TAPPI Hand Sheet Former

Definition : when pulp suspension passed through a standard wire mesh fitted on a circular grid plate under standard barometric height to provide the necessary vacuum over the grid plate to form the paper sheet under uniform parameter such as consistency , temperature , water volume is defined as lab hand sheet making.

Standardization : TAPPI T 205 , ISO 5269/1 , SCAN C26

Device Description : the sheet former is intended for installation into a laboratory bench (not included). The individual stages are carried out by moving hand levers . Swirling is done with an agitator with perforated bottom plate and the couching is done with the 10kg stainless steel roller (both included in the delivery). Additionaly 10 polished mirror plates and drying rings are included in the delivery for drying . all parts are constructed of corrosion resistant materials

Test Description : by opening the hand valve the former column is half filled with water and suspensions, which has been prepared in the disintegrator , and equalizer is added . Then the former column gets filled up until the mark is reached . the agitator is used to swirl the content of the column , once the settling phase is finished , the second hand lever gets moved to open the drainage valve and the water is drained through the forming screen. The freshly formed hand sheet remains on the screen. The former column can then be opened and two blotting papers are placed on the top of wet hand sheet. With the stainless steel roller the sheet is couched and then carefully be removed from the screen and further processed with the sheet press, the drying rings or the speed dryer.