop during this period was about 20 to 50 ° C.

It is a flowchart which shows the example of the bookbinding process of a perfect binding system. It is a perspective view which shows the structure of the application | coating status inspection apparatus of the glue which is one Example of this invention. It is explanatory drawing of the intended purpose of the position sensor in this invention. It is a figure which shows the example of the temperature measurement result of the back glue application part in a present Example.

Explanation of symbols

1 piece 2 slit nozzle 3 pipe 4 clamp 5 guide plate 6 light sensor 7 radiation thermometer 8 data processing device 9 light projecting light source 10, 10a, 10b light receiving sensor 11 paper 12 cutter blade

Claims (5)

An apparatus for inspecting whether glue is applied to a predetermined part of a book,
An apparatus for inspecting the application state of glue, comprising means for measuring the temperature of the book part to which the glue has been applied with a radiation thermometer.   2. The glue application state inspection apparatus according to claim 1, wherein temperature measurement by the radiation thermometer is performed during conveyance of the book to which the glue is applied.   The glue application state inspection apparatus according to claim 2, further comprising position detection means for detecting the position of the leading and / or trailing edge of the book being conveyed in the vicinity of the radiation thermometer.   4. The paste according to claim 3, wherein the position detection means includes a light source of detection light projected so as to intersect the conveyance direction on a book conveyance path, and a light receiving element that receives the detection light. Application status inspection device.   The paste application state inspection device according to any one of claims 1 to 4, wherein the paste is a polyurethane-type reactive hot melt adhesive (PUR paste).

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