TAPPI sheet machine manual (Conventional sheet-former method)

TAPPI Sheet Former: Features • TAPPI standard (159mm diameter), • Sheet forming with manual mixing • Couching with supplied couch roll • De-watering only by gravitation, no vacuum pump necessary Description The sheet former has to be built into a laboratory table (not included). Water supply via ball valve. Manual mixing with supplied stirrer. De-watering via ball valve. Couching with supplied couch disc and couch roll. For the drying process polished stainless steel discs and drying-rings are included. Test description With the sheet machine open, turn on the water and gently rub the surface of the wire with the fingers to clear away any adhering fibres. Close the machine and half fill it with water. Pour the amount of stock needed for one sheet into the sheet machine. Add water up to the line marked inside the cylinder. Insert the perforated stirrer and in 6 ± 1 sec move it down and up five times, keeping the perforated disc beneath the level of the liquid. Make a sixth double movement slowly in 6 ± 1 sec, and at the end of the up stoke gently withdraw the stirrer. After a pause of 5 ± 1 sec, during which time the surface of the liquid should become almost motionless, fully open the drain of the machine with a rapid movement and let the water drain through the sheet under suction from the water leg. Open the sheet machine. Place two pieces of standard blotting paper centrally on the drained sheet with the smoother side of the lower blotter against the wet sheet. Lay the couch disc centrally on the blotters and place the couch roll gently on the middle of the disc. Rotate the roll backward and then forward five times in 10 ± 2 sec, with no pressure being applied except from the weight of the roll. The roll should come within less than 5 mm of the edge of the plate each time. After the fifth forward rotation, rotate it back to the middle and lift it off. Remove the couch disc. Lift the blotters in a manner similar to that of opening the cover of a book. The sheet should be found to adhere to the underside of the lower couch blotter. Discard the second blotter. Use an indelible pencil to identify the test sheet if desired. Specifications Delivery content: • TAPPI sheet machine manual (to be mounted into a laboratory table) • Stirrer • Couch roll • 2 couch discs • 10 polished drying discs • 10 drying rings • User-manual • OPTIONAL: Screen mounting device RK -Dryer (P41525): RK-dryer to be mounted into a laboratory table. For drying laboratory sheets under vacuum using an aspirator. RK-dryer with external water bath and water circulation up to 97°C included. Delivery content: • RK-dryer ready to be built into a tabletop • Water bath with heat resistant hoses • Aspirator with vacuum tube to install beneath the dryer • Electrical components (230V power supply required) Technical data Electricity: 230 V, 50 Hz Water supply: water (drinking water quality), min. 2 bar, Drain Ø 50 mm Compressed air: 400-600 kPa Dimensions (WxDxH): 30x35x140 cm Net weight: 80 kg Gross weight: 130 kg