DE2016377C2 - Screen printing machine with stationary doctor blade - has moving screen frame pivoting about rear edge, with front edge liftable - Google Patents

Abstract

The screen printing machine for flat web has a fixed doctor blade. The web to be printed is located between a movable base and a screen frame moving with it. The frame is so mounted as to swivel at its front edge to raise the screen behind the pull exerting doctor blade. The screen frame (4) swivels about its rear edge, and is raisable at its front edge. The distance of the screen (3) from a support printing cylinder (2) may be adjustable for its travel against a stationary doctor blade (14). PS.

Description

The invention relates to a screen printing device for flat items to be printed with a stationary squeegee arrangement, in which the print material is between a printing base and a printing base during printing moving screen frame is located and the screen frame is pivotably arranged at the front edge to the Raise the screen steadily as it passes behind the pulling squeegee.

Such a screen printing device is described in DE-AS 11 16 688. After the printing process, there the screen frame in a plane that is inclined to the horizontal, i.e. at an angle, is returned. Here there is a risk that if the screen of the screen frame is sagging, it will come into contact with the material to be printed so that there is a risk of paint smudging. This is especially true on that side of the Case on which the paint was smeared. In this known screen printing device can also only thinner objects, e.g. B. paper, are printed, but not objects of greater thickness. this is based on the larger radius of curvature of thicker objects on the cylinder, which also makes it here smearing and register inaccuracies can occur.

The US-PS 32 52 411 describes a screen printing device in which the entire screen after Printing is raised. This requires a complicated mechanism, including one complicated column guide for the entire frame at its four corners.

The invention is based on the object of providing a screen printing device of the type mentioned at the beginning to propose, with which it is possible in a structurally simple manner, a flawless print without To achieve paint smears.

To solve this problem, the invention is characterized in that the screen frame around its rear edge pivotable and liftable at its front edge

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This results in a significant simplification, combined with a larger jump at Return after the printing process and a flawless print without ink smears is achieved

It is preferred if the distance between the screen and a printing cylinder is used as a printing substrate for the latter Start against a fixed preliminary squeegee is adjustable. This results in a return of the screen in one Plane parallel to the preliminary squeegee. This prevents the rear end of the screen printing device a thicker layer of paint is applied than in the front area of the screen.

An embodiment of the invention is shown schematically in the drawings

Fig. 1 is a side view of the machine, partially cut after printing,

F i g. 2 is a side view of the machine while the screen frame is retracting.

The printing cylinder 2 is mounted in the machine frame in a known manner. Above the printing cylinder there is the sieve 3, which is clamped in the sieve frame 4 and displaceable in the direction of the arrow. Of the Siebmhrnen, in turn, is in the screen main frame 5 stored, which is connected to the gear 7 on the printing cylinder 2 via toothed racks 6

The sheet material to be printed is fed to the printing cylinder 2 via the feeder 8 and via the Outrigger 9 transported away Depending on the rigidity of the material to be printed on, feeders and outriggers are in the Height adjustable.

F i g. 1 shows that the stencil frame is attached to the Leading edge is lifted. It is raised by means of a spring 10, which can be adjusted using the handwheel 11. to At the beginning of the return, the rear end of the sieve frame is also raised, with the bolt 12 moved upwards in the slot 13 Towards or after the end of the return, the Whole sieve lowered in parallel to the starting position When the sieve returns in the raised position

the distance between the latter and the printing cylinder 2 is selected in such a way that it is on a stationary pre-doctor blade 14 starts During the printing process, the main doctor blade 15 moves into the position on the lowered screen, as in F i g. 1 can be seen.

To raise and lower the screen frame, a displaceable or pivotable element 16 is on Screen main frame attached, the lifting and lowering of the screen in the two via the stops 17 and 18 Controls end positions automatically

For this purpose 2 sheets of drawings

Claims (2)

Patent claims: ί. Screen printing device for flat items to be printed with a stationary squeegee arrangement in which the Material to be printed during printing between a printing base and a screen frame moved with it is located and the screen frame is pivotally mounted at the front edge to the screen at Continuously to raise the passage behind the pulling squeegee, characterized in that the screen frame (4) is designed to be pivotable about its rear edge and liftable at its front edge is 2. Screen printing device according to claim 1, characterized in that the distance of the screen (3) to a printing cylinder (2) as a printing pad for its run-up against a fixed preliminary squeegee (14) is adjustable