| (19) |
 |
|
(11) |
EP 0 838 550 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
04.08.1999 Bulletin 1999/31 |
| (43) |
Date of publication A2: |
|
29.04.1998 Bulletin 1998/18 |
| (22) |
Date of filing: 23.10.1997 |
|
|
| (84) |
Designated Contracting States: |
|
AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE |
| (30) |
Priority: |
25.10.1996 US 738450
|
| (71) |
Applicant: NALCO CHEMICAL COMPANY |
|
Naperville
Illinois 60563-1198 (US) |
|
| (72) |
Inventors: |
|
- Surface, Thomas G.
Chesterfield, VA 23838 (US)
- Noe, Jeffrey S.
Millersport, OH 43046 (US)
- Weatherman, David J.
Claremore, OK 74017 (US)
|
| (74) |
Representative: Harrison, David Christopher et al |
|
MEWBURN ELLIS
York House
23 Kingsway
London WC2B 6HP
London WC2B 6HP (GB) |
|
| |
|
| (54) |
Method of retention aid addition for improved paper board production |
(57) The present invention relates to a method for manufacturing paper board which contains
no inorganic filler. Pulp fines from the white water system and retention agents are
mixed and then fed to the stock upstream of the paper machine prior to blending with
the long fiber stock. Once flocculation takes place, the stock is drained to form
a sheet and the sheet is dried.