FORM 2
THE PATENTS ACT 1970
(39 of 1970)
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
1. TITLE OF THE INVENTION : FUMIGATION COVER
2. APPLICANT(S)
(a) NAME : EXCEL CROP CARE LIMITED
(b) NATIONALITY: AN INDIAN COMPANY
(c) ADDRESS: 184-87 S.V. ROAD, JOGESHWARI (WEST),
MUMBAI 400 102, MAHARASHTRA, INDIA.
3. PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION
This invention relates to a fumigation cover which is flexible, gas-tight, easy to handle, durable and protective to the person carrying out fumigation.
BACKGROUND AND PRIOR ART
Fumigation is a method of pest control in which an area is completely filled with gaseous pesticide to suffocate or poison the pests within it. Fumigants act at all stages of lifecycle of insects. They diffuse through spaces between grains and grain kernels as well as into the kernels themselves. Thus fumigants can penetrate into places where insecticide sprays or dust cannot reach.
There are three commercially used fumigants, viz. phosphine, chloropicrin, and methyl bromide. Among these, phosphine-producing materials have become the predominant fumigants used for the treatment of bulk-stored grain throughout the world.
Phosphine generating formulations contain metal phosphides such as aluminium phosphide, magnesium phosphide etc. When exposed to moisture, these metal phosphides react to form phosphine gas which is released into the atmosphere.
Fumigants are toxic to insects and warm blooded animals as well as humans.
The pest control process will be effective if fumigation area is enclosed with a suitable means.
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For effective fumigation, it is necessary to hold an adequate concentration of the fumigant for sufficient time necessary to kill the target pest in the area to be fumigated. Type of structures used for fumigation, their material of construction and gas-tightness influence the amount of fumigant to be used and its effectiveness.
Wooden structures are not effective in retaining fumigants. Steel or concrete structures are neither flexible nor easy to transport. They permanently occupy huge space even during non-use period.
Setting up a fumigation chamber is expensive. Moreover, moving commodities to and from the chamber is difficult.
In vacuum fumigation, air in the chamber is removed before the fumigant is introduced. Hence it is necessary to have a specially constructed chamber which is capable of sustaining vacuum. It involves pumps, valves, and pipes for introducing and exhausting the fumigant and thus it is not simple. Moreover, phosphine generating fumigants such as phosphides of aluminium, magnesium, zinc etc. cannot be used in vacuum fumigation method because phosphine is explosive under these conditions. The cost of vacuum fumigation is also higher and limited types of commodities can be treated by this method.
Known methods of fumigating produce involve covering the pallets of produce with a polyethylene or plastic impregnated tarpaulin and then introducing a gas under the tarp. Since it is necessary for the gas to circulate freely on all sides and the top of the pallets, the tarp cannot lay flat on the top of the pallets. One method to overcome this problem is to erect wood frames on the top of the pallets. In addition, there are many steps in the operation of this type of device.
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improvements to the conventional method of fumigating produce include permanently suspending the tarpaulin from an overhead frame and lowering the frame over the pallets as needed. The frame may be raised and lowered by a system of cables and pulleys.
Several types of large mechanized fumigation tents have been described in the prior art. US 6,776,178 discloses a mechanized fumigation tent having a plural clew system with composite closing structure. It further comprises a support frame having a top, a tarp mounted atop said frame, side curtains having a lower periphery, two sets of cables to raise and lower the curtains and frame, sealing component selected from the group consisting of flexible hosing, flexible synthetic foam, flexible rubber and rubber foam.
US 6,450,188 also describes a fumigation tent which includes a frame suspended from a structure by support cables a sealing arrangement and a means for raising and lowering curtains.
US 6,422,253 describes a mechanized tent with a tarp adapted to be mounted to the underside of the frame.
Abovementioned methods of fumigation are not suitable to meet the requirements of all farmers including small farmers. Moreover, the inventions of the prior art do not teach optimum requirements of the dosage of specific fumigants to be used for a given type of enclosures. Arrangement of containers such as gunny bags in a fumigation enclosure is also an important criteria which determines the effectiveness of fumigation, which is not discussed in the prior art.
The present invention provides a fumigation cover which is durable, gas-tight, flexible, easy to handle and effective to serve the purpose of all, including small farmers. The invention also relates to a method of
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fumigation in which optimum parameters have been established in such a way so as to achieve effective fumigation at a minimum cost.
OBJECTS OF INVENTION
The main object of present invention is to provide a fumigation cover suitable for use to all including small farmers, or those concerned with storage and preservation of grains.
Another object of the invention is to provide a fumigation cover which is durable, flexible, gas-tight, easy to handle and not occupying large space during the period of non-use.
Another object of invention is to protect non-target living beings from exposure to harmful fumigants.
Another object of invention is to minimize the amount of fumigant to be used for a given quantity of grains and thereby reduce the cost of fumigation and decrease the environmental load.
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 is the schematic diagram of the fumigation cover Fig. 2 shows the arrangement of gunny bags
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to a fumigation cover and the method of using the same. This cover is designed in such a way that farm level safe fumigation can be done effectively when carried out as described hereunder.
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The fumigation cover may be made up of commonly available materials such as polymer film selected from the group consisting of polypropylene, low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), or blends thereof etc. The film may also contain an additive like fatty acid amines, amides or esters to reduce fumigant gas-permeability through the film. These examples are only illustrative but not limitative. Any material with properties described hereinabove can be used to construct the fumigation cover of this invention. Multilayered cross laminated (MLCL) sheets as described in Indian Standard IS 14611 : 1998 can be preferably used to construct the article of the invention.
The fumigation cover of this invention as per the preferred embodiment consists of three main components as shown in the Fig. 1.
1. A first sheet (1) of about 5'-8' x 10'-13' size which may be of rectangular shape. Each longer side of the said first sheet is joined with two sides of a second sheet (2) of about 8'-9' base and a side length of 5'-7' each or height of 2.5'-4.5', said second sheet may be of a triangular shape, to form a tent like structure. The length of the longer side of the said first sheet is preferably double of the side-length of the said second sheet.
In place of the triangular sheet, a sheet of any other shape can also be used in such a way that its side-length is preferably half of the longer side of the said rectangular sheet. Shape of the sheets is not a limiting factor of this invention, the criteria is the ability to effectively cover gunny bags when they are arranged as described hereunder. A cover of this dimension may also be made as one-piece.
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2. Another sheet, hereinafter referred to as the third sheet (3), of 7'-8' x 9'-10' size, which may be of rectangular shape is used on which the gunny bags are arranged in a particular manner as described hereunder. Here also, the shape of the sheet is not a limiting factor.
3. A 10-12cm dia preferably cylindrical container (4) made up of material such as MLCL(multilayered cross-laminated sheets), used away gunny bags etc., partially filled with a heavy material like sand, is placed at the bottom of the cover along the periphery thereof, preferably leaving some margin from the edge. This arrangement makes the system air-tight to the extent sufficient to serve the purpose of the invention. The length of the said cylindrical container is long enough to extend it across the periphery of the main cover.
Arrangement of gunny bags on the sheet:
Gunny bags are arranged on the sheet in four layers as shown in Fig. 2. 1st Layer consists of 2 rows of 4 gunny bags each. 2nd Layer consists of 2 rows of 3 gunny bags each. 3rd Layer consists of 2 rows of 2 gunny bags each and 4th Layer consists of 2 rows of 1 gunny bag each.
After arranging gunny bags on the rectangular sheet, they are covered with the component of fumigation cover as described in 1 above. A pouch containing metal phosphide (preferably l0 gm aluminium phosphide) is placed between the gunny bags while covering them as mentioned above. The cylindrical container as described in 3 above is then placed to get desirable air-tightness. It is kept for about 5-7 days. Phosphine gas liberates from phosphide, which kills pests. After 5-7 days, the cylindrical container which is used to seal the system is removed and the fumigation cover is kept partially open for a day or two to allow the phosphine gas to escape. Use may be made of any device such as a fan to accelerate aeration.
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The fumigation cover with abovementioned specifications is effective for fumigation of around 1 Ton of grain preferably using 20 gunny bags of about 50 Kg each, by fumigating with phosphine gas generated from about 8-12 gm aluminium phosphide.
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WE CLAIM:
1. A fumigation cover comprising a main component consisting of a first sheet of 5'-!' x 10'-13' size, each longer side of the said first sheet joined with sides of a second sheet of 7'-9' base and 2.5'-4.5' height; and optionally a third base-sheet of 6'-10' x 7'-10' size which is separate or attached with side(s) of any other sheet(s) to form a tent-like structure.
2. A fumigation cover as claimed in claim 1, wherein a container of 10-15cm dia filled with a heavy material like sand, is placed at the bottom of the cover along the periphery thereof, preferably leaving some margin from the edge of the cover, the length of the said container is long enough to extend across the periphery of the main cover.
3. A fumigation cover which effectively encloses the space occupied by 20 gunny bags of 40-60 Kg each, more preferably 50 Kg each, when arranged in four layers, 1st layer consisting of 2 rows of 4 gunny bags each, 2nd layer consisting of 2 rows of 3 gunny bags each, 3rd layer consisting of 2 rows of 2 gunny bags each and 4th layer consisting of 2 rows of 1 gunny bag each.
4. A fumigation cover as claimed in any of the claims 1-3, wherein the fumigation is carried out with phosphine.
5. A fumigation cover as claimed in any of the claims 1-4, wherein the
fumigation is carried out with phosphine generated by 8-12 gm of
aluminium phosphide.

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EXCEL CROP CARE LTD.
ABSTRACT
This invention relates to a fumigation cover suitable for fumigation of one ton of grain with phosphine gas generated from 8-12 gm of aluminium phosphide. The said cover is flexible, gas-tight, inexpensive, durable and does not occupy huge space while not in use. It minimizes the quantity of fumigant to be used.
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