Method of printing

A method of printing wherein a material to be printed is applied onto a pattern which is preprinted on an extendible film which is extended on an accumulated granule layer composed of a number of spherical granules so that the preprinted pattern at its whole surface is adhered to the surface of the material to be printed by forcing the material to be printed into the accumulated granule layer.

BACKGROUND OF THE INVENTION 
The present invention relates to a method of printing on a curved surface 
of a extendible film. 
This kind of conventional printing method, as described in the 
specification of the U.S. Pat. No. 4,010,057, depends on a technique by 
which an inflatable film on which a transcription pattern is printed in 
advance is kept afloat on water, to be expanded and impressed by a 
material to be printed to be immersed into water, and the film is adhered 
to the material to be printed by virtue of water pressure while the film 
is extended. 
However, the conventional method is disadvantageous in that it is difficult 
to supply the film since it should be kept stationary on the water 
surface, a favorable print cannot be obtained if the timing of impression 
of the material to be printed is delayed since the film begins to extend 
and expand as soon as it contacts water, it is troublesome to impress the 
material to be printed against the film, and the printing of the pattern 
on the specified position of the material to be printed is difficult. 
SUMMARY OF THE INVENTION 
The present invention provides a method of printing wherein a transcription 
film made of an extendible film is placed on an accumulated granule, layer 
composed of a number of fine granules a transcription pattern is 
preprinted on the transcription film to form a transcription surface and 
the opposite surface of the film is made to contact the accumulated 
granule layer, the material to be printed contacts the transcription 
surface, the material to be printed is impressed into the accumulated 
granule layer, and vibration is applied to at least one of the accumulated 
granule layer and the material to be printed during impression of the 
material to be printed into the accumulated granule layer. 
Furthermore, the present invention provides a method of printing to cover 
the material to be printed with the extendible film made of a thermally 
fusible material. 
According to this method, the film need not be removed since at least one 
of the material to be printed and the accumulated granule layer is heated 
to make a covering film adhere to the material to be printed by utilizing 
the heat generated. 
The present invention also provides a method of printing in which a 
covering film is adhered to the material to be printed with an adhesive 
layer interposed between them. 
This method is advantageous in that the transparency of the covering film 
is not impaired if a transparent film is used since the covering film can 
be adhered to the material to be printed without fusing the covering film. 
Moreover, the present invention provides a method of printing adopted to 
uniformly distribute the pressure of the accumulated granule layer applied 
to the transcription film or the covering film through a sheet layer made 
of a plastically deformable material such as, for example, silicon rubber 
interposed between the transcription film or the covering film and the 
accumulated granule layer.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIG. 1, there is shown the printing tub 1 which is filled with 
a number of fine granules such as, for example, steel balls 2 which form 
the accumulated granule layer. 
Steel balls used, for example, in miniature bearings can be directly used 
as said balls 2, or the balls 2 can be otherwise made of synthetic resin 
material. 
Said printing tub 1 is provided with a vibrating means such as, for 
example, ultrasonic oscillator 4 and a vibratory film 4' which is vibrated 
by said vibrating means, which gives vibratory waves to the accumulated 
granule layer 3. 
The transcription film 5 made of an extendible film is supplied to said 
printing tub 1. The transcription pattern 6 such as, for example, wood 
grain pattern or cloud pattern is preprinted on the transcription film 5 
to form the transcription surface 5'. 
This transcription film 5 is supplied to keep its rear surface 5", opposite 
the transcription surface 5', in contact with the accumulated granule 
layer 3, and is kept stationary on the accumulated granule layer 3. Said 
transcription film 5 can be cut in advance in a specified size but, in 
case of the embodiment shown in FIG. 1, it is supplied from a roll of 
film. 
The transcription pattern 6 is formed on said transcription film 5 and can 
be printed by printing means provided in the vicinity of the printing tub 
1 as shown in FIG. 1 or printed at a different place. As shown in the 
embodiment, however, if the transcription pattern is printed on the 
transcription film 5 shortly before the printing tub 1, the transcription 
film is fed into the printing tub 1 while the transcription pattern 6 is 
not yet dried and therefore this printing method is advantageous in the 
transcription effect. 
If the transcription pattern is printed at a separate place, it can be 
printed in multiple colors, and also, a solvent for dissolving the dried 
ink should be sprayed or applied onto the ink to activate the 
transcription pattern 6 just prior to transcription. 
Printing means 7 contains the printing roller 8 and the ink supply tank 9 
and the transcription film 5 is printed by the printing roller 8 as in 
case of the conventional printing apparatus. 
An elevating means 11 for elevating the material 10 to be printed is 
provided just above said printing tub 1 to hold the material 10 to be 
printed, and impress it onto the transcription surface 5' of the 
transcription film 5 and subsequently depress it against the accumulated 
granule layer 3. The material 10 to be printed is lifted by the elevating 
means 11 after transcription and separated from the accumulated granule 
layer 3. 
This elevating means 11 and the printing tub 1 can contact and part from 
each other at relative positions; accordingly, the elevating means 11 can 
be fixed and the printing tub 1 can be elevated or both the elevating 
means 11 and the printing tub 1 can be moved to contact and part from each 
other. Moreover, the elevating means 11 and the printing tub 1 can be 
relatively alternated, for example, it is convenient for mass printing to 
provide the elevating means 11 on a trolley conveyor to convey the 
material 10 to a recovery means after transcription. 
Said transcription film 5 can be made of a material which is extendible at 
the time of transcription; for example, an elastic film or an expandable 
film such as a thin rubber strip or a thermally softening film, or a film 
which is softened by a solvent can be used. 
In case the transcription film 5 is made of an elastic film, cleaner 12 is 
provided following the printing tub 1 to clean the transcription surface 
5' and the transcription film 5 can be wound up by a winding means after 
cleaning. 
In case the transcription film 5 is made of a thermo-fusible film, the 
transcription film 5 can be given an extendibility by heating the 
accumulated granule layer 3 in the printing tub 1 with heater 13 as shown 
in FIG. 2. 
In case the transcription film 5 is an expandable film made of, for 
example, polyvinyl alcohol or methyl cellulose, water supply and discharge 
system 14 as shown in FIG. 3 can be provided as a means for expanding the 
transcription film 5, in which pump P is adapted to raise the water level 
L in the printing tub 1 to make the transcription film 5 absorb water when 
the transcription film 5 is extended over the accumulated granule layer 3, 
and lower the water level to prevent spontaneous extension of the 
transcription film 5 after expansion of the transcription film 5. 
In case said transcription film 5 can be made extendible with a solvent or 
is made of a film using butyl rubber or vinyl acetate, the solvent can be 
sprayed onto the transcription film 5 which is extended over the 
accumulated granule layer 3. 
Said transcription film 5 is removed in most cases from the material 10 
after transcription by using an exfoliating or dissolving means. 
The transcription pattern 6 can be adhered to the material 10 to be printed 
to transcribe the transcription pattern 6 from the transcription film 5 to 
the material 10. Transcription can be made by means of an impression force 
or the impression force and another method, for example, so-called hot 
stamping method for heating the transcription pattern 6. 
The material 10 can be printed through the following processes when the 
printing tub 1 shown in FIG. 3 in used. 
The transcription film 5 stored in the printing tub 1 is expanded and 
soaked with water in which the accumulated granule layer 3 is immersed as 
shown in FIG. 4A, to give it extendibility. 
If the water level L is lowered by the water supply and discharge system 14 
as shown in FIG. 4B, the transcription film 5 is kept stationary without 
spontaneous extension. 
As shown in FIG. 4C, when the material 10 to be printed is lowered into the 
printing tub 1 under this condition to contact the transcription film 5, 
and is depressed down while a vibration is applied to the accumulated 
granule layer 3, the spherical granules 2 forming the accumulated granule 
layer 3 move to rub the surface of the material 10 to be printed, through 
the film 5, thus permitting the material 10 to be submerged into the 
accumulated granule layer 3. 
In this case, the transcription film 5 between the material 10 to be 
printed and the accumulated granule layer 3 is impressed against the 
surface of the material 10 by the granules 2 of the accumulated granule 
layer 3 and receives the weight in the direction of recovery of the 
accumulated granule layer 3 and can be closely adhered to the surface of 
the material 10 to be printed while being extended over the surface of the 
material 10, whereby the transcription pattern 6 is transcribed onto the 
material 10. 
Accordingly, when the transcription film 5 is removed from the material 10, 
the transcription pattern 6 remains on the surface of the material 10 and 
therefore the printing can be satisfactorily carried out even on a curved 
surface of the material 10. 
The vibrating means 4 need not always be provided at the accumulated 
granule layer 3 side. Depending on the particular case, the vibrating 
means can be provided only at the side of the material 10 to be printed or 
both at the accumulated granule layer said and at the material 10 side. 
In the above processes, a top coating will be required in some cases after 
the transcription pattern 6 has been printed on the material 10 since the 
transcription film 5 is removed after printing. 
The method shown in the second embodiment is effective in the above case. 
This second apparatus utilizes the embodiment shown in FIG. 2, and is 
characterized by using an extendible film made of thermo-fusible resin 
shown in FIG. 5A as the covering film 15 on which a printing pattern 16 is 
provided at one of its front and rear surfaces, extending this covering 
film 15 in the printing tub 1 shown in FIG. 2, raising the temperature of 
the accumulated granule layer 3 of the printing tub 1, for which granules 
2 with excellent heat conductivity are used, up to the dissolving 
temperature of the covering film 15, and impressing the material 10 to be 
printed onto the covering film 15 and immersing the material 10 into the 
accumulated granule layer 3 while said layer 3 is being vibrated. The 
covering film 15 is made to closely contact the surface of the material 10 
to be printed by the vibrating granules 2 as shown in FIG. 5B, and is 
heated by the granules 2 so as to be adhered to the material 10 to be 
printed. 
According to the present invention, a desired outer surface can be obtained 
by selecting the material of the covering film 15 since the surface of the 
material 10 to be printed can be covered with the covering film 15. 
Moreover, if the covering film 15 is made of a transparent material as 
shown in FIG. 5A, the covering film 15 can be used as the top coat by 
providing the printing pattern 16 on the internal surface, that is, the 
surface which contacts the material 10 to be printed, of the covering film 
15. 
The heating means for the accumulated granule layer 3 need not be the 
heater 13; an ultrasonic vibrator can be employed as the vibrating means 
4, and can generate heat from its vibratory wave. 
In this case, an advantage is that the heating means need not be provided. 
Said heating means can be means to heat the material 10 to be printed. In 
this case, the effect of adhesion is improved since the temperature at the 
surface of the material 10 to be printed is increased. 
The heating to raise the temperature of said accumulated granule layer 3 
and the material 10 to be printed can be carried out while the material 10 
is being depressed into the accumulated granule layer 3 or after the 
former has been depressed into the latter. However, since it is suitable 
to raise the temperature of the accumulated granule layer 3 at all times, 
it is actually carried out in general to raise the external surface 
temperature while the material 10 to be printed is kept depressed against 
the accumulated granule layer 3 for a specified period of time. 
In case of said second embodiment, the covering film 15 is thermally fused 
to adhere to the material 10 to be printed. In this case, the temperature 
should be relatively high because the fusion of the covering film 15 is a 
requirement. 
The third embodiment is intended to eliminate such disadvantage. This 
embodiment is also intended to adhere the covering film 15 to the material 
10 to be printed with an adhesive layer 15' formed on the internal surface 
of the covering film 15 as shown in FIG. 6A and FIG. 6B or on the surface 
of the material 10 to be printed. 
The adhesive layer 15' of said covering film 15 can be made as a 
thermo-fusible type or a pressure sensitive type. In case of a 
thermo-fusible type, it is desirable to select a kind of material which is 
adhered at a temperature lower than the fusing temperature of the covering 
film 15. 
The thermo-fusible or pressure sensitive type adhesive layer can be 
selected for said material 10 to be printed. 
The adhesive layer 15' of said covering film 15 is formed by applying an 
adhesive agent to the covering film 15 as shown in FIG. 6A. In case the 
covering film 15 is transparent and the printing pattern 16 is printed 
entirely on the film surface which comes in contact with the material 10 
to be printed, the printing pattern 16 can be printed with an adhesive 
type ink such as a thermally-soluble ink to form the adhesive layer as 
shown in FIG. 6B. 
According to the third embodiment, the covering film 15 can be made of a 
material other than the thermo-fusible material and it can be 
advantageously adhered to the material 10 to be printed without 
excessively fusing the covering film 15 even if the covering film 15 is 
made of a thermo-fusible material. 
A sheet layer 17 made of a plastically deformable material such as silicon 
rubber can be interposed between said transcription film 5 or the covering 
film 15 and the accumulated granule layer 3 in the printing tub 1. Thus 
the pressure of the accumulated granule layer 3 against the films 5 and 15 
is uniformly distributed and the films 5 and 15 can be protected against 
damage due to the balls 2 since they do not directly contact the balls 2.