Method and device for varying the basis weight in a paper machine headbox

(19)

(11)

EP 1 160 375 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	06.03.2002 Bulletin 2002/10

(43)	Date of publication A2:
	05.12.2001 Bulletin 2001/49

(21)	Application number: 01113119.0

(22)	Date of filing: 29.05.2001

(51)	International Patent Classification (IPC)⁷: D21F 1/02, D21F 1/06

(84)	Designated Contracting States:
	AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
	Designated Extension States:
	AL LT LV MK RO SI

(30)

Priority:

30.05.2000 IT VI000116

(71)	Applicant: COMER S.p.A.
	36030 San Vito di Leguzzano (IT)

(72)	Inventor:
	Aver, Franco 36030 Valli del Pasubio (VI) (IT)

(74)	Representative: Bonini, Ercole
	c/o STUDIO ING. E. BONINI SRL Corso Fogazzaro 8 36100 Vicenza 36100 Vicenza (IT)

(54)	Method and device for varying the basis weight in a paper machine headbox

(57) A method of varying the basis weight of the fibrous suspension coming out from a head box of a paper making machine is disclosed, wherein said variation of basis weight is obtained by extraction of controlled quantities of fibrous suspension from said head box. The head box (1) carrying out said variation of basis weight comprises a perforated plate (2) with a plurality of troughs (3) and a delivery chamber (6) ending with a slice (7) arranged above a movable filtering surface (F). One or more of said troughs (3) communicate with at least a suction pipe (8) connected to suction means (9) for extracting variable quantities of fibrous suspension.

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