Patent · US Expired

Manufacture of paper

US5676796A · kind A · utility

37Cited by
8References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 1, 1996
Grant dateOct 14, 1997
Priority date
Expiry dateFeb 1, 2016

Classification

  • Technology area (CPC D)Textiles; Paper
  • CPC primaryD21H21/10
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

Paper is made by forming a thick stock cellulosic suspension, flocculating the thick stock by adding a relatively high molecular weight and relatively low cationic charge density polymer, diluting the flocculated thick stock to form a thin stock and then draining the thin stock to form a sheet. Usually coagulant is added to the thin stock before drainage and best results are achieved by adding coagulant followed by anionic colloidal material such as bentonite. The process can be operated to give good retention and good formation and, if the thick stock is dirty, to minimise pitch problems.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.