JP3058359B2 - Sludge treatment bag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sludge treatment bag, and more particularly, to a sludge-filled bag having excellent water distribution capacity and high strength. In particular, the present invention relates to a sludge treatment bag that can be used as a solid sandbag without breaking the bag.

[0002]

[Prior art and its problems] Sludge deposited in rivers and lakes not only drastically changes the ecology of fish and birds living there, but also destroys human living environments. The dredging is being actively carried out. However, in this sludge dredging project, it is a big problem how cheaply the collected sludge can be disposed of, and each company is suffering from such measures. Conventional sludge treatment methods include adding a flocculant to the sludge and solidifying it, filling it with holes, or filling flat yarn bags, transporting them to another location, and disposing of them. ing.

[0003] However, in the method of solidifying with a flocculant, it takes too much time from the addition of the flocculant to solidification, and during that time, not only is it bothered by bad smell, but also the solidified sludge is discarded. Land is needed, time and money are irrational, and bags of flat yarn do not drain quickly due to poor drainage, and until the end. In addition to the time-consuming uneconomical inability to transport, the strength is not always sufficient, so stacking them in multiple layers will break the bag, making it unsuitable as a sludge treatment method.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to fill a sludge containing a large amount of water and to prevent the bag from breaking even when the sludge is piled up in multiple stages, and to show a superior drainage capacity. Is to provide.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object, and at least one surface of a knitted fabric comprising a molecularly oriented molded product of a specific polymer is made of a polyolefin or polyester. The present invention is characterized by a sludge treatment bag composed of a laminate in which a series of nonwoven fabrics are laminated. That is, according to the present invention, a lamination in which a polyolefin-based or polyester-based nonwoven fabric is laminated on at least one surface of a knitted fabric made of a molecularly oriented molded product of an ultrahigh molecular weight ethylene-based polymer having an intrinsic viscosity [η] of at least 5 dl / g. A sludge disposal bag composed of a body is provided. Further, according to the present invention, the nonwoven fabric,
By using a polypropylene nonwoven fabric, it is possible to provide a sludge-treating bag with the above-mentioned performance being further improved. Further, according to the present invention, the ultrahigh molecular weight ethylene copolymer contains an α-olefin having 3 or more carbon atoms in an average of 0.1 to 20 per 1000 carbon atoms, and is a copolymer of ethylene and α-olefin. Of ethylene and α-olefin, in which the α-olefin is one or more selected from the group consisting of butene-1, 4-methylpentene-1, hexene-1 and decene-1. When the copolymer is used, a bag for sludge treatment having higher strength is provided.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrahigh molecular weight ethylene polymer having an intrinsic viscosity [η] of at least 5 dl / g, particularly an α-olefin having 3 or more carbon atoms.
A bag composed of a laminate in which a polyolefin-based or polyester-based nonwoven fabric is laminated on at least one surface of a knitted fabric comprising a molecularly oriented molded product of a copolymer of ethylene and an α-olefin containing an average of 0.1 to 20 per 1000 pieces. It has been completed based on the finding that it has high strength and exhibits excellent drainage capacity. The sludge treatment bag according to the present invention has an intrinsic viscosity [η] measured in a decalin solvent at 135 ° C. of at least 5 dl / g, preferably 6 to 30 dl / g. A laminate in which a polyolefin-based nonwoven fabric is laminated on at least one surface of a knitted fabric formed of a molded article is formed in a bag shape. Examples of the nonwoven fabric include polyethylene, polypropylene, and polyethylene terephthalate, and polypropylene is preferably used in terms of strength.

The ultrahigh molecular weight ethylene polymer includes not only ultrahigh molecular weight polyethylene but also ethylene having the intrinsic viscosity and an α-olefin having 3 or more carbon atoms, for example, propylene, butene-1, pentene and the like. -1,
4-methylpentene-1, hexene-1, heptene-
1, a copolymer of one or more selected from the group consisting of octene-1 and decene-1 is preferably used, and among them, ethylene, butene-1,4-methylpentene-1, A copolymer with one or more selected from the group consisting of hexene-1, octene-1 and decene-1 has a high strength and exhibits not only excellent drainage ability but also cut resistance. It has excellent abrasion resistance, creep resistance, and chemical resistance, and is suitably used as a bag for sludge treatment which is the object of the present invention. When the ultrahigh molecular weight ethylene polymer is a copolymer of ethylene and an α-olefin, the α-olefin comonomer has 1000 carbon atoms.
It is desirable that the content is 0.1 to 20 on average, preferably 0.5 to 10 on average. When the content of the α-olefin comonomer in the copolymer is within the above range, the α-olefin component forms an intermolecular entangled structure effective for achieving high breaking energy, and this structure has strength and cut resistance. Contribute to the improvement of the physical properties including the properties, at least one surface of the knitted fabric made of the molecular orientation molded body, for example, a polyolefin nonwoven fabric such as polypropylene or a polyester nonwoven fabric such as polyethylene terephthalate and laminated into a bag. The formed sludge treatment bag quickly drains water from the filled sludge due to its excellent drainage capacity,
The drained bags can be used as sandbags as they are in landfills and revetment works, and because the bags have high strength and excellent cut resistance, they can be broken even when stacked in multiple stages. It is possible to build a stable and stable sandbag without performing.

FIG. 1 is a sectional view showing the state of the construction.
If the sludge-treating bag (1) as a sandbag is disposed continuously in a landfill or the like, as shown in FIG. This continuous bag (1) functions as a drainage ditch, allowing the accumulated water to flow smoothly to the outside (arrow) even if it contains a large amount of water, thereby preventing the catastrophic landslide. is there. Further, by the water discharged through the bag, in order to prevent erosion of the earth and sand in the embankment portion of the slope, a laminate constituting the sludge treatment bag of the present invention, or a non-woven fabric such as polypropylene, polyester, or the like. If only the slope is protected with the sandbag (3) or the like used, a more robust construction can be achieved.

In the bag for sludge treatment of the present invention, the molecularly oriented formed body is formed into a cloth or net-like knitted fabric by a known method such as plain weaving, twill weaving, knitting weaving, satin weaving, and at least one surface thereof. One or both sides are partially or wholly formed with a laminate obtained by laminating a polyolefin-based nonwoven fabric in a bag shape. In this case, a plain weave is preferable as the weaving method, and the knitted fabric is an inner layer or a core. It is preferable to be laminated as a layer. As a method of laminating both, needle punch, water jet punch, ultrasonic welder, high frequency welder,
A method by heat embossing can be exemplified, but a method by needle punch is preferably adopted in that the fibers are firmly joined by entanglement of the fibers of both layers and the obtained laminate is excellent in water distribution ability. . Needle punching 30 to 150 times per cm ² , especially 5
One or more times has good bonding between layers, and the needle depth is preferably 8 to 15 mm, particularly preferably 10 to 14 mm.

The knitted fabric is composed of monofilaments or multifilaments obtained by drawing the ultra-high molecular weight ethylene polymer, and a drawn film or drawn tape of the polymer is opened as a multifilament by a carding machine. A defibrated yarn may be used. The basis weight of the knitted fabric differs depending on whether the knitted fabric is a cloth or a net.
0 g / m ² and denier is usually 500 to 3
000 denier, especially 1000 to 2000 denier is preferably used.

The ultrahigh molecular weight ethylene α- according to the present invention
The quantification of the α-olefin component in the olefin copolymer is as follows:
The measurement was performed using an infrared spectrophotometer (manufactured by JASCO Corporation). That is, the absorbance at 1378 cm ^-1 representing the bending vibration of the methyl group of the α-olefin incorporated into the ethylene chain was measured, and the test line was prepared in advance using a model compound with a ¹³ C nuclear magnetic resonance apparatus. And calculated from the value measured by converting into the number of methyl branches per 1000 carbon atoms.

When the ultrahigh molecular weight ethylene polymer has an intrinsic viscosity [η] of less than 5 dl / g, even if the stretching ratio is increased, a sufficiently oriented molecular oriented molded product cannot be obtained,
Conversely, when [η] is 30 dl / g or more, the melt viscosity at a high concentration is extremely high, melt fracture occurs at the time of extrusion, and the melt spinnability is poor, so that a suitable multifilament cannot be obtained. .

The ultra-high molecular weight ethylene polymer is obtained by converting ethylene or ethylene and the above-mentioned conomer with each other.
Slurry polymerization in an organic solvent, for example, in the presence of a catalyst comprising a Vb, VIb, or VIII transition metal compound and a metal hydride or an organic metal of Groups I to III of the Periodic Table, and adjusting the intrinsic viscosity [η] thereof It can be obtained by adjusting to 5 dl / g or more.

The ultra-high molecular weight ethylene polymer thus obtained is melt-extruded, for example, by blending a diluent for enabling melt molding or mixing a normal temperature paraffin wax, and then drawing. As a result, a molecularly oriented molded article such as a fiber or a tape is obtained.

As the diluent, a solvent for the ultrahigh molecular weight ethylene polymer and various wax-like substances having dispersibility in the ultrahigh molecular weight ethylene polymer are used.

The solvent is preferably a solvent having a boiling point not lower than the melting point of the polymer, more preferably not lower than + 20 ° C. As such a solvent, specifically, n-nonane, n-decane, n-undecane, n-dodecane, n-
Tetradecane, n-octadecane or liquid paraffin, aliphatic hydrocarbon solvents such as kerosene, xylene, naphthalene, tetralin, butylbenzene, p-cymene, cyclohexylbenzene, diethylbenzene, benchylbenzene, dodecylbenzene, bicyclohexyl, decalin, methyl Aromatic hydrocarbon solvents such as naphthalene and ethylnaphthalene or hydrogenated derivatives thereof, 1,1,2,2-tetrachloroethane, pentachloroethane, hexachloroethane, 1,2,3-trichloropropane, dichlorobenzene, 1,2 Halogenated hydrocarbon solvents such as 1,4-trichlorobenzene and bromobenzene, and mineral oils such as paraffin-based process oils, naphthene-based process oils, and aromatic-based process oils.

As the wax, an aliphatic hydrocarbon compound or a derivative thereof is used.

The aliphatic hydrocarbon compound mainly comprises a saturated aliphatic hydrocarbon compound and usually has a molecular weight of 2
It is a so-called paraffin wax having a molecular weight of 000 or less, preferably 1000 or less, and more preferably 800 or less. Specific examples of these aliphatic hydrocarbon compounds include n-alkanes having 22 or more carbon atoms, such as docosane, trichosane, tetracosane, and triacontane, or mixtures with lower n-alkanes containing these as main components, and separation and purification from petroleum. -Low-pressure polyethylene wax, high-pressure polyethylene wax, ethylene-copolymer wax or medium-low pressure method, which is a so-called paraffin wax, a low-molecular-weight polymer obtained by copolymerizing ethylene or ethylene and other α-olefins. Waxes obtained by reducing the molecular weight of polyethylene such as polyethylene and high-pressure polyethylene by thermal degradation and the like; oxides of these waxes; oxidized waxes such as maleic acid-modified wax; and maleic acid-modified wax.

As the aliphatic hydrocarbon compound derivative, for example, one or more, preferably one to two, and particularly preferably one, terminal or internal terminal of an aliphatic hydrocarbon group (alkyl group, alkenyl group). A compound having a functional group such as a carboxyl group, a hydroxyl group, a carbamoyl group, an ester group, a mercapto group, a carbonyl group, etc., having 8 or more carbon atoms, preferably 12 to 50 carbon atoms or a molecular weight of 130 to 2000, preferably 200 to 80.
0 fatty acid, aliphatic alcohol, fatty acid amide, fatty acid ester, aliphatic mercaptan, aliphatic aldehyde, aliphatic ketone and the like. Specifically, as a fatty acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, lauryl alcohol, myristyl alcohol as an aliphatic alcohol,
Cetyl alcohol, stearyl alcohol, fatty acid amides such as caprinamide, laurinamide, palmitinamide, stearylamide, and fatty acid esters such as stearyl acetate.

The ratio between the ultrahigh molecular weight ethylene polymer and the diluent varies depending on the type of the polymer, but is generally from 3:97 to 80:20, especially from 15:85 to 60:40. It is better to use in a ratio. When the amount of the diluent is lower than the above range, the melt viscosity becomes too high, so that melt-kneading and melt-molding become difficult, and the surface of the molded product is extremely rough, and the stretch-cut is easily caused. On the other hand, if the amount of the diluent is larger than the above range, it becomes difficult to melt-knead, and the stretchability of the molded product becomes poor.

The melt kneading is generally carried out at 150 to 300.
C., especially 170 to 270.degree. C., and if the temperature is lower than the above range, the melt viscosity is too high to make the melt molding difficult. The molecular weight of the ultra-high molecular weight polyethylene decreases, and it becomes difficult to obtain a molded article having a high elastic modulus and a high strength. The compounding may be performed by dry blending using a Henschel mixer, a V-type blender, or the like, or may be performed by melt mixing using a single-screw or multi-screw extruder.

Melt molding is generally performed by melt extrusion molding.
Will be For example, melt extrusion through a spinneret
With this, a drawing filament can be obtained and
Extrusion through a die or ring die
Is obtained. At this time, the melt extruded from the spinneret
Draft, that is, stretch in the molten state
You can also. Extrusion of molten resin through die orifice
Speed V _O And the winding speed V of the unstretched material solidified by cooling.
The ratio can be defined as a draft ratio by the following equation: Draft ratio = V / V_O Such a draft ratio depends on the temperature of the mixture and the
Varies depending on the molecular weight of the ethylene polymer, etc.
Can be 3 or more, preferably 6 or more.

Next, the unstretched molded article of the ultrahigh molecular weight ethylene polymer thus obtained is stretched. The stretching operation can be performed in one stage or in two or more stages. The stretching ratio depends on the desired molecular orientation and the accompanying effect of improving the melting temperature, but it is generally satisfactory if the stretching operation is performed so that the stretching ratio is 5 to 80 times, particularly 10 to 50 times. You get the results you need. Generally, multi-stage stretching of two or more stages is advantageous.
The stretching operation is performed while extracting the diluent in the extruded product at a relatively low temperature of 0 to 120 ° C., and in the second and subsequent stages, the temperature is 120 to 160 ° C. and higher than the first stage stretching temperature. It is preferable to continue the stretching operation of the molded body at the temperature. The thus obtained molecularly oriented molded article can be subjected to a heat treatment under constrained conditions, if desired. This heat treatment can be carried out at a temperature of generally 140 to 180 ° C., in particular 150 to 175 ° C., for 1 to 20 minutes, in particular 3 to 10 minutes. The heat treatment further promotes the crystallization of the oriented crystal part, resulting in a shift of the crystal melting temperature to a high temperature side, improvement in strength and elastic modulus, and improvement in creep resistance at high temperatures. The stretched molded article thus obtained, such as ultrahigh molecular weight ethylene polymer fiber or tape, has a tensile strength of 1.5 GPa or more and a tensile modulus of 20 GPa or more.

[0024]

According to the present invention, as a bag material,
By using a laminate in which a polyolefin-based or polyester-based nonwoven fabric is laminated on at least one surface of a knitted fabric made of a molecular orientation body of a specific polymer, a bag for sludge treatment with excellent drainage ability and high strength is provided. After draining the sludge, this bag can be used as a solid sandbag for land reclamation and revetment work, and can be used in parallel or outward during land reclamation. If buried in a connected state with a slope so that it becomes lower, even if a large amount of water infiltrates into the earth and sand due to precipitation, the bag as the sandbag functions as a drainage ditch, and the accumulated water inside is effectively used. Since the water is drained to the outside, disasters such as landslides can be prevented beforehand.

[0025]

The present invention will be described below with reference to examples. Example 1 < Polymerization of ultrahigh molecular weight ethylene / butene-1 copolymer > Using a Ziegler-based catalyst and using 1 liter of n-decane as a polymerization solvent, slurry polymerization of ultrahigh molecular weight ethylene / butene-1 copolymer was carried out. Was. A mixed monomer gas having a composition of ethylene and butene-1 in a molar ratio of 97.2: 2.8 was continuously supplied to the reactor so as to maintain a constant pressure of 5 kg / cm ² . The polymerization was completed at a reaction temperature of 70 ° C. for 2 hours. The yield of the resulting ultrahigh molecular weight ethylene / butene-1 copolymer powder was 160 g and the intrinsic viscosity [η] (decalin: 135 ° C) was 8.2 dl.
/ g, butene-1 content as determined by infrared spectrophotometry was 1.5 per 1000 carbon atoms.

< Ultra high molecular weight ethylene / butene-1 copolymerization
Preparation of Stretched Oriented Product > A mixture of 20 parts by weight of the ultrahigh molecular weight ethylene / butene-1 copolymer powder obtained by the above polymerization and 80 parts by weight of paraffin wax (melting point = 69 ° C., molecular weight = 490) is prepared as follows. Under the following conditions. The mixture 100
0.1 part by weight of 3,5-di-tert-butyl-4-hydroxytoluene was added to the parts by weight as a process stabilizer. Next, the mixture was fed to a screw type extruder (screw diameter = 25).
mm, L / D = 25, manufactured by Thermoplastics)
Melt kneading was performed at a set temperature of 190 ° C. Subsequently, the mixed melt was melt-spun from a spinning die having an orifice diameter of 2 mm attached to the extruder. The extruded melt was taken at a draft ratio of 36 times with an air gap of 180 cm, cooled and solidified in air to obtain an undrawn fiber. Further, the undrawn fiber was drawn under the following conditions.

Two-stage stretching was performed using three godet rolls. At this time, the heat medium of the first stretching tank was n-decane, the temperature was 110 ° C., the heating medium of the second stretching tank was triethylene glycol, and the temperature was 145 ° C. The effective lengths of the tanks were each 50 cm. At the time of stretching, the rotation speed of the first godet roll was 0.5 m / min and the rotation speed of the third godet roll was changed to obtain oriented fibers having a desired draw ratio. The rotation speed of the second godet roll was appropriately selected within a range where stable stretching was possible. Almost all of the paraffin wax initially mixed was extracted into n-decane during stretching. Thereafter, the oriented fibers were washed with water, dried at room temperature under reduced pressure for a day and night, and subjected to measurement of various physical properties. The stretching ratio was calculated from the rotation speed ratio between the first godet roll and the third godet roll.

[ Measurement of Tensile Properties ] The elastic modulus and tensile strength were measured at room temperature (23 ° C.) using a DCS-50M tensile tester manufactured by Shimadzu Corporation. At this time, the sample length between the clamps is
100mm, tensile speed 100mm / min (100% / min strain rate)
Met. The elastic modulus was calculated using the tangent slope at the initial elastic modulus. The fiber cross-sectional area required for the calculation was calculated from the weight with the density set to 0.960 g / cc.

< Tensile elastic modulus and strength retention after heat history > The heat history test was performed using a gear oven (perfect oven: perfect oven:
(Manufactured by Tabai Seisakusho).
The sample was folded back on a stainless steel frame having a plurality of pulleys at both ends of a length of about 3 m to fix both ends of the sample. At this time, fix both ends of the sample so that the sample does not sag.
No tension was actively applied to the sample. The tensile properties after the thermal history were measured based on the description of the measurement of the tensile properties described above.

< Measurement of Creep Resistance> The creep resistance was measured using a thermal stress / strain measuring apparatus TMA / SS10 (manufactured by Seiko Instruments Inc.) with a sample length of 1 cm and an ambient temperature of 70.
C., the load was carried out under accelerated conditions with a weight corresponding to 30% of the breaking load at room temperature. The following two values were obtained to quantitatively evaluate the amount of creep. That is, the creep elongation (%) at 90 seconds after applying a load to the sample, the value of CR ₉₀ ,
Average creep speed from the time 90 seconds elapse to the time 180 seconds elapse
(sec ^-1 ) is the value of ε.

Table 1 shows the tensile properties of a multifilament obtained by bundling a plurality of obtained oriented fibers.

The original crystal melting peak of the ultrahigh molecular weight ethylene / butene-1 copolymer drawn filament (sample-1) was 126.7 ° C., and the ratio of Tp to the total crystal melting peak area was 33.8%. The creep resistance is CR ₉₀ = 3.1%,
ε = 3.03 × 10 ⁻⁵ sec ⁻¹ . Further, the elastic modulus retention after heat history at 170 ° C. for 5 minutes is 102.2%, and the strength retention is 10%.
At 2.5%, no decrease in performance due to heat history was observed. The work required to break the drawn filament is 10.3 kgm
/ g, density was 0.973 g / cm ³ , dielectric constant was 2.2, dielectric loss tangent was 0.024%, and impulse voltage breakdown value was 180 kV / mm. The reduction rates of the knot strength and the loop strength of the multifilament with respect to the linear strength were 38% and 36%, respectively. The drawn filament (sample-1) of the ultra-high molecular weight ethylene / butene-1 copolymer thus obtained was prepared using 1000 denier / 100 filament.
R> After preparing a plain weave cloth by the following method,
A polypropylene-based nonwoven fabric was laminated on both sides of the cloth by a needle punch technique. Using the obtained laminate as a material, a cylindrical sludge treatment bag having a depth of 1.5 m and a circumference of 3 m was processed.

(1) Using a weaving ring twisting machine for a core material cloth, the multifilament of Sample-1 having a structure of 1000 denier / 100 filaments was used for 36 filaments.
Twist / m twist was added. Next, a plain-woven cloth having a number of warp yarns of 15 / m and a number of weft yarns of 17 / m was woven with this twisted yarn to obtain a core material cloth of a laminate. Table 2 shows the physical properties of the obtained cloth.

[0034] (2) polypropylene polypropylene non-woven fabric on both sides of the core material cross, which was prepared in accordance with the method described above bonded non-woven fabric (trade name Tufnell PA1031, a basis weight of 150g / m ^2, Mitsui Petrochemical Industries Co., Ltd.) of the needle punching technique To obtain a laminated laminate. Laminating device: FEHRER NL12 / 33 type NR79 Needle punch needle: FOSTER NEEDLE 40HDB Laminating condition: Needle depth 12mm Laminating speed: 6m / min

With respect to the obtained laminate, the tensile strength and the tufnel peel strength of the laminate were measured using a constant-speed elongation type tensile tester. Table 3 shows the results.

(3) Drainage capacity According to JIS A 1218 (Soil permeability test method), the permeation coefficient of the laminate obtained by needle-punching Tafnel PA1031 on both sides of the cloth was determined using the Darcy equation. . As a result, even when a compressive load of 40 + f / m ² is applied, the thickness direction (vertical direction) is 1 × 10 ⁻² cm / sec, and the plane direction (horizontal direction) is 1 × 10 ⁻¹ cm / sec. It was found that the sand had the same or higher water permeability as the natural sand. In addition, both the cloth and the tufnel have high hydrophobicity, do not have affinity with mud particles having a water layer film formed on the surface by the action of static electricity and ions, and do not adsorb the particles. Did not.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a construction state when a sludge treatment bag of the present invention is used as a sandbag.

[Explanation of symbols]

 1 Bag for sludge treatment 2 Sand 3 Sandbag

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI D03D 1/04 D03D 1/04 D06M 17/00 E02B 3/04 301 E02B 3/04 301 8/00 8/00 D06M 17/00 H (56) References JP-A-2-157099 (JP, A) JP-A-4-210203 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C02F 11/00-11 / 20 B01D 29/00-29/48 B01D 39/00-41/04 B32B 1/00-35/00 D01F 6/00-6/60 D02J 1/00-13/00 D03D 1/00-27/18 D06M 17/00 E02B 3/04 E02B 8/00 E02D 17/20

Claims (5)

(57) [Claims] 1. An intrinsic viscosity [η] of at least 5 dl / g.
A bag for sludge treatment, comprising a laminate obtained by laminating a polyolefin-based or polyester-based nonwoven fabric on at least one surface of a knitted fabric made of a molecular orientation molded product of an ultrahigh molecular weight ethylene polymer. 2. The sludge treatment bag according to claim 1, wherein the nonwoven fabric is a polypropylene nonwoven fabric. 3. An ultra-high molecular weight ethylene-based polymer comprising an α-olefin having 3 or more carbon atoms per 1000 carbon atoms on average.
The sludge treatment bag according to claim 1 or 2, wherein the bag is a copolymer of ethylene and an α-olefin containing 0.1 to 20. 4. The method according to claim 3, wherein the α-olefin is one or more selected from the group consisting of butene-1, 4-methylpentene-1, hexene-1 and decene-1. Sludge treatment bag. 5. The content of α-olefin is 1000 carbon atoms.
An average of 0.5 to 10 pieces per piece.
The sludge processing bag according to the above.