JP4093487B2 - Cap printing surface pretreatment device - Google Patents

Description

  The present invention relates to a cap printing surface pretreatment device for improving ink adhesion on the surface of a synthetic resin when printing product information data such as a product name and a shelf life on a synthetic resin cap for a beverage container or the like.

  Conventionally, many plastics are used for caps attached to beverage containers, etc. in terms of aesthetics, light weight, and cost. Product information is printed directly. However, the surface of plastic containers usually has a small surface polarity and is chemically stable and rarely immersed in an organic solvent. Therefore, when no surface treatment is performed, the adhesiveness of the ink is inferior and practical. In order to obtain adhesiveness, a surface treatment for improving the printability of the printing surface is required.

Surface treatment methods for such plastic molded products include corona discharge treatment for allowing plastic to pass through an electric field where corona discharge occurs, primer treatment for undercoating a coating material with excellent adhesion, and additives attached to the surface. Also known are solvent treatment for washing unreacted monomers and the like with a chlorinated solvent and flame treatment for partially oxidizing the surface in an oxidation flame. Of these, corona discharge treatment is expensive due to the treatment of the generated ozone, etc., and primer treatment and solvent treatment leave the surface sticky and difficult to adjust. Is often adopted. In connection with this frame processing, for example, in Patent Document 1, the ratio (L / D) of the distance L between the burner inner flame tip and the outer surface of the molded article to be processed and the inner diameter D of the burner nozzle is set to 80 to 170, There is described a frame processing method for a cyclic olefin-based resin molded product in which the outer surface speed of the processed product when the outer surface of the processed product passes the front of the gas burner is 50 to 100 cm / second.
JP 2004-18772 A

Usually, the cap manufacturer prints the customer's designated product name, character, etc. on the top surface of the cap after molding, and then ships at the filling factory after filling the bottle contents and closing the cap. Sun, manufacturing plants, etc. are printed on the peripheral wall surface of the cap by inkjet or the like.
However, in the prior art described in Patent Document 1, the flame of the burner nozzle is jetted from the vertical direction with respect to the top surface portion of the cap, which is a processed article, and the cap passes through the frame in the horizontal direction. Therefore, printing on the top surface of the cap is processed sufficiently by the frame, so there is no problem in ink adhesion, but there is a difference in the processing effect between the front side and the rear side of the peripheral wall surface of the cap. In particular, when the rear side processing becomes insufficient and printing is performed on the rear side portion, there is a problem in that printing defects such as peeling of the print are likely to occur.

  The present invention has been made in order to solve the above-described conventional problems, and can perform uniform and good printing by ink jet along the peripheral wall surface of a cylindrical synthetic resin cap, and has a simple structure. It is an object of the present invention to provide a cap printing surface pretreatment device that is excellent in maintainability and economy, and that can perform pre-printing processing efficiently while maintaining appropriate frame conditions according to the processing amount of the synthetic resin cap. To do.

(1) The cap printing surface pretreatment device according to claim 1 of the present invention is a cap printing surface pretreatment device that improves the ink adhesion by blowing an oxidation flame on the outer surface of the synthetic resin cap, A frame processing comprising: a cap moving means that is fixedly placed in an upright state on a carrier and moved in a fixed direction; and a burner nozzle that injects the oxidation flame from above the cap moving means toward the outer surface of the cap And the burner nozzle is disposed at an inclination angle of 85 ° to 65 ° toward the traveling direction of the cap.

(2) The cap print surface pretreatment device according to claim 2 is a cap print surface pretreatment device that improves the ink adhesion by blowing an oxidation flame on the outer surface of the synthetic resin cap, and the cap is placed on the carrier. And a frame processing means comprising a plurality of burner nozzles for injecting the oxidation flame from above the cap moving means toward the outer surface of the cap. The frame processing means includes at least a first burner nozzle disposed at an inclination angle of 135 ° to 90 ° toward the traveling direction of the cap, and 85 toward the traveling direction of the cap. It has the 2nd burner nozzle arrange | positioned with the inclination-angle of (degree)-45 degrees, It is characterized by the above-mentioned.

(3) The cap print surface pretreatment device according to claim 3 is characterized in that in (1) or (2), the cap print surface pretreatment device has an adjusting means for adjusting an inclination angle of the burner nozzle.

(4) The cap print surface pretreatment device according to claim 4 is characterized in that, in any of (1) to (3), the synthetic resin cap is made of a polyethylene-based or polypropylene-based synthetic resin. is doing.

(5) In the cap print surface pretreatment device according to claim 5, in any one of (1) to (4), the ratio of the fuel gas supplied to the burner nozzle of the frame processing means to the combustion air is 1. : 25 to 1:30, the cap moving time in the frame of the cap moving means is 0.5 to 5 seconds, and the frame temperature is 500 to 1000 ° C.

  According to the cap printing surface pretreatment apparatus of the present invention, the cap is fixedly mounted in an upright state on the carrier and moved in a certain direction, and the oxidation flame is inclined by 85 ° to 65 ° toward the traveling direction of the cap. Since it is sprayed at an angle toward the outer surface of the cap, it can be printed uniformly and well along the cylindrical peripheral wall surface of the synthetic resin cap, and it is appropriate according to the throughput of the synthetic resin cap. It is possible to easily perform pre-printing processing while maintaining various frame conditions.

The cap printing surface pretreatment apparatus according to the present embodiment includes a cap moving means for fixing and moving a synthetic resin cap such as polyethylene or polypropylene in an upright state on a carrier such as a conveyor belt and moving the cap in a certain direction. Frame processing means having a burner nozzle for injecting an oxidizing flame from above the cap moving means toward the outer surface of the cap, and the jetting direction of the oxidizing flame of the burner nozzle is 85 toward the traveling direction of the cap. They are arranged with an inclination angle of from ° to 65 °.
By maintaining the injection direction of the oxidation flame at a predetermined inclination angle in this way, when the cap moves in the frame that is injected from the burner nozzle, the frame processing effect on the rear side of the cap is enhanced to improve the frame processing before and after the cap. The effect can be made uniform. In this way, an oxygen bond or a double bond can be introduced into the molecule on the surface of the synthetic resin due to the oxidation flame to make the ink adhesion good and uniform.

  The synthetic resin cap is formed of a disk-shaped top surface portion and a substantially cylindrical peripheral wall surface depending from the periphery of the top surface portion. As the synthetic resin used as the material, for example, olefin resins such as high-density polyethylene, polypropylene, and polypentene-1: impact-resistant styrene resin, ABS resin, polyoxymethylene resin, vinyl chloride resin, and the like can be applied. These caps can be molded by injection molding, compression molding, or the like. Generally, propylene-based resins such as high-density polyethylene, polypropylene, and propylene-ethylene-based copolymers have heat resistance and mechanical properties. It is desirable from the aspect of.

  The cap moving means can be a heat-resistant belt conveyor driven by a motor or the like, and a synthetic resin cap is fixedly placed in an upright state on the belt conveyor serving as the carrier, and a predetermined transport is performed. A synthetic resin cap can be efficiently processed by sequentially performing frame processing, printing processing, ultraviolet irradiation processing (UV processing) and the like while moving at a speed.

  The flame processing means includes a burner nozzle that injects the oxidation flame at a predetermined inclination angle, a burner nozzle support portion that sets and holds a flame injection port of the burner nozzle at a predetermined inclination angle (frame injection angle of 85 ° to 65 °), A gas supply unit that supplies combustion air and fuel gas to the burner nozzle at a predetermined ratio and supply amount, respectively. When this inclination angle becomes smaller than 65 °, oxidation in the frame on the front side of the cap that moves on the carrier becomes insufficient, and the tendency that the frame processing before and after the cap becomes non-uniform becomes conspicuous. If the angle exceeds 85 °, the plastic oxide layer on the rear side of the cap tends to be insufficiently modified as in the prior art.

The cap printing surface pretreatment apparatus of the embodiment of the present invention is
A cap printing surface pretreatment apparatus for improving ink adhesion by blowing an oxidation flame on the outer surface of a synthetic resin cap, wherein the cap is fixedly placed upright on a carrier and moved in a fixed direction. Moving means and frame processing means provided with a burner nozzle that injects the oxidation flame from above the cap moving means toward the outer surface of the cap, wherein the frame processing means is at least in the advancing direction of the cap. The first burner nozzle arranged with an inclination angle of 135 ° to 90 ° toward the second and the second burner nozzle arranged with an inclination angle of 85 ° to 45 ° toward the advancing direction of the cap. Are arranged.
By using a plurality of burner nozzles arranged toward the top surface portion and the peripheral wall surface of the cap in this way, the synthetic resin cap is passed through the frame region for injecting the oxidation flame at a predetermined speed. Preprinted surface pretreatment around the peripheral wall surface can be performed uniformly, and the effect of preventing printing peeling on the peripheral wall surface of the cap can be further achieved.
That is, the oxidation flame emitted from the first burner nozzle is mainly processed from the front side of the cap to the top surface of the cap, and the oxidation flame output from the second burner nozzle is mainly processed from the top surface of the cap to the rear side of the cap, and the cap. The frame processing effect before and after can be made uniform.

The cap printing surface pretreatment device of this embodiment is also characterized by having an adjusting means that makes it possible to adjust the inclination angle of the burner nozzle. By this adjustment means, the inclination angle of the burner nozzle can be set to an appropriate value according to the transfer speed of the synthetic resin cap, etc., and it is possible to easily cope with variations in process conditions.
The adjusting means is configured to rotate the burner nozzle on the carrier of the cap moving means within a range of a predetermined inclination angle, and to fix and hold the inclination angle. Has a stop.

The cap printing surface pretreatment apparatus of this embodiment is also characterized in that the synthetic resin cap is made of a polyethylene-based or polypropylene-based synthetic resin, and is printed using a material that is relatively inexpensive and excellent in handleability. A cap with excellent properties can be provided economically.
Polyolefin-based plastics such as polyethylene-based and polypropylene-based synthetic resins are generally chemically stable and rarely soaked in an organic solvent, and the surface is not wet when flame treatment is not performed. By passing this through an oxidation flame injected from a burner nozzle under a predetermined flame condition, the plastic surface is exposed to a gas oxidation flame, and oxygen bonds or double bonds are introduced into the surface molecules. By properly adjusting the gas amount of the gas burner, the amount of air, the distance between the oxidation flame and the plastic surface, etc., the wetting characteristics with respect to the ink component on the surface of the synthetic resin can be maintained well.

In the cap printing surface pretreatment apparatus of this embodiment, the ratio of the fuel gas to the combustion air supplied to the burner nozzle of the frame processing means is 1:25 to 1:30, and the cap moving means passes through the frame of the cap. Another characteristic is that the time is 0.5 to 5 seconds and the flame temperature is 500 to 1000 ° C. As a result, the peripheral wall surface of the cylindrical synthetic resin cap moving on the carrier can be set within a range of frame conditions that can be uniformly processed, effectively preventing the occurrence of printing defects in the subsequent printing process. Can be suppressed. That is, if the fuel gas is less than 1:30 in the ratio of the fuel gas to the combustion air, it becomes difficult to stably maintain the oxidization flame, and conversely if the fuel gas is more than 1:25, the flame is insufficient in oxygen. This is not preferable because the modification effect on the surface of the synthetic resin tends to be significantly reduced.
If the frame passing time is less than 0.5 seconds, it becomes difficult to form a predetermined uniform oxide layer on the surface of the synthetic resin cap. Conversely, if it exceeds 5 seconds, the cap surface is deformed or melted. Therefore, it is not preferable. If the flame temperature is lower than 500 ° C., the oxidation effect and its processing ability are remarkably lowered. Conversely, if it exceeds 1000 ° C., oxidation is excessive and the surface properties are deteriorated.

  The cap printing surface pretreatment apparatus according to the present embodiment is configured as described above, and oxidizes the flame toward the outer surface of the cap at an inclination angle of 85 ° to 65 ° toward the traveling direction of the cap. Printing can be performed uniformly and satisfactorily along the peripheral wall surface of the synthetic resin cap, and pre-printing processing is easy while maintaining appropriate frame conditions according to the throughput of the synthetic resin cap. Can be done.

Hereinafter, the cap printing surface pretreatment apparatus of the present embodiment will be described more specifically with reference to the drawings. 1 is a partially enlarged front view of a cap printing surface pretreatment apparatus according to an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a side view thereof.
As shown in the figure, the cap printing surface pretreatment device 10 of the present embodiment is an upright in which a plurality of synthetic resin caps C such as polyethylene and polypropylene are put on a fixing pin arranged on the conveyor belt 11 and arranged in plural. A cap moving means for placing and moving in a fixed direction, and a frame processing means having a burner nozzle 12 for injecting an oxidizing flame from above the conveyor belt 11 toward the outer surface of the cap C. Yes. The burner nozzle 12 is formed such that the frame injection port 12a is enlarged in the width direction of the conveyor belt 11, and the frame injection angle θ, which is an inclination angle with respect to the cap moving direction (in this case, the horizontal direction), is in the range of 85 ° to 65 °. An inclination angle setting section 12b as an adjusting means for setting and an ignition electrode 12c for igniting the mixed gas are provided. Thus, the frame injection angle θ can be appropriately set to an appropriate value in accordance with the moving speed of the conveyor belt 11, the size of the synthetic resin cap C, the material thereof, and the like. As shown in FIG. 3, the burner nozzle 12 is connected to a gas supply unit 13 for supplying a mixed gas of fuel gas and air. The gas supply unit 13 includes a mixer 13a. The mixer 13a is supplied with a predetermined amount of fuel gas at a predetermined pressure via an electromagnetic valve 13b, a governor 13c, and a needle valve 13d. A predetermined amount of air is supplied through the gauge 13f and the needle valve 13g.

FIG. 4 shows a cap printing surface pretreatment device for arranging a plurality of synthetic resin caps C (four rows in this embodiment) and printing product information or the like on the surface (top surface and peripheral wall surface) of the cap C. It is the schematic diagram of the pre-processing and the printing processing process which it had.
As shown in the figure, the synthetic resin cap C supplied from the alignment chute on the upstream side of the conveyor belt 11 is processed under a predetermined frame condition by passing through the cap printing surface pretreatment device 10, and the top of the cap serving as the printing surface. The surface and the peripheral wall surface are modified.
The printing device 15 in the next step performs printing on the top surface of the modified cap C, and the UV irradiation device 16 irradiates the printing surface with ultraviolet rays to improve the ink fixing property. The printed cap is completed.
Next, after the contents are filled, the cap is attached to the bottle, and predetermined product information such as a manufacturing date and a manufacturing factory is printed on the peripheral wall surface of the cap C by an inkjet or the like and shipped.

Table 1 shows data of experimental results obtained by processing the synthetic resin cap C by setting the inclination angles of the burner nozzle 12 of the cap printing surface pretreatment apparatus 10 to different angles (90 °, 80 °, 70 °, 60 °). Is shown.
Note that the printed surface of the synthetic resin cap C is affixed with a tape on the printed surface, and the tape is peeled off. The evaluation table in FIG. It was evaluated by giving an evaluation score.
From the data in Table 1 above,
(1) By changing the inclination of the burner nozzle (frame injection angle θ), the evaluation point by the tape peeling test is improved as the printing adhesion force on the peripheral wall surface of the cap increases as the angle increases.
(2) An inclination of 70 ° is in a state where the front and rear are balanced, and it has become clear that it is the best state without being illegible.

FIG. 5 is a schematic configuration diagram of a modified example of the cap printing surface pretreatment apparatus of the present invention. As shown in the figure, the cap printing surface pretreatment device 20 includes a first burner nozzle 21 as a main nozzle and a second burner nozzle 22 as an auxiliary nozzle, and the burner nozzles 21 and 22 are arranged in parallel at a predetermined interval. The inclination angle θ1 of the first burner nozzle 21 is arranged at 120 °, and the inclination angle θ2 of the second burner nozzle 22 arranged on the upstream side thereof is arranged at 60 °. The oxidation flame emitted from the first burner nozzle 21 is mainly processed from the cap front side to the cap top surface portion, and the oxidation flame emitted from the second burner nozzle 22 is mainly processed from the cap top surface portion to the cap rear side. it can. As a result, a frame region having a predetermined shape is formed on the conveyor belt 11 that moves in a wide and appropriate manner, and the cap circumference of the synthetic resin cap C is adapted to the moving speed, cap shape, number of caps arranged, etc. The frame conditions can be set so that the wall surface can be uniformly processed.
The inclination angles of the first burner nozzle 21 and the second burner nozzle may be arbitrarily set according to the cap conveyance conditions.

  Table 3 shows the evaluation results of the tape peeling test of the synthetic resin cap C processed by the printing processing apparatus including the cap printing surface pre-processing apparatus 20. The total score is shown. From the results in Table 3, the following became clear. That is, the tape peeling test was performed by printing on the cap bottom (periphery of the peripheral wall surface) on the front, back, left and right four sides, and as a result, good results with no problem in ink adhesion were obtained on all four sides.

As described above, the cap printing surface pretreatment apparatus 10 of the present embodiment is configured as described above, and has the following excellent industrial applicability.
(1) When the synthetic resin cap C moves in the frame sprayed from the burner nozzle 12 while maintaining the direction in which the oxidization flame of the burner nozzle 12 is sprayed at a predetermined inclination angle, the frame processing effect is provided on the rear side of the cap. To improve the uniformity of the frame treatment effect before and after that, and introduce oxygen bonds or double bonds into the molecules on the surface of the synthetic resin due to the oxidation flame to improve the uniformity of ink adhesion.
(2) Frame processing on the peripheral wall surface of the synthetic resin cap by passing the synthetic resin cap C through the formed frame region using the plurality of burner nozzles 21 and 22 arranged at predetermined angles, respectively. Can be made uniform.
(3) Since the inclination angle setting section 12b (adjustment means) that enables adjustment of the inclination angle of the burner nozzle 12 is provided, the flame injection angle of the burner nozzle is set to an appropriate value in accordance with the transfer speed of the synthetic resin cap. It can be set and can easily cope with variations in process conditions.
(4) By making the synthetic resin cap C made of a polyethylene-based or polypropylene-based synthetic resin that is inexpensive and excellent in handleability, it is possible to economically provide a cap free from printing defects.
(5) Cylindrical synthetic resin that moves on the conveyor belt 11 by setting the ratio of the fuel gas and air in the burner nozzles 12, 21, and 22, the passage time of the cap in the frame, and the frame temperature within a predetermined range. The peripheral wall surface of the cap made can be set within a range of frame conditions that allows uniform processing, and the occurrence of printing defects in the subsequent printing process can be effectively suppressed.
In addition, embodiment of this invention only illustrated one specific example, and does not limit this invention by this. That is, the shape and capacity of the burner nozzle, the type of synthetic resin cap to be applied, and the like can be appropriately changed to those other than those described.

It is a partial expanded front view of the cap printing surface pretreatment apparatus of one Embodiment of this invention. It is a top view of the cap printing surface pretreatment apparatus of one embodiment of the present invention. It is a side view of the cap printing surface pretreatment apparatus of one embodiment of the present invention. It is a schematic diagram of a printing processing apparatus having a cap printing surface pre-processing apparatus. It is a schematic block diagram of the cap printing surface pre-processing apparatus in the modification example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cap printing surface pretreatment apparatus 11 Conveyor belt 12 Burner nozzle 12a Frame injection port 12b Inclination angle setting part 12c Ignition electrode 13 Gas supply part 13a Mixer 13b Electromagnetic valve 13c Governor 13d Needle valve 13e Air supply 13f Pressure gauge 13g Needle valve 15 Printing device 16 UV irradiation device 20 Cap printing surface pretreatment device 21 First burner nozzle 22 Second burner nozzle θ, θ1, θ2 Inclination angle (frame ejection angle)

Claims (5)

  A cap printing surface pretreatment apparatus for improving ink adhesion by blowing an oxidation flame on the outer surface of a synthetic resin cap, wherein the cap is fixedly placed upright on a carrier and moved in a fixed direction. And a frame processing means having a burner nozzle for injecting the oxidation flame from above the cap moving means toward the outer surface of the cap, and the burner nozzle is 85 ° toward the traveling direction of the cap. A cap printing surface pretreatment apparatus, which is arranged with an inclination angle of ˜65 °. A cap printing surface pretreatment apparatus for improving ink adhesion by blowing an oxidation flame on the outer surface of a synthetic resin cap, wherein the cap is fixedly placed upright on a carrier and moved in a fixed direction. A moving means, and a frame processing means comprising a plurality of burner nozzles for injecting the oxidation flame toward the outer surface of the cap from above the cap moving means,
The frame processing means includes at least a first burner nozzle disposed with an inclination angle of 135 ° to 90 ° toward the traveling direction of the cap, and an angle of 85 ° to 45 ° toward the traveling direction of the cap. A cap printing surface pretreatment device, comprising: a second burner nozzle arranged with an inclination angle.   The cap printing surface pretreatment device according to claim 1, further comprising an adjusting unit that makes it possible to adjust an inclination angle of the burner nozzle.   The cap printing surface pretreatment device according to any one of claims 1 to 3, wherein the synthetic resin cap is made of a polyethylene-based or polypropylene-based synthetic resin.   The ratio of the fuel gas to the combustion air supplied to the burner nozzle of the frame processing means is 1:25 to 1:30, and the passage time of the cap in the frame in the cap moving means is 0.5 to 5 seconds, The cap printing surface pretreatment device according to claim 1, wherein the frame temperature is 500 to 1000 ° C.

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