JP2022015203A - Oil adsorbing sheet for grease trap - Google Patents

Abstract

To provide an oil adsorbing sheet for a grease trap which is excellent in adsorption of grease floating in waste water in a grease trap.SOLUTION: An oil adsorbing sheet for a grease trap contains a polyolefin-based resin fiber, is wholly integrated, and is attached with a gelling agent of grease.SELECTED DRAWING: None

Description

The present invention relates to an oil adsorption sheet, and more specifically, to an oil adsorption sheet for adsorbing oil and fat (grease) contained in drainage in a grease trap (interfering device).

In recent years, with the development of public sewerage, maintenance of sewerage has become an issue. Wastewater from commercial kitchens in restaurants and food processing plants contains a large amount of oil and fat, and if it is discharged as it is, the cooled and solidified oil and fat may adhere to the sewer pipe and cause clogging. There is. Therefore, it is obligatory to install a grease trap to remove oils and fats in commercial kitchens, etc. (Ministry of Construction Notification No. 1597, 1975 (revised in 1982)). A grease trap is a facility that temporarily stores wastewater before it is discharged to a sewer pipe, and then floats and separates the oil and fat in the wastewater using the principle of natural floating due to the difference in specific gravity between water and oil.

If the oil and fat separated in the grease trap is left unremoved on a regular basis, it may overflow from the grease trap and cause clogging of pipes, or it may oxidize and rot and cause a foul odor. Generally, the oil and fat in the grease trap is removed by the employee scooping out the oil and fat with a cassotte or a container once a week on average and every day in many places. In addition, a specialist may clean it with a large suction machine.

Further, as a method for easily removing oils and fats floating on the water surface, a method of adsorbing and removing oils and fats on a non-woven fabric sheet (oil adsorption sheet) made of synthetic fibers such as polyolefin resin fibers or natural fibers is also known and is used for business purposes. In addition to oils and fats contained in wastewater from kitchens and the like, oil adsorption sheets for adsorbing crude oil spilled into seawater due to a marine accident and machine oil used in factories and the like have been proposed (for example, Patent Documents 1 to 3). reference). In particular, the oil adsorption sheet for crude oil that has flowed out into seawater has passed the "Performance Test Standards for Emission Oil Control Materials" (Ministry of Transport, Ship Inspection No. 52, 1984). The oil adsorption performance of the oil adsorption sheet for animal and vegetable fats and oils is about 3 to 5 kg / m ² .
The above-mentioned conventional oil adsorption sheet is considered to simplify the work of removing the oil and fat accumulated in the grease trap and significantly shorten the work time, and it should have a great merit of use, but it is not widely used. It is the actual situation. One of the reasons is that the amount of oil and fat accumulated in the grease trap exceeds the oil adsorption performance of the conventional oil adsorption sheet. Therefore, a proposal has been made to improve the oil adsorption performance of the oil adsorption sheet.

As a method for increasing the oil absorption amount of the oil adsorption sheet, for example, in an oil adsorption sheet containing a polyolefin resin fiber such as polypropylene, the thickness of the sheet may be increased, the raw material fiber may be made smaller in diameter, or the fiber may be increased. It has been proposed to crush a part of the fiber to increase the specific surface area of the fiber (see, for example, Patent Documents 4 and 5).
However, it has been found that the oil adsorption sheet containing the polyolefin-based resin fiber cannot fully exhibit its original oil absorption performance when actually used in a grease trap. The cause is that the oil adsorption sheet also absorbs the water in the wastewater, so that the amount of oil absorbed is reduced.

The oil adsorption sheet containing the polyolefin-based resin fiber has a specific gravity (about 0.9) of the polyolefin-based resin fiber smaller than the specific gravity of water (1.0) and higher than the specific gravity of fats and oils such as rapeseed oil (about 0.8). Because it is large, when it floats on the drainage, it is located between the water content of the drainage (lower water layer) and the oil and fat content (upper oil and fat layer), even though it is in the form of a non-woven fabric or web. Will come into contact with water and the upper surface will come into contact with oils and fats.
The oil adsorption sheet containing the polyolefin resin fiber is hindered from absorbing water due to its water repellency (lipophilicity) even if it comes into contact with ordinary water or seawater. However, when it comes into contact with water containing a surfactant such as dishwashing detergent or kitchen detergent / disinfectant, such as drainage from a commercial kitchen, its water repellency cannot be exhibited and water absorption occurs. The amount of oil absorbed is reduced.
Further, the oil adsorption sheet that has absorbed water gradually increases in its specific gravity and sinks below the surface of the water. The adsorbed oil and fat gradually escapes from the oil adsorption sheet that has sunk below the surface of the water, and the amount of oil absorbed is further reduced.
Patent Document 6 describes a technique for inducing and adsorbing oils and fats on the oil-absorbing material on the upper surface through a hole made in the deodorant-controlling paper in the deodorizing and humidity-controlling paper in which the oil-absorbing material is applied only to the upper surface. There is. However, since the entire deodorant / humidity control paper gradually sinks below the surface of the water, there is room for further improvement in order to exhibit sufficient oil absorption performance.

Japanese Unexamined Patent Publication No. 6-277657 Japanese Unexamined Patent Publication No. 2000-5597 Japanese Unexamined Patent Publication No. 2002-346380. Japanese Unexamined Patent Publication No. 2004-33838 Jikkenhei 3-74694 Gazette Japanese Unexamined Patent Publication No. 2004-308807

Therefore, in order to bring out the original oil absorption performance of the oil adsorption sheet, the oil adsorption sheet stays in the oil and fat content (inside the oil and fat layer in the upper layer) to reduce contact with water (water layer in the lower layer) and the oil adsorption sheet. Is required to prevent water from being absorbed and sinking below the surface of the water (inside the water layer).
As a method of preventing the oil adsorption sheet containing the polyolefin resin fiber from sinking under the water surface, it is considered to attach a float like a general air bag to the oil adsorption sheet. However, it is difficult to stably float (retain) the oil adsorption sheet in the oil and fat due to floating, and a part of the oil adsorption sheet may sink below the water surface or float above the oil and fat, which is efficient. There is room for further improvement in terms of oil absorption.
It is also considered to cover the oil adsorption sheet with a water-repellent bag, but since it is difficult to impregnate the highly viscous oil and fat into the water-repellent bag, the oil absorption amount is still low, and further improvement is desired. ..

Therefore, an object of the present invention is to provide an oil adsorption sheet for a grease trap, which is excellent in adsorbing oils and fats floating in the drainage in the grease trap.

As a result of diligent studies to solve the above-mentioned problems, the present inventor has found that the above-mentioned problems can be solved by adhering a gelling agent for fats and oils to a sheet containing a polyolefin-based resin fiber, and completed the present invention. I came to do.

That is, the present invention is as follows.
[1]
An oil adsorption sheet for a grease trap, which contains polyolefin resin fibers, is integrated as a whole, and has a gelling agent for oils and fats attached.
[2]
The oil adsorption sheet for a grease trap according to [1], wherein the oil / fat gelling agent contains 12-hydroxystearic acid and α-terpineol.

According to the present invention, it is possible to provide an oil adsorption sheet for a grease trap, which is excellent in adsorbing oils and fats floating in the drainage in the grease trap.

It is a side sectional view which shows the schematic structure of a general grease trap.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail, but the present invention is not limited to the following description and varies within the scope of the gist thereof. It can be transformed and implemented.

The grease trap oil adsorption sheet of the present embodiment (hereinafter, also simply referred to as “oil adsorption sheet”) can be applied to any grease trap installed in a commercial kitchen such as a restaurant or a food processing plant. , Oil and fat floating in the drainage in the grease trap can be adsorbed.
First, the basic structure of a general grease trap will be described with reference to the drawings.

FIG. 1 is a side sectional view showing a schematic configuration of a general grease trap. The grease trap 1 has a rectangular parallelepiped tank structure as a whole, and has a partition wall 8 and a partition wall 10 to form a first tank (pretreatment tank) 3, a second tank (oil separation tank) 4, and a third tank (post-treatment tank). It is divided into 3 tanks of 5.
The wastewater A from the commercial kitchen or the like first flows from the inflow pipe 2 into the first tank (pretreatment tank) 3. In the first tank (pretreatment tank) 3, waste B such as leftover food and vegetable waste in the wastewater A is captured by the mesh-like basket 7, and scum (sludge / sediment) C is settled on the bottom due to its own weight. Subsequently, the drainage moves to the second tank (oil separation tank) 4 through the gap at the lower end of the partition wall 8, and moves upward along the partition plate 9.
In the second tank (oil separation tank) 4, the oil and fat in the drainage and the water are separated, and the oil and fat having a specific density smaller than that of water floats on the liquid surface side, so that the oil and fat content D (upper layer) floats on the upper part of the drainage. It separates into oil and fat layer) and water (lower water layer). The drainage that has passed through the partition plate 9 moves downward and moves to the third tank (post-treatment tank) 5 through the gap at the lower end of the partition wall 10.
In the third tank (post-treatment tank) 5, oils and fats, scums and the like that could not be separated up to the second tank (oil separation tank) 4 are further separated. The wastewater treated in this way is discharged from the trap pipe 6 to the sewer or the like as treated water E.
The arrow in FIG. 1 indicates the distribution direction of wastewater.

The amount of oil and fat separated in the second tank (oil separation tank) 4 varies depending on the scale, form, and operating conditions of restaurants and food processing plants, but it prevents overflow, offensive odors, and reduction of trapping efficiency. Therefore, it needs to be removed regularly.
The oil adsorption sheet for a grease trap of the present embodiment can be particularly preferably used for adsorbing the oil / fat component D accumulated in the second tank (oil separation tank) 4. The oil / fat content D can be efficiently and easily removed simply by floating the oil adsorption sheet of the present embodiment on the drainage to adsorb the oil / fat content D, then taking it out and discarding it. The oil adsorption sheet of the present embodiment is not limited to the second tank (oil / water separation tank) 4, but is a liquid tank in which drainage containing fats and oils stays and separates into fats and oils (oil and fat layer) and water (water layer). If so, it can be used in any liquid tank.

<Oil adsorption sheet for grease trap>
The oil adsorption sheet for a grease trap of the present embodiment is characterized in that it contains a polyolefin-based resin fiber, is integrated as a whole, and has a gelling agent for oils and fats attached.

The oil adsorption sheet for a grease trap of the present embodiment can exhibit water repellency by containing a polyolefin-based resin fiber.
Further, since the oil adsorption sheet for the grease trap of the present embodiment is integrated as a whole, it can be easily taken out from the drainage after the oil is adsorbed, and it is easy to dispose of it.

The oil adsorption sheet for the grease trap of the present embodiment has oils and fats floating on the upper part of the drainage due to the gelling agent of the oils and fats attached, and the oils and fats dispersed in the form of emulsified particles and oil droplets. It gels quickly with a gelling agent and can be reliably adsorbed. The oil adsorption sheet that gels and adsorbs fats and oils has a general specific density of fats and oils (about 0.8) and the specific density of the oil adsorption sheet before oil absorption (the specific gravity of the polyolefin resin fiber is about 0.83 to about 0.83). Since the value is between 0.97), it can stably float and stay in the oil and fat content (oil and fat layer) floating on the upper part of the drainage. As a result, contact with water (water layer) containing a surfactant and water absorption are suppressed, and it is possible to prevent subduction under the water surface (inside the water layer) due to water absorption and a decrease in the amount of oil absorption. Can maximize the oil absorption performance of.
In the grease trap oil adsorption sheet of the present embodiment, the portion to which the oil / fat gelling agent is attached is not particularly limited, and even in the form in which the gelling agent is attached (impregnated) to the entire sheet substrate. It may be a form in which it is attached only to a part or the whole of the surface of the sheet base material, or it may be a form in which it is attached only to a part such as between fiber layers of the sheet base material. As described above, the gelling agent for fats and oils is uniformly adhered (impregnated) to the entire sheet from the viewpoint that it can stably float and stay in the fats and oils (fat and oil layer) floating in the wastewater. preferable.

As described above, the specific gravity of the grease trap oil adsorption sheet of the present embodiment is 1.0, from the viewpoint that it can stably float and stay in the oil and fat content (oil and fat layer) floating in the wastewater. It is preferable that it is smaller than and larger than the specific density of 0.8 of general oils and fats.

The shape and size of the oil adsorption sheet for the grease trap of the present embodiment are not particularly limited and may be determined according to the shape and size of the grease trap (particularly, the oil separation tank), but the handling strength and the amount of oil adsorption may be determined. From the viewpoint, the thickness is preferably 0.3 to 20 mm, more preferably 1.0 to 10 mm, and even more preferably 1.5 to 5.0 mm.
Further, the grease trap oil adsorption sheet of the present embodiment may have a layer structure composed of a plurality of layers.

The basis weight of the grease trap oil adsorption sheet of the present embodiment is preferably 50 to 1000 g / m ² , more preferably 100 to 700 g / m ² , and further preferably 200 to 400 g / m ² . preferable. When the basis weight of the oil adsorption sheet is within the above range, it is easy to float on the drainage, and the waste oil accumulated in the grease trap can be efficiently adsorbed and removed.

In the grease trap oil adsorption sheet of the present embodiment, the oil absorption amount 5 minutes after the start of oil absorption is preferably 0.45 to 10.0 g per 1 g of the mass of the oil adsorption sheet before oil absorption, preferably 0.60 to 0.60 to. It is preferably 6.0 g, more preferably 0.70 to 3.0 g. When the amount of oil absorbed 5 minutes after the start of oil absorption is within the above range, the oil adsorption sheet stably stays in the oil and fat (oil and fat layer) floating above the drainage, and the moisture (water layer) containing the surfactant is present. Contact and water absorption are sufficiently suppressed, and oil absorption performance can be sufficiently exhibited.
The amount of oil absorbed 5 minutes after the start of oil absorption can be measured by the method described in Examples described later.

<< Polyolefin-based resin fiber >>
The polyolefin-based resin fiber contained in the oil-adsorbing sheet for a grease trap of the present embodiment is not particularly limited, and examples thereof include fibers such as polyethylene resin, polypropylene resin, ethylene-based copolymer, and propylene-based polymer. .. Further, the fiber may be a fiber having a core-sheath structure. Among them, the fiber having a core-sheath structure having a polypropylene resin as a core and a polyethylene resin as a sheath can be easily heat-bonded between the fibers by a thermal bond method or the like. , Can be preferably used.
The above-mentioned polyolefin resin fiber may be used alone or in combination of two or more. For example, a fiber such as a polyethylene resin, a polypropylene resin, an ethylene-based copolymer, or a propylene-based polymer may be used in combination with a fiber having a core-sheath structure having a polypropylene resin as a core and a polyethylene resin as a sheath.

The average fiber diameter of the polyolefin resin fiber is preferably 1 to 20 dtex, more preferably 4 to 15 dtex, and further preferably 5 to 10 dtexm from the viewpoint of oil absorption performance, fiber strength, and cost.

The polyolefin-based resin fiber is preferably processed into a sheet shape (plate shape), and may be in any form such as a non-woven fabric, a web, a woven fabric, a knitted fabric, and a unidirectional array sheet. Of these, non-woven fabrics and webs are preferable because oils and fats easily enter the gaps between the fibers. Further, different forms such as a laminated non-woven fabric and a web may be laminated.

The basis weight of the sheet of the polyolefin resin fiber is preferably 50 to 1000 g / m ² , more preferably 100 to 700 g / m ² , and even more preferably 200 to 400 g / m ² . When the basis weight of the polyolefin-based resin fiber sheet is within the above range, it is easy to float on the drainage, and the waste oil accumulated in the grease trap can be efficiently adsorbed and removed.

The content of the polyolefin resin fiber is 100% by mass based on the mass of the sheet base material constituting the oil adsorption sheet (mass obtained by subtracting the mass of the oil gelling agent from the mass of the oil adsorption sheet) from the viewpoint of enhancing water repellency. It is preferably 90 to 100% by mass, more preferably 95 to 100% by mass, and even more preferably 100% by mass.

<< Gelling agent for fats and oils >>
The oil / fat gelling agent contained in the grease trap oil adsorption sheet of the present embodiment has a temperature of about 40 ° C. from the viewpoint that the oil / fat floating in the wastewater (usually about 40 ° C.) can be gelled without heating. It is preferable that the oil and fat can be quickly melted and gelled.
The gelling agent capable of gelling fats and oils at about 40 ° C. is not particularly limited as long as it can adhere to a sheet substrate containing a polyolefin resin fiber, and may be a liquid or a solid (powder). However, from the viewpoint that it can be easily adhered to the sheet substrate by impregnation, coating, or the like, a liquid at room temperature is preferable. Examples of the method for adhering a solid (powder) gelling agent at room temperature include a method of applying by heating and melting at about 40 ° C., a method of sandwiching between fiber layers of a sheet, and the like.

The gelling agent that is liquid at room temperature is not particularly limited, and for example, an oily gelling agent described in JP-A-2012-77113 (hydroxy fatty acid having 16 to 30 carbon atoms such as 12-hydroxystearic acid). , Himashi hydrogenated oil, etc.) dissolved in a terpene-based solvent (α-terpineol, dihydroterpineol, etc.) and the like.
Of these, those obtained by dissolving 12-hydroxystearic acid in α-terpineol at a mass ratio of 10:90 to 25:75 are preferable. Since α-terpineol has an aromatic odor, it also has the effect of masking the bad odor of the grease trap and making cleaning more comfortable.

The gelling agent which is solid (powder) at room temperature is not particularly limited, and for example, resin acids and / or rosins described in International Publication No. 2006/051653 and alkaline earth metal salts. Examples thereof include a mixture of.

The content of the gelling agent is preferably 0.5 to 200% by mass, more preferably 2 to 100% by mass, still more preferably 20 to 50% by mass, with the mass of the oil adsorption sheet as 100% by mass. be. When the content of the gelling agent is within the above range, the oil and fat can be quickly gelled before the water absorption progresses, so that the oil adsorption sheet stays stably in the oil and fat content (oil and fat layer) floating in the upper part of the drainage. There is a tendency.

<< Other ingredients >>
The oil adsorption sheet for a grease trap of the present embodiment includes various flame retardants, heat stabilizers, antioxidants, antistatic agents, pigments, fragrances, water repellents, waterproofing agents, etc., as long as the object of the present invention is not impaired. Additives, synthetic fibers other than the above-mentioned polyolefin resin fibers, natural fibers and the like can be contained as required.
The content of various additives is preferably 10% by mass or less, with the mass of the oil adsorption sheet being 100% by mass.

Hereinafter, the present embodiment will be described with reference to specific examples and comparative examples, but the present embodiment is not limited thereto.

The raw materials used in Examples and Comparative Examples will be described below.
(1) Polypropylene sheet Polypropylene cotton (fiber diameter 7.8 dtex, fiber length 64 mm) was hung on a carding device to prepare a uniform web having a basis weight of 190 g / m ² . The obtained web was laminated on a polypropylene non-woven fabric (with a grain of 30 g / m ² ) by a needle punching method, and wound up. The wound sheet was cut to prepare a polypropylene sheet (10 cm × 10 cm × thickness 2.7 mm, basis weight 220 g / m ² , polypropylene fiber specific density 0.90).
(2) Gelling agent for fats and oils 2 g of 12-hydroxystearic acid and 8 g of α-terpineol were mixed and dissolved in a water bath at about 80 ° C. The mixture was allowed to cool to room temperature (about 25 ° C.) to obtain a liquid gelling agent (about 10 g, specific density about 1.0).

The measurement method and evaluation method used in Examples and Comparative Examples will be described below.
(1) Measurement of oil absorption In a 145 mm x 145 mm x 63 mm square plastic container, a 0.05% aqueous solution (surfactant) of dishwashing detergent (Frosch (registered trademark) dishwashing detergent perfume-free, manufactured by Asahi Kasei Home Products Co., Ltd.) 250 mL of activator concentration (about 0.005%) was added, and 4 mL of rapeseed oil (manufactured by Bosso Oil & Fat Co., Ltd.) was injected onto the upper surface thereof with a syringe. The mixture was vigorously stirred about 50 times with a stirring rod to create a state similar to that of the oil separation tank in the grease trap. Immediately after stirring, the oil adsorption sheets obtained in Examples and Comparative Examples were floated and allowed to stand for 5 minutes. Next, the oil adsorption sheet was taken out with tweezers and left on a mesh-shaped wire mesh (17 mm mesh, wire diameter 1 mm) for 5 minutes to remove the oil water dripping under its own weight. Then, the oil adsorption sheet was dried overnight in a constant temperature bath at 60 ° C. to evaporate the water. The mass of the oil adsorption sheet (the total mass of the adsorbed rapeseed oil and the oil adsorption sheet before oil absorption) is measured, and the oil absorption amount (the mass of the adsorbed rapeseed oil (g) / the mass of the oil adsorption sheet before oil absorption (g)) is measured. I asked. The oil absorption amount was taken as the average value of the values measured for each of the three oil adsorption sheets. Further, the ratio of the oil absorption of the other examples and the comparative examples when the oil absorption amount of Comparative Example 1 (mass of adsorbed rapeseed oil (g) / mass of oil adsorption sheet before oil absorption (g)) is 100% ( %) Was asked.

[Comparative Example 1]
One polypropylene sheet was used as it was as an oil adsorption sheet without being impregnated with an oil gelling agent.
The measurement results are shown in Table 1.

[Example 1]
An oil adsorption sheet impregnated with a 1 mL / 100 cm ² oil gelling agent was prepared by dropping 1 mL of an oil gelling agent onto the entire polypropylene sheet with a dropper and leaving it to stand for 30 minutes or longer.
The measurement results are shown in Table 1.

[Examples 2 to 4]
An oil adsorption sheet impregnated with the oil gelling agent was prepared in the same manner as in Example 1 except that the amount of the oil gelling agent shown in Table 1 was added dropwise.
The measurement results are shown in Table 1.

[Comparative Example 2]
An oil adsorption sheet impregnated with α-terpineol was produced in the same manner as in Example 1 except that α-terpineol (specific gravity: about 0.93) was used instead of the oil gelling agent.
The measurement results are shown in Table 1.

Since the oil adsorption sheet for a grease trap of the present invention is excellent in absorbing oil and fat floating in wastewater, it is suitably used in a grease trap that separates and removes oil and fat from wastewater from commercial kitchens such as restaurants and food processing plants. be able to.

1: Grease trap 2: Inflow pipe 3: First tank (pretreatment tank)
4: Second tank (oil separation tank)
5: Third tank (post-treatment tank)
6: Trap pipe 7: Basket 8, 10: Bulkhead 9: Partition plate A: Drainage B: Garbage C: Scum (sludge / sediment)
D: Oil and fat E: Treated water

Claims (2)

An oil adsorption sheet for a grease trap, which contains polyolefin resin fibers, is integrated as a whole, and has a gelling agent for oils and fats attached. The oil adsorption sheet for a grease trap according to claim 1, wherein the oil / fat gelling agent contains 12-hydroxystearic acid and α-terpineol.

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