Patent ID: 7926420

Claim:
A printing unit comprising: at least a first side frame part and a second side frame part, a spacing distance between said first side frame part and said second side frame part, relative to each other, being adjustable in a horizontal direction of displacement by movement of at least one of said first side frame part and said second side frame part, relative to the other of said at least first side frame part and said second side frame part in said horizontal direction of displacement; at least one of a printing couple and a part of a printing couple accommodated on each of said first and second side frame parts; a mounting supporting said movable one of said at least first and second side frame parts for movement in said direction of displacement between a closed functional position, in which said first and second side frame parts are moved together and are fixed relative to each other, and an open position in which said at least first and second side frame parts are spaced from one another in said direction of displacement; at least one sliding surface in said mounting and supporting said movable one of said at least first and second side frame parts, said at least one sliding surface being a composite plastic comprised of multiple materials including a thermoplastic polyester component; and a plurality of depressions in said at least one sliding surface, said plurality of depressions being capable of holding soil.