Process for making paper, paperboard or the like

1. A process for making paper or paperboard comprising

providing a cellulosic fibre suspension;

optionally diluting the fibre suspension;

delivering the fibre suspension to a headbox, draining the fibre suspension on a screen to form a wet web of paper, or paperboard;

wherein the cellulosic fibre suspension comprises at least 40% on dry weight basis, based on the paper or paperboard, of recycled fibre material, and has a conductivity of at least 1.5 mS/cm as measured at the headbox of the paper, or paperboard,

adding a high molecular weight cationic flocculant to the fibre suspension, wherein the high molecular weight cationic flocculant comprises a copolymer of acrylamide and cationic monomers; and

wherein a glyoxalated copolymer of acrylamide and cationic monomers having a weight-average molecular weight in a range of 1 000 000-5 000 000 g/mol, and a charge density over 0.2 meg/g (dry basis) as measured by Mutek charge titration at pH 4.0, and inorganic siliceous microparticles comprising silica sol having a degree of aggregation defined by an S-value of less than 20%, and a specific surface area of at least 1000 m 2 /g, are added to the fibre suspension sequentially or simultaneously.

2. The process of claim 1 , wherein the cellulosic fibre suspension comprises at least 50%, on dry weight basis, based on the paper, or paperboard of the recycled fibre material.

3. The process of claim 2 , wherein the cellulosic fibre suspension comprises at least 60%, on dry weight basis, based on the paper, or paperboard of the recycled fibre material.

4. The process of claim 1 , wherein the cellulosic fibre suspension has a conductivity of at least 2.0 mS/cm, as measured at the headbox of the paper, or paperboard.

5. The process of claim 1 , wherein the recycled fiber material is selected from a group consisting of old corrugated cardboard, mixed office waste, double liner kraft, and any mixtures thereof.

6. The process of claim 1 , wherein the glyoxalated copolymer of acrylamide and cationic monomers is added to the fiber suspension before the addition of the inorganic microparticles.

7. The process of claim 1 , wherein the glyoxalated copolymer of acrylamide and cationic monomers is added to the fibre suspension having a concentration of above 20 g/I.

8. The process of claim 1 , wherein the glyoxalated copolymer of acrylamide and cationic monomers has a charge density in the range of 0.2-3.5 meq/g (dry basis) as measured by Mutek charge titration at pH 4.0.

9. The process of claim 1 , wherein the glyoxalated copolymer of acrylamide and cationic monomers has a charge density over 0.8 meq/g.

10. The process of claim 9 , wherein the glyoxalated copolymer of acrylamide and cationic monomers has a charge density in a range of 0.8-3.0 meq/g.

11. The process of claim 10 , wherein the glyoxalated copolymer of acrylamide and cationic monomers has a charge density in a range of 1.0-2.0 meq/g.

12. The process of claim 11 , wherein the glyoxalated copolymer of acrylamide and cationic monomers has a charge density in a range of 1.2-1.8 meq/g.

13. The process of claim 1 , wherein the glyoxalated copolymer of acrylamide and cationic monomers is added to the fibre suspension as a blend with a polyamidoamine epihalohydrin.

14. The process of claim 1 , wherein the process further comprises

adding an anionic acrylamide based flocculant to the fibre suspension, wherein the anionic acrylamide based flocculant comprises a copolymer of acrylamide and acrylic acid, a homopolymer of acrylic acid, or a mixture of a copolymer of acrylamide and acrylic acid and a homopolymer of acrylic acid.

15. The process of claim 1 , wherein the glyoxalated copolymer of acrylamide and cationic monomers is added in an amount from 0.025% to 1.0% dry solids based on dry weight of the cellulosic fiber suspension and the silica sol is added in an amount from 0.005% to 0.20% dry solids based on dry weight of the cellulosic fibre suspension.