Polymetaal

• Preparations for use

Normally this press will be assembled in the printmaking studio by Polymetaal employees or by associates who have our permission to do the assembly or disassembly.
The machine is too heavy and too complex to do it in an other way. The machine can be sent, completely assembled, in a crate. The dimensions of the crates are as follows:

 It is important to check out first if the crate can enter the building. Also important to choose, together with Polymetaal, the way of transportation.
If it is impossible to enter with the crate, workers of Polymetaal will have to assemble the crate in the studio. We can make a detailed quote regarding the transport method and assembly costs.

If the press has been delivered to you in a crate, the crate must be taken apart with care. Remove the screws that keep the press on the pallet. Now the press needs to be lifted from the pallet, either with a 2 tons tackle block or with a forklift truck.

When the press is on the ground, the press must be adjusted. For that purpose the press has four "adjustable feet".
The rollers are covered with packaging paper with grease underneath. Remove this, with a solvent, and clean the rollers and make them dry.

Now the press is ready for use.

• General instructions

This press works in general the same way as any other etching press; the paper, blanket(s) and plate are positioned on the bed and passes through the rollers under pressure. Some features of this press make printing easier, like the hydraulic pump to set pressure on the top roller. Other features make is safer, like the anti-overload-coupling. Some features make it easier to work accurate and precise, like being able to read the exact pressure of the top roller.
The hydraulic pump has actually two functions;

1. it creates the oil pressure in the system, which allows the reading of the gauge. The reading of the gauge gives a very accurate indication of the downward force of the upper roller.
2. the pressure, raised by the pump, will be distributed equally to both hydraulic cylinders, one on each side of the press. This pressure makes the top roller move downwards, thus setting pressure to the whole press. The actual setting of pressure is not done any more with the pressure spindles, which makes the press a lot easier to operate. The pressure spindles will only be used to move the top roller vertically into the approximate correct position.

Use of the press
This press is very well suitable for printing intaglio (copper and zinc plates) as well as woodcuts and linocuts.
The following drawing shows the situation while printing from an etched or engraved metal plate. (intaglio)

The purpose of the felt is to press the paper into the small engraved lines of the plate, in order to accept ink.
Some people use cardboard shims under the pressure spindle (between the small moveable part and the bearing block of the top roller) to generate more "flexibility" in the press. For etching is has not much effect, but for printing woodcuts or linocuts it can be of help. It helps to compensate the irregularities of the wood's surface.

Printing woodcuts and linocuts with this press

The drawing shows a layer of felt. This felt has also the feature to compensate for irregularities of the woodcut or linocut. (differences in thickness). If the woud or lino should be perfectly plane, no felt was needed. Underneath the felt is a plastic layer (PVC) of appr. 5mm thick. This is only functional in combination with the felt. If the PVC layer should not be used, the felt would press the paper into the hollows of the woodcut or linocut. If you want embossing, very well. If not, prevent this from happening by using the plastic layer.

Maintenance

• The bearings of this do press not need lubrication. (all ball bearings)
• All clean steel surfaces have been threated with a protective spray (Tectyl) to prevent rusting, with the exception of the rollers. (felt would attract dust if in contact with this spray)
• It is recommanded to use and store this press in a dry room, to prevent rusting. (For example, etching with aggressive agents should be done in a different room, for the same reason)