JP2002337450A - Printing method with hot stamping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a printing with hot stamping in high cycle. SOLUTION: In a printing method, in which a transfer printing is executed with hot stamping by pressing a hot stamping foil 39 with a heated printing head 36 against a surface to be printed W1, the surface to be printed W1 is heated in advance with a preheating mechanism 4 and then the transfer printing is executed against the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing method using a hot stamp, and more particularly, to a printing method using a hot stamp capable of printing at a high cycle.

[0002]

2. Description of the Related Art As a method for printing on a product such as a magnetic tape cartridge, transfer printing using a hot stamp is widely and generally used. For example, as shown in FIG. 7, it is used when a machine-readable identification L for identifying the product is printed on the side surface of a magnetic tape cartridge W such as a video tape cassette.
The hot stamp is made of polyethylene terephthalate (PE
T) A substrate sheet such as T) is coated with ink or a pattern is printed with ink (hereinafter, referred to as "hot stamp foil"). The ink layer side is applied to a printing object, and heat and pressure are applied by a print head. A printing method in which, after the ink layer is adhered to the printing target, the base sheet is peeled off and the inverted pattern is transferred to the printing target.

The print head used for the above-described hot stamp is mainly made of metal, and a heater is provided behind the print head. And on the surface of the print head,
An elastic sheet such as silicone rubber is attached as necessary. The elastic sheet is for absorbing undulations in the surface shape of the printing material and irregularities such as curved surfaces provided as designs. The heat generated in the heater is transmitted through the metal print head, and then to the elastic body and the hot stamp foil, so that the ink layer of the hot stamp foil can be fused. Further, the print head transfers the ink layer to the print object by pressing against the print object for a certain period of time, for example, about 1 second or less. At this time, heat is simultaneously conducted to the printing substrate.

[0004] Therefore, the heat is deprived by the printing material,
Immediately after printing is completed, the temperature of the print head is lowered by about several tens of degrees Celsius. Therefore, the print head is heated by the heater, and the print head is controlled so as to reach a necessary temperature before printing the next printing material.

[0005]

However, when the print cycle is long, for example, when printing is performed about 10 times per minute, it is possible to heat the print head to a sufficient temperature. When the printing time is shorter, for example, when printing is performed 20 times or more per minute, the heat taken by the printing material cannot be supplemented by the heater,
There is a problem that the temperature of the print head gradually decreases. If the temperature of the print head is lowered, the ink layer on the hot stamp foil cannot be sufficiently heated, which may cause chipping or peeling in printing.

Further, since the thermal conductivity of an elastic body is generally lower than that of a metal, when an elastic sheet such as silicon rubber is stuck to a print head, the elastic sheet is moved from the metal portion of the print head. Heat cannot be received quickly, and the temperature of the head surface pressing the hot stamp foil tends to be particularly low.

Accordingly, an object of the present invention is to solve the above-mentioned problem and to provide a printing method using a hot stamp which can perform printing in a high cycle.

[0008]

According to the present invention, there is provided a printing method using a hot stamp in which transfer printing is performed by pressing a hot stamp foil against a printing surface with a heated print head. The surface is heated in advance, and then the transfer printing is performed.

By preheating the printing surface in this way, the amount of heat taken from the print head to the printing material can be reduced. As a result, even when performing high-cycle printing,
The temperature of the print head can be prevented from lowering, and defects such as missing prints can be prevented.

[0010]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG.
FIG. 2 is a plan view of the entire printing apparatus that performs the hot stamp printing method of the present invention, and FIG. 2 is an enlarged perspective view of a main part of the printing apparatus of FIG. In the present embodiment, description will be made on the assumption that the identification mark L is printed on a magnetic tape cartridge such as a video tape cassette. As shown in FIGS. 1 and 2, a printing apparatus 1 according to the present embodiment includes a stamping machine 3 that performs hot stamping, and a printing surface W1 (see FIG. 1) of a magnetic tape cartridge W before hot stamping is performed by the stamping machine 3. 7
), And a transport conveyor 2 for transporting the magnetic tape cartridge W.

The hot stamping machine 3 has an unwinding reel 31a for supplying the hot stamping foil 39 and the unwinding hot stamping foil 39 wound thereon.
A plurality of guide pins 32,...
A take-up reel 31b for winding the hot stamp foil 39 used for printing, and the hot stamp foil 39 by the heated print head 36 to the printing surface W1 of the magnetic tape cartridge W.
(See FIG. 7).

The hot stamp foil 39 is obtained by coating a base film such as polyethylene terephthalate (PET) with a special ink layer that can be fused at a high temperature.

The guide pins 32,... Guide the hot stamp foil 39 unwound from the unwind reel 31a.
Is arranged so as to pass through a gap between the printing surface W1 (see FIG. 7) and the print head 36, and further guides the hot stamp foil 39 used for printing in the gap and winds it around the take-up reel 31b. It is arranged to take.

The stamp section 35 includes a hot stamp foil 39.
A printing head 36 for heating the printing surface W1 of the magnetic tape cartridge W to pressurize the printing head 36, a heater unit 37 for heating the printing head 36, and the entire printing head 36 and the heating unit 37 on the printing surface W1. And a drive mechanism 38 for moving the body closer to and away from it. FIG. 5 shows a time chart of the printing apparatus according to the present embodiment. In FIG. 5, the pressing mechanism means the print head 36 or the preheating mechanism 4. As shown in FIG. 5, the driving mechanism 38
The print head 36 is controlled so as to heat and press the printing surface W1 for about 0.7 seconds.

The preheating mechanism 4 comprises a preheating head 42 for heating and pressurizing the printing surface W1 and a heater section 41 for heating the preheating head 42. A driving mechanism (not shown) drives the preheating head 42 for a predetermined time similarly to the printing head 36. (Approximately 0.7 seconds) It is controlled so as to be close to the printing surface W1, pressurized, and then separated. The preheating mechanism 4 is located upstream of the stamping machine 3 and preheats the magnetic tape cartridge W immediately before the magnetic tape cartridge W to be printed by the stamping machine 3.

The transport conveyor 2 is a device that transports the assembled magnetic tape cartridge W from right to left in FIG. 1 by pitch feed or the like. The pitch of the transport conveyor 2 is such that the magnetic tape cartridge W is stopped at the printing position for about 1.9 seconds, and the next magnetic tape cartridge W is transported to the printing position in about 0.6 seconds. That is, the magnetic tape cartridge W is pitch-fed in one cycle in about 2.5 seconds. The conveyed magnetic tape cartridge W is placed in the stamping machine 3 or the preheating mechanism 4.
Conveyor 2 to determine the positional relationship between
Is positioned and fixed on a transport pallet 21 transported on the pallet.

A CCD (Charge-Coupled Device) for checking print quality is provided on the downstream side of the conveyor 2.
e) The camera 5 is installed facing the printing surface W1.
The identification display L photographed by the CCD camera 5 is input to an image processing device (not shown), and the print quality is confirmed by pattern matching with the master identification display image previously input to the image input device. It has become.

Next, details of the stamp machine 3 and the preheating mechanism 4 will be described. FIG. 3 is a sectional perspective view of the print head and the heater section, and FIG. 4 is a sectional perspective view of the preheating head and the heater section.

As shown in FIG. 3, the print head 36 has a substantially L-shaped aluminum print head block 36a. The front end of the print head block 36a, which extends forward, forms a head portion 36c of the print head 36. An elastic sheet 36b made of silicon rubber, fluorine rubber, or the like for absorbing the undulation of the printing surface W1 is attached to the head portion 36c. The head portion 36c has a trapezoidal shape with its center slightly raised in accordance with the print pattern. The shape of the head portion 36c may be simply a planar shape if a portion of the print pattern is slightly convex in the magnetic tape cartridge W.

The head section 36 of the print head block 36a
A small hole 36d is formed near c. Small hole 36d
The tip of a thermocouple 36e is inserted into the thermocouple 36e.
It is fixed by pressing it from the side with bolts (not shown). The thermocouple 36e is connected to a print head temperature controller (not shown). Print head block 36a
The rear surface opposite to the head portion 36c has the heater portion 3
7 is fixed by bolts (not shown) so as to be in close contact with the fixing member 7. The heater section 37 includes a heater block 37a whose main body is a metal block.
Among them, a heater hole 37b is opened from above in the vicinity where the print head block 36a is fixed. An electric heater 37c is inserted into the heater hole 37b, and the electric heater 37c is connected to the above-described temperature control device. In the temperature control device, the set temperature and the thermocouple 36
e, the output of the electric heater 37c is controlled such that the temperature of the head section 36c approaches the set temperature. It should be noted that the temperature of the print head 36 may be about 15 ° C., depending on the specifications of the printing material and the hot stamp foil 39.
It is controlled at 0 to 250 ° C.

The preheating head 42 shown in FIG. 4 comprises an inverted L-shaped preheating head block 42a whose main body is made of brass. Then, the preheating head block 42a
The front end of the head part 42c is a head part 42c.
The head 42c has a trapezoidal shape with the center slightly raised in accordance with the print pattern.

Head section 42 of preheating head block 42a
A small hole 42d is formed near c. Small hole 42d
The tip of the thermocouple 42e is inserted into the thermocouple 42e.
It is fixed by pressing it from the side with bolts (not shown). The thermocouple 42e is connected to a temperature control device for a preheating head (not shown). Preheating head block 42a
The rear surface opposite to the head portion 42 c has a heater portion 4.
1 and is fixed by a bolt (not shown) so as to be in close contact with the first member. The heater section 41 includes a heater block 41a whose main body is a metal block.
Among them, a heater hole 41b is opened from the lower portion in the vicinity where the preheating head block 42a is fixed. An electric heater 41c is inserted into the heater hole 41b, and the electric heater 41c is connected to the above-described temperature control device. In the temperature control device, the set temperature and the thermocouple 42
The output of the electric heater 41c is controlled such that the temperature of the head section 42c approaches the set temperature by comparing the temperature measured by e. The temperature of the preheating head 42 is set to, for example, 140 to 200 ° C., depending on the outside air temperature and the material of the printing material.

The printing apparatus 1 configured as described above operates as follows to achieve the operation and effect of the present invention. The magnetic tape cartridge W assembled by an assembling device (not shown) is placed on the pallet 21 and fixed by fixing means (not shown). The magnetic tape cartridge W on the pallet moves on the conveyor 2 from right to left in FIG. 1 in about 0.6 seconds, and is pitch-fed at a stop timing of about 1.9 seconds (see FIG. 5).

When the magnetic tape cartridge W stops in front of the preheating mechanism 4, the pallet is positioned for about 0.4 seconds as shown in FIG. 5, and then the preheating head 42 advances toward the magnetic tape cartridge W. Then, the printing surface W1 is pressed for about 0.7 seconds. The printing surface W1 is heated by the preheating head 42, and the heat is stored. When the preheating is completed, the magnetic tape cartridge W is transported to the front of the stamp machine 3 for about 0.6 seconds, and stops. When the magnetic tape cartridge W stops, the pallet is positioned for about 0.4 seconds, and then the print head 36 advances toward the magnetic tape cartridge W to heat and heat the printing surface W1 via the hot stamp foil 39. Press. At this time, since the printing surface W1 has already been heated, less heat is transmitted from the print head 36 to the magnetic tape cartridge W, and therefore, the temperature of the print head 36 is not required to decrease much. After the heating and pressurizing for about 0.7 seconds, when the print head 36 is retracted, the ink layer of the hot stamp foil 39 is transferred to the printing surface W1, and the identification L is printed.

When the transfer printing by the printing head 36 is completed, the printed magnetic tape cartridge W is carried out, and
The next preheated magnetic tape cartridge W is carried in front of the stamp machine 3 in place of the carried-out magnetic tape cartridge W. The time from the end of the transfer printing to the start of the next transfer printing is about 1.8 seconds. During this time, the print head 36 is heated by the heater unit 37 and raised to the set temperature. As described above, since the temperature drop of the print head 36 during printing is small, even if printing is performed in a high cycle such as one cycle of 2.5 seconds as in the present embodiment, the print head 36 is not printed. The temperature 36 can keep the set temperature, so that the print quality can be kept high.

The magnetic tape cartridge W after printing is C
When stopped in front of the CD camera 5, an image captured by the CCD camera 5 is input to the image processing device. In the image input device, pattern matching is performed with the master identification display image input in advance, and the quality of the print quality is determined.

Although the embodiment of the present invention has been described above, the present invention is not limited to the embodiment. For example, in the present embodiment, the magnetic tape cartridge W is taken up as a print target, but the print target is not limited to this, and can be applied to various products. In particular,
When the printing method using the hot stamp of the present invention is applied to a product having a high thermal conductivity such as a metal product, the effect of preventing the temperature of the print head from lowering can be remarkably exhibited.

In the present embodiment, the print head 36
Although the case where the elastic sheet 36b is attached to the surface of the elastic sheet 36b is shown, the elastic sheet 36b is an optional component, and even when the elastic sheet 36b is not provided, the effect of the present invention can be similarly obtained. it can. However, the elastic sheet 36b
In the case of a print head having the following characteristics, heat conduction in the elastic sheet 36b is relatively poor as compared with metal or the like, and it takes time for the heat of the print head block 36a to reach the outer surface of the elastic sheet 36b. For this reason, there is a limit to the efficiency of supplying heat to the printing surface of the elastic sheet 36b, and the temperature tends to decrease. Therefore, the present invention is particularly effective when the elastic sheet 36b is attached to the surface of the print head.

The preheating mechanism includes a preheating head 42
Can be heated in a non-contact manner by irradiating electromagnetic waves such as light.

[0030]

Next, an embodiment in which the effect of the present invention has been confirmed will be described. The printing results were compared between the case where preheating was performed and the case where preheating was not performed using the printing apparatus of the above embodiment.

A magnetic tape cartridge made of polycarbonate was used as a printing material. The printing head and preheating head materials and the magnetic tape cartridge heating conditions were as shown in Table 1. That is,
In the preheating head, the preheating head block was made of brass and pressed against the magnetic tape cartridge with a surface pressure of 1.7 (N / mm ² ) for 0.7 seconds. Then, the print head, the print head block made of aluminum, using what pasted fluororubber having a thickness of 0.5mm on the head unit, 7.1 to printing surface (N / mm ²⁾ With the surface pressure of
Pressed for 0.7 seconds. The time from the pre-heat treatment of the printing material to the start of printing was set to 1.8 seconds, and printing and feeding were set so that one cycle of printing was performed in 2.5 seconds.

[0032]

[Table 1]

Using the preheating head and the printing head, tests were performed at each temperature while changing the preheating and printing temperatures as shown in Table 2. That is, the preheating head was tested at five temperatures of 140 ° C., 160 ° C., 180 ° C., and 200 ° C. without preheating, and the print head was tested at 140 ° C. to 240 ° C. every 10 ° C.

The quality of the printing is visually checked.
In comparison with the samples shown in (a) to (c), those having clear printing defects were marked with X, those with slight printing defects were marked with X to Δ, and those completely printed were marked with ○. Evaluated using three symbols. Also, put the adhesive tape over the print, then slowly peel off the adhesive tape vertically, test the peeling resistance, visually inspect the printed surface in the same manner as the printing, the peeling resistance It was judged.

Table 2 shows the results of tests performed under the above-described methods and conditions. As shown in Table 2, when preheating was not performed, complete printing could not be performed unless the temperature of the print head was 210 ° C. or higher. Complete printing could be performed even at this temperature. That is, when the temperature of the preheating head is 140 ° C. or 160 ° C., the print head is 170 ° C. or more,
When the temperature of the preheating head is 180 ° C, complete printing can be performed when the printing head is 160 ° C or higher, and when the temperature of the preheating head is 200 ° C, the printing head is 150 ° C or higher. Was. In other words, for example, if the print head temperature is set to 170 ° C.,
It can be seen that complete printing can be performed if preheating is performed at a temperature equal to or higher than ° C, but that printing will be defective if preheating is not performed. According to such examples, it has been found that the printing method using the hot stamp of the present invention can perform high-cycle printing with high quality.

[0036]

[Table 2]

[0037]

As described in detail above, according to the printing method using the hot stamp of the present invention, high quality printing can be performed even when performing high cycle printing.

[Brief description of the drawings]

FIG. 1 is a plan view of an entire hot stamp printing apparatus according to an embodiment.

FIG. 2 is an enlarged perspective view of a main part of the hot stamp according to the embodiment.

FIG. 3 is a sectional perspective view of a print head and a heater unit.

FIG. 4 is a sectional perspective view of a preheating head and a heater unit.

FIG. 5 is a time chart of the printing apparatus according to the embodiment.

FIGS. 6A and 6B are diagrams showing print quality levels, where FIG. 6A shows a case where a clear chip has occurred (×), FIG. 6B shows a case where a slight chip has occurred (× to Δ), and FIG. ) Is the case where printing was completed completely (○).

FIG. 7 is an external perspective view of a magnetic tape cartridge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printing apparatus 2 Conveyor 3 Hot stamping machine 4 Preheating mechanism 36 Printing head 39 Hot stamping foil 42 Preheating head L (W1) Printing surface

Claims (1)

[Claims] 1. A printing method using hot stamping in which transfer printing is performed by pressing a hot stamp foil against a printing surface with a heated print head, wherein the printing surface is heated in advance, and then the transfer printing is performed. Printing method by hot stamping.