JPH10296184A - Marking method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a marking suitable to mass production obtaining excellent rapid drying property by using a dispersion medium being in a liquid state at a time of jetting and being solidified on a surface to be marked, when the marking is executed on the surface to be marked by jetting a marking agent made of dispersing a pigment, etc., into the dispersion medium. SOLUTION: In the case that a consumption period and a production date, etc., are marked on a product to be produced, a marking agent in which a pigment or a dyestuff is dispersed into a dispersion medium being in a liquid state at a time of jetting from a nozzle and immediately stuck and solidified on the surface to be marked, is used. As the dispersion medium, to be used hot melt type resin comprising primarily a thermoplastic resin, a moisture hardening polyurethane adhesive, moisture hardening resin, which reacts with moisture in air to immediately harden, low melting point glass which is multi- component glass powders comprising primarily PbO-B2 O3 and is mixed with a self-sintering bonding agent such as nitrocellulose and wax, etc., are listed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marking method for marking the date of manufacture, quality indication, etc., and marking a defective portion of a material detected in a manufacturing process on a product manufactured in the manufacturing industry. More specifically, the present invention relates to a method for marking using a safe marking agent that does not use an organic solvent.

[0002]

2. Description of the Related Art In a manufacturing industry, for a manufactured product, for a logistics, a quality control, and a quality assurance, a consumption expiration date, a best-before date, a quality retention date, a production date, an expiration date, a shipping date, a production date Number, NET, quantity, price, size, classification,
Marking is performed to mark the place of origin, brand, ingredients, additives, composition, quality label, code number, registration number, rating, characteristic type, manufacturing factory name, distributor name, country of origin, etc. Also, in the production process of the raw material, marking is performed to mark the detected material defect, size measurement, and other results on the material in order to maintain quality.

[0003] As one of the marking methods, there is a method in which ink is ejected from a nozzle to mark a character or the like on a surface to be marked. As a marking device using such a method, an ink jet device of an ink jet printer or an air spray gun is used. and so on.

[0004] A marking agent such as ink or paint used in these marking devices comprises a pigment or dye for imparting a color and a dispersion medium thereof, and the dispersion medium includes a pigment or the like and a surface to be marked. A fixing polymer serving as a binder, a solvent for the polymer, and the like are included. As a solvent, since a spray method is often used as a marking method, an organic solvent (acetone, toluene, xylene, methyl ethyl ketone, etc.) generally called a thinner is used from the viewpoint of workability and quick drying. I have.

[0005]

These organic solvents are:
Generally flammable and dangerous, and harmful to the human body. Also, while these organic solvents are volatile,
Since pigments have poor dispersibility, there is also a problem that a marking agent using an organic solvent tends to cause clogging of nozzles.

On the other hand, there is a halogen-based solvent as a nonflammable solvent, but it is required not to use it because of environmental pollution.

[0007] Emulsion-based marking agents using water, which is safe as a solvent, are inadequate as quick-drying agents and are therefore unsuitable as marking agents used in mass production or automatic production processes. Generally, a solvent is not used because it is a liquid, but it is inappropriate when the surface to be marked is a heat-sensitive material such as paper or plastic.

The present invention has been made in view of such circumstances, and a purpose thereof is to provide a marking method suitable for automatic production and mass production using a safe and quick-drying marking agent. Is to provide.

[0009]

That is, the marking method of the present invention is directed to a method of marking a character or the like on a surface to be marked by jetting a marking agent comprising a pigment or dye dispersed in a dispersion medium. The medium is characterized in that it is solidified on the surface to be marked in a liquid state at the time of jetting.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The marking agent used in the marking method according to the present invention is a dispersion in which a pigment or a dye is in a liquid state when ejected from a nozzle, but can be immediately fixed and solidified on the surface to be marked. It is dispersed in a medium. In short, the dispersion medium used in the present invention is in a liquid state at the time of jetting and acts as a solvent such as a pigment, does not volatilize on the surface to be marked, and is dried by solidifying itself. is there.

As such a dispersion medium, specifically,
Hot melt resin mainly composed of thermoplastic resin such as polyolefin, polyester, nylon, ethylene-vinyl acetate copolymer; reacts with moisture in the air like moisture-curable polyurethane adhesive, cyanoacrylate adhesive, etc. moisture-curable resin is cured immediately; PbO-B ₂ O ₃ multi-component glass powder consisting mainly of a low melting point glass of a mixture of self-sintering binder such as nitrocellulose; solder, low melting point metal such as silver solder A wax; an energy-curable resin that is cured by irradiation with ultraviolet rays, an electron beam, or the like. To lower these melting points, a flux may be further added and used.

These dispersion media depend on the type of object to be marked (object to be marked), particularly the type of surface to be marked (material, melting point, softening point, wettability with the dispersion medium, etc.), and the type of marking device. What is necessary is just to select suitably according to it. These dispersion media are cooled and solidified on the surface to be marked,
Alternatively, it is cured by reaction or polymerization. Therefore, by using a dispersion medium having good wettability with the surface to be marked, the dispersion medium can be fixed and fixed to the surface to be marked only by solidification of the dispersion medium itself, so that the entire dispersion medium can act as a fixing polymer serving as a binder. This means that by adjusting the viscosity of the dispersion medium, a solvent (mainly an organic solvent) serving as a diluent for the fixing polymer is not required. The viscosity of the dispersion medium can be adjusted by adjusting the temperature at the time of injection.

The fact that the solidification itself without volatilization does not dissipate into the atmosphere like an organic solvent, so that there is little problem of environmental pollution and it is safe for workers. Further, the elimination of the use of an organic solvent does not require the management to be restricted by regulations such as the Fire Service Law and the Ordinance on Prevention of Organic Solvent Poisoning. In addition, since it is not volatile, the problem of clogging hardly occurs, and maintenance is easy. Furthermore, since it has a quick-drying property without passing through a drying step as in the prior art, the step after the injection of the marking agent can be simplified, and the running cost can be reduced. Furthermore, if the dispersion medium is a hot-melt dispersion medium, it is solid at room temperature, so that it is easy to handle. Furthermore, since a wide range of dispersion media can be selected without using an organic solvent as described above, by appropriately selecting a dispersion medium, marking on an object to be marked, which could not be applied conventionally, can be performed. For example, the present invention can be applied to marking of automatic flaw detection using radiation performed in a closed room, completion of an oil or heavy oil tank, a ship, a tanker, etc., and automatic marking at the time of ultrasonic inspection in a periodic inspection.

As the pigment or dye contained in the marking agent, those used in the conventional marking agent can be used according to the marking requirement.

The marking agent used in the present invention may contain a fixing polymer, a dispersant, and the like, if necessary, in addition to the above-described dispersion medium and dye or pigment. However, since many of the dispersion media used in the present invention have an adhesive function, if a dispersion medium having good wettability with the surface to be marked is selected, a fixing polymer is generally unnecessary.

As a means for injecting such a marking agent onto the surface to be marked in accordance with a marking command, a conventionally used ejecting means such as a dispenser or a gun is used. An air pump, a gear pump, a plunger pump, or the like may be used. Either means requires less repelling of the marking agent on the surface to be marked. This leads to the effect that when printing characters or the like, the printing is beautiful.

In the case where a hot-melt type dispersion medium is used, the pressurizing means must be maintained at a temperature higher than the melting point or melting point of the dispersion medium because of the necessity of maintaining the marking agent in a liquid state at the time of injection. It is necessary to keep. In the case of a moisture-curable dispersion medium, it is necessary to appropriately provide a waterproof means so as not to mix moisture.

In the case of using an energy-curable dispersion medium as the dispersion medium, it is necessary to solidify the marking agent by irradiating an electron beam, ultraviolet rays, or the like according to the type of the dispersion medium after spraying the surface to be marked.

Further, the marking method of the present invention can be applied to a marking object to which a laser marker or a dye-based ink jet is conventionally difficult to apply, by combining the laser marker or the ink jet with a character, a symbol, or a complicated bar code. Applicable to printing of.

That is, in the case of a dark object such as rubber, iron, steel or the like having a low reflectivity or a transparent object such as glass, an inexpensive dye-based ink jet is used because the mark is inferior in clarity. There were times when I could not do that. On the other hand, leather, cloth, ceramic, even whitish marking object with relatively high reflectance such as aluminum,
In some cases, the laser marker is inappropriate due to an increase in the amount of energy, damage to the object to be marked, or the like. In these cases, an ink jet or a laser marker can be applied by performing a base treatment with a marking agent in which a white pigment having a high concealing property is dispersed, but the base treatment by a conventional marking method requires a long time for drying. For this reason, in the automation line, a label is often attached, but there is a problem that the label is peeled off when the surface of the object to be marked is rough. However, since the marking agent used in the present invention is quick-drying, a continuous process of performing a base treatment on an automated line and then applying a laser marker or a dye-based ink jet to the base-treated part to mark characters or the like is performed. It becomes possible.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to specific embodiments.

FIG. 1 is a diagram showing a state in a steel mill of φ18 mm to 1 mm.
A 20 mm round bar is automatically inspected for defects inside and on the surface of the round bar at a speed of 40 m / min to 150 m / min, and a marking method using a hot-melt type marking agent is adopted for a line for marking a defective portion. It shows the case where it is done.

That is, while the round bar 1 to be inspected is conveyed by the roller 2, an automatic combination of a penetrating flaw detector 3 for examining internal flaws and a rotary flaw detector 4 for examining flaws on the outer surface is provided. Pass through the flaw detector. The defect of the round bar 1 found by each of the flaw detectors 3 and 4 is sent to the marker controller 5 as a flaw signal. A clock signal is sent to the marker controller 5 from a pulse generator (PG) 6 provided near the automatic flaw detector. The marker controller 5 transmits the flaw signal input from the flaw detectors 3 and 4 to the marking head 7 as a spray signal after a predetermined pulse of the clock signal. The spray signal is used to determine the defect position by the clock signal.
Is set so as to spray the marking agent when it is conveyed to the front of the printer. The marking head 7 to which the spraying signal has been input is the nozzle 7a,
From 7b, a marking agent is sprayed onto a predetermined position of the round bar 1. Since the marking agent used is a hot-melt type, the tank 8 containing the marking agent is maintained at a high temperature equal to or higher than the melting point of the marking agent. The marking agent can be maintained in a molten liquid state at the time of injection by circulating the marking agent between the tank 8 and the nozzles 7a and 7b by the pump 9. The hot-melt type marking agent injected into the round bar 1 is transported while the round bar 1 is being transported.
It cools on the surface and solidifies and sets. Because of the quick drying, even in such a high-speed line for automatic production,
There is no need to stop the transport line for drying.

In the marking head 7 shown in FIG.
The two nozzles 7a and 7b are arranged side by side to perform marking of different colors according to the type of defect detected by each of the penetrating type flaw detector 3 and the rotary type flaw detector 4. Therefore, if there is no need for color coding, only one nozzle 7a is sufficient. On the other hand, if it is desired to use three or more types of markings, it is sufficient to arrange a number of nozzles in parallel according to the number of colors.

In FIG. 1, the marking head 7 and the ink tank 8 are connected by a heating hose. For example, a gun 11, an ink tank 12, and a heating block 13 as shown in FIG. Alternatively, an ink-jet device connected with the above may be used. A nozzle 14 for spraying a marking agent is attached to a tip of the gun 11, and an air hose is connected to a base end of the gun 11. On the other hand, the tip of the tank 12 is connected to the nozzle 14 so that the marking agent 15 in the tank 12 is supplied to the nozzle 14. An air hose different from the gun 11 is connected to the base end of the tank 12. Each of the air hoses is connected to an air pump (not shown).
And supply air to the gun 11. When air is supplied into the tank 12, the marking agent 15 in the tank 12 is pushed out to the pool space 18. On the other hand, the gun 11 controls the opening and closing of the nozzle 14 by air supply, and sprays the marking agent supplied to the pool space 18 from the nozzle 14 toward the surface to be marked.

In a conventional line employing a marking method in which a marking agent using an organic solvent is jetted, an average of 80 liters of an organic solvent is used as a paint or ink per month to prevent clogging and lubrication and cleaning. Was. In a year, six drums of organic solvent are used in one line, and all of them are released to the atmosphere. However, according to the method of the present invention, such a large amount of organic solvent is not used and released. In addition, since the liquid state can be obtained by maintaining the temperature of the tank at a temperature equal to or higher than the melting point of the dispersion medium, there is no need to worry about clogging of the nozzles and the maintenance property is excellent.

Further, since the hot-melt type marking agent can be solidified and fixed on the surface to be marked without going through a drying step, even if it is an ultra-low speed inspection line opposite to the above embodiment, it is shown in FIG. A marking system can be applied. This is because even if the application amount of the marking agent becomes too large, the marking agent does not flow. This means that the present invention can be applied to an object other than a flat plate, such as a round bar.

In the above embodiment, a hot-melt type marking agent is used. However, other types of marking agents can be applied to the flaw detection marking system as shown in FIG. In the case of a moisture-curing type marking agent, it is not necessary to control the temperature of the tank filled with the marking agent, and instead, it is necessary to manage so that moisture does not enter. When an energy ray-curable marking agent is used, an energy irradiation device may be provided downstream of the marking head.

The marking pattern may be spiral (see FIG. 3 (a)), dot or bead (see FIG. 3 (b)), curtain spray (see FIG. 3 (c)), etc., depending on the shape and type of the nozzle. Can be used.

When a character is to be marked, first, a white marking agent having a high concealing property is sprayed on the surface to be marked with a nozzle 7a installed on the upstream side, and then a nozzle 7b installed on the downstream side. Mark the character with. Since the marking agent of the present invention is quick-drying, it is also possible to perform continuous marking of a base and printing in an automated line.

[0031]

According to the marking method of the present invention, since a marking agent that does not use an organic solvent is used, it is safe for workers and the environment, and is excellent in maintenance without fear of clogging. Further, the present invention can be applied to an object to be marked which could not be applied conventionally because of the use of an organic solvent.

Further, since the marking agent used in the present invention is quick-drying, it does not require a drying step, has a low running cost, and is suitable for an automated product line. It can also be applied to marking surfaces.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a system according to an embodiment to which a marking method of the present invention is applied.

FIG. 2 is a diagram illustrating a configuration of an embodiment of a marking head.

FIG. 3 is a diagram illustrating an example of a marking pattern.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Marking object 7 Marking head 14 Nozzle 15 Marking agent

Claims (1)

[Claims] 1. A method of marking a character or the like on a surface to be marked by ejecting a marking agent obtained by dispersing a pigment or dye in a dispersion medium, wherein the dispersion medium is in a liquid state at the time of ejection, and A marking method characterized by being solidified on a marking surface.