Polymetaal

Instruction manual for the Polymetal etching presses in the JZE series

• Preparations for use

Normally this press will be assembled in the graphic workshop by Polymetaal employees.
The machine is too heavy and complex to do it differently. The machine can also be sent to the customer in a crate, completely assembled. The dimensions of the crate are as follows:

It is very important to first find out if and how such a large crate can go into the intended building. It is also important to choose the transport method (together with Polymetaal).
If it is impossible to transport such a crate, or to get it into the building, a number of Polymetaal employees will compile the press on site. We can make a detailed offer regarding the transport method and assembly costs, if you let us know which press you are interested in and where it should be built.
If the press has been delivered to you in a crate, you must carefully take the crate apart. Then you see the press, fixed with screws on a pallet. Remove the screws that secure the press to the pallet. The press must now be carefully removed from the pallet. The way in which this should be done depends on the local situation. The easiest way is to attach a 2-tonne chain hoist above the press and thereby lift the press. The pallet can then be removed. If that is not possible, there might be someone with a forklift nearby who can help you.
If the press is on the ground, the press must be set. The four "feet" of the press are made adjustable for this purpose.
The rollers are covered with a layer of packaging paper with a layer of fat underneath. Remove this, using a solvent, and clean and dry the rollers.

The press is now ready for use.

• General instructions

This press works in the same way as other presses; the paper, the plate and the felt are laid on the bed, and the whole passes under pressure between the rotating rollers. Some features of this press make printing easier, such as the electric drive system and the hydraulic pump that pressurizes the top roller. Other features make printing safer, such as the "anti-overload coupling", and the photocells on both sides of the upper roller. Some features make it easier to work accurately, such as the infinitely variable speed control and the manometer with which the working pressure can be read.
Sometimes it is easier to use the hand drive during "proofing". Because of the gearbox it is easy to drive the press by hand. Once the important parameters have been determined, such as pressure, paper moisture, printing speed, etc., one can switch to the electric drive by shifting a lever.
The photocells increase safety when working with this machine. However, it is important to adjust the position of the sensors to the type of work that is being done. If the "printing form" is thin, as with etching, the photocell must be in a low position. For example, when printing from a woodcut, the printing form is thicker, and the light cell will have to be placed higher.

The hydraulic pump has two functions;

1. the pump builds up oil pressure in the system, so that the pressure gauge can be read. The readout value of the manometer gives an accurate indication of the force exerted by the upper roller.
2. the pressure generated by the pump will be the same in both hydraulic cylinders (on each side of the press). The upper roller will hereby be pressed downwards, whereby the press "comes under pressure". The "pressurization" is no longer done by the pressure spindles, making the press easier to use. The pressure spindles only serve to move the upper roller vertically..

• Electric

This machine must be connected to a 230 Volt AC socket with ground. Changes to the electrical circuit may only be made by a qualified electrician.

Starting the machine:

1. Plug it into the socket.
2. Switch on the main switch (vertical position)
3. The orange lamp must now light up. (if the lamp is blinking, there is a problem with the alignment of the light cells)
4. The two small lights on the light cells should now also be lit. If that is not the case, the light cells and the reflectors are not properly aligned, or there is an object in the light path. Please correct this before continuing. (depends on the year of manufacture, the aligment is OK if the orange/red lamp on the control box is not blinking)
5. Test the "left", "stop" and "right" buttons. The bed must move in the right direction.
6. Adjust the speed by turning the knob on the side of the electrical cabinet.

Stopping the machine:

The drive system will stop if:

• The "stop" button is activated.
• The emergency button (mushroom button) is activated.
• There is an object between the light cell and the reflector.

Note: The bed will also stop if an end switch is activated on either side.

Fuses:

There are three fuse holders in the side of the electrical box, just below the main switch. The fuses must be ceramic, with a size of 6x32mm. The left one is the main fuse: 16 Ampere, the right one is from the control circuit, and the middle one is the motor fuse from 12 Ampere.

Drawings:

There are two drawings; one from the main circuit and one from the control circuit. The drawings are currently displayed in English.

Standards:

The manufacturer of these products:

Polymetaal
PO Box 694
2300 AR Leiden
The Netherlands
declares that this equipment complies with the European directive IEC 335-1 "Safety of household and similar electrical appliances" and has been produced according to CE standards (Machinery Directive and Magnetic compatibility) and bears the CE mark.

The use of the press

This press is suitable for printing "intaglio plates" (etched or engraved copper or zinc plates), but also for printing woodcuts and linocuts. The following diagram shows the situation when printing an intaglio plate.

The felt has the function of pressing the paper into the grooves of the plate, allowing the paper to receive the ink in those grooves. Some people use a stack of cardboard under the pressure spindles (with these printing presses beteween the "pressure plate" and the "bearing block" of the upper roller, making the press somewhat more" flexible). It has little effect for printing an "intaglio plate", but it can be useful for printing woodcuts and linocuts. A woodcut is never completely flat, which means that the ink distribution on the paper may not be even. A "flexible" upper roller compensates to a limited extent for the unevenness of the printing forme.

Printing woodcuts and linocuts with the help of this etching press

The diagram above shows the situation when printing a "relief forme" (woodcut, linocut, typography). Felt is also used here, but this has a different function than when printing an etching. Here the felt serves to compensate for unevenness in the relief forme (especially important for a woodcut made from "ply wood"). If the printing forme were completely flat, the felt was not necessary. A plastic plate is visible under the felt (approximately 5 mm thick PVC). This is only effective in combination with the felt. If the PVC sheet were not used, the paper would be pressed into the cavities of the printing forme, and this is usually not the intention.

Maintenance

• The bearings of this press do not need maintenance (all ball bearings)
• The electrical system requires hardly any maintenance. Do not allow the system to come into contact with liquids. The light cells and reflectors are sensitive to dust. So make it dust free now and then.
• The gearbox is filled with oil or grease. The gearbox never needs to be topped up later.
• It is recommended to use the press in a dry room. Preferably, etching with aggressive media (such as nitric acid or iron chloride) should be done in another (ventilated) area.