The invention relates to a method for pitch control and/or removal during bleaching of cellulosic fibres. Cellulosic fibres are obtained from a pulping process and formed into an aqueous cellulosic fibre suspension, and bleaching of the cellulosic fibre suspension is performed in a bleaching process comprising at least one acidic stage, where pH of the cellulosic fibre suspension is <6. A pitch control agent is added to the cellulosic fibre suspension before the acidic stage, wherein the pitch control agent comprises at least one cationic polymer comprising cationic functional groups which are hydrolysed at pH 9.0

The present invention is related to a method to produce a treated condensate substantially free of organic matter by treating the condensate with at least one of physical, chemical, chemical-physical treatment or combinations thereof. Further, it is also provided a method to treat a condensate in a pulp processing fiber line utilizing multiple washing stages having at least a treated condensate circulating in a closed loop, prior to feeding the condensate into the fiber line, the method comprising the steps of: a) identifying the colloidal organic compounds in the condensate; b) subjecting the condensate to at least one chemical, physical, chemical-physical treatment or a combination thereof; and c) reducing contamination of the condensate, feeding it to the last washer stage, or to some other stage of the pulping.

A process for treatment of lignocellulosic biomasses with a process solvent selected from an eutectic solvent consisting of a hydrogen bond acceptor and of a hydrogen bond donor, an ionic liquid, and a mixture of the eutectic solvent and the ionic liquid, may include: A. mixing the biomasses with the process solvent and possibly separating insoluble cellulose residues and/or inorganic material; B. treating the possibly filtered process solvent solution from step A with water, thereby separating lignin; and C. separating hemicellulose from the mixture of the process solvent and possibly the water. Step C may be carried out by adding an organic solvent soluble in the process solvent and in the water, whereby hemicellulose precipitates and is subsequently separated with conventional techniques from a liquid phase comprising the process solvent, the organic solvent, and possibly the water.

A use of organofunctionalized mesoporous silica for the production of recycled paper; the organofunctionalized mesoporous silica comprises a base mesoporous silica having, on its surface, groups having the following general formula (I), wherein Si.sup.1 is a silicon atom of the base mesoporous silica, R.sup.1 is a C.sub.1-C.sub.5 aliphatic; R.sup.2 is chosen in the group consisting of: a C.sub.1-C.sub.5 aliphatic and an oxygen atom bound with a silicon atom of the base mesoporous silica; and R.sup.3 is chosen in the group consisting of: a hydroxyl, a C.sub.1-C.sub.5 aliphatic and an oxygen atom bound with a silicon atom of the base mesoporous silica (I). ##STR00001##

A method of forming an aqueous solution comprising mircrofibrillated cellulose, the method comprising the steps of providing a substantially dry composite material, comprising microfibrillated cellulose and a filler material, wherein said filler material is precipitated onto fibers or fibrils of said microfibrillated cellulose; providing an aqueous media, wherein the method further comprises the step of lowering the pH value of said aqueous media and then mixing said aqueous media with said substantially dry composite material, such that the filler material is released from said microfibrillated cellulose, thus dissolving said microfibrillated cellulose; or the step of mixing said aqueous media with said substantially dry composite material, and then lowering the pH of said mixture, such that the filler material is released from said microfibrillated cellulose, thus releasing said microfibrillated cellulose.

Methods to reduce sticky and fluff induced rewinder breaks by reducing the adhesive character of adhesive materials, fluff and sticky contaminants in fibers are described. One method involves contacting the fibers with a composition containing at least one of each of a cellulase, a hemicellulase, a -glucosidase, a lipase, an esterase, a pectinase, a pectate lyase and a laccase for a sufficient time and in a sufficient amount to control the removal or controlling adhesive materials, fluff and sticky contaminants present in the fibers. Preferably, the fibers are recycled fibers originating from a variety of sources such as old corrugated containers, old newsprint, mixed office waste, and the like. Resulting paper products formed from the processed fibers are also described as well as methods to make them.

The present invention provides a process for preparing a cellulose solution. NMMO with a relatively low concentration and non-activated pulp are continuously mixed online, the mixed premix is dewatered in evaporation dewatering equipment until an NMMO concentration suitable for swelling is achieved, then, sufficient swelling is carried out under this condition, and the uniformly-mixed and sufficiently swelled pre-swelling solution is subjected to depressurized evaporation dewatering and dissolving by thin-film-evaporation equipment thereby obtaining a high-concentration, uniformly-dissolved and excellently-uniformity cellulose solution. The present invention further provides continuous preparation equipment for the process for preparing a cellulose solution. According to the present invention, the conflict between uniform mixing and sufficient swelling during the preparation of a high-concentration cellulose solution is solved, and problems in storage and transportation safety caused by using high concentration NMMO in the conventional technologies are prevented.

Compositions comprising enzyme compositions are provided. Also provided are methods of treating virgin fiber and recycled wastepaper containing mineral oils using the compositions comprising enzyme compositions. The mineral oils generally originate from wastepapers with mineral oil based inks and certain other hydrocarbon-based chemistries used during the manufacturing, paperboard converting, and packaging process. The enzymes break down or modify mineral oils present in the fiber and paper, mobilize and liberate them from the fibers, and increase removal of mineral oils during paper recycling, pulping and papermaking processes. The method results in the break down or modification of mineral oil components in wastepaper, recycled pulp, and paper products by the enzyme compositions so that the mineral oils can be more efficiently detached and removed. The resulting pulp and paper has much reduced mineral oil concentration or less problematic forms of mineral oils and is beneficial for making food packaging paper products.

To provide a contamination inhibitor composition capable of effectively inhibiting pitch contamination on a dry part. The present invention is a contamination inhibitor composition 1 which is imparted to a dry part D of a paper-making machine, and comprising a film forming agent and a gelling agent, wherein the film forming agent is an emulsion consisting of water, a modified silicone and an emulsifier and the gelling agent is a compound represented by the following formula (1): ##STR00001##
[in the formula (1), R.sup.1 each independently represents a hydrogen atom, a hydroxyl group, a carboxyl group or a hydrocarbon group optionally having a substituent having 1 to 3 carbon atoms, R.sup.2 each independently represents a hydroxyl group or a carboxyl group, R.sup.3 represents a hydrogen atom, a hydroxyl group or a carboxyl group, m is an integer of 1 to 5, and n is an integer of 0 to 5.].

Provided are a pitch-formation suppressor and the like which can be widely applied independently of the substance that causes a pitch and of the situation to generate a pitch in a paper manufacturing process, and which can effectively suppress and prevent the troubles due to the pitch, such as foreign spots and defects in a paper, breakage of a paper, and lowering of workability. This pitch-formation suppressor comprises an alkaline solution in which a phenol resin and/or a modified phenol resin is dissolved, or an acid solution in which a phenol resin and/or a modified phenol resin is dissolved.