The present invention discloses a method for detackifying organic contaminants in the process of pulping and papermaking and a composition used for the same. Specifically, the invention discloses that the water circulation system of pulping and papermaking process can be provided with non-ionic cellulose ether and cationic coagulant in lower amount, through which, the deposition of organic contaminants can be inhibited under the synergistic action of pre-coagulation and detackification.

The present invention discloses a method for detackifying organic contaminants in the process of pulping and papermaking and a composition used for the same. Specifically, the invention discloses that the water circulation system of pulping and papermaking process can be provided with non-ionic cellulose ether and cationic coagulant in lower amount, through which, the deposition of organic contaminants can be inhibited under the synergistic action of pre-coagulation and detackification.

Disclosed is a method for thickening or dehydrating sludge, which includes at least: a) a step of adding flocculants to the sludge to be treated; b) a step of flocculation by agitation of the sludge with the flocculants thus added in order to form a mixture of flocks and an aqueous solution; c) a step of mechanical separation of the flocks and the aqueous solution formed during the preceding step; d) a step of recovering the aqueous solution and the flocks that make up a treated sludge; wherein: the added flocculants are made up of at least one cationic starch (S) and at least one cationic polyacrylamide (P); the cationic starch or starches (S) including a fixed weight percentage of nitrogen of at least 2%; and the weight ratio (R) w.sub.s/(w.sub.s+w.sub.p), expressed as solids, is included between 0.6 and 0.99.

Disclosed is a method for thickening or dehydrating sludge, which includes at least: a) a step of adding flocculants to the sludge to be treated; b) a step of flocculation by agitation of the sludge with the flocculants thus added in order to form a mixture of flocks and an aqueous solution; c) a step of mechanical separation of the flocks and the aqueous solution formed during the preceding step; d) a step of recovering the aqueous solution and the flocks that make up a treated sludge; wherein: the added flocculants are made up of at least one cationic starch (S) and at least one cationic polyacrylamide (P); the cationic starch or starches (S) including a fixed weight percentage of nitrogen of at least 2%; and the weight ratio (R) w.sub.s/(w.sub.s+w.sub.p), expressed as solids, is included between 0.6 and 0.99.

The invention relates to a composition for sizing of a surface of paper, board or the like and its use for increasing strength properties of paper, board or the like. The composition has a solids content of 3-30%, and it comprises degraded non-ion is starch, and at least 0.5 weight-% of anionic polyacrylamide, which has a molecular weight, MW, >500 000 g/mol and <2 500 000 g/mol and an anionicity in the range of 4-35 mol-%. The invention further relates also to a method for producing paper, board or the like, which comprises addition of a first strength composition, which comprises a cationic agent, to a fibre stock, formation of a fibrous web from the fibre stock, drying of the fibrous web to dryness of at least 60%, and application of a second strength com position, which comprises an anionic hydrophilic polymer and a starch component, on the surface of the fibrous web.

Methods and apparatus for manufacturing a microwavable food container include: forming a wire mesh over a mold comprising a mirror image of the microwavable food container; immersing the wire mesh in a fiber-based slurry bath; drawing a vacuum across the wire mesh to cause fiber particles to accumulate at the wire mesh surface; and removing the wire mesh including the accumulated fiber particles from the slurry bath; wherein the slurry comprises one or more of a moisture barrier, an oil barrier, and a vapor barrier.

Methods and apparatus for manufacturing a microwavable food container include: forming a wire mesh over a mold comprising a mirror image of the microwavable food container; immersing the wire mesh in a fiber-based slurry bath; drawing a vacuum across the wire mesh to cause fiber particles to accumulate at the wire mesh surface; and removing the wire mesh including the accumulated fiber particles from the slurry bath; wherein the slurry comprises one or more of a moisture barrier, an oil barrier, and a vapor barrier.

A dry strength composition for manufacture of paper, board or the like is disclosed. The dry strength composition includes, as a mixture, at least one anionically derivatized polysaccharide, and cationic starch having an amylopectin content ≥80 weight-%. The anionically derivatized polysaccharide and the cationic starch provide the composition with a charge density in a range of 0.1-1.5 meq/g, when measured at pH 2.8, and −0.1-−3 meq/g, preferably −0.3-−2.5 meq/g, more preferably −0.5-−2.0 meq/g, when measured as an aqueous solution, at pH 7.0. Further disclosed are a use of the composition and a method for manufacturing paper, board or the like.

A dry strength composition for manufacture of paper, board or the like is disclosed. The dry strength composition includes, as a mixture, at least one anionically derivatized polysaccharide, and cationic starch having an amylopectin content ≥80 weight-%. The anionically derivatized polysaccharide and the cationic starch provide the composition with a charge density in a range of 0.1-1.5 meq/g, when measured at pH 2.8, and −0.1-−3 meq/g, preferably −0.3-−2.5 meq/g, more preferably −0.5-−2.0 meq/g, when measured as an aqueous solution, at pH 7.0. Further disclosed are a use of the composition and a method for manufacturing paper, board or the like.

Methods and apparatus for manufacturing a microwavable food container include: forming a wire mesh over a mold comprising a mirror image of the microwavable food container; immersing the wire mesh in a fiber-based slurry bath; drawing a vacuum across the wire mesh to cause fiber particles to accumulate at the wire mesh surface; and removing the wire mesh including the accumulated fiber particles from the slurry bath; wherein the slurry comprises a moisture barrier, an oil barrier, and a vapor barrier.