VERFAHREN ZUM DREIDIMENSIONALEN UMFORMEN VON MATERIAL

description

A method for three dimensional forming of material

The invention relates to a method for three dimensional forming of sheet material, in particular natural fibers, such as paper or cardboard, with a piston and a sleeve-shaped opposite, in which the material is drawn into it.

In such forming processes to form uncontrolled folds in different sizes which can not be corrected afterwards, but the appearance of the finished article and may even take the form stability, strength, and

significantly affect sealing the edges.

The invention has the object of providing a metal forming process by which this uncontrolled wrinkling is avoided. In addition, a

Created an opportunity to make a complex final shape with increased deformation ratio dimensionally stable and retain its shape.

This object is achieved according to erfmdungs ​​characterized in that the diameter of the deep-drawing piston plus the material thickness of the deep-drawn material at least approximately corresponds to the diameter of the die. Characterized in that at any time of the deep-drawing process, the diameter of the

Thermoforming piston plus the material thickness of the deep-drawn material, in

corresponds at least approximately so cross-sectional diameter of the piston, plus twice the material thickness, the diameter of the die, the in

Deep drawing resulting folds in the material uniformly and finely distributed.

It has proved to be very advantageous if the material is sandwiched between the die and a so-called blank holder, whereby the material can slide down targeted during forming.

Thus the thermoforming result is improved. Among other things, the wrinkles distribution can be improved.

Extremely advantageous is in this connection, when the blank holder presses with a variable pressure against the sheet material, said blank holder

can push spring-loaded against the sheet material and / or acting against the sheet material of the blank holder pressure may be controllable or tax.

Thus, the sloughing of the material is accurately determined and controlled.

According to a further embodiment of the invention it is very advantageous when the diameter of the die is changed.

By varying the diameter of the die can also be deep-drawn conical. The diameter is not limited only to circular deep drawing. Rather, all conceivable forms are possible. This includes flat circular, oval, polygonal, rectangular, etc.

Here, it has proved extremely advantageous if the template is constructed from segments which are mutually movable. In this way, the diameter in a simple manner can be changed.

It is also very advantageous according to an embodiment of the invention, when the die is of sleeve-shaped, with a conical configuration may be provided.

Even so can be conical shapes thermoform.

According to a further embodiment of the invention it is very advantageous if the thermoforming piston is conical.

In combination with a variable diameter die can so the

Drawing gap always be kept constant.

Another very advantageous embodiment of the invention is also present when the thermoforming piston is variable with respect to its diameter, said segments may be provided, which are movable towards one another.

A deep-drawing piston variable diameter can be used very well with a conical die. One possibility for variability in the diameter of the thermoforming piston is a structure of mutually adjustable segments.

Extremely advantageous is erfmdunsgemäß also when the thermoforming piston is changeable by internal pressure in its shape and / or its dimensions, wherein the pressure by means of compressed air or a hydraulic medium can be established.

So that the drawing gap is also kept constant. Such thermoforming piston can be used both in a conical Martrize as well as a variable diameter die. Erfmdungsgemäß it has also proved to be very advantageous if a counter-punch is provided in the axial direction of the deep-drawing piston which presses the material during forming against the thermoforming piston, said counter-punch can be variable and controllable formed.

Characterized the material is reliably performed during forming, so that can enter any uncontrolled movements of the material. The holding force can be adjusted very accurately.

Furthermore, it is very advantageous if according to the invention there is provided a calibration device, in which the formed material is pressed against the piston.

Thereby resulting in forming small wrinkles can be equalized easily.

As also very It has proven advantageous if according to a further

Embodiment of the invention, the material before, during and / or is wetted at least on one side after forming and / or calibration.

Through this moistening the formability and calibration capability of the material is considerably improved.

According to an advantageous further embodiment of the invention it is provided that the material before, during and / or after the forming process is heated and / or before and / or during the calibration.

Also thereby the formability and calibration capability of the material is considerably increased. It has proved to be very advantageous if in accordance with a further

Embodiment of the invention, the temperature and / or the processing moisture of the material selected or adjusted depending on the material used.

A further advantageous embodiment of the invention is that the material is at least on one side with a plastic layer or is.

Thus, the fiber-containing material against internal and / or external influences is effectively protected.

it is also very favorable when the forming during forming finely divided folds are compressed according to a further embodiment of the invention.

This allows to achieve a very smooth surface of the formed part.

It is very advantageous even when the open end is folded to a sealing edge in accordance with another embodiment of the invention.

So that the container created can be closed easily after its filling.

Extremely advantageous is according to the invention also if the sealing edge is additionally compressed, the compression under supply of heat and / or according to the preceding moistening can be carried out.

This provides a very smooth and uniform sealing edge is created, which also has good strength values.

However, it is conceivable, other embodiments of the open end;

For example, the formation of a so-called mouth roll is possible. In the drawing the invention with reference to an exemplary embodiment is illustrative. They show:

Fig. 1 is a schematic flow diagram of the invention

Process with conical female mold, and

Fig. 2 is a schematic flow diagram of the invention

Process variable template.

1, a device is referred to, can be formed from a flat condition into a cup or cup-shaped state with the paper or cardboard or fibrous material. 2

The device 1 comprises a piston 3, and a conical sleeve-shaped in this exemplary embodiment, female mold 4, which acts as the opposite of the piston. 3 The material 2 is pushed by the piston 3 into the female mold. 4 The material 2 is pressed by a blank holder 5 against the top surface of the die 4 so that it can slide down only checked when entering the female mold. 4

The piston 3 is formed variable. Either of these is composed of segments, so that the respective diameter of the piston 3 by moving the segments can be changed to each other, or the piston 3 can be changed by the application of compressed air or a hydraulic medium in size and / or shape.

Other embodiments of the piston 3 are conceivable.

It is important that the diameter of the piston 3 corresponds at all times at least approximately to the respective diameter of the die 4 minus twice the thickness of the material 2, so that the piston 3, the material 2 and the female mold 4 lie close together. It is to be built at most a small gap. It is also conceivable that the piston 3 slightly presses the material 2 against the inner side of the die. 4

By combining these dimensions and the blank holder 5 is ensured that not only small and evenly distributed pleats arise in deep drawing of the material 2, but these are also largely equalized at least. When the piston 3 with respect to the female mold 4 slightly smaller, so it is also conceivable that the manufactured article 7, the formed part is calibrated after the forming process again and thereby the finely divided wrinkles are pressed.

The result is a smooth surface in the walls of the deep-drawn out of paper or cardboard article.

By means of the die 4 and a conical adapted thereto piston 3 is made directly, an article having tapered walls.

As shown in the second embodiment it is also conceivable that a conical piston 23 is provided, and the female mold 24 adjusts its diameter at the respective position of the piston 23rd

For this purpose, the female mold 24, for example, against each other movable

be constructed segments.

The blank holder can in this case spring-loaded press against the sheet material. 2 but it is also possible a hydraulic, electromechanical or other

provide contact pressure that is designed or adjustable control. A combination between the spring load and controlled or regulated hydraulic / pneumatic / actuators is also conceivable. A counter-punch 6 which is arranged in the axial direction of the piston 3 presses from below against the material 2, so that no material from the bottom portion to flow into the wall to be deformed area. It is possible, however, that the material is 2 converted in the base region between the piston 3 and the counter die 6 itself. It is also conceivable in this context, that the imprint of the piston 3 and the counter die 6 is carried out before the actual forming process.

While piston 3 and counter-punch 6 can already connect with blank holder force and bring the coinage. Here, a drawing process is carried out against the actual pulling forming, which increases the margin as regards

Forming degree and configuration of the bottom is expanded.

It is also possible that after forming the formed part 7 in a

Calibration device 8 is moved by the piston 3 where the wall portion against the piston 3 is pressed and thereby the small and finely distributed folds formed are equalized.

It is also conceivable that the material is trimmed after forming.

After the calibration, the ready-formed part 7 is ejected after the startup of the piston 3 from the counter-punch. 6

Also peeling of the article 7 from the top with lifters or suckers is conceivable.

If the forming process executed overhead can also provide gravity for falling out of the objects 7 generated.

During this calibration, the upper wall portion can be expanded before or after, or a peripheral flange are formed. This edge flange can be converted either into a flat seal edge or in a mouth roll. To improve the forming result, the material can be moistened on both sides one or 2 prior to forming or during this process.

Also, a heating is possible, with a radiant heater for the heating of the material or forming tools is also conceivable.

A coating, impregnating or otherwise treating the material for example with a plastic material is also possible to improve the tightness of the finished part 7 wherein this coating can be made on both sides of the inside or outside or even.

A coating or treatment may also affect the deep-drawing process.