DESC:FIELD OF INVENTION
The present invention relates to an engineered plastic composition, a process for preparation of the engineered plastic composition, a process for manufacturing of a reverse osmosis (RO) membrane housing (4) from the engineered plastic composition and a RO membrane housing (4).

BACKGROUND OF INVENTION
Reverse osmosis (RO) housing is a reverse osmosis filtration system widely utilized for water purification in residential, commercial, pharmaceutical or industrial applications. Presently, the housings of the said RO membrane are mostly designed with fibre reinforced plastic (FRP) or stainless steel (SS) to withstand high pressure requirement. However, the SS housing has problem of corrosion with continuous use, which can potentially cause metals to leach into the water, resulting in contamination of the treated/purified water. The FRP housings are non-corrosive, but these FRP housings are not eco-friendly as they are not recyclable. Moreover, the conventional FRP housings typically features SS inserts in the circlip slots. Over time, these inserts may be prone to corrosion, which can result in metal leaching into the treated water, potentially contaminating it and compromising water quality.
Therefore, there is a strong need of an environment friendly and non-corrosive components / products for day-to-day use, which can overcome at least one of the aforementioned problems and provide solution for a corrosion free, contamination free, and environment friendly RO housing. This remains the object of the present invention.

SUMMARY OF THE INVENTION
In an aspect, the present invention provides an engineered plastic composition comprising resin in a range from 85% wt. to 95% wt., titanium dioxide in a range from 0.1% wt. to 2.5% wt., titanate in a range from 0.2% wt. to 0.45% wt., impact modifier in a range from 0.1% wt. to 2.5% wt., and auxiliaries in a range from 4.9% wt. to 10.6% wt.
In an aspect, the present invention provides a process for preparation of engineered plastic composition comprising:
(i) Heating a mixture comprising resin in a range from 85% wt. to 95% wt., titanium dioxide in a range from 0.1% wt. to 2.5% wt., impact modifier in a range from 0.1% wt. to 2.5% wt., and auxiliaries in a range from 4.9% wt. to 10.6% wt.; and
(ii) Adding titanate in a range from 0.2 % wt. to 0.45 % wt.
In another aspect, the present invention provides a process for manufacturing of a reverse osmosis (RO) membrane housing (4) from the engineered plastic composition comprising the steps of:
(i) melting the engineered plastic composition at a temperature in a range from 200? to 250?,
(ii) extruding the melted engineered plastic of step (i) to obtain a continuous cylindrical melt, subjecting the melt to a pressure calibration process, and
(iii) cooling the melt of step (ii) to obtain a pipe.
In yet another aspect, the present invention relates to an RO membrane housing (4) comprising:
(i) a bell-shaped end (5);
(ii) a moulded end cap (2) and
(iii) a circlip groove (3).

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The detailed description is described with reference to the accompanying figures.
FIG. 1 illustrates an exploded view of a reverse osmosis membrane housing, according to an embodiment of the present invention.

DETAIL DESCRIPTION OF INVENTION
Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts. Wherever possible, corresponding, or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts.
Where the term “comprising” is used in the present description and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun, e.g. “a” “an” or “the”, this includes a plural of that noun unless something otherwise is specifically stated.
The invention is described below in detail with reference to accompanying drawings to make the purposes, technical solutions and advantages of invention understood more clearly with help of the specific embodiment of the invention.
The present invention provides an engineered plastic composition, a process for preparation of the engineered plastic composition, a process for manufacturing of a reverse osmosis (RO) membrane housing (4) from the engineered plastic composition and a RO membrane housing (4).
The engineered plastic is a modified version of synthetic polymer of plastic. The said modified synthetic polymer is obtained from modification of standard ingredients. The composition of the engineered plastic comprises a resin, a titanium dioxide, a titanate, an impact modifier, and auxiliaries.
More particularly, the engineered plastic composition according to the present invention comprises resin in a range from 85% wt. to 95% wt., titanium dioxide in a range from 0.1% wt. to 2.5 % wt., titanate in a range from 0.2% wt. to 0.45% wt., impact modifier in a range from 0.1% wt. to 2.5% wt., and auxiliaries in a range from 4.9% wt. to 10.6% wt.
The resin is a synthetic resin. Preferably, the resin is selected from polyvinyl chloride such as k-6701, k-6702, k-6711.
The titanate is selected from stearyl titanate and isostearyl titanate. Preferably the titanate is isostearyl titanate. The titanate in the composition acts as a coupling agent or a binder having particle size in a range from 25 microns to 75 microns. The titanate in this specific range of 0.2% wt. to 0.45% wt. gives a smooth mirror finish and desired impact strength to the RO housing manufactured therefrom and further as described below. The titanate if added in excess beyond 0.45% wt. will lead to improper adhesion and hence loss of impact strength, making it unsuitable for manufacturing of RO membrane housing.
The impact modifier is selected from methacrylate butadiene styrene (MBS) terpolymer, acrylate polymethacrylate copolymer (acrylic), chlorinated polyethylene (CPE), ethylene vinyl acetate copolymer (EVA), acrylonitrile butadiene styrene (ABS) terpolymer and its mixture thereof.
The auxiliaries are selected from 1.2% wt. to 1.5% wt. of master batch, 0.2% wt. to 0.5% wt. of wax, 5% wt. to 6% wt. of calcium, 0.2% wt. to 0.7% wt. of stearic acid, and its mixture thereof. The master batch is a mixture of pigments, or a coloring pigment that is commercially available, which imparts a specific color tone to the RO membrane housing. Preferably, the master batch is an inorganic based pigment. The wax is paraffin wax.
In an aspect, the present invention provides a process for preparation of engineered plastic composition comprising:
(i) Heating a mixture comprising resin in a range from 85% wt. to 95% wt., titanium dioxide in a range from 0.1% wt. to 2.5% wt., impact modifier in a range from 0.1% wt. to 2.5% wt., and auxiliaries in a range from 4.9% wt. to 10.6% wt., and
(ii) Adding titanate in a range from 0.2 % wt. to 0.45 % wt.
The mixture of step (i) is heated at a temperature in a range from 90? to 95 ? for 25 mins to 35 mins.
In another aspect, the present invention provides a process for manufacturing of a reverse osmosis (RO) membrane housing (4) from the engineered plastic composition comprising the steps of:
(i) melting the engineered plastic composition at a temperature in a range from 200? to 260?,
(ii) extruding the melted engineered plastic of step (i) to obtain a continuous cylindrical melt, subjecting the melt to a pressure calibration process, and
(iii) cooling the melt of step (ii) to obtain a pipe.
In step (i), the melting is performed in a barrel of a screw extruder having inner diameter of 116 mm and/or 225 mm. The engineered plastic composition is fed at a feed rate in a range from 250 kg/hr to 400kg/hr into the barrel through a hopper of the screw extruder. The engineered plastic composition fed, is in a powder form, having particle size in a range from 300 microns to 500 microns.
In step (ii), the extrusion is carried out with a 116 mm and/or 225mm annular die. The size of the annular die defines the outer diameter of the cylindrical melt. The pressure calibration process is carried out by supplying air at a pressure in a range from 4000PSI to 6000 PSI. In an exemplary embodiment, the pressure calibration process is carried out in a calibration tank. The cooling is performed at a temperature in a range from 5? to 10? to obtain a pipe having outer diameter of 116 mm and/or 225mm.
Further, the process comprises cutting and bell-molding the pipes. The cutting is carried out to obtain pipes having length in a range from 1115mm to 3294 mm. The bell-molding is carried out at both the ends of the pipes by the processes known in the art. Preferably, the bell-molding is done using specially designed socketing mandrel. The dimension of the mandrel is determined by the outer diameter of the pipe. Accordingly, for the pipe having an outer diameter of 116 mm, the bell molding is carried out with a mandrel having dimensions of 104.4mm (diameter) X 50 mm (length). Similarly, for a pipe with 225 mm outer diameter, mandrel having dimensions of 204.4mm (diameter) X 65 mm to 68mm (length) is employed.
The process of the present invention for manufacturing of RO membrane housing (4) is relatively simple, cost-effective and scalable. This is attributed to the engineered plastic composition of the present invention employed for the manufacturing, which is relatively simple to process, does not require complex or expensive process conditions/steps/equipment as compared to conventionally available methods for preparation of fiber reinforced plastic (FRP) and stainless steel (SS) housings.
The RO membrane housing (4) manufactured has a smooth finish without any scratches. This is attributed to the presence of titanate in the engineered plastic composition which gives a mirror finish, scratch free finish to the manufactured RO membrane housing. This finish eliminates surface defects, reduces the risk of failures and enhances the product performance both during the manufacturing of the RO membrane housing and throughout its operational life, since the presence of scratch can lead to development of cracks in the RO membrane housing when subjected to pressure, thus compromising its product performance as well as its long-term operational ability.
The RO membrane housing (4) has a relatively good impact strength (>800j/m2) when subjected to drop test, hammer test and cyclic test as compared to conventional FRP housing, which is rigid and hard with no elasticity. Further, the RO membrane housing of the present invention can sustain a pressure in a range from 300 PSI to 330 PSI and can also sustain the water hammering which occurs during pump start and stop. The RO membrane housing of the present invention remains stable up to a period of 60 months to 72 months without any cracks, leakage, corrosion or defects thus, highlighting its long-term operational efficiency and storage.
The RO membrane housing (4) manufactured is anti-corrosive as, the engineered plastic composition employed for manufacturing of the RO housing, is devoid of any corrosive materials and thereby leading to its potential long-term storage and utility, as compared to conventionally available stainless-steel (SS) housing.
Further, the RO membrane housing (4) manufactured in accordance with the present invention is easily recyclable, thus contributing to green technologies as compared to conventionally available fiber reinforced plastic (FRP) housing which must be disposed-off to landfill after use.
In an aspect, the present invention also provides a RO membrane housing (4) manufactured from the engineered plastic composition and as per the process of the present invention as depicted in Figure 1. Figure 1 shows different components of a RO housing (4) membrane. The housing (4) defines a hollow cylindrical shape. The housing (4) includes two ends (5) opposite to each other which are customized bell ends. The bell ends (5) are generated by bell-molding process, with the help of a socketing mandrel as described in examples.
The housing (4) also includes two moulded end caps (2) to facilitate the feed, reject, and permeate pipe connection. The end caps (2) are circular in shape which can be inserted into the ends (5) of the housing. To secure the end caps (2) at a desired location a suitable circlip groove (3) is developed after the bell molding operation. This end cap circlip groove (3) is generated using a Computerized Numerical Control (CNC) machine which is programmed according to the dimensions of the RO membrane housing, in which thereafter the circlip (1) is inserted.
In an embodiment, the dimensions of the RO membrane housing comprise length in a range from 1115mm to 3294 mm, outer diameter of 116 mm and/or 225 mm, internal diameter of 102.1 mm and/or 202.1 mm and groove to groove diameter in a range from 1054 mm to 3185 mm. The groove to groove diameter refers to the distance between the edges of two opposite grooves or ends (5) inside the membrane housing, where the end caps (2) shall be inserted and locked.

The engineered plastic composition, its process for preparation and the reverse osmosis membrane manufactured therefrom is described below by non-limiting examples

EXAMPLES

Example 1: Process for preparation of engineered plastic composition
The engineered plastic composition of the present invention was prepared by heating a mixture comprising 87.3% k-6701 resin, 0.4% of titanium dioxide, 1.5% chlorinated polyethylene and 7.6% of auxiliaries, wherein the auxiliaries comprised of 6% calcium, 0.2% stearic acid, 0.2% paraffin wax and 1.2% commercially available inorganic based master batch in a reactor tank at a temperature of 90? for 25 mins followed by addition of 0.2% isostearyl titanate. The mixture is thereafter allowed to cool at room temperature to obtain the engineered plastic composition.
Example 2:
Process for manufacturing of RO membrane housing (4) from engineered plastic composition of Example 1
The composition as prepared in Example 1 was employed in the manufacturing of the RO membrane housing. The engineered plastic composition having particle size of 150 microns was fed at a feed rate of 300 kg/hr into the barrel of the screw extruder through a hopper. Within the barrel, the engineered plastic composition was melted at a temperature of 230 ? and thereafter extruded through an annular die of 116 mm and/or 225mm to obtain a continuous cylindrical melt. The obtained cylindrical melt was subjected to a pressure calibration process in a calibration tank by supplying air at a pressure of 4500 PSI. The melt was then cooled at a temperature of 10? to obtain a water-cooled pipe having outer diameter of 116 mm and/or 225 mm which was then subjected to cutting to obtain a pipe of length in a range from 1115mm to 3294 mm.
Then, the bell molding process was carried out using a socketing mandrel as described below:
For 116mm pipe: both the ends of the pipe were heated at 220 ? in a heating machine followed by insertion of the pipe in the socketing mandrel having dimensions of 104.4mm (diameter) X 50 mm (length). Thereafter, the pipe was sprayed with cold water at a temperature of 5? to 10? for 80 seconds to 90 seconds to obtain a reverse osmosis (RO) membrane housing (4) of the present invention.
For 225 mm pipe: the bell molding process as described above for 116 mm pipe was similarly followed for the 225 mm pipe except, that the mandrel having dimensions of 204.4mm (diameter) X 65 mm to 68mm (length) was used and the spraying was carried out for 112 seconds to 120 seconds.
The dimensions of the RO membrane housing (4) manufactured as per the present invention are represented in the table below. The model number of the RO membrane are assigned as per the standard nomenclature.
Table 1
Model length Internal diameter Outer diameter Groove to groove diameter
40E40300PSI 1115 MM 1054-1060 MM 116 MM 102.1
40E80300PSI 2131 MM 2070-2076 MM 116 MM 102.1
80E40300PSI 1262 MM 1147-1153 MM 225 MM 202.1
80E80300PSI 2278 MM 2163-2169 MM 225 MM 202.1
80E120300PSI 3294 MM 3179-3185 MM 225 MM 202.1
Example 3: performance and structural evaluation of the RO membrane housing manufactured according to example 2
Hydrotesting:
A total of 1444 RO membrane housings manufactured according to example 2 comprising 550 of 40E40300PSI, 360 of 40E80300PSI, 420 of 80E40300PSI, 64 of 80E80300PSI and 50 of 80E120300PSI (as given in Table 1 above) prepared in a batch production process and 170 commercially available FRP (manufactured with epoxy resin and glass fiber) housing was subjected to an hydrotesting method for 6 months to evaluate the structural integrity and performance of the RO housing when subjected to high pressure. The hydrotesting method is conducted by filling the RO housings with water and subjecting to a pressure with a plunger pump. The pressure is raised to 1.1 times the RO housing's operating pressure and maintained for 15 minutes. 7 out of 170 FRP housing were rejected due to failure in performance or structural integrity while all the RO membrane housings as per the present invention demonstrated comparatively better performance without developing any structural defects such as leakage or cracks. The results obtained are presented in the Table below:
Table 2
Model No. Operating pressure (PSI) Testing Pressure (PSI) Hold time (mins) Result
Present invention 40E40300PSI 300 330 15 No defect
Present invention 40E80300PSI 300 330 15 No defect
Present invention 80E40300PSI 300 330 15 No defect
Present invention 80E80300PSI 300 330 15 No defect
Present invention 80E120300PSI 300 330 15 No defect
Comparative Example A
80E1201200PSI 1200 1320 15 O ring leakage issue
Comparative Example B
80S280450PSI 450 495 15 Damage during extraction process
Comparative Example C
80S280600PSI 600 660 15 Damage during extraction process
Comparative Example D
80S200300PSI 300 330 15 Body crack issue
Comparative Example E
40S160600PSI 600 660 15 Face leakage and port crack issue
Comparative Example F
40S120300PSI 300 330 15 Port Crack and face leakage issue
Comparative Example G
40S240600PSI 600 660 15 Port crack and Face crack issue
The engineered plastic composition according to present invention, results in the production of RO membrane housing without any defects thereby enabling the said housing to withstand high pressure as compared to comparative examples A to G. The engineered plastic composition imparts a smooth mirror finish to the said housing without any scratches thus, preventing the formation of cracks or any damages when subjected to high-pressure conditions. In contrast, the comparative examples (A to G), due to the complexities of the FRP manufacturing process such as filament winding, curing process etc., likely developed scratches or other defects during production. These imperfections, when subjected to hydrotesting, were exacerbated, leading to the formation of cracks, face leakage or other damages to the RO housing. This signifies that the engineered plastic composition of the present invention contributes to the performance stability and structural integrity of the RO membrane housings manufactured therefrom. Additionally, it eliminates the need for hydrotesting of each RO membrane housings manufactured therefrom which is typically required for conventional FRP and SS housings to investigate cracks or leakage issues for each manufactured RO housing unit. Thus, the RO membrane housing manufactured from the engineered plastic composition is 100% leakage proof and crack resistant.
Impact strength assessment:
Burst test: -
The 40E40300PSI and 80E40300PSI RO membrane housing manufactured according to Example 2 was subjected to a burst test, wherein the housing was filled with water and the pressure was gradually increased above their operating pressure at a regular interval of 10 PSI and held for 10 seconds, with a plunger pump. The increase in pressure was continued till the housing breaks due to pressure. The RO housing of the present invention sustained a pressure of 1100 PSI before bursting, which was approximately 4 times its operating pressure of 300 PSI, without any cracks or leakage. This suggest that the housing can sustain the maximum expected pressure without failing or bursting, thus demonstrating better impact resistance.
Drop test:
The 40E40300PSI and 80E40300PSI RO membrane housing manufactured according to Example 2 was subjected to a drop test, where it was dropped from a height of 10 feet onto a hard, rigid surface, such as concrete. Following the impact, the housing showed no signs of damage, cracking, or leakage, demonstrating the impact resistance and structural integrity of the RO membrane housing, without compromising its performance.
Cyclic test:
The 40E40300PSI and 80E40300PSI RO membrane housing manufactured according to Example 2, was subjected to repeated pressure cycling, by pressuring (up to its maximum operating pressure) that is, 300 PSI and de- pressuring (to zero PSI) for 15 to 20 times in a minute by a pressure intensifier system. The RO housing passed the cyclic test for 1 lakh (100,000) pressure cycles without exhibiting any signs of damage, deformation, or leakage. This suggest that the RO housing can withstand fluctuating pressures over an extended period thereby, demonstrating impact resistance when subjected to repeated pressure changes, without hampering its performance.
Hammering test:
A hammer of 400 grams was repeatedly hammered on the 40E40300PSI and 80E40300PSI RO membrane housings manufactured according to Example 2 at a height of 800cm for 50 times to determine the impact strength of the RO membrane housing. The impact strength was calculated using the formula:
E=1/2m(v)2 ,
where m = weight of hammer (400 grams) and v = velocity (2meter/sec)
The impact strength of the RO membrane housings was determined to be 800j/m2 based on the above formula.
In the above description, for purpose of explanation, specific details are set forth in order to provide an understanding of the present disclosure. It will be apparent, however, to one skilled in the art that the present disclosure may be practiced without these details. One skilled in the art will recognize that embodiments of the present disclosure, one of which is described below, may be incorporated into a number of systems. Further, structures and devices shown in the figures are illustrative of exemplary embodiment of the present disclosure and are meant to avoid obscuring the present disclosure.
,CLAIMS:
1. An engineered plastic composition comprising resin in a range from 85% wt. to 95% wt., titanium dioxide in a range from 0.1% wt. to 2.5% wt., titanate in a range from 0.2% wt. to 0.45 % wt., impact modifier in a range from 0.1% wt. to 2.5% wt. and auxiliaries in a range from 4.9% wt. to 10.6% wt.

2. The engineered plastic composition as claimed in claim 1, wherein the resin comprises a polyvinyl chloride selected from k-6701, k-6702, k-6711.

3. The engineered plastic composition as claimed in claim 1, wherein the titanate is selected from stearyl titanate and isostearyl titanate having particle size in a range from 25 microns to 75 microns.

4. The engineered plastic composition as claimed in claim 1, wherein the impact modifier is selected from methacrylate butadiene styrene terpolymer, acrylate polymethacrylate copolymer, chlorinated polyethylene, ethylene vinyl acetate copolymer, acrylonitrile butadiene styrene terpolymer and its mixture thereof.

5. The engineered plastic composition as claimed in claim 1, wherein the auxiliaries are selected from 1.2% wt. to 1.5% wt. of master batch, 0.2% wt. to 0.5% wt of wax, 5% wt. to 6% wt of calcium, 0.2% wt. to 0.7% wt of stearic acid, and its mixture thereof.

6. A process for preparation of an engineered plastic composition comprising:
(i) Heating a mixture comprising resin in a range from 85% wt. to 95% wt., titanium dioxide in a range from 0.1% wt. to 2.5% wt., impact modifier in a range from 0.1% wt. to 2.5% wt., and auxiliaries in a range from 4.9% wt. to 10.6% wt., and
(ii) Adding titanate in a range from 0.2 % wt. to 0.45 % wt.

7. The process as claimed in claim 6, wherein the heating in step (i) is carried out at a temperature in a range from 90? to 95 ? for 25 mins to 35 mins.

8. A process for manufacturing of a reverse osmosis (RO) membrane housing (4) comprising:
(i) melting the engineered plastic composition as claimed in claim 1 at a temperature in a range from 200? to 260?,
(ii) extruding the melted engineered plastic of step (i) to obtain a continuous cylindrical melt, subjecting the melt to a pressure calibration process, and
(iii) cooling the melt of step (ii) to obtain a pipe.

9. The process as claimed in claim 8, wherein the engineered plastic composition in step (i) is fed in a powder form having particle size in a range from 300 microns to 500 microns at a feed rate in a range from 250 kg/hr to 400 kg/hr.

10. The process as claimed in claim 8, wherein the pressure calibration process in step (ii) is carried out at a pressure in a range from 4000 PSI to 6000 PSI.

11. The process as claimed in claim 8, wherein the cooling of step (iii) is carried out at a temperature in a range from 5? to 10?.

12. The process as claimed in claim 8, comprising the step of cutting and bell-molding the pipe of step (iii) from both the ends with socketing mandrel.

13. A reverse osmosis (RO) membrane housing (4) comprising:
(i) a bell-shaped end (5);
(ii) a moulded end cap (2) and
(iii) a circlip groove (3).