A method of producing a finely fibrous cellulose composite prepreg sheet, sheet or laminate sheet, the method including a mixing an emulsion of a reactive compound with an aqueous suspension containing a finely fibrous cellulose to prepare a mixed liquid dewatering the mixed liquid by filtration on a porous substrate to form a water-containing sheet; and heating and drying the water-containing sheet. A method of producing a finely fibrous cellulose composite sheet, the method including subjecting the finely fibrous cellulose composite prepreg sheet produced by the method described above to a curing treatment.

Resin systems and methods for making and using same are provided. The method for making a paper product can include contacting a plurality of pulp fibers with a resin system. The resin system can include a first polyamidoamine-epihalohydrin resin and a second resin that can include a second polyamidoamine-epihalohydrin resin, a urea-formaldehyde resin, or a mixture thereof to produce a paper product. The first resin and the second resin can be sequentially or simultaneously contacted with the plurality of pulp fibers. The period for sequential addition between the first resin and the second resin is about 1 second to about 1 hour.

The invention provides methods and compositions for increasing the strengthening effect of a starch coating on paper. The method involves contacting the starch with a synthetic polymer before the starch is cooked. This changes how the starch gelatinizes and how the polymer gets distributed on the paper resulting in greater paper surface strength.

A method for manufacturing a sheet of paper and/or board having improved retention and drainage properties is provided, according to which, before the formation of the sheet and/or board, at least two retention aids are added to the fibrous suspension. These two retention aids are a main retention aid corresponding to a (co)polymer having a cationic charge density above 2 meq/g, obtained by the Hofmann degradation reaction, and a secondary retention aid corresponding to a water-soluble or water-swellable polymer having an anionic charge density above 0.1 meq/g. The main retention aid is introduced into the fibrous suspension in a proportion of 100 to 800 g/t of dry pulp, and the secondary retention aid is introduced into the fibrous suspension in a proportion of 50 to 800 g/t of dry pulp and has an intrinsic viscosity IV above 3 dl/g.

The invention relates to a method or methods of operating an apparatus for treating material by cutting, soaking and/or washing of the material, wherein the apparatus comprises a receptacle, a discharge element with a vortex generator and a pump arranged to pump fluid and material from the receptacle towards the vortex generator, wherein the vortex generator and the pump in combination are adapted to generate a vortex in the form of a conic helix in the fluid extending into the receptacle.

A process for making bleached pulp comprises contacting an unbleached pulp mixture with a first recycled filtrate obtained from a first location (3) of a first recycled filtrate loop, to obtain a first pulp mixture having a first consistency; bleaching the first pulp mixture, to obtain a first bleached pulp mixture; pressing or dewatering the first bleached pulp mixture, to obtain a first pressed bleached pulp mixture and a second filtrate; sending at least a portion of the second filtrate to a second location (5) of the first recycled filtrate loop, wherein the second location (5) is downstream of and in fluid communication with the first location (3); contacting the first pressed bleached pulp mixture with a second recycled filtrate obtained from a third location (6) of the first recycled filtrate loop, to obtain a second pulp mixture having a second consistency, wherein the second consistency is greater than the first consistency, and wherein the third location (6) is downstream of and in fluid communication with the second location (5); bleaching the second pulp mixture, to obtain a second bleached pulp mixture; pressing or dewatering the second bleached pulp mixture, to obtain a second pressed bleached pulp mixture and a third filtrate; sending at least a portion of the third filtrate to a fourth location (8) of the first recycled filtrate loop, wherein the fourth location (8) is downstream of and in fluid communication with the third location (6); and recycling at least a portion of the third filtrate in the first recycled filtrate loop to the first location (3); to obtain the bleached pulp.

An industrial textile belt, a method for making it, and its use. The belt includes a seam with joining ends that can be joined together so that the belt becomes an endless loop. The joining ends have seam areas with cross-machine direction wear yarns on their machine surface. The wear yarns receive wear stress when the belt slides against the support surface of a processing device.

A process is disclosed for converting biomass to fuels and/or valuable chemicals. The process comprises the steps of a) activating biomass to make it more susceptible to conversion; c) partially converting the biomass to a solubilized material; and d) subjecting the unconverted biomass to a second conversion step. The process optionally comprises a step b) of adding a solvent to the activated biomass. In a preferred embodiment the solubilized biomass obtained in step c) is removed before the unconverted biomass is subjected to step d).

A method is provided for forming a fire resistant cellulose product. A fire-retarding solution and a bonding agent are combined with refined cellulose fibers to form a fiber mixture, and the fire-retarding solution and bonding agent are substantially uniformly distributed with respect to the cellulose fibers within the fiber mixture. The fiber mixture is exposed to an actuating element, wherein the actuating element is configured to actuate the bonding agent so as to facilitate cohesion of the cellulose fibers and form the fiber mixture into a fiber board member, the fiber board member having opposing major surfaces. A cellulose sheet member is engaged with each major surface of the fiber board member, such that each cellulose sheet member substantially covers the respective major surface. An associated apparatus is also provided.

Latent dispersants were made by the hydrogenation of an alkyl ketene dimer, alkenyl ketene dimer, or ketene multimer. Adding the latent dispersant to paper or paperboard increased its resistance to water and water vapor while maintaining recyclability and repulpability. Additionally, provided is a method for increasing the repulpability of a wax coated paper or paperboard. Dispersants made by the hydrolysis of the alkyl ketene dimer, alkenyl ketene dimer, and ketene multimer are also described.

A press felt includes: a base fabric comprising a plurality of repeat units, each of the repeat units comprising a plurality of exterior machine direction (MD) yarns, each of which includes an upper run and a lower run merging with seam loops at each end, a plurality of middle MD yarns positioned between the upper and lower runs of the exterior MD yarns, a plurality of cross machine direction (CMD) yarns interwoven with the exterior MD yarns and the middle MD yarns in a predetermined regular weave pattern, the seam loops defining the longitudinal ends of the press felt; and a batt layer overlying the base fabric.

The invention relates to a method for obtaining cellulose by separating lignin from a biomass comprising lignocellulose in the form of plants or plant parts, wherein the biomass comprising lignocellulose is solubilized in a boiler in an alkaline medium comprising alkanol amine, and dissolved lignin is separated from the resulting raw cellulose. Said method is characterized in that the biomass comprising lignocellulose is not from a wood source, and is solubilized at a temperature of less than approximately 170° C. in a solubilizing agent based on alkanol amine and water, wherein the weight ratio of alkanol amine to water is set to 80:20 to 20:80, and raw cellulose thus produced is separated from the waste lye using a typical method. Said method is particularly advantageous for obtaining cellulose from annual plants, particularly wheat straw. The method is advantageously improved in that the solubilization takes place in the presence of a catalyst, particularly of anthrachinon. An advantageous bleaching process may be performed subsequently. Said method is characterized by great economic efficiency, particularly due to the high reclamation rates of the alkanol amine used, and leads to lower environmental impact in wastewater, and to reduced disposal costs. The design of the method leads to a greater yield of cellulose and largely prevents degradation of alkanol amine, particularly monoethanol amine (MEA).

Fibrous structures that exhibit a Free Fiber End Count greater than the Free Fiber End Count of known fibrous structures in the range of free fiber end lengths of from about 0.10 mm to about 0.75 mm as determined by the Free Fiber End Test Method, and sanitary tissue products comprising same and methods for making same are provided.

A sheet-forming unit of a papermaking machine includes a headbox which outputs a suspension jet and an inner fabric and an outer fabric, which in each case form a loop. A forming element is arranged within the loop of the inner fabric and guide rolls and a white-water box are arranged within the loop of the outer fabric. The inner fabric and the outer fabric form a gap for receiving the suspension jet and jointly wrap around the forming element at least partially in a wraparound region. A machine-wide guide element is arranged in the wraparound region within the loop of the outer fabric and/or, in the region of at least one of the guide rolls of the outer fabric, a machine-wide guide apparatus is provided outside the chamber which is formed by the loop of the outer fabric.

Disclosed herein are cellulase compositions useful as papermaking performance additives for improving paper dry strength of a paper product and reducing refining energy in papermaking processes, and improving paper production. These cellulase compositions are formulated using cellulase, papermaking contaminant control polymers, protein stabilizers and cellulase enhancers. These cellulase compositions measure higher in endo-cellulase activity with better stability than conventional cellulase, and have shown differentiating performance in improving paper dry strength properties versus cellulase alone.

A papermaking belt. The papermaking belt has a reinforcing element comprising a surface and a plurality of irregularly shaped, discrete raised portions extending from portions of the surface of the reinforcing element. The discrete raised portions are situated in an irregular pattern, wherein each of the discrete raised portions has a major axis, A, and a minor axis, B, and wherein the length of the major axis, A, is greater than or equal to the length of the minor axis, B; and a substantially continuous deflection conduit defines at least some of the discrete raised portions.

A process for preparing a seam area for a paper machine clothing (PMC) base fabric includes the steps of: forming the PMC base fabric by flat-weaving, the PMC base fabric including warp yarns extending in machine direction and weft yarns extending in cross machine direction and interwoven with the warp yarns, the weft yarns including first weft yarns and a second weft yarn, the second weft yarn being a multifilament yarn, the warp yarns, the first weft yarns, and the multifilament yarn being woven together on a loom in an original weaving process, the multifilament yarn being positioned in an anticipated seam area; and folding over the PMC base fabric, after weaving the multifilament yarn with the warp yarns, to form a seam loop of the PMC base fabric such that the multifilament yarn is a first one of the weft yarns on a sheet side of the seam loop.

Method for production of cellulose and hemicellulose fibers from lignocellulose biomass obtained from sugarcane leaves and buds by applying a process comprising the stages of: a) Diminishing the particle size of the lignocellulose biomass to a range between 3 and 15 mm, b) Subjecting the product obtained to treatment with one or more solvents and/or a mixture of specific catalysts, c) Carry out sudden decompression to an atmospheric pressure, d) Collecting the pretreated material in a cyclone, e) Optionally separating the liquid and solid fractions through washing and filterung f) Optionally, treating the solid fraction in a reactor with a mixture of ethanol and chlorine dioxide, d) Wash the product obtained to achieve cellulose efficiency above 50% and of lignin of 5 to 7%, fiber lengtht in a range to 1,5 to 2,7 mm, breaking length (km) of 7,0 -8,9, Burst index (kPam2/g) of 4,5-7,2 and Tear index (mNm2/g) of 8,2-8, The obtained high-resistance cellulose and hemicellulose is especially suitable for the paper production and polymer-type plastics.

A method of making a belt-creped absorbent cellulosic sheet. A papermaking furnish is compactively dewatered to form a dewatered web having an apparently random distribution of papermaking fiber orientation. The dewatered web is applied to a translating transfer surface moving at a transfer surface speed. The web is belt-creped from the transfer surface utilizing a generally planar polymeric creping belt provided with a plurality of perforations through the belt, the belt-creping step occurring under pressure in a belt creping nip defined between the transfer surface and the creping belt. The belt travels at a belt speed that is slower than the transfer surface speed, and the web is creped from the transfer surface and redistributed on the creping belt to form a web. The web includes hollow domed regions, connecting regions, and transition areas. The web is dried to produce the belt-creped absorbent cellulosic sheet.

The present invention relates to a process for the production of a surface-treated calcium carbonate, the use of this surface-treated calcium carbonate in a process for the control of organic material in an aqueous medium, as well as to a composite of surface-treated calcium carbonate and organic material, such as a composite of surface-treated calcium carbonate and to the use of such a composite.

The present invention relates to a process for the production of a surface-treated calcium carbonate, the use of this surface-treated calcium carbonate in a process for the control of organic material in an aqueous medium, as well as to a composite of surface-treated calcium carbonate and organic material, such as a composite of surface-treated calcium carbonate and to the use of such a composite.

Paper coating or binding formulations are provided that comprise aqueous copolymer emulsions including copolymers derived from one or more copolymerizable surfactants of formula I and one or more monomers. The paper coating or binding formulations can include one or more mineral fillers, coating pigments, or mixtures thereof, wherein the total weight concentration of the one or more mineral fillers, coating pigments, or mixtures thereof is 65% or higher, based on the total weight of the composition. Paper products coated with the paper coating or binding formulations, methods of making the paper coating or binding formulations, and methods of making the coated paper products are also disclosed.

A pellet made of aramid pulp and filler material. The pellet has at most 90 weight percent aramid pulp and at least 10 weight percent filler material. A method for manufacturing a pellet that has at most 90 weight percent aramid pulp and at least 10 weight percent filler material.

The disclosure provides a dispersion for making décor paper having improved optical performance without negatively impacting mechanical strength comprising a TiO2 particle slurry comprising a treated TiO2 particle having a surface area of at least about 30 m2/g, and a cationic polymer; wherein the treatment comprises an oxide of silicon, aluminum, phosphorus or mixtures thereof; and the treatment is present in the amount of at least 15% based on the total weight of the treated titanium dioxide particle; paper pulp; and a cationic polymer; wherein the cationic polymer in the slurry and the cationic polymer in the dispersion are compatible; wherein for equal optical performance, the amount of treated TiO2 particle in the dispersion is reduced by about 10% when compared to a dispersion not comprising the treated TiO2 particle of (a). These dispersions are useful in making décor paper that may be used in paper laminates.

A method of production of a product from a stock pulp sheet uses conveyor rolls to convey a stock pulp sheet to a crusher. During conveyance to the crusher, a defective part in the stock pulp sheet is detected by a detector. The detected defective part is removed from the stock pulp sheet by a remover. The stock pulp sheet from which the defective part is removed is supplied to the crusher to produce crushed pulp. The produced crushed pulp is used to produce a product in a product producer.

This technology relates to a method of sizing paper through the use of an aqueous solution of ketene dimer and vinylamine-containing polymers. It also relates to the stability of the ketene dimer/polyvinylamine solution.

Absorbent members, especially bulked absorbent members, and methods of making the same are disclosed. The absorbent member may be in the form of a unitary absorbent fibrous layer comprising at least some cellulose fibers. The unitary absorbent fibrous layer is at least partially stratified through its thickness. The absorbent member may also have a plurality of discrete deformations, such as depressions and/or apertures in its surfaces. The method involves subjecting a precursor web to at least one cycle (or pass) through a mechanical deformation process. The mechanical deformation process utilizes a first forming member and a second forming member that form a nip therebetween through which the precursor web is passed. The first and second forming members are moving at different speeds relative to each other when they come together to form the nip.

A method for mixing a chemical into a process liquid including: injecting the chemical into the process liquid flowing through a flow pipe; forming reaction products by a reaction involving the chemical occurring in the process flow; applying an electric field or magnetic field to a region of the flow pipe adjacent to the reaction occurring in the process flow, and suppressing the precipitation of the chemical or the reaction products on the surfaces of the pipe due to the electric or magnetic field.

The invention provides methods and compositions for improving the characteristics of paper substrates. The method involves adding to a paper substrate an NCC-polymer. NCC-polymers have unique chemical properties which result in improvements in wet strength, dry strength and drainage retention properties of the paper substrates.

Disclosed are methods for increasing the filler content of paper or paperboard, comprising (a) combining a heterogeneous polymer blend with a ground calcium carbonate filler; (b) combining the resulting mixture with a pulp slurry; and (c) processing the resulting slurry mixture to form a sheet of paper or paperboard. Also disclosed are methods of increasing the filler content of paper or paperboard comprising (1) combining either a heterogeneous polymer blend or a ground calcium carbonate filler with a pulp slurry, (2) combining the remaining component with the pulp slurry; and (c) processing the resulting pulp slurry mixture to form a sheet of paper or paperboard.

A sheet manufacturing apparatus includes a defibrating unit configured to defibrate a defibration object including at least a fiber, in air. The sheet manufacturing apparatus forms a sheet by adding quantity of heat to a defibrated material defibrated at the defibrating unit. The sheet manufacturing apparatus includes a measuring unit configured to acquire moisture amount information of the defibrated material or the defibration object, and a controller configured to control the quantity of heat to be added to the defibrated material on the basis of the moisture amount information.

Compositions and methods related to new wet strength resins are provided. By using functionally-symmetrical cross-linkers and mono-functional modifiers, and separating the steps of reacting a prepolymer with the cross-linkers from the reaction of intermediate cross-linked prepolymer with epichlorohydrin, new wet strength resin products are provided having improved properties.

The invention relates to a method for precipitating calcium carbonate, in which method calcium hydroxide is introduced to a fiber suspension containing cellulose-containing fibers, the calcium hydroxide is allowed to attach onto the surfaces of fibers for a pre-determined time, and the aqueous suspension of calcium hydroxide and fibers is brought into contact with carbon dioxide for precipitating the calcium carbonate. The invention also relates to a corresponding system for precipitating calcium carbonate in connection with cellulose-containing fibers. In addition, the invention relates to a fibrous product, which comprises pulp material produced by said method and comprising calcium carbonate.

A pneumatic radial tire in which a plurality of land portion rows 2 are formed by a plurality of main grooves that extend in the circumferential direction on a tread portion of a tire, and a thin groove 3 that extends in the tire circumferential direction is formed in at least one shoulder land portion row 2A that is positioned on the tread end among the plurality of land portion rows. A land portion 5 that is positioned between, the thin groove 3 and the tread end 4 is partitioned into a plurality of blocks 5a by a lug groove 6 that extends in the tire width direction and whose maximum groove depth is set deeper than the groove depth of the thin groove, and the groove depth of the lug groove continuously changes so as to become a maximum at an intermediate position between the thin groove and the tread end. According to the present invention, it is possible to provide a pneumatic radial tire that can achieve improved drainage performance.

Tyre and rubber composition for tyre, based on at least one isoprene elastomer (for example natural rubber), an inorganic filler as reinforcing filler (for example silica) and a coupling system which provides the bonding between the said reinforcing inorganic filler and the isoprene elastomer, the said coupling system comprising, in combination: as first coupling agent, a silane sulphide compound;as second coupling agent, an at least bifunctional organosilicon compound (for example an organosilane or an organosiloxane) which can be grafted to the elastomer by means of an azodicarbonyl functional group (—CO—N═N—CO—).

A method for locking a tire to a wheel rim, includes the steps of mounting a tubular tire locking element on the wheel rim, which tubular locking member is arranged with a valve, which valve is pushed through a hole in the rim; mounting a tire on the rim such that the tire encloses the tubular tire locking element and a pressure chamber is obtained between the tire locking element and the tire; pressurizing the tubular tire locking element via the valve such that it expands, whereby the beads of the tire are pressed against the flanges of the wheel rim; inserting a hollow needle through the tire and into the pressure chamber, which hollow needle is connected to a pressurized air source; pressurizing the pressure chamber to desired pressure, removing the hollow needle; and sealing the hole caused by the needle with sealing fluid or plug.

A non-pneumatic tire includes a plurality of springs. Each spring includes a first end portion, a second end portion, and an arching middle portion. Each spring is interwoven with at least one other spring thereby forming a toroidal structure extending about an entire circumference of the non-pneumatic tire. The toroidal structure is at least partially coated with an elastomer. One end portion of at least one spring is wrapped around a first bead structure adjacent a rim.

Bicycle tires with at least one reinforcement layer that contains strength supports and that is arranged between carcass and tread rubber and/or between carcass layers below the tread rubber and/or within the tread rubber. For a high resistance to puncturing with low weight, the reinforcement layer contains multifilament threads of more than 30 polyester/polyarylate filaments, and the filaments are spun from molten liquid-crystal polymer.

A belt structure for a two-wheeled vehicle made by means of strip-like segments or elements, each including parallel cords embedded in an elastomeric layer, sequentially laid along the circumferential extension of a toroidal support so as to form a reinforcing layer having a continuous circumferential extension around a geometric rotation axis of the toroidal support, wherein each strip-like element is laid in a laying trajectory defining, at each point, a laying angle; at each point of the laying trajectory a laying gap is formed between adjacent strip-like elements; the laying trajectory is formed starting from preselected laying angles on the shoulder and on the crown of the tire; the laying gap between adjacent strip-like elements varies along at least one length of said laying trajectory between crown and shoulder so as to cause variation of the laying angle and obtain the preselected angles on the shoulder and on the crown.

Particular embodiments of the present invention include a multi-stage tire tread having a plurality of wear layers, each said layer being located at a different depth of the tire tread, the tread including one or more tread elements including a contact surface and having a first wear layer and a second wear layer, wherein the second wear layer is located below the first wear layer. The tire tread also includes a longitudinal groove extending in a longitudinal direction within the second wear layer of the tread element, wherein said longitudinal groove becomes exposed after a depth of the first wear layer has been worn. The tire tread further includes one or more lateral grooves extending from the longitudinal groove in a lateral direction within the second wear layer of the tread element. The invention also provides a mold element for forming portions of the multi-stage tread.

A tire (10) for driving on ice, comprising: a tread (20) having a rolling surface configured to come into contact with the ground when the tire is rolling along, and two lateral faces (27), this tread comprising at least one groove (25, 26) in the rolling surface; at least one stud (30) having a longitudinal axis (33), a part (31) of the stud projecting from the rolling surface, the intersection between the stud and the plane tangential to the portion of the rolling surface around the stud forming a contour C, that part of the stud that projects from the rolling surface having a minimum cross section Sm, Sm corresponding to the smallest cross section of the said part in any plane containing the radial direction that passes through the point of intersection between the longitudinal axis of the stud and the plane tangential to the portion of the rolling surface around the stud; at least one conduit (200-205) that forms, on the rolling surface of the tire, at least two opposing edges (211, 221; 212, 222; 213, 223), the minimum distance D between the conduit and the contour C being less than or equal to 1 cm, the conduit opening into the groove and/or onto a lateral face of the tread; wherein, for each stud, the sum of the mean cross sections Sn of the conduits, each mean cross section Sn being measured at right angles to one of the opposing edges formed by the conduit, is greater than or equal to half the minimum cross section Sm of that part of the stud that projects from the tread.

A rubber composition for tire treads is obtained by blending, per 100 parts by mass of a diene rubber, 5 to 150 parts by mass of silica and 0.5 to 20 parts by mass of a silicone oligomer represented by the following siloxane average formula (1): (X)a(Y)b(R1)c(R2)dSiO(4-a-b-c-d)/2 (wherein X is a mercapto group-containing organic group; Y is a hydrolyzable group, R1 is a monovalent hydrocarbon group having from 4 to 10 carbon atoms, R2 is a monovalent hydrocarbon group having from 1 to 3 carbon atoms, 0

The present invention provides a rubber composition that improves in terms of the fuel economy of a rubber composition containing an isoprene-based rubber and also offers favorable durability and favorable processability or adhesion to steel cords, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for a bead apex, sidewall packing, base tread, or breaker cushion, including: a specific rubber component; a specific amount of a specific carbon black; a specific amount of sulfur; and a specific amount of a compound represented by formula (I) below. The present invention also relates to a rubber composition for a steel cord topping, strip adjacent to steel cords, or tie gum, including: a specific rubber component; a specific amount of a specific carbon black; a specific amount of an organic acid cobalt salt; and a specific amount of a compound represented by the formula (I).

The present invention relates to a tire tread comprising a plurality of circumferential grooves separating circumferential ribs, each groove comprising a bottom and two sidewalls, and a plurality of laterally separated reinforcements, wherein one reinforcement is arranged adjacent each circumferential groove, and wherein each reinforcement extends from the radially inner surface of the tread in a radial direction at least to the bottom of an adjacent circumferential groove to form the bottom of that groove. Further, the invention relates to a tire comprising a tread in accordance with the present invention.

A mounted assembly of a wheel and a tire. The tire inflation pressure is greater than 9 bar, and a relative deflection of the tire greater than 30%. The rim comprises a drop-center functionality and is of monobloc type. A carcass reinforcement includes a circumferential alignment of carcass reinforcement elements anchored in the beads by a stack of circumferentially oriented reinforcement elements, and by an anchoring rubber mix having an elasticity modulus of less than 30 MPa at 10% deformation.

A tire containing a pair of beads, at least one carcass ply extending from one bead to the other bead forming a pair of sidewall areas of the tire and a tread area of the tire, and at least one layer of a knit fabric in the sidewall area of the tire, where the knit fabric has a warp and weft direction and is a double cord stitch knit fabric. A method of making the fabric and tire are also disclosed.

In the invention, at least a tire outer circumferential side portion of a tread portion is formed of a non-conductive rubber layer. The non-conductive rubber layer is formed by winding and laminating a non-conductive rubber ribbon along a tire circumferential direction. A conductive layer is provided on an outer circumference of the non-conductive rubber ribbon, and the conductive layer continuously and spirally extends along the tire circumferential direction, and is exposed on a tread surface from a bottom surface of the non-conductive rubber layer toward a tire outer circumferential side. Accordingly, an electricity generated in a vehicle body is discharged to a road through the conductive layer. Since the conductive layer is scattered within the non-conductive rubber layer and exposure on the tread surface is preferably secured, it is possible to achieve an excellent conductivity.

A pneumatic tire in which: a carcass layer is laid between paired bead sections; a belt layer is buried, on the outer peripheral side of the carcass layer, in a tread section; and multiple main grooves extending in a tire circumferential direction are provided in the tread section. In the pneumatic tire, a maximum groove depth of each of the main grooves is 8.5 mm to 15.0 mm, a ratio α of a section height SH of an actual tire to a section height SHstd calculated from a tire size is set in a range of 0.97≦α≦0.99, a contact area ratio is 65% to 70% under a measurement condition where an air pressure is 200 kPa and a load is 50% of a load carrying ability with the air pressure of 200 kPa, and an average contact pressure P is 300 kPa to 400 kPa under the measurement condition. The tire achieves enhanced wet performance without increasing tire weight.

A pneumatic tire comprises an annular tread portion including a plurality of circumferentially extending main grooves comprising an innermost groove, an outermost groove, and at least one middle groove arranged between the innermost groove and the outermost groove. The outermost groove comprises an inner sidewall, an outer sidewall, a groove bottom, and a groove opening opposite to the groove bottom, wherein the outermost groove has an asymmetric cross section with respect to any straight line perpendicular to the groove opening, and wherein the outer sidewall of the outermost groove is tilted by more than 20° with respect to a straight line perpendicular to the groove opening.

A tire 1 comprises rib-shaped land portions 20 extending in a tire circumferential direction TC and has a circumferential groove 30 adjacent to the land portions 20 and extending in the tire circumferential direction TC. Tread contact surfaces 10 of the land portions 20 form smooth surfaces with no gap when a normal load is applied and the tread contact surfaces are in contact with a road surface. The circumferential groove 30 includes a shallow groove portion 40 extending in the tread-width direction TW, and a deep groove portion 50 adjacent to the shallow groove portion 40 in the tire circumferential direction and extending in the tread-width direction. A deep groove portion 50 is recessed more inwardly in a tire radial direction TR than the shallow groove portion 40 with a groove bottom 40c of the shallow groove portion 40 being an upper end of the deep groove portion 50.