Patent Description:
Dry fiber assembly-forming apparatuses using substantially no water for the purpose of size reduction and energy saving have been proposed. For example, <CIT> describes that, in a dry paper recycling apparatus, the paper strength is increased in such a manner that water containing a paper strength additive such as starch or polyvinyl alcohol (PVA) is sprayed from a water sprayer on deposits of deinked fibers deposited on a mesh belt.

However, in the manner described in <CIT>, while the deposits of the fibers are being transported on the mesh belt, the fibers rise from the mesh belt in the form of paper dust to clog nozzles of the water sprayer in some cases. Therefore, it is difficult to uniformly spray the paper strength additive on the deposits and formed paper is variable in strength.

<CIT> discloses a sheet manufacturing apparatus having a defibrating unit configured to defibrate, in air, feedstock containing fiber, and a mixing unit configured to mix, in air, resin with the fiber defibrated from the feedstock by the defibrating unit. The apparatus also has an air-laying unit configured to lay a web from the mixture output from the mixing unit, a wetting unit configured to add water to part of the web laid by the air-laying unit, and a sheet forming unit configured to form a sheet with parts having different light transmittance by heating and compressing the web to which water was added by the wetting unit.

According to an aspect of the present invention, a fiber assembly-forming method used in sheet forming according to claim <NUM> is provided.

According to another aspect of the present invention, a fiber assembly-forming apparatus used in sheet forming according to claim <NUM> is provided.

Preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.

A fiber assembly-forming apparatus <NUM> according to an embodiment of the present disclosure is described with reference to a drawing. <FIG> is a schematic view of the fiber assembly-forming apparatus <NUM>.

As shown in <FIG>, the fiber assembly-forming apparatus <NUM> includes, for example, a supply section <NUM>, a rough crushing section <NUM>, a disintegration section <NUM>, a screening section <NUM>, a first web-forming section <NUM>, a rotator <NUM>, a deposition section <NUM>, a second web-forming section <NUM>, a sheet-forming section <NUM>, a cutting section <NUM>, and a provision section <NUM>.

The supply section <NUM> supplies a feedstock to the rough crushing section <NUM>. The supply section <NUM> is, for example, an automatic input section for continuously inputting the feedstock to the rough crushing section <NUM>. The feedstock supplied by the supply section <NUM> contains, for example, fibers of waste paper, pulp sheets, or the like.

The provision section <NUM> provides the feedstock supplied from the supply section <NUM> with a binding material bonding the fibers to each other. Details of the provision section <NUM> are described below.

The rough crushing section <NUM> cuts the feedstock supplied by the supply section <NUM> into small pieces in gas such as air. The small pieces are, for example, several centimeters square pieces. In an illustrated example, the rough crushing section <NUM> includes rough crushing blades <NUM> and can cut the input feedstock with the rough crushing blades <NUM>. The rough crushing section <NUM> used is, for example, a shredder. The feedstock cut by the rough crushing section <NUM> is received in a hopper <NUM> and is then transferred to the disintegration section <NUM> through a pipe <NUM>.

The disintegration section <NUM> disintegrates the feedstock cut by the rough crushing section <NUM>. The term "disintegrate" as used herein means that a feedstock containing a plurality of bonded fibers is disentangled into the fibers one by one. The disintegration section <NUM> has the function of removing substances, such as resin particles, ink, toner, and a bleeding inhibitor, adhering to the feedstock from fibers.

One having passed through the disintegration section <NUM> is referred to as "disintegrated matter". The "disintegrated matter" contains disentangled disintegrated fibers and also contains resin particles separated from fibers when the fibers are disintegrated, a colorant such as ink or toner, or an additive such as a bleeding inhibitor or a paper strength additive in some cases. Disentangled disintegrated matter is string-shaped. The disentangled disintegrated matter may be present in such a state that the disentangled disintegrated matter is not intertwined with other disentangled fibers, that is, such a state that the disentangled disintegrated matter is independent or in such a state that the disentangled disintegrated matter is intertwined with other disentangled fibers to form aggregates, that is, such a state that the disentangled disintegrated matter forms lumps.

The disintegration section <NUM> performs disintegration in a dry mode. Herein, performing treatment such as disintegration in gas, such as air, rather than liquid is referred to as a dry mode. The disintegration section <NUM> used is, for example, an impeller mill. The disintegration section <NUM> has the function of generating such an air flow that sucks the feedstock and discharges the disintegrated matter. This enables the disintegration section <NUM> to suck the feedstock from an inlet <NUM> by means of an air flow generated by the disintegration section <NUM> together with the air flow, to disintegrate the feedstock, and to transport the disintegrated matter to an outlet <NUM>. The disintegrated matter having passed through the disintegration section <NUM> is transferred to the screening section <NUM> through a pipe <NUM>. Incidentally, an air flow for transporting the disintegrated matter from the disintegration section <NUM> to the screening section <NUM> may be the air flow generated by the disintegration section <NUM> or an air flow generated by an air flow generator such as a blower.

The screening section <NUM> imports the disintegrated matter having passed through the disintegration section <NUM> from an inlet <NUM> and screens the disintegrated matter depending on the length of fibers. The screening section <NUM> includes a drum portion <NUM> and a housing portion <NUM> that houses the drum portion <NUM>. The drum portion <NUM> used is, for example, a sieve. The drum portion <NUM> includes a net and can separate fibers or particles smaller than the size of openings of the net, that is, first screened fractions passing through the net, and fibers, undisintegrated pieces, or lumps larger than the size of the openings of the net, that is, second screened fractions not passing through the net. For example, the first screened fractions are transferred to the deposition section <NUM> through a pipe <NUM>. The second screened fractions are returned to the disintegration section <NUM> from an outlet <NUM> through a pipe <NUM>. In particular, the drum portion <NUM> is a cylindrical sieve rotationally driven with a motor. The net of the drum portion <NUM> used is, for example, a metal gauze, an expanded metal obtained by expanding a slit metal plate, or a punching metal obtained by forming holes in a metal plate with a press or the like.

The first web-forming section <NUM> transports the first screened fractions having passed through the screening section <NUM> to the pipe <NUM>. The first web-forming section <NUM> includes a mesh belt <NUM>, tension rollers <NUM>, and a suction mechanism <NUM>.

The suction mechanism <NUM> can suck the first screened fractions which have passed through openings of the screening section <NUM> and which have been distributed in air onto the mesh belt <NUM>. The first screened fractions are deposited on the moving mesh belt <NUM> to form a web V. The basic configuration of the mesh belt <NUM>, the tension rollers <NUM>, and the suction mechanism <NUM> is substantially the same as that of a mesh belt <NUM>, tension rollers <NUM>, and suction mechanism <NUM> of the second web-forming section <NUM> as described below.

The web V passes through the screening section <NUM> and the first web-forming section <NUM> and is thereby formed in such a state that the web V contains a lot of air, is soft, and is bulgy. The web V deposited on the mesh belt <NUM> is input to the pipe <NUM> and is transported to the deposition section <NUM>.

The rotator <NUM> can cut the web V. In the illustrated example, the rotator <NUM> includes a base portion 49a and protruding portions 49b protruding from the base portion 49a. The protruding portions 49b have, for example, a plate shape. In the illustrated example, the number of the protruding portions 49b is four and the four protruding portions 49b are arranged at equal intervals. The base portion 49a rotates in a direction R and therefore the protruding portions 49b can rotate about the base portion 49a. Cutting the web V by the rotator <NUM> enables, for example, the change in amount of the disintegrated matter supplied to the deposition section <NUM> per unit time to be reduced.

The rotator <NUM> is placed in the vicinity of the first web-forming section <NUM>. In the illustrated example, the rotator <NUM> is placed in the vicinity of a tension roller 47a located downstream in the path of the web V. The rotator <NUM> is placed at a position where the protruding portions 49b can come into contact with the web V and do not come into contact with the mesh belt <NUM>, on which the web V is deposited. This enables the mesh belt <NUM> to be inhibited from being worn by the protruding portions 49b. The shortest distance between each protruding portion 49b and the mesh belt <NUM> is, for example, <NUM> to <NUM>. This is the distance that the web V can be cut without damaging the mesh belt <NUM>.

The deposition section <NUM> imports the first screened fractions from an inlet <NUM>, disentangles the intertwined disintegrated matter, and sprays the disentangled disintegrated matter such that the disentangled disintegrated matter is dispersed in air. The deposition section <NUM> can uniformly deposit the first screened fractions on the second web-forming section <NUM>.

The deposition section <NUM> includes a drum portion <NUM> and a housing portion <NUM> that houses the drum portion <NUM>. The drum portion <NUM> used is, for example, a rotary cylindrical sieve. The drum portion <NUM> includes a net and sprays fibers or particles smaller than the size of openings of the net. The configuration of the drum portion <NUM> is the same as, for example, the configuration of the drum portion <NUM>.

Incidentally, the "sieve" of the drum portion <NUM> need not have the function of screening a specific target. That is, the "sieve" used as the drum portion <NUM> means one equipped with a net. The drum portion <NUM> may spray all of the disintegrated matter imported into the drum portion <NUM>.

The second web-forming section <NUM> deposits a passing object having passed through the deposition section <NUM> to form a web W. The second web-forming section <NUM> includes, for example, a mesh belt <NUM>, tension rollers <NUM>, and a suction mechanism <NUM>.

The mesh belt <NUM> allows the passing object having passed through an opening of the deposition section <NUM> to be deposited thereon while moving. The mesh belt <NUM> is tensioned by the tension rollers <NUM> and is configured such that the passing object is unlikely to pass through the mesh belt <NUM> and air passes through the mesh belt <NUM>. The mesh belt <NUM> moves because the tension rollers <NUM> rotate. The passing object having passed through the deposition section <NUM> is deposited on the mesh belt <NUM> that is continuously moving, whereby the web W is formed on the mesh belt <NUM>.

The suction mechanism <NUM> is placed under the mesh belt <NUM>. The suction mechanism <NUM> can generate an air flow directed downward. The disintegrated matter dispersed in air by the deposition section <NUM> can be sucked onto the mesh belt <NUM> by the suction mechanism <NUM>. This enables the discharge rate from the deposition section <NUM> to be increased. Furthermore, a down-flow can be formed in the fall path of the disintegrated matter by the suction mechanism <NUM>, thereby enabling the disintegrated matter and an additive to be prevented from being intertwined during falling.

As described above, passing through the deposition section <NUM> and the second web-forming section <NUM> allows the web W to be formed in such a state that the web W contains a lot of air, is soft, and is bulgy. The web W deposited on the mesh belt <NUM> is transported to the sheet-forming section <NUM>.

The sheet-forming section <NUM> pressurizes and heats the web W deposited on the mesh belt <NUM> to form a sheet S. In the sheet-forming section <NUM>, heat is applied to a mixture of the disintegrated matter and binding material mixed together in the web W, thereby enabling a plurality of fibers in the mixture to be bonded to each other with the binding material.

The sheet-forming section <NUM> includes a pressurizing portion <NUM> pressurizing the web W and a heating portion <NUM> heating the web W pressurized by the pressurizing portion <NUM>. The pressurizing portion <NUM> is composed of a pair of calender rollers <NUM> and applies a pressure to the web W. Pressurizing the web W reduces the thickness of the web W and increases the bulk density of the web W. The heating portion <NUM> used is, for example, a heating roller, a hot press molding machine, a hotplate, a hot air blower, an infrared heater, or a flash-fusing system. In the illustrated example, the heating portion <NUM> includes a pair of heating rollers <NUM>. Composing the heating portion <NUM> using the heating rollers <NUM>, rather than composing the heating portion <NUM> as a plate-like press machine, enables the sheet S to be formed in such a manner that the web W is continuously transported. The calender rollers <NUM> and the heating rollers <NUM> are arranged such that, for example, the axes of rotation thereof are parallel. The calender rollers <NUM> can apply a higher pressure to the web W than the pressure applied to the web W by the heating rollers <NUM>. The number of the calender rollers <NUM> and the heating rollers <NUM> is not particularly limited.

The cutting section <NUM> cuts the sheet S formed by the sheet-forming section <NUM>. In the illustrated example, the cutting section <NUM> includes a first cutting portion <NUM> cutting the sheet S in a direction crossing the transport direction of the sheet S and a second cutting portion <NUM> cutting the sheet S in a direction parallel to the transport direction thereof. The second cutting portion <NUM> cuts the sheet S having passed through, for example, the first cutting portion <NUM>.

The above allows the sheet S to be formed such that the sheet S is a single sheet with a predetermined size. The cut sheet S, which is such a single sheet, is discharged to a discharge section <NUM>.

The provision section <NUM> provides the feedstock, which contains the fibers, with the binding material, which bonds the fibers to each other. The feedstock, which contains the fibers, is, for example, waste paper. In the illustrated example, the provision section <NUM> provides the feedstock which is supplied from the supply section <NUM> and which is roughly uncrushed by the rough crushing section <NUM> with the binding material. The length of the fibers contained in the feedstock is, for example, <NUM> to <NUM> as length-weighted mean length. The length-weighted mean length of the fibers can be measured in accordance with ISO <NUM>-<NUM>:<NUM> using L&W Fiber Tester CODE <NUM>.

The provision section <NUM> may apply liquid containing the binding material to a surface of the feedstock. The provision section <NUM> may include a roller applying the binding material to the feedstock. Alternatively, the provision section <NUM> may include a spray discharging the binding material to the feedstock. Alternatively, the provision section <NUM> may be an inkjet head discharging the binding material to the feedstock.

The binding material, which is provided from the provision section <NUM>, may be dissolved or dispersed in liquid. The liquid is preferably emulsion in which the binding material is dispersed. The binding material is preferably nano-sized. When the liquid is the emulsion, the viscosity of the liquid can be reduced, the liquid can penetrate to the inside of a fiber assembly, and the bonding force can be further enhanced, which is preferable. When the binding material is nano-sized, for example, nozzle clogging, which occurs in sprays and ink jet heads, is likely to be avoided, which is preferable.

The binding material, which is provided from the provision section <NUM>, is, for example, a thermoplastic resin or a thermosetting resin.

Examples of the thermoplastic resin include an acrylonitrile-styrene (AS) resin, an acrylonitrile-butadiene-styrene (ABS) resin, polypropylene, polyethylene, polyvinyl chloride, polystyrene, an acrylic resin, a polyester resin, polyethylene terephthalate, polyphenylene ether, polybutylene terephthalate, nylon, polyamide, polycarbonate, polyacetal, polyphenylene sulfide, and polyether ether ketone. These resins may be used alone or in combination and may be copolymerized or modified. Examples of a family of these resins include styrenic resins, acrylic resins, styrene-acrylic copolymers, olefinic resins, vinyl chloride resins, polyester resins, polyamide resins, polyurethane resins, polyvinyl alcohol resins, vinyl ether resins, N-vinyl resins, and styrene-butadiene resins.

Examples of the thermosetting resin include a phenol resin, an epoxy resin, a melamine resin, a urea resin, an unsaturated polyester resin, an alkyd resin, polyurethane, and a thermosetting polyimide resin.

The glass transition temperature of the thermoplastic resin and the thermosetting resin is preferably high from the viewpoint of high-temperature resistance and is in an appropriate range in consideration of reasons such as energy saving in terms of manufacture. The glass transition temperature is appropriately selected depending on, for example, the thickness or heat treatment temperature of the sheet S. The glass transition temperature is preferably <NUM> or higher, more preferably <NUM> or higher, and further more preferably <NUM> or higher. The glass transition temperature is preferably <NUM> or less and more preferably <NUM> or lower. When the glass transition temperature is <NUM> or higher, the softening of the binding material at high temperature is suppressed and the obtained sheet S has high paper strength. Furthermore, when the glass transition temperature is <NUM> or higher, it can be suppressed that the binding material is softened by the heat of the disintegration section <NUM> to adhere to the disintegration section <NUM> in the course of disintegrating the feedstock provided with the binding material in the disintegration section <NUM>. The binding material is preferably resin having a melting point higher than or equal to the temperature of the disintegration section <NUM>. The melting point of the binding material is preferably <NUM> or lower.

The provision section <NUM> provides the feedstock with the binding material such that the binding material accounts for <NUM>% by mass or more of the fibers contained in the feedstock, preferably <NUM>% by mass or more. When the binding material accounts for <NUM>% by mass or more of the fibers, the paper strength of the sheet S can be enhanced. The sheet S contains the binding material such that the binding material accounts for, for example, <NUM>% by mass or more of the fibers.

The provision section <NUM> may provide the feedstock with an additive such as a flame retardant, a perfume, an antistatic agent, or an ultraviolet absorber in addition to the binding material. If the additive is provided from the provision section <NUM> together with the binding material, a cartridge for providing the additive need not be used. Therefore, the downsizing of an apparatus is possible. The provision section <NUM> does not provide the feedstock with any colorant.

When the feedstock is undisintegrated by the disintegration section <NUM>, the provision section <NUM> may provide the feedstock roughly crushed by the rough crushing section <NUM> with the binding material. This is not shown. In this case, the provision section <NUM> is preferably a spray. In a case where the binding material is applied to the feedstock using a roller, the provision section <NUM> preferably provides the feedstock roughly uncrushed by the rough crushing section <NUM> with the binding material.

The provision section <NUM> may provide the binding material to the feedstock in the form of powder instead of the liquid containing the binding material. However, when the binding material is powder, the binding material is preferably fixed to the feedstock by heat for the purpose of suppressing the fall of the binding material from the feedstock. For example, the binding material may be charged into the disintegration section <NUM> such that the binding material is fixed to the feedstock by the heat of the disintegration section <NUM>.

The fiber assembly-forming apparatus <NUM> has, for example, effects below.

The fiber assembly-forming apparatus <NUM> includes, the provision section <NUM>, which provides the feedstock containing the fibers with the binding material bonding the fibers to each other; the disintegration section <NUM>, which disintegrates the feedstock provided with the binding material to form the disintegrated matter; the deposition section <NUM>, which deposits the disintegrated matter; and the heating portion <NUM>, which heat the deposited disintegrated matter. Therefore, in the fiber assembly-forming apparatus <NUM>, the binding material need not be provided to the disintegrated matter deposited by the deposition section <NUM> and therefore there is no possibility that the fibers rise from the mesh belt <NUM> in the form of paper dust to clog a nozzle of the provision section <NUM>. Thus, the sheet S (fiber assembly) can be formed so as to have little variation in paper strength.

Furthermore, in the fiber assembly-forming apparatus <NUM>, the disintegration section <NUM> has the function of mixing the feedstock and the binding material together. Therefore, even if the binding material is unevenly distributed at the point in time when the binding material is provided to the feedstock, the uneven distribution of the binding material can be reduced by the disintegration section <NUM> and the sheet S can be formed so as to have little variation in paper strength. Thus, if the nozzle of the provision section <NUM> is partly clogged, the binding material can be provided without regard to the unevenness of the binding material. Furthermore, since a mixing section mixing the feedstock and the binding material together is not necessary, the downsizing of an apparatus is possible.

In the fiber assembly-forming apparatus <NUM>, the provision section <NUM> may include a roller applying the binding material to the feedstock. Therefore, in the fiber assembly-forming apparatus <NUM>, the binding material can be uniformly applied to the feedstock. The roller can readily apply the binding material to the feedstock without consideration of the viscosity of the liquid containing the binding material as compared to sprays and ink jet heads.

In the fiber assembly-forming apparatus <NUM>, the binding material may be the thermoplastic resin or the thermosetting resin and the glass transition temperature of the binding material may be <NUM> or higher. Therefore, in the fiber assembly-forming apparatus <NUM>, the binding material can be readily melted by the heating portion <NUM>.

Next, a fiber assembly-forming method according to an embodiment of the present disclosure is described with reference to a drawing. <FIG> is a flowchart illustrating the fiber assembly-forming method.

The fiber assembly-forming method is performed using, for example, the above-mentioned fiber assembly-forming apparatus <NUM>. The fiber assembly-forming method may be performed using an apparatus other than the fiber assembly-forming apparatus <NUM>.

As shown in <FIG>, the fiber assembly-forming method includes a binding material-providing step (Step S11) of providing a feedstock containing fibers with a binding material bonding the fibers to each other, a disintegration step (Step S12) of forming disintegrated matter by disintegrating the feedstock provided with the binding material, a deposition step (Step S13) of depositing the disintegrated matter, and a heating step (Step S14) of heating the deposited disintegrated matter.

The binding material-providing step (Step S11) is performed using, for example, the provision section <NUM> of the fiber assembly-forming apparatus <NUM>.

The disintegration step (Step S12) is performed using, for example, the disintegration section <NUM> of the fiber assembly-forming apparatus <NUM>.

The deposition step (Step S13) is performed using, for example, the deposition section <NUM> of the fiber assembly-forming apparatus <NUM>.

The heating step (Step S14) is performed using, for example, the heating portion <NUM> of the fiber assembly-forming apparatus <NUM>.

The fiber assembly-forming method may include, for example, a step such as a step of pressurizing the web W by the pressurizing portion <NUM> as described in above-mentioned "<NUM>. Fiber Assembly-Forming Apparatus" in addition to the above steps.

In the fiber assembly-forming method, the sheet S can be formed so as to have little variation in paper strength as described in above-mentioned "<NUM>. Fiber Assembly-Forming Apparatus".

In an example shown in <FIG>, in the disintegration step, the feedstock provided with the binding material in the binding material-providing step is disintegrated. As shown in <FIG>, in the disintegration step, the feedstock (first feedstock) provided with the binding material in the binding material-providing step and the sheet S formed through the heating step may be disintegrated. In an example shown in <FIG>, the sheet S is a feedstock (second feedstock) on which no binding material providing step is performed between the heating step and the disintegration step. The disintegration section <NUM> may disintegrate the first feedstock and the second feedstock.

As shown in <FIG>, in the disintegration step, the feedstock provided with the binding material in the binding material-providing step and the sheet S, formed through the binding material-providing step, provided with the binding material in the binding material-providing step may be disintegrated.

Next, a modification of the fiber assembly-forming method is described with reference to a drawing. <FIG> is a flowchart illustrating the modification. Hereinafter, in the modification, what is different from the fiber assembly-forming method is described and what is common to the fiber assembly-forming method is not described.

As shown in <FIG>, the fiber assembly-forming method includes the binding material-providing step (Step S11). As shown in <FIG>, the modification includes a material-preparing step (Step S21) of preparing material containing fibers and a binding material boding the fibers to each other.

As shown in <FIG>, the modification includes the material-preparing step (Step S21), a disintegration step (Step S22) of forming disintegrated matter by disintegrating the material, a deposition step (Step S23) of depositing the disintegrated matter, and a heating step (Step S24) of heating the deposited disintegrated matter.

In the material-preparing step (Step S21), the material contains, for example, waste paper and a resinous substance made of the binding material. The resinous substance may be composed of a thermoplastic resin or a thermosetting resin or may be composed of the thermoplastic resin and the thermosetting resin.

The shape of the resinous substance is not particularly limited and is, for example, a sheet shape (single sheet shape), a strip shape formed by fragmenting a single sheet, a dice shape, or a spherical shape. The resinous substance is preferably a sheet-shaped resin sheet. When the resinous substance is such a resin sheet, the resinous substance can be supplied by attaching a sheet-feeding stacker for supplying the resinous substance to the supply section <NUM> of the fiber assembly-forming apparatus <NUM>. In the material-preparing step, the same number of resin sheets as that of sheets of waste paper may be prepared. In a case where the modification is performed using the fiber assembly-forming apparatus <NUM>, the provision section <NUM> need not be driven. Alternatively, the provision section <NUM> need not be used.

In the material-preparing step, the material is prepared such that the binding material accounts for <NUM>% by mass or more of the fibers. In a case where, for example, waste paper and the resinous substance are prepared as material, supposing that the mass of fibers contained in the waste paper is <NUM>, the sum of the mass of resin contained in the waste paper and the mass of the resinous substance is <NUM> or more. In the material-preparing step, the material is preferably prepared such that the binding material accounts for <NUM>% by mass or more of the fibers. When the material is such that the binding material accounts for <NUM>% by mass or more of the fibers, the sheet S can be formed so as to have high paper strength.

The disintegration step (Step S22) is substantially the same as the above-mentioned disintegration step (Step S12). The deposition step (Step S23) is substantially the same as the above-mentioned deposition step (Step S13). The heating step (Step S24) is substantially the same as the above-mentioned heating step (Step S14).

The modification has, for example, effects below.

In the modification, as well as the fiber assembly-forming method, the sheet S can be formed so as to variation in paper strength.

In the modification, no provision step is performed unlike the fiber assembly-forming method; hence, for example, the provision section <NUM> of the fiber assembly-forming apparatus <NUM> can be omitted. Therefore, the downsizing of the fiber assembly-forming apparatus <NUM> is possible.

In the modification, in the material-preparing step, the material may contain a resinous substance made of the binding material. Therefore, liquid containing the binding material need not be applied; hence, a drying step subsequent to the application of the liquid can be omitted.

Furthermore, a sheet-shaped resinous substance is easy in stock control and has good operation efficiency. Furthermore, the type of the resinous substance can be selected without being restricted by crushability, powder characteristics such as fluidity, dispersibility, dischargeability, storage stability, or compatibility.

Furthermore, a plurality of different functional agents can be provided to the fibers depending on purposes using a resinous substance made of resins with different glass transition temperatures or a resinous substance containing a flame retardant, an antistatic agent, an ultraviolet absorber, a perfume, and the like; hence, functional customization is easy.

In the modification, if the material can be prepared in the material-preparing step such that the binding material accounts for <NUM>% by mass or more of the fibers, the sheet S, which is formed through the heating step, may be prepared as material in addition to the waste paper and the resinous substance as shown in <FIG>.

In the modification, if the material can be prepared in the material-preparing step such that the binding material accounts for <NUM>% by mass or more of the fibers, the waste paper and the sheet S may be prepared as material without preparing the resinous substance.

Liquid was provided to recycled paper, G80 (a basis weight of <NUM>/m<NUM>), available from Mitsubishi Paper Mills, Ltd. using an inkjet printer, EW-M770T, available from Seiko Epson Corporation, whereby a feedstock was prepared. Components of the liquid were as described below.

Polyurethane used was SUPERFLEX <NUM> available from Dai-ichi Kogyo Seiyaku Co. Polyurethane is a binding material bonding fibers to each other. In Table <NUM>, "PG" is polypropylene glycol and "E1010" is Olfine E1010 available from Nissin Chemical Industry Co.

Next, a sheet with a basis weight of <NUM>/m<NUM> was prepared using a papermaking machine, PaperLab A8000, available from Seiko Epson Corporation and the feedstock coated with the liquid. The content of the binding material with respect to fibers in the sheet was <NUM>% by mass. In PaperLab A8000, no binding material was provided to the feedstock. That is, in Example <NUM>, after liquid containing the binding material was applied, disintegration was performed.

A web was prepared using G80 as a feedstock without providing the binding material in PaperLab A8000. Next, the liquid shown in <FIG> was applied to the web using EW-M770T. Thereafter, the web was pressurized with a pressurizing portion and was heated with a heating portion, whereby a sheet with a basis weight of <NUM>/m<NUM> was prepared. That is, in Comparative Example <NUM>, after disintegration was performed, liquid containing the binding material was applied.

Printing with EW-M770T was performed in such a state that four nozzles were clogged. As shown in <FIG>, in Comparative Example <NUM>, dropouts N due to dot loss were observed on the prepared sheet. In Example <NUM>, since disintegration was performed after printing, no dropout was observed on the prepared sheet. Each of the prepared sheets was cut to a rectangle with a width of <NUM>. In Comparative Example <NUM>, the sheet was cut such that the dropouts N were contained. Referring to <FIG>, the sheet cut in Comparative Example <NUM> is drawn with a dashed line. The sheets were measured for specific tensile strength in a longitudinal direction by a method specified in JIS P <NUM>:<NUM> using a tensile tester, AGS-X-500N, available from Shimadzu Corporation.

Evaluation standards for specific tensile strength were as described below.

Printing with EW-M770T was repeatedly performed in such a state that four nozzles were clogged. Subsequently, the uneven application of the liquid was visually checked.

Evaluation standards for uneven application were as described below.

Evaluation results of specific tensile strength and uneven application were as shown in Table <NUM>.

Claim 1:
A fiber assembly-forming method used in sheet forming comprising:
providing a first feedstock containing fibers with a binding material bonding the fibers to each other (S11);
forming disintegrated matter by disintegrating the first feedstock provided with the binding material (S12);
depositing the disintegrated matter (S13); and
heating the deposited disintegrated matter (S14).