DESC:DETAILED DESCRIPTION OF THE INVENTION

According to the present invention, it has been observed that the pipes manufactured following the method of mixing of the compounds in particular proportion can be employed as anti-rodent resistant pipes in the industries specifically CGD industry. The chemical compounds/products added for anti-rodent properties during the manufacturing of the pipes are non-hazardous and can be transported by Road, Sea or Air. The present invention provides the anti- rodent pipe that is tested and found non-toxic with no carcinogenic effects, no teratogenicity or not any mutagenic effects as per toxicological report of Material Safety Data Sheet (MSDS), provided by OEM.

As used herein, the term "rodents’ refers to members of the rodentia order, for example, mice, rats, squirrels, guinea pigs, hamsters, chipmunks, pocket gophers and other rodents.

As used herein, compounds and compositions are “rodent repellent” mixed during the process of manufacturing of anti-rodent MDPE pipes, it substantially decreases the damages done by the rodent as compared to the normal pipes used in CGD Services.

One of the main embodiment of the present invention is to provide a method of making Medium Density Polyethylene Pipes (MDPE) having anti-rodent properties comprising of adding Ethylene Vinyl Acetate (EVA), Rodent Repellent Additives and Lubricants, during extrusion wherein, the rodent repellant additives comprises of 3 to 5% of total composition and method of manufacture comprising the steps of:
(a) measuring the weight of Raw material of medium density Polyethylene (MDPE)
(b) measuring 3 % or 5 % of Anti rodent raw material.
(c) mixing both raw materials.
(d) adding the mixed raw material into the extrusion hopper.
wherein, the machine produces the MDPE pipe with anti-rodent properties

Another embodiment of the present invention is to provide a method, wherein, the anti-rodent raw material is Ethylene Vinyl Acetate – Anti-Rodent Master Batch (EVA-ARMB).

Still another embodiment of the present invention is to provide a method, wherein the method is compatible for pipes made of PVC (Polyvinyl Chloride), PE (polyethylene), PP (polypropylene), LSZH (Low Smoke Zero Halogen), HFFR (Halogen Free Flame Retardant cables) and PBT (Polybutylene Terephthalate).

Yet still another embodiment of the present invention is to provide a method, wherein the composition comprising EVA, Rodent Repellent Additives and Lubricants was in the form of solid plastic granules.

Further still another embodiment of the present invention is to provide a method, wherein the raw material for the pipes were 20 MM MDPE PE 100, 32 MM MDPE PE 100, 63 MM MDPE PE 100, 90 MM MDPE PE 100, 125 MM MDPE PE 100, 180 MM MDPE PE 100, 20 MM MDPE PE 80, 32 MM MDPE PE 80, 63 MM MDPE PE 80, 90 MM MDPE PE 80, 125 MM MDPE PE 80, 180 MM MDPE PE 80.

Still another embodiment of the present invention is to provide a Medium Density Polyethylene Pipes (MDPE) having anti-rodent properties comprising of adding EVA, Rodent Repellent Additives and Lubricants, during extrusion wherein, the rodent repellant additives comprises of 3 to 5% of total composition, the said pipe comprising impact strength of as per Standard IS14885, differential scanning calorimetry of 134.69, melt flow rate of 0.28, heat deflection temperature (HDT) of 83.5, VICAT softening temperature (VST) of 130, slow crack growth rate (SCGR) of greater than 165-500 hrs, tensile elongation of 350%, Hydrostatic, oxidation induction time (OIT) of >63.54, density of 950, resistance to gas constituents, pigment dispersion of >3 and environmental stress cracking resistance (ESCR) of 0/10.

Yet still another embodiment of the present invention is to a Medium Density Polyethylene Pipes (MDPE) having anti-rodent properties, wherein, the colour of pipe is yellow when manufactured from PE-80 grade and orange colour when manufactured from PE-100 grade.

Products: In the present invention the product used is Rodent Repellant Masterbatch with GRADE: EVA ARMB(Anti-Rodent Masterbatch) .

Chemical Composition and Properties of EVA ARMB
Chemical Composition details:
Composition: Contains EVA + Rodent Repellent Additives + Lubricants.
Appearance: Light Ivory granules
Odor: Strong odor / Extremely Bitter Taste
Melting Point: 90º C to 110 º C
Compatible with: PVC / PE / PP / LSZH / HFFR / PBT
PART III: Hazards Identification.
Color: Light Ivory Color
Physical Appearance: Solid Plastic granules
Odor: Strong Odor
Physical and Chemical properties
Physical form: Solid plastic granules
Color: Light Ivory
Odor: Strong odor
Taste: Extremely bitter and pungent taste (avoid oral contact)
MFI: > 3 (@2.16 kg @190°C)
Boiling point: Not available
Melting point: 90º C to 110 º C
Density: 1.05 t0 1.10 gm / cm3
Processing Temp: 110 – 200 º C (Depends on the Base RM)
Recommended Dosage: 2% to 4%

The method and means of accomplishing this will become apparent from the detailed description of the invention, tests and reports as provided herein below:

Manufacturing: The Raw Material of 20 MM MDPE PE 100 adds with anti-rodent properties of 3% and 5 % added in the pipe. The pipes are manufactured as per the following procedure.
? Measure the weight of Raw material of medium density Polyethylene (MDPE)
? Measure the 3 % or 5 % of Anti rodent raw material.
? Mix both raw material.
? Add the mixed raw material in to the extrusion hopper.
? The machine produces the MDPE pipe with anti-rodent properties.
The samples of PE( Polyethylene) pipes manufactured by adding compounds of anti-rodent 20MM pipe.
Testing Procedure: The testing of PE pipes would be exposed to these rodent species housed individually in iron mesh cages under laboratory conditions. Two different types of tests may be undertaken for PE pipes: properties are given to certified/recognized testing agencies for testing of:
1. Choice Tests: In this trial the pipes of 15-30 cm length are exposed to the test rodents along with food, thus the rodents have a choice between food and the test duct/cable. This test may be run for longer periods (30-45 days). Tap water should be provided to the rodents.
2. No-Choice tests: The rodents are exposed to the test Pipes only and no food is given to the rodents during the period of trial. The test pipes are exposed to the test rodents. This trial may be run for 5-7 days depending upon the health status of starved test rodents. Tap water should be provided to the rodents. Observation of tooth marks, rodent behavior toward exposed pipes, relative extent of damage in treated and untreated pipes should be computed for both types of pipes. Health status of test animals in choice and no choice test must also be monitored for the record of any ill effect of exposure of treated/ control pipes on these animals.

The samples of PE pipes having anti-rodent properties have been tested for following properties as per IS 14885 and the test results are provided herein below:
a. IMPACT STRENGTH
b. DIFFERENTIAL SCANNING CALORIMETRY (DSC)
c. MELT FLOW RATE
d. HEAT DEFLECTION TEMPERATURE (HDT)
e. VICAT SOFTENING TEMPERATURE (VST)
f. SLOW CRACK GROWTH RATE (SCGR)
g. TENSILE ELONGATION
h. HYDROSTATIC (100, 165 & 1000 H)
i. OXIDATION INDUCTION TIME (OIT)
j. DENSITY
k. RESISTANCE TO GAS CONSTITUENTS
l. PIGMENT DISPERSION
m. ENV. STRESS CRACKING RESISTANCE (ESCR)

METHODS OF TESTS CARRIED OUT in M/s ICAR, Jodhpur

1.1. The Test samples:
Following types of PE pipe samples with various concentrations of anti-rodent treatments as supplied by the Firm were evaluated in the laboratory for their anti-rodent properties.

TABLE 1

S. No. Sample ID Referred as Base material as per the manufacturer Ani-rodent Master
Batch
1 S1 PE 5%
2 S2 PE 3%
3 S3 PE Nil

2.2.Test rodent species: The above mentioned pipe samples were evaluated in the Laboratory against five common rodent species viz., Lesser bandicoot rat, Bandicota bengalenssis, House rat, Rattus rattus,lndian gerbil, Tatera indica, Northern palm squirrel, Funambulus pennantii and Soft field furred rat, Millardia meltada. The test species were live trapped from fields (T..indica, F. pennantii and M. meltada), from grain mandies and stores (B. bengalensis and R. rattus). The trapped rodents were acclimatized in laboratory for 2 weeks before initiating the trials. They were maintained in wire mesh cages and provided with pearl millet grains and tap water. The ecological characteristics of the test species are briefed as under.

i. Lesser bandicoot rat, Bandicota bengalensis: The lesser bandicoot rat is one the most important rodent pest in Indian agriculture, occurring in and around human settlements and also in fields. The species is cosmopolitan in distribution, colonial in habit, well adapted to various habitats and ecological conditions which include cultivated fields, pastures, forests, mountains, intertidal mangrove zones, semiarid zones and also as a commensal rodent in towns and cities across India. The rat is nocturnal and fossorial. Breeding occurs throughout the year. The species is regarded as number I rodent pest in agriculture and food storage.

ii. House rat, Rattus rattus : The house rats are also called roof rat, black rat and ship rat is the most abundant and widely distributed rodent species in india as well as the world. It is a medium sized rat characterized by long tail, slender body and pointed snout. The species is mostly commensal living in houses, godowns, stores, poultry farms, crop fields, adjacent to villages and inflicts serious damage to stored commodities, structures etc. The species is nocturnal and colonial in habit. House rats breed throughout the year, reportedly with two peaks of reproduction viz. March-April and August-September.

iii. Indian gerbil, Tatera indica: The Indian gerbils are essentially a field rodent species distributed in various parts of the country (except the hills). The species is nocturnal inhabiting open plains and is usually found at the edges of cultivation. Burrows are dug near hedges, thickets or under bushes, sometimes inside the field also when conditions are dry. T. indica breeds throughout the year with maximum littering in the month of August and a minor peak in February.

vi. Squirrel, Funambulus pennanti: Also known as five-stripped squirrel is a medium sized squirrel weighing 90g with a bushy tail. The dorsal side is greyish brown with five distinctly white stripes separated by four off white bands. Distributed in India, Pakistan, Nepal and parts of lran. It is highly active, playful, running around up and down the trees, chirpy and diurnal. Peaks of activity occur in the morning and early evenings. Generally, lives close to human being orchards, gardens and parks and in areas with fairly good number of trees. The squirrel nests in holes in tree trunks ancl crevices in the walls of buildings, windowsills, compounds etc. Breed throughout the year, breeding is generally seasonal from March to September with peaks during March-April and July-September in Rajasthan with a litter size varying from 1-5.

v. The soft furred field rat, Millardia meltada: It is a medium sized field rodent with a very soft fur. Body colour light to dark grey dorsally with foot and belly being off white. Tail is naked with annular rings similar to body colour with dark grey above and pale below. The soft furred field rat is essentially a field rat distributed throughout lndia in irrigated crop fields, scrub grassland and sandy plains except the north-east mountainous areas. It is a nocturnal rodent and lives in simple and shallow burrows, which are slightly slanted. The species breeds throughout the year with peak reproduction occurring in monsoon and spring season. It is also regarded as a pest in agriculture.

2.3. Test Protocols: The supplied PE pipes as such without any modification in shape/size or treatment were exposed to all the three rodent species in laboratory cages. Only healthy and adult animals were selected for the trials. The trials were undertaken under no choice and choice conditions. Under no choice only test samples (without food) were exposed to rodents for three days, whereas in choice tests the samples were exposed to rodents along with laboratory food. Choice tests were run for 45 days. For each rodent species four replications were maintained. Tap water was provided ad libitum. Observation on tooth/scratch marks and weight of the samples (before and after exposure) was recorded at regular intervals to evaluate extent of damage to the anti-rodent treated samples and untreated sample of PE pipe against all the five rodent species.

3. RESULTS

3.1. No choice tests: In this trial the rodents were not provided with any alternate plain food, they were exposed to anti-rodent treated samples of PE pipes and untreated sample of PE pipe. The samples were not touched by any of the test species of the rodents. This indicated that the PE pipes are not at all preferred for feeding/nibbling purposes by test rodent species under no-choice conditions.

3.2. Choice tests: In choice tests the test rodents were exposed to samples of PE pipes treated with different concentrations of anti-rodent master batch and untreated sample of PE pipes along with plain food for 45 days. The responses of test rodents towards these materials were observed daily for 45 days. The species wise results are discussed as under:

3.2.2. The Lesser bandicoot rat, Bandicota bengalensis : None of the replicates of both the anti-rodent master batch treated PE pipes S1 (5%) and S2 (3%) showed any signs of attack by lesser bandicoot rats during 45-day long exposure. This indicates that the anti-rodent master batch treated samples are not preferred and may be regarded as safe from this species.

3.2.3. The house rat, Rattus rattus: Like lesser bandicoot rats, the house rats also showed no signs of attack on both the anti-rodent master batch treated PE pipes S1 (5%) and S2 (3%) during the trial period. Thus, the anti-rodent master batch treated PE pipes S1 (5%) and S2 (3%) samples in trial may also be regarded as safe from the house rats, R. rattus.

3.2.1. The Indian gerbil, Tutera indica: During the 45-day long exposure in choice tests one of the replications of both the anti-rodent master batch treated PE pipes S1 (5%) and S2 (3%) received very mild damage of 1.25 and 0.75 per cent, respectively at the edges only (on the basis of weight loss before and after exposure) upto 45th days of exposure. Rest of the replications of anti-rodent master batch treated PE pipes (S1 & S2) did not receive any sign of damage. The damage recorded in one replicate of both the anti-rodent master batch treated PE pipes was non-significant in comparison to untreated pipe (S3) which received a damage of 05 per cent and that too was on the edges only. On the basis of these observations, both the anti-rodent master batch treated PE pipes S1 (5%) and S2
(3%) may be regarded as safe against, T. india.

3.2.4. Squirrel, F. pennanti: All the samples of anti-rodent master batch treated PE pipes (S1 and S2) were free from the attack of squirrel during the 45-day long exposure period.

Thus, the anti-rodent master batch treated PE pipes S1 (5%) and S2 (3%) samples may be regarded as safe from squirrel.

3.2.4.The soft furred field rat, Millardia meltada: No sign of activity by this species was noticed on any of the anti-rodent master batch treated PE pipes (S1, and S2) during 45-day long trial. Thus, the anti-rodent master batch treated PE pipes may be regarded as safe against, M. meltada also.

All the rodents used in the trial showed normal feeding behaviour and no ill effects of bites on the PE pipes were seen on test rodents.
Based on the laboratory trials conducted on rat repellent treated samples (code S 1 and S2) against five rodent species, following conclusions may be drawn;

(i) In no-choice all the treated test samples (coded S1 and S2) as mentioned in the results proved safe against all the five test species, viz., lesser bandicoot rat, B. bengalensis, house rats, R. rattus, Indian gerbil, T. indica, squirrel, F. pennant and soft fur field rat, M. meltada. The test samples were not touched by any of the test species.

(ii) In choice test insignificant nibbling by T. indica in one of the replication of anti-rodent master batch treated PE pipes sample S1 (5%) and S2 (3%) was observed. Rest of test species of rodents showed negligible preference to the test samples (S1 and S2).

(iii) It may be concluded that anti-rodent master batch treated PE pipes sample S1 (5%) and S2 (3%) may be regarded as safe against attack by the five test rodents.
Rodents being highly evolved mammals show very diverse behavioral manifestations in different situations and therefore can easily adapt to the changing field situations in their home range/territory. Therefore, in addition to safer pipes, it is further advised for adoption of rodent control practices in area where these are to be used. Likewise, for laying them underground also adequate precautionary measures should be taken. These may be (i) increasing the depth of laying (>1m) (ii) with lining of stone/ brick pebbles (iii) adequate proofing at pipe joints, so that the rodents do not get access to the ends ends/ inside the pipes and (iv) adoption of rodent control practices in area.

TABLE 1 : Method of test is carried out in the M/s CIPET, Hyderabad as per IS 14885.
Certificate No. 0136986 for 3% and 0136987 for 5%
Report No. 2308148/1 for 3% and Report No. 2308148/2 for 5%
Sr. No. Clause Test Test Method Specified Requirement Results Obtained- 3% Results Obtained - 5%
1 4.1 Pipe Designation IS 14885:2022 PE 100 DN 20 X 3.0 SDR 11 GAS PE 100 DN 20 X 3.0 SDR 11 GAS
4.4 Colour of Pipe IS 14885:2022 The colour of the pipes shall be Yellow when manufactured from PE-80 grade & Orange when manufactured from PE-100 grade. PE 100 Grade Orange PE 100 Grade Orange
2 - Resistance to External Blows at 0 Deg. Cel. IS 12235 (Part-9) Pipe shall have a true impact rate of not more than 10% (0/25) 0%
No Failure Observed (0/25) 0%
No Failure Observed
3 - Differential Scanning Calorimetric (DSC) (Melting Point) ASTMD 3418 135.42 134.69
4 - Heat Deflection Temperature (HDT) ASTMD 648 84.6 83.5
5 - Vicat Softening Temperature (VST) ASTMD 1525 128 130
6 8.4 Melt Flow Rate (g/10 min) (at 190 Deg. Cel. / 5 kgf load) IS 2530 Shall not deviate 20% of declared value 0.28 0.28
7 8.1 & 8.10.1 i Slow Crack Growth Rate Test
a. Internal Test Pressure: Mpa
b. Test Temp: 80 Deg. Cel.
C. Test Duration: 165 h IS 4984-2016 Annex E & J The Pipe shall no show no sign of localised swelling, leakage or weeping & shall not burst during the prescribed test period. Confirmed Confirmed
8 8.1 & 8.10.1 ii Slow Crack Growth Rate Test
a. Internal Test Pressure: Mpa
b. Test Temp: 80 Deg. Cel.
C. Test Duration: 500 h IS 4984-2016 Annex E & J The Pipe shall no show no sign of localised, swelling, leakage or weeping & shall not burst during the prescribed test period. Confirmed Confirmed
9 8.8 Tensile Properties 32.7 33.32
a Yield Stress IS 4984-2016 Annex H Min. 15.0 MPa 464 493
b Elongation at Break Min. 350%
10 8 Performance Requirement

8.1 Hydraulic Characteristics - Plain Pipe Type Test
8.1
Table 9 i. Internal Pressure Creep Rupture Test of Pipe
(20 Deg. Cel. / 100 h / 12.0 MPa) IS 4984-2016 Annex E The Pipe shall no show no sign of localised swelling, leakage or weeping & shall not burst during the prescribed test period. Confirmed Confirmed
8.1
Table 9 ii. Internal Pressure Creep Rupture Test of Pipe
(80 Deg. Cel. / 1000 h / 5.0 MPa) IS 4984-2016 Annex E The Pipe shall no show no sign of localised swelling, leakage or weeping & shall not burst during the prescribed test period. Confirmed Confirmed
8.1
Table 9 Acceptance Test
iii. Internal Pressure Creep Rupture Test of Pipe
(80 Deg. Cel. / 165 h / 5.4 MPa) IS 4984-2016 Annex E The Pipe shall no show no sign of localised swelling, leakage or weeping & shall not burst during the prescribed test period. Confirmed Confirmed
11 8.6 Thermal Stability (Oxidation Induction Time) (Min.) IS 4984-2016 Annex B Shall not be less than 20 min. > 63.54 > 47.62
12 8.3 Density @ 23 Deg. Cel. (kg/m3) IS 7328-2020 = 930.0 kg/m3 950.0 949.0
13 5.5, 5.5.1 & 5.5.2 Effects of Gas Constituents of the Hydrostatic Strength
Test at 2 Mpa Induced Stress for 20 h at 80 Deg. Cel. / 2.0 MPa (After Conditioned @ 23 Deg. Cel. / 1500 h) IS 4984-2016 Annex E The pipe under test shall not show any failure during the test period. Confirmed Confirmed
14 8.5 Pigment Dispersions IS 14885:2022 Annex A = 3 < 3 < 3
15 - Environmental Stress
Cracking Resistance (ESCR)
(10% IGEPOL Solution at 50 ± 1 Deg. Cel. For 96 h) ASTMD 1693 There shall be no Cracks & Failure (0/10) 0%
No Cracks Observed (0/10) 0%
No Cracks Observed

The potential route for commercialization, companies that may be interested, alternative markets would be the CGD industries and other businesses using MDPE and are the potential customers of this technology in future.

Although, the present invention has been described with references to features, it will be apparent to those skilled in the art that this description is only a preferred embodiment and does not limit the scope of the present invention. Variations and modifications are possible without departing from the scope of the invention disclosed / described herein and are intended to be encompassed therein.

Abbreviations:
MDPE: Medium Density Polyethylene
CGD: City Gas Distribution.
EVA-ARMB: Ethylene Vinyl Acetate – Anti-Rodent Master Batch.
PVC: Polyvinyl Chloride
PE: polyethylene
PP: Polypropylene,
LSZH: Low Smoke Zero Halogen
HFFR: Halogen Free Flame Retardant cables
PBT: Polybutylene Terephthalate.
IS: Indian Standard
IS 14885: Polyethylene Pipes for the Supply of Gaseous Fuels – Specification.
OEM: Original Equipment Manufacturer
,CLAIMS:We Claim:

1. A method of making Medium Density Polyethylene Pipes (MDPE) having anti-
rodent properties comprising of adding Ethylene Vinyl Acetate (EVA), Rodent Repellent Additives and Lubricants, during extrusion wherein, the rodent repellant additives comprises of 3 to 5% of total composition and method of manufacture comprising the steps of:
(e) measuring the weight of Raw material of medium density Polyethylene (MDPE)
(f) measuring 3 % or 5 % of Anti rodent raw material.
(g) mixing both raw materials.
(h) adding the mixed raw material into the extrusion hopper.
wherein, the machine produces the MDPE pipe with anti-rodent properties

2. The method as claimed in claim 1, wherein the anti-rodent raw material is Ethylene Vinyl Acetate – Anti-Rodent Master Batch (EVA-ARMB).

3. The method as claimed in claim 1, wherein the method is compatible for pipes made of PVC (Polyvinyl Chloride), PE (polyethylene), PP (polypropylene), LSZH (Low Smoke Zero Halogen), HFFR (Halogen Free Flame Retardant cables) and PBT (Polybutylene Terephthalate).

4. The method as claimed in claim 1, wherein the composition comprising EVA, Rodent Repellent Additives and Lubricants was in the form of solid plastic granules.

5. The method as claimed in claim 1, wherein the raw material for the pipes were 20 MM MDPE PE 100, 32 MM MDPE PE 100, 63 MM MDPE PE 100, 90 MM MDPE PE 100, 125 MM MDPE PE 100, 180 MM MDPE PE 100, 20 MM MDPE PE 80, 32 MM MDPE PE 80, 63 MM MDPE PE 80, 90 MM MDPE PE 80, 125 MM MDPE PE 80, 180 MM MDPE PE 80.

6. A Medium Density Polyethylene Pipes (MDPE) having anti-rodent properties comprising of adding EVA, Rodent Repellent Additives and Lubricants, during extrusion wherein, the rodent repellant additives comprises of 3 to 5% of total composition, the said pipe comprising impact strength of as per Standard IS14885, differential scanning calorimetry of 134.69, melt flow rate of 0.28, heat deflection temperature (HDT) of 83.5, VICAT softening temperature (VST) of 130, slow crack growth rate (SCGR) of greater than 165-500 hrs, tensile elongation of 350%, Hydrostatic, oxidation induction time (OIT) of >63.54, density of 950, resistance to gas constituents, pigment dispersion of >3 and environmental stress cracking resistance (ESCR) of 0/10.

7. The Medium Density Polyethylene Pipes (MDPE) having anti-rodent properties, as claimed in claim 6, wherein, the colour of pipe is yellow when manufactured from PE-80 grade and orange colour when manufactured from PE-100 grade.