Process for printing on aluminium bars with sublimable inks

FIELD OF THE INVENTION

0001This invention refers to a transfer printing process on Architectural Aluminum Profiles, in order to decorate them, using sublimable inks.

DESCRIPTION

0002This method is based on sublimable inks which have been known for a number of years. Such inks are used in a process of heat transfer printing. Sublimable inks are used in order to prepare a <u>paper transfer sheet</u> or a <u>transfer fabric.</u> The above insures the printing of the pattern, having as a result various decorations on Architectural Aluminum profiles. Pressing the transfer paper or the transfer fabric on an Aluminum profile just heated to 180 - 225 C, the inks penetrate the base coat immediately, achieving the instant stamping of the pattern. This invention is characterized by (4) four steps.

1 Base coat application.

0003A base coating of polymeric powder is applied and cured as in the standard process of industrial powder coating, constituting a subsoil to receive the sublimable inks.

2 Heating preparation .

0004In this phase the aluminum profile bars are driven one after the other in to a tunnel oven with recycling hot air. At the entrance of the oven a mechanism, responsible for the movement of the architectural profile bars is placed. This mechanism causes one profile to push the other entering the oven in a straight uninterrupted line. To insure the best printing result, the whole system is supported by an alignment mechanism.

0005By calculating the speed of the aluminum profile bars and with the help of optical thermometers we ensure the temperature of the metal bar to reach 185-225 C at the exit from the oven.

3 Printing unit .

0006It is essential for the hot aluminum profile bars to be driven out from the oven <u>straight</u> into the printing area. The printing is obtained by pressing the transfer paper or the transfer fabric on the aluminum profile bars, using silicon cylinders, properly shaped, in order to achieve an equal pressure and full contact of the transfer paper or transfer fabric on all points of the surfaces and edges of the bars. Various shapes of silicon cylinders are used in the printing unit, according to the shape of the architectural aluminum profile. These silicon cylinders press and drive the transfer paper or the transfer fabric on the surfaces to be printed. After the contact with the hot aluminum profile bar, the transfer paper or the transfer fabric releases, by sublimation, the ink on the base coat , creating the pattern. The color of the base coat together with the sublimated ink create the final effect. These pressing silicon cylinders are fixed to the knurling of several metal rings, through which the aluminum profile bars are driven. The metal rings must be knurled on both the internal and external edge, enabling the silicon cylinders to be fixed at any inclination angle of the 360 degrees of the circumference oh the ring. This is needed in order to have the silicon cylinders to follow any shape the Architectural Aluminum profile bar may have. Moreover, the above mentioned cylinders are supported by a mechanical or hydraulic regulating pressing system, which enable the desirable pressure to be adjusted. After this contact the printing material is removed.

4 Top coat.

0007Applying a specially formulated transparent polyester powder coating as a top coat, we achieve maximum outdoor resistance as well as an excellent aesthetic appearance.

BRIEF DESRIPTION OF THE DRAWINGS

0008For the present invention to be readily understood and easily practiced we attach three different drawings along with analytical details. <u>FIGURE 1</u>. Total perspective of the production line. Prepared with the base coat, the aluminum profile bars are placed onto the working area (1).

0009Each aluminum profile bar, hooked to the movement system, pushes all the preceding profile bar so that running production is obtained. This movement transmitting system is placed before the entrance of the oven (2). The aluminum profile bars travel through a recycling hot air oven in order to reach the desired temperature (3). The reaching of the desired temperature on the aluminum profile bar is controlled at the exit of the oven by an optical thermometer (4). The just heated aluminum profile bar enters immediately into the printing unit (5). At the end of the line the printed aluminum profile bars are collected (6).

FIGURE 2 Printing Unit

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0010As soon as the heated aluminum profile bars reach the printing area, it comes in contact with the transfer paper or transfer fabric that has been previously placed on an existing feeding system (7). The knurled metal rings are shown (8).

FIGURE 3 Printing Unit

0011The alignment mechanism (9) insures ideal alignment of the aluminum profile bar, to meet printing requirements . Pressing mechanic or hydraulic mechanisms (10) support the silicon cylinders (11) in order to adjust the pressure as needed.

0012The aluminum bar is pushed through round knurled metal rings (8). Placing the pressing silicon cylinders in the required position, which is determined by the shape of the architectural profile bars, we oblige the transfer paper or the transfer fabric to come in full contact with all points of the surface and the edges of the hot architectural profile bar. After this contact the transfer paper or transfer fabric releases, by sublimation, the ink which penetrate the base coat creating the pattern. Inside the printing unit a mechanism is responsible for the collection of the used paper or fabric (12).