CLIAMS:WE CLAIM:
1. An apparatus (100) for manufacturing a fluid storage container (124), the apparatus (100) comprising:
a moulding machine (102), wherein the moulding machine (102) works on a rotational moulding technique, and wherein the moulding machine rotates along two perpendicular axes simultaneously;
a first mould for an inner tank (114) of a fluid storage container (124);
a second mould for an outer shell of the fluid storage container (124);
a raw material (108) for the inner tank (114) and the outer shell of the fluid storage container (124);
a heating means (110) to heat the first mould and the second mould and melt the raw material (108) placed inside the first mould and the second mould;
a cooling means (112) to cool each of the moulds; and
an insulating means, wherein the insulating means is adapted to insulate the inner tank (114) and to fill a gap between the inner tank (114) and the outer shell.
2. The apparatus of claim 1, wherein the first mould and the second mould is a hollow container made up of two or more parts, a lower half and an upper half respectively, used to give shape to hot and molten raw material (108) on cooling and hardening, and wherein each of the moulds is mould mounted on the moulding machine (102) with fixtures.
3. The apparatus of claim 2, wherein the raw material (108) is selected from a group comprising polymers such as a polyethylene, a polycarbonate, a polypropylene and a polyamide and the like.
4. The apparatus of claim 1, wherein the cooling means (112) comprises at least a water spray, a water nozzle or a blower fan to air cool each of the moulds.
5. The apparatus of claim 1, wherein a filament winding technique is adapted to provide re-enforcement and insulation, and wherein the filament winding technique is adapted based upon application for which the fluid storage container (124) is manufactured.
6. A process for manufacturing a fluid storage container (124), the process comprising:
moulding an inner tank (114) of a fluid storage container (124) by
mounting a lower half of a first mould (106) for an inner tank (114) on a moulding machine (102) with fixtures,
adding a raw material (108) to the first mould,
rotating the first mould after enclosing the first mould with an upper half of the first mould, wherein the rotation is accompanied by heating the first mould using a heating means (110),
cooling the first mould using a cooling means (112), and
removing
the inner tank (114) from the first mould, and
the first mold from the molding machine (102);
insulating or reinforcing the inner tank (114) by covering the inner tank (114) from outer surface with an insulating using an insulating means to form an insulated inner tank assembly (118);
moulding the fluid storage container (124) by moulding an outer shell around the insulated inner tank assembly (118) by
mounting
a lower half of a second mould for an outer shell on the molding machine (102) with fixtures, and
the insulated inner tank assembly (118) into the second mould,
adding the raw material (108) to the second mould,
rotating the second mould after enclosing the second mould with the upper half of the second mould, wherein the rotation is accompanied by heating the second mould using the heating means (110),
cooling the second mould using the cooling means (112), and
removing the outer shell from the second mould; and
insulating a gap formed between the inner tank (114) and the outer shell using the insulating means to obtain the fluid storage container (124).
7. The process of claim 5, wherein the fluid storage container (124) comprises of the inner tank (114), the outer shell, the insulating material sandwiched between the inner tank (114) and the outer shell, and a plurality of seamless molded-in nozzles (116) from the inner tank (114) with the inlet nozzles and outlet nozzles protruding from the insulation and the outer shell.
8. The process of claim 5, wherein the inner tank (114) and the outer shell is molded in any shape, color and size. ,TagSPECI:
FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
A PROCESS AND APPARATUS FOR MANUFACTURING A CONTAINER WITHIN ANOTHER CONTAINER

Applicant:
B. D. Industries

A Partnership Firm Registered under The Indian Partnership Act, 1932
Having address:
5, Raj Rajeshwari Road, Opp.
Naval Stores Main Gate, Off LBS Marg,
Narayan Nagar, Ghatkopar (W)
Mumbai - 400 086, Maharashtra, India

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application does not claim priority from any patent application.
TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to a process and apparatus for manufacturing a fluid storage container/tank using a molding machine, more particularly, the present subject matter relates to the process and apparatus by which a double walled, closed and single piece fluid storage container/tank is moulded using a rotational moulding technique.
BACKGROUND
[003] Rotational molding is a method for manufacturing hollow articles such as containers, tanks using a material from polymer family. The particles of said material in the form of liquid, powder or pellets, are provided within a hollow mould and the mould rotates in a heated environment until the material is soften and stick within all the inner surface of the mould. There are several kinds of machines, from the small and simple ones, to the ones with large rotation diameters with sophisticated controlling system. Its selection is made based on certain parameters to consider, as the size of the article, production rate, planned investment etc.
[004] Basically, the moulding process consists of placing the material in finely divided form inside of the hollow mould. The hollow mold is then heated to a temperature above the melting point of the material used for the article and, at the same time, the hollow mould is rotated on two perpendicular axes. The powdered material inside the mould is heated by the heat transfer from the hollow mould surface and sticks to the inner mould surface. Heating is continued for a sufficient length of time for complete melting of all the material particles and to permit bubbles to be released from the semi-molted/softened material. The thickness of the article moulded is determined by the amount of material placed within a given hollow mould.
[005] Although the prior art shows various apparatus and processes utilizing a rotational techniques, however are limited to the rotational moulding of single layer/wall or multi-layer/wall of the container/tank. Such moulded container/tank may pose few in-built problems such as leakage from inlet/outlet adaptors/nozzles etc., which are attached externally/ post-moulding to the container/tank. Furthermore, other problems like corrosion and rusting of any active metal parts etc. Further research in this domain has offered double walled vessel having polymeric inner wall encapsulated with metallic outer wall of the vessel. However, rotational moulding of the double walled vessel is a steep challenge due to easy fire catching nature of the insulating material, and causing changes in the inner rotomoulded part dimensions because of lack of thermal resistance or thermal protection to the inner rotomoulded parts.
[006] Therefore there exist a quality concerns during the rotational moulding process such as insulation proof and leak proof double walled fluid storage container/tank moulding.
SUMMARY
[007] Before the present process(s), composition(s) and product(s), enablement are described, it is to be understood that this disclosure in not limited to the particular processes, compositions, products, apparatus and methodologies described, as there can be multiple possible embodiments of the present disclosure and which are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present disclosure.
[008] The present disclosure discloses an apparatus and a process for manufacturing a fluid storage container/tank using a moulding machine. The apparatus for manufacturing a fluid storage container/tank is disclosed. The apparatus may comprise a moulding machine, wherein the moulding machine works on a rotational moulding technique, and wherein the moulding machine rotates along two perpendicular axes simultaneously. The apparatus may further comprise a first mould for an inner tank of the fluid storage container/tank and a second mold for an outer shell of the fluid storage container/tank. Furthermore, the apparatus may comprise a raw material for the inner tank and the outer shell of the fluid storage container/tank. A heating means to heat the first mould and the second mould and melt the raw material placed inside the first mould and the second mould and a cooling means to cool each of the moulds may also form part of the apparatus. Further the apparatus may comprise an insulating means. Alternatively, the apparatus may comprise a filament winding insulating means to insulate.
[009] A process for manufacturing a fluid storage container/tank is disclosed. The process comprising moulding an inner tank of a fluid storage container/tank by mounting a lower half of a first mold for an inner tank on a molding machine with fixtures. The process may further comprise adding a raw material to the first mould. Furthermore, the process may comprise rotating the first mould after enclosing the first mould with an upper half of the first mould, wherein the rotation is accompanied by heating the first mould using a heating means. After predefined time, the process may comprise cooling the first mould using a cooling means, and removing the inner tank from the first mould and further removing the first mould from the moulding machine. Also, the process may comprise insulating the inner tank by covering the inner tank from outer surface with an insulating material using an insulating means to form an insulated inner tank assembly. Further in the process, the process comprise moulding the fluid storage container/tank by moulding an outer shell around the insulated inner tank assembly by mounting a lower half of a second mould for an outer shell on the moulding machine with fixtures, and the insulated inner tank assembly into the second mould using special insulating holders. The process may further comprise adding the raw material to the second mould. After adding the raw material, the process further comprise rotating the second mold after enclosing the second mould with the upper half of the second mould, wherein the rotation is accompanied by heating the second mould using the heating means. After predetermined time, the process comprise cooling the second mould using the cooling means, and further removing the outer shell from the second mould. In the final step, the process comprise insulating a gap formed between the inner tank and the outer shell using the insulating means to obtain the fluid storage container/tank. Alternatively, the process may comprise a filament winding insulating means to insulate, the inner tank.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The detailed description is described with reference to the accompanying figure. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawing to refer like features and components.
[0011] Figures 1(a) to 1(h) illustrates a step wise process and an apparatus 100 set-up for manufacturing a fluid storage container/tank, in accordance with an embodiment of the present subject matter.
[0012] Figure 2 illustrates the fluid storage container/tank manufactured using the process 100, in accordance with an embodiment of the present subject matter.
[0013] Figure 3 illustrates the process 300 for manufacturing the fluid storage container/tank.
DETAILED DESCRIPTION
[0014] The exemplary embodiments of the present disclosure are described herein in detail, though the present disclosure is not limited to these embodiments. Constituting elements in the embodiments include elements easily achieved by a person skilled in the art, or elements being substantially equivalent to those elements.
[0015] The words “comprising”, “having”, “containing”, and “including”, and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that as used herein, the singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
[0016] Figures 1(a) to 1(h) illustrates an apparatus 100 set-up and step-wise process for manufacturing a fluid storage container/tank, more particularly the process for manufacturing the fluid storage container/tank 124 (hereinafter referred to as “the container 124”) using a moulding machine 102 operating on a rotational moulding technique. The rotational moulding technique involves a heating a mould filled with a charge or a weight of raw material 108. The rotational molding technique further involves slowly rotating, usually around two perpendicular axes, causing the raw material 108 to get soften and melt. Upon achieving softened state, due to rotational moulding the raw material 108 like the polymer powder/granules/pellets from the polymer family, hits the hot mould wall and stick to inner wall of the mould. The process for the rotational moulding may comprise number of parts forming together the apparatus utilized for manufacturing the container 124. The apparatus 100 may comprise the moulding machine 102, wherein the moulding machine 102 may work on the rotational moulding technique. Also, the moulding machine 102 may rotate along two perpendicular axes simultaneously. Further, the moulding machine 102 may operate on any other similar moulding techniques.
[0017] In an embodiment of the present subject matter, the container 124 may further made up of two sub parts like an inner tank and an outer shell. The apparatus 100 may further comprise a first mould for the inner tank 114 of the container 124. Additionally, the first mould may further made up of two halves namely a lower half 104 and an upper half 106. The apparatus 100 may further comprise second mould for the outer shell of the fluid storage container/tank 124. Similarly, the second mould may be made up of two halves namely a lower half 120 and an upper half 122. The process may be further explained in detail using the figure 1(a) to 1(h).
[0018] Now referring to the figure 1(a), which illustrates mounting of the lower half of the first mould 104 on the moulding machine 102 with few fixtures. After mounting the lower half 104, the raw material 108 may be added into the lower half 104. The raw material 108 may be selected from a group comprising the polymer family such as a polyethylene, a polycarbonate, a polypropylene and a polyamide etc. The raw material 108 may be selected according to the requirement of an application for which the container 124 may be put in use. The raw material 108 may be introduced in any form such as granules, powder, crystal or semi-liquid. Upon introducing the raw material 108, the upper half of the first mould 106 may be put back to close the open end of the first mould which is shown in detail in the figure 1(b). After closing the open end of the first mould, the first mould may be heated using a heating means. The heating means may comprise mainly diesel, coal, CNG, LPG etc. based heating means110 as shown in the figure 1(b). In the figure 1(b), arrows show the instance where the first mould is being heated. The heating may go on for a predetermined time period based on the type of raw material used. In an embodiment, the heating may be accompanied by rotation of spindles of the molding machine 102. The rotation and the heating may be carried out parallel to achieve better results of the process. Due to simultaneous rotation and the heating of the first mold may result into evenly thickened inner tank 114.
[0019] Figure 1(c) illustrates cooling of the first mould. To cool the first mould, the rotation of the first mould may be continued. Further, a cooling means 112 may be adapted to either spray cold water or coolant over the outer surface of the rotating first mould or a blower fan may be used to blow cold air over the first mould for a predefined time interval based on the type of raw material 108 used which is shown in the figure 1(c). In next step, the rotation and the cooling means may be terminated and the first mould may be allowed to further cool. As shown in the figure 1(d), the upper half of the first mould 106 may then be removed and a mould formed i.e. inner tank 114 may be taken out from the first mould. The inner tank 114 may be designed to have inlet, outlet, etc. nozzles moulded-in as per design requirement, which is built into the inner tank mould.
[0020] In an aspect of the present subject matter, the process further comprise of moulding the container 124 over the inner tank 114 using the rotational molding technique. To mold the container 124, the process may further comprise encapsulating the inner tank 114 i.e. insulating the inner tank 114 by covering the outer surface of the inner tank 114 with an insulating material. The encapsulating may be performed using the insulating means such as putting a PUF layer over the inner tank or other methods. After putting the insulating material an insulated inner tank assembly 118 may be obtained as depicted in the figure 1(e). The insulating material used to cover the inner tank 114 should have higher burning/ignition point. Higher burning point may assist in flaw less molding of the outer shell without consuming the insulating material.
[0021] Alternatively, in another embodiment, based upon application for which the container is manufactured, for the purpose of insulation of the inner tank 114, the inner tank 114 may be filament wound using a filament winding technique, for winding of carbon fiber, glass fibers, composites, FRP, etc. for two purposes. The first and foremost purpose of the filament winding may be to provide strength to the inner tank by reinforcement of the inner tank. Second purpose may be to protect the inner tank from burning out while moulding the outer shell. The filament winding technique may be adapted as an optional technique to add insulation and strength or rigidity to the inner tank 114, depending upon the application requirements for which the container 124 is being manufactured. Furthermore, in the applications where the filament winding technique may have to be adopted, instead of adapting the nozzles moulded-in 116 as per design requirement, the nozzles may be attached post-moulding of the inner tank 114 by giving necessary arrangement in the inner tank 114 by means of metal inserts, during the rotational moulding. The filament winding may be carried out using filament winding equipment.
[0022] In next step of the process, as shown in the figure 1(f), the insulated inner tank assembly 118 may be introduced in to a lower half of the second mould 120. The raw material may be introduced in to the second mould. After this an open end of the second mould may be closed using an upper half of the second mould 122. After putting the insulated inner tank assembly 118 inside the second mould, this whole thing may be mounted on the moulding machine 102 with few fixtures after removing the first mould from the moulding machine 102. A gap of few millimeters may be kept in between the inner tank and the inner surface of the second mould. The gap may later be filled with the insulating material using the insulating means.
[0023] On similar lines, the process may further comprise heating of the second mould mounted over the moulding machine 102 using the heating means 110. Further, heating may be accompanied by rotation of the second mould for a predetermined time interval based on the type of raw material used. After the predetermined time interval, the heating may be terminated and cooling of the second mould may begin using the cooling means 112.
[0024] According to the process, the cooling may be carried out for the predetermined time interval after which the rotation and the cooling may be terminated and the second mould may be allowed to further cool down. Finally, the process may comprise unloading the mould i.e. container 124 from the second mold. During the rotational moulding of the second mould i.e. outer shell, the insulated inner tank assembly 118 may be protected using a higher quality insulating material having higher burning or ignition point. After moulding the outer shell, a gap between the inner tank and the outer shell may be filled by using insulating means to ensure proper sealing of the container124 in terms of fluid leakage and heat loss in and out from the container 124. The figure 2 illustrates the container124 with protruding molded-in nozzles 116. The molded-in nozzles116 ensures leakage proof sealing of the nozzles for any inlet/ outlet connections made to the inner tank 114.
[0025] Figure 3 illustrates the process 300 through a flow diagram for manufacturing the container 124 using a moulding machine 102 operating on a rotational moulding technique. A step 302 may comprise of mounting a first mold on a molding machine 102 with fixtures, wherein the first mould is for an inner tank114 of the container 124.
[0026] In step 304, a raw material 108 may be added in to the first mould and further the open end of the first mould may be closed using the upper half of the first mould 106.
[0027] In step 306, the first mould may be rotated using the moulding machine 102 accompanied by heating of the first mould using a heating means 110 simultaneously. The simultaneous heating and rotation may ensure flaw-less moulding of the inner tank 114.
[0028] In step 308, after predetermined time interval, the first mould may be cooled by using the cooling means 112 with rotation.
[0029] In step 310, the inner tank 114 after cooling may be taken out from the first mould.
[0030] In step 312, the inner tank may be insulating using an insulating means to obtain an insulated inner tank assembly 118. Alternatively, depending upon the application requirement, the inner tank 118 may be reinforced and insulated by the filament winding technique using a carbon fiber composites, glass fiber, and Fiber-reinforced plastic (FRP) to add extra strength to the inner tank.
[0031] In step 314, the insulated inner tank assembly 114 may then be mounted in to a second mould for an outer shell of the fluid storage vessel/the container 124. Before the step 314, the first mould may be removed from the moulding machine 102.
[0032] In step 316, the raw material may be adding in to the second mould.
[0033] In step 318, the second mould may be rotated accompanied by heating of the second mould using the heating means 110 at the same time.
[0034] In step 320, the second mould may be cooled using the cooling means 112.
[0035] In step 322, the outer shell may be taking out from the second mould. Hence the container 124 may be obtained at step 322 with protruding moulded-in nozzles 116.
[0036] In view of the variety of embodiments of the present disclosure, it will be appreciated that various modifications or changes can be made in the preferred embodiments without departing from the principle of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein. It is to be particularly understood that the former descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.