[0001] The present invention relates to a plastics cylindrical body with a printed pattern
formed on the peripheral surface thereof, and, more particularly, to a plastics cylindrical
body having a pattern formed by the multicolor printing which exhibits a very attractive
halftone.
[0002] Heretofore, the printed pattern on a plastics cylindrical body has been formed by,
almost without exception, the complicated "masking process" in the case where the
pattern is a multicolor one. The reason for this is that if inks of different color
are simply printed one over another, the inks mix together and do not show the desired
tone of color. In addition, printing for a multicolor pattern has to be performed
by "masking process" for each color, and the desired color has to be prepared previously
because the masking process does not permit color mixing. This makes it necessary
to provide inks of a great variety of colors.
[0003] As mentioned above, conventional plastics cylindrical bodies having a multicolor
pattern have a disadvantage that the process for printing the multicolor pattern is
complicated, a great variety of inks are required, and yet a subtle halftone cannot
be made at the boundary between different colors.
[0004] The present invention has been completed in order to obviate the above-mentioned
disadvantage involved in conventional plastics cylindrical bodies having a multicolor
pattern. The invention will be described into detail with reference to the accompanied
drawing illustrating an example.
Fig. 1 is a perspective view of an embodiment of the invention.
Fig. 2 is a partly enlarged sectional view of an embodiment of the invention.
Fig. 3 is a schematic view illustrating the most preferable method for producing the
cylindrical body according to the invention.
[0005] The plastics cylindrical body according to the present invention is made of a synthetic
resin such as polystyrene resin, polypropylene resin, and polyethylene resin. The
peripheral surface of the thin wall 1 of the plastics cylindrical body is decorated
with a pattern 2 which is formed by printed layers 2a, 2b, 2c, ... of ultraviolet
curable inks of at least yellow, red, and blue placed one over another. The inks of
different color are cured individually by irradiation of ultraviolet rays, and they
are placed one over another in the order of the brightness, with the one having the
highest brightness being in contact with the peripheral surface of the wall 1.
[0006] The printed layers 2a, 2b, 2c, ... forming the pattern 2 are placed one over another,
and thus it is possible to obtain an attractive halftone by overlapping two or more
colors.
[0007] Since the printed layers 2a , 2b, 2c , ... are cured individually by irradiation
of ultraviolet rays, the ultraviolet curable inks do not mix together prior to curing.
[0008] This ensures the formation of desired tone of color.
[0009] The printed layers 2a , 2b, 2c, ... are placed one over another in the order of the
brightness, with the one having the highest brightness being in contact with the peripheral
surface of the wall 1 . This permits overprinting of black letters on the pattern
(2) wihtout the need of the conventional complicated "masking process".
[0010] The process for curing individually the printed layers 2a , 2b , 2c , ... of the
pattern (2) will be described with reference to Fig. 3, in which the cylindrical body
is transferred intermittently along the arrows, with stoppage at stations marked by
single circles and double circles. Printing is performed at the stations I indicated
by single circles, and irradiation is carried out at the stations K marked by double
circles. During the transfer along the line, the cylindrical body is turned in one
direction at a constant speed.
[0011] The cylindrical body put on the line undergoes-printing with an ultraviolet curable
yellow ink at station I
1, and then moves to the next station K
1 for curing with irradiation of ultraviolet rays. Thus, the first printed layer 2a
of yellow ink is formed. In the same manner, the second printed layer 2b of red ink,
the third printed layer 2c of blue ink, and a fourth printed layer 2d of black ink
are formed at the subsequent stations, and finally, the pattern 2 is completed.
[0012] The printing immediately followed by curing prevents inks from mixing together even
when inks of different color are put one over another continuously.
[0013] As mentioned above, the present invention has advantages that overprinting without
mixing of inks provides a very attractive halftone and the ink of lowest brightness
placed on the outermost layer provides distinct letters or lines without the need
of "masking process".
1. A plastics cylindrical body with a printed pattern (2) formed on the peripheral
surface thereof, said printed pattern being formed by ultraviolet-curable ink layers
(2a, 2b, 2c) of at least three colors of yellow, red, and blue placed by printing
one over another in the order of the brightness of the colors, with the color of highest
brightness being in contact with the peripheral surface, said ink layers being cured
individually by irradiation of ultraviolet rays.
2. A plastics cylindrical body according claim 1 with black letters overprinted on
the pattern (2).
