|Title of Invention||
A NEW MIX PROCESS OF WASTE PLASTICS-AGGREGATE-BITUMEN FOR FLEXIBLE PAVEMENT
|Abstract||ABSTRACT Waste plastics have binding property in their molten state. Using this property, waste plastics, aggregate and bitumen mix having waste plastics upto 2 parts by weight, bitumen 3- 6 parts by weight and the aggregate 92 to 95 parts by weight. The mix then used for flexible road construction. A process of manufacturing the above said waste plaslics-aggregates-bitumen mix (composite) is having the following steps. a) Sorting and cleaning of waste plastics to identify polyethylene, polypropylene and polystyrene and to reject polyvinyl chloride. b) Shredding the film to a size, which passes through 6.75mm sieve and retains in 2.36mm sieve c) Heating the aggregate to 155- 165deg.C d) Heating the bitumen separately to 160deg.C (should not be heated more) e) Adding the plastics pieces over hot aggregate, having chosen composition and mix it through puddler for uniform coating. f) Add the hot bitumen (160deg.C) over the plastics coated aggregate and mix it uniformly. g) Waste polymer-aggregate -bitumen mix is now taken for road laying. A method of manufacturing the mix (composite) of waste plastics-aggregate-bitumen as described in the complete specification is our invention.|
Field of Invention:
The invention generally relates to Construction technology. This invention in particular relates to road forming material. More particularly this invention is related to a novel and unique road forming material.
It is the primary object of invention to invent a novel composite in the form of blend of polymer and bitumen reinforced with adequate Quantity of gravel.
Accordingly it is the primary purpose of invention to invent an unique and novel composition through a process by which waste material will be converted to value added product. The implication and ramification of the unique material composition as road forming material in the field of construction technology is great.
The invention specifically addressed to a novel use of disposed waste polymer materials like carry bags, cups, bottles, and thermo cool, which are made out of polyethylene, polypropylene, and polystyrene. These materials are otherwise disposed either by land filling or by incineration which are causing serious environmental hazard. BACKGROUND OF INVENTION:
It is a well known fact that Polymer materials like carry bags, cups, etc., made out of polyethylene, polypropylene, and polystyrene are most used materials in daily life. It is difficult to ban the use of these polymers.
Alternate method to find the ideal use of these disposed waste polymers is the need of the hour other than recycling. It is the salient feature of this invention is to invent a novel process, which results in value addition.
Polymers like polyethylene, polypropylene and polystyrene are hydrocarbons. Bitumen (Tar) also contains higher percentage of hydrocarbons.
Mixing of the two substances is possible to form a blend. Mixture of polymer-aggregate-bitumen is invented and such blends are used for road laying.
The invented process is a new technology.
The invented process is a better way of disposal of polymer waste.
Detailed studies have been carried as regard to utility of invention. This has helped to invent
new novel road laying material.
It is also important to note that the total quantity of bitumen used for road laying in India is nearly 40 to 50 times more than the polymer waste available per year. OBJECT OF INVENTION:
The primary object of invention is to invent the noval way of disposing waste polymer in a useful way and thereby generating a value added product.
It is another object of invention to invent the suitable blending of waste polymer with bitumen, which can be used for road laying.
It is another object of invention to invent a process whereby the solid waste disposal becomes easy and useful.
It is another object of invention to invent a process, which is eco friendly.
Further objects of the invention will be clear from the ensuing description.
A SUMMARY OF INVENTION:
Now the invention will be described in detail. The nature of the invention and the manner in which the invention is performed is clearly described in the following description of the complete specification.
Polymers, commonly known as plastics are finding their use in our daily life in many ways. Preventing the use of polymers is impossible but an alternate way of reusing them would prevent the damage caused by them to the ecosystem.
Polymers like polyethylene, polypropylene, and polystyrene are mixed with bitumen. The solubility of these polymers in Bitumen is from 2 to 3% by weight of Bitumen. This forms a homogeneous mixture. This homogeneous blend shows better properties with respect to softening point, penetrating values and ductility. The softening point increases: the penetration values decreases. This suggests that the mix is good for road laying
But, addition of higher percentage of plastic waste to bitumen i.e. more than 3%, does not result in homogeneous product and they get separated on cooling.
Hence the polymer material is coated over hot aggregate (150 - 170 deg. C) and to the polymer coated aggregate, the hot bitumen is added. The mix is called - Polymer - Aggregate -Bitumen mix. It is tested for Marshall test & stripping test. The Marshall value is 2,5times higher and there is no stripping even after 72hrs. The results are positive. Hence the mix is used for road laying.
This polymer bitumen mixture has distinct advantages in road laying, especially in India, whose climatic conditions require lower penetration property. The mixture demonstrates this property. The mixture reduces cracks in pavements.
Above all, it facilitates the disposal of polymer waste in a more useful way, rather than by burning or burying. The burning causes air pollution and the burying causes land pollution.
At the same time, it is to be noted that recycling of plastics, has become a major activity in this country through which thousands of families earn their live hood.
In this context, the use of plastic waste in road laying will be an answer to protect the environment. There is no disturbance to the ecosystem. By doing this, the polymer waste remain only on the roads, mixed with bitumen, and not elsewhere.
It is to be further noted that the effects like water resistance and pot holes formation have been studied by actually laying the road using this mixture. There is good water resistance and pot¬hole formation is very much reduced.
Plastics wastes are available as bags, cups and solid foam. They are made out of polyethylene (PE), polypropylene (PP), and polystyrene (PS). These wastes are used for road laying. Polyvinylchloride (PVC) wastes are, not used for road laying.
Plastic wastes are shredded into small pieces, the size being-passing 6mm Sieve and retaining in 2.36mm sieve. Films made out of PE, PP & PS and with a maximum thickness upto 80micron find their use in road laying. Metal (Aggregate):
Granite pieces (or) porcelain pieces Flyash:
Coal ash available as industrial waste The Process:
The process of manufacturing the mix (composite) is described in the following descriptions of the complete specification. Step-I
Waste plastics, namely bags, cups and thermocole, made out of PE. PP&PS are collected and segregated. The PVC wastes are eliminated. The dry segregated plastics are shredded into small pieces with size passing through 6.0mm sieves and retained in 2.36mm sieves. Step: n (a)
The solid aggregate (granite, ceramic) with proper proportion of metals having different size and dust (quarry dust/flyash) is heated to around ! 70°C and the heated materials is transferred to the puddling chamber. Step: II (b)
Simultaneously the Bitumen 60/70 or 80/100 or Crumb is heated to around 160°C. Precaution- Heating to higher temperature (>160deg.C) should be avoided. Step: m
The shredded plastics is sprayed uniformly over the heated aggregate to get an uniform coating at the surface of the aggregate. The quantity of addition of plastic depends on the nature of the surface to be prepared. [The percentage addition can vary from 5 to 20% by weight to the weight of Bitumen. The percentage addition is calculated as the percentage by weight of plastics to the weight of Bitumen], In the total composition, the addition of plastics wastes various from the minimum ratio of 0.25 : 5 : 95 to the maximum of 2 : 6 : 92. The quantity of Bitumen can be reduced suitably.
The aggregate is coated with plastics waste. To this, add the Bitumen (!60°C) and mix uniformly, Maintaining of temperature range 155 tol63 deg. C is very important. After mixing, the material is withdrawn around 140°C and the mix (composite) is used for road laying. The mix (composite) is referred as waste plastics- aggregate-bitumen mix by the iDventor. The road laying temperature is between 110-140°C. Step:V
It is rolled using 8 Ton roller. The process can be carried out using either Mini hot mix plant or by Central mixing plant with proper monitoring regarding the temperature and quantity of addition. Here the waste polymer is coated over the aggregate at around 160°C and over this the Bitumen is added. The molten plastics waste not only covers the surface of the aggregate but also binds well with the aggregate and helps bitumen for better binding with the aggregate.
The added binding property due to the addition of plastics, helps to improve the quality of the road in terms of withstanding increased load, abrasion, preventing bleeding and improving resistance of water. A better quality road is formed.
1. A process of manufacturing a mix (composite) consisting of waste plastics (namely polyethylene, polypropylene & polystyrene) and aggregate and bitumen in the ratio of waste plastics up to 2 parts by weight, bitumen 3 to 6 parts by weight and the aggregate 92 to 95 parts by weight, wherein the said process consists of the following steps.
a. Sorting and cleaning of waste plastics to identify polyethylene,
polypropylene and polystyrene and to reject polyvinyl chloride.
b. Shredding the film to a size, which passes through 6.75nim sieve and
retains in 2.36mm sieve
c. Heating the aggregate to 155- 165deg.C
d. Heating the bitumen separately to l60deg.C (should not be heated
e. Adding the plastics pieces over hot aggregate, having chosen
composition and mix it through puddler for uniform coating.
f Adding the hot bitumen (160deg.C) over the plastics coated aggregate
and mixing it uniformly. g. The mix, known as Waste plastics-aggregate -bitumen mix (composite), is now taken for road laying. 2. A method of manufacturing the mix (composite) of waste plastics-aggregate-bitumen as described in the complete specification.
|Indian Patent Application Number||488/MAS/2002|
|PG Journal Number||20/2006|
|Date of Filing||27-Jun-2002|
|Name of Patentee||THIAGARAJAR COLLEGE OF ENGINEERING|
|Applicant Address||TIRUPPARANKUNRAM, MADURAI 625 015|
|PCT International Classification Number||C08L95/00|
|PCT International Application Number||N/A|
|PCT International Filing date|