Tympan For Hand Lithography
Purpose:The tympan is a thin durable sheet material that has an even thickness used in hand lithography. The tympan is essentially a wear layer, protecting the printing paper and matrix form the horizontal friction created as the press bed travels through the upper pressure head of the lithography press. Hand held tympan sheets are used on hand operated litho presses, when printing fine art lithography.
Qualities:Regardless of the material the tympan should be thin, even, smooth, low friction durable material.
Polycarbonate tympans work well with Takach scraper bars as they have a very smooth surface, resulting in less friction. Polycarbonate tympans will possibly scratch and should be handled with care. Larger polycarbonate tympans will become increasingly difficult to handle and stabilize. When raised for inking, large polycarbonate tympans may flex and fall onto the work surface. The flexibility allows the printer to curve the polycarbonate tympan as it is lowered to meet the paper and matrix, reducing the contact surface area. This will create less air pressure between the paper and tympan resulting in less registration shift.
G-10 tympans resist scratching, and are rigid. This makes them easy to stand up against the pressure assembly of the litho press. As G-10 tympans wear the fibrous core is exposed, this greatly increases the friction, and the tympan should be replaced. The cost of shipping G-10 tympans may be prohibitive, as they are extremely rigid and ship in large packages as a result.
Size:Various tympan sizes, are necessary to print a variety of corresponding sized matrices (both plate and stone). To prevent damage to the scraper bar or scraper bar strap the tympan must be wider than the scraper bar. If not the scraper bar will have lines worn into it form the edges of the tympan, these lines will create uneven printing pressure in future use.
.062" Polycarbonate Hand-Held Tympan Sheets
|Item #||Sheet Name||Size|
|1403648||Full Sheet Polycarbonate Tympan||36" x 48" x .062"|
|1403248||Three Quarter Polycarbonate Tympan||32" x 48" x .062"|
|1402436||Half Sheet Polycarbonate Tympan||24" x 36" x .062"|
|1401824||Quarter Sheet Polycarbonate Tympan||18" x 24" x .062"|
.032" G-10 Hand-Held Tympan Sheets
|Item #||Sheet Name||Size|
|1413648||*Full Sheet G-10 Tympan||36" x 48" x .032"|
|1413248||*Three Quarter G-10 Tympan||32" x 48" x .032"|
|1412436||Half Sheet G-10 Tympan||24" x 36" x .032"|
|1411824||Quarter Sheet G-10 Tympan||18" x 24" x .032"|
Use:The Tympan should be placed gently onto the paper, clean side down. The top side should be lubricated with tympan grease. Tympan grease should be applied with a pallet knife in a bead the same width as the scraper bar. Having a bead of tympan grease between the tympan and the scraper bar will reduce the friction greatly. This bead of tympan grease will be pushed to the far end of the tympan as it is run through the press. The grease bead should be collected with a pallet knife and reapplied to tympan at the starting point of the print.
Lubrication:A high pressure grease should be used, choose a tympan grease that stays thick, as it will be more manageable and less likely to seep onto clean areas in the print shop.
Static:Tympans are prone to building up static, both through the printing friction and during lifting of the tympan from the paper. The severity of the static buildup will vary with many variables. If severe static is generated it can begin to lift the paper from the matrix, causing registration problems. Anti static spray is an option for reducing the generated static. Good lubrication and slowing the speed of lifting of the tympan from the paper will reduce the build up of static.
Storage:Tympans should be stored clean and on end, to reduce the accumulation of dust on the surface. A small hole can be drilled into the tympan so that it may be hung from a nail.
Cleaning:Tympans should be cleaned before and after use. Wipe the tympan clean before use, removing any accumulated dust, ensure that one side is extremely clean as it will contact the printing paper. To remove tympan grease after use, scrape the majority of grease off with a pallet knife, use a dry shop towel to remove as much grease as possible. A small amount of solvent such as Soysolv II may be used to break down the grease. A final wipe down with Windex or alcohol will leave the tympan oil free.
Automatic Tympans:The automatic tympan systems, lays down and lifts the tympan across the matrix and paper as the press bed travels.
The purpose of the automatic tympan is to reduced handling of the tympan during printing. Essentially the tympan is raised and lowered as the press bed moves through the pressure head. The automatic tympan is attached to the press bed on the starting edge, and fed under the scraper bar. It rides on a guide roller as it is lifted towards a ceiling mounted pulley by a counterweight. The automatic tympan system works with 1/32" clear polycarbonate tympans.
Installation: The automatic tympan system requires drilling of holes into the press, and is easily assembled with common hand tools and some mechanical knowledge.
|Item #||Litho Press Size|
Automatic Tympan Replacement Sheets:1/32" clear polycarbonate replaces 14 mil. mylar automatic tympan sheets.
|Item #||Litho Press Size|