Title of Invention

A PROCESS FOR THE PREPARATION OF EPOXY CONCRETE USEFUL FOR MAKING MOULDED PARTS"

Abstract A process for the preparation of epoxy concrete useful for making molded parts which comprises: i) cleaning and drying stone chips/gravel/granite, sand/silica flour and stone dust/cement/graphite powder/chalk dust by known methods, mixing the said cleaned and dried stone chips/gravel/granite, sand/silica flour and stone dust/cement/graphite powder/chalk dust in a ratio in the range of 2 to 4.5: 1 to 3: 1 by weight, respectively. To obtain an aggregate; ii) mixing epoxy resin and hardener in a ratio in the range of 100 : 6 to 10 by weight to obtain a binder; iii) mixing thoroughly the aggregate and binder, so obtained, in a ratio in the range of 3.2 to 10.5 : 1 by weight to obtain epoxy concrete.
Full Text The present invention relates to a process for the preparation of epoxy concrete useful for making moulded parts
The present invention particularly relates a process of manufacture and application of epoxy concrete & items made thereof, particularly the machine structure arid machine elements. The epoxy concrete of the present invention is a cold curing mixture of a reactable epoxy resin system (binder) with carefully selected and graded aggregate system (filler). The technology is suitable for manufacturing machine bases, other castable items and components.
The main usages of the epoxy concrete of the present invention are for the manufacture of :
1.Mechanical Engineering : Machine structure, bed and elements specially machine tools structure, bed and elements.
2.Civil Engineering : Engineering structures in ocean engineer ing as well as in many usual civil engineering like roof deck, window frame, etc. 3.Chemical Engineering : Pipes, pumps, valves, storage
tanks, etc. 4.Electrical & Electronics Engineering : Components of
electrical machinery, printed board, insulator, etc. 5.Miscellaneous applications : Biomedieal engineering, artistic work, etc.

Conventional materials used to manufacture machine structures and components are cast iron, mild steel and hydraulic concrete (cement concrete). Each material has its advantages and limitations. The main drawbacks of cast iron are high fabrication cost, very long manufacturing lead times and it gets rusted whereas mild steel has low damping, poor sliding characteristics, long manufacturing lead times, gets rusted and hydraulic concrete has low tensile strength, large shrinkage & moisture absorption, very long curing time. But these are conventional materials in the field of casting technology. Although epoxy concrete has been used for the purpose of casting of machine elements but the technology is well guarded and extensive search in the patent domain revealed no information. While working in this field for several years, thorough search was conducted in the domain of patent, literature, commercial publicity, but no data was available in the public domain to develop the "process" through specific proportions of the composition of the components of the "mixture" to achieve the mechanical properties appropriate for the machine building programmes under the present invention domain. Some references used to arrive at this invention; the process and method of moulding :
1. Ciba-Geigy Brochure, Technical Notes 2/1980, pp. 2-6.
2. Ciba-Geigy Resin Aspects, No. 22, pp. 8-9.

3. PEMAB AG, MICRO-GRANIT, PP- 1-7.
4 . Synthetic Granite -Gran i tan S,l 00 , PAMAcK/GHM/smb/CMSD, Issue 2-August 1901, pp 1-2.
5. Epoxy Granite : a Structural Material for Precision
Machines, Precision Engineering, 0141-6359/79/040227, 1979, pp. 227-229.
6. Araldite Based Epoxy Resin Concrete, Ciba-Geigy
Publication, Publ. No. 28219/e, June 1985, pp. 1-8.
7. Mechanical Packing of Spherical Particles : Journal of
the American Ceramic Society, R.K. McGeary, Vol. 44,
No. 10, pp. 513-522.
8. Molded Polymer Composites, Pat. No. [13]4,784,894
Johnstone, oL. al. Nov. 15, 1988.
9. Method of. Manufacturing Machine Supports by means of
Concrete Polymer, [15]4,670,208.
10. Polymer Concrete Articles and Process for
Manufacturing Same, US Patent 4,696,839 Renker, et.
al. Sept. 29, 1978. '
11. Schulz H. and R.G. Nicklau,"Machine Tool Frames made
of Polymer Concrete" in Werkstatt und Betrieb, Vol.
114, No. 10, 1981, pp. 747-752, 14 pp.
12. Machinery & Production Engineering, "Machine
Beds-Concrete goes into the Mix", Oct. 10, 1979, pp.
67-68.
The main object of the present invention is to provide a

process for t:he preparation of epoxy concrete useful for making moulded parts.
Another object is to provide a process for making moulded parts using the epoxy concrete of the present invention which obviates the drawbacks as mentioned above and has all the necessary properties of an excellent casting material to replace metal and cement concrete in the art of casting, in strength, freedom from rust, quick in curing and strong in tension and having excellent surface finish which almost does not require any machining.
The three starting raw materials are epoxy resin, epoxy hardener and the aggregate consisting of stone chips/grave 1/granite, sand/silica flour and stone dust/cement/graphite powder/chalk dust. The epoxy resin and hardener are weighed and mixed to prepare the binder. Aggregate or the filler materials after cleaning, drying and weighing are mixed with the binder. The epoxy concrete so prepared as a casting material is ready to be used for casting in a mould which has been assembled after applying mould release agent. The epoxy concrete is poured into the mould and compacted. After appropriate period of curing, demouldirig is done arid fine finishing is applied, if necessary, to get the finished epoxy concrete products.
Accordingly, the present invention provides a process for the preparation of epoxy concrete useful for making moulded

parts which comprises (i) cleaning and drying stone chips/gravel/granite, sand/silica flour and stone dust/cement/graphite powder/chalk dust by known methods, mixing the said cleaned & dried stone chips/gravel/granite, sand/silica flour and stone dust/cement/graphite powder/chalk dust in a ratio in the range of 2 to 4.5 : 1 to 3 : 1 by weight, respectively, to obtain an aggregate; (ii) mixing epoxy resin arid hardener in a ratio in the range of 100 : 6 to 10 by weight to obtain a binder; (iii) mixing thoroughly the aggregate and binder, so obtained, in a ratio in the range of 3.2 to 10.5 : 1 by weight to obtain epoxy concrete.
The stone chips/gravel/granite used may be of size in the range of (1.4-2.0) to (25-40) mm.
The epoxy resin and hardener used may be such as
thermosetting resin and amines, both aliphatic & aromatic, respectively.
In the process of the present invention the epoxy
concrete comprises three starting raw materials, namely epoxy resin & hardener, the third component being the aggregate consisting of stone chips/gravel/granlte, sand/silica flour and stone dust/cement/graphite powder/chalk dust in the proportion by weight 2 to 4.5 is to 1 to 3 is to .1 . The aggregates are cleaned and dried at 100 to 350 degree Centigrade. The epoxy resin and hardener are

mixed in the proportion by weight 100 is to 6 to 10 and then the aggregate in the above mentioned proportion is mixed wilh "cpoxy rosin and hardener mixture" in the proportion by weight 3.2 to 10.5 is to 1 to complete the formation of epoxy concrete as a pouring material for casting.
Accordingly, the present invention provides a process for making moulded parts using epoxy concrete, prepared by the process of the present invention as described above, which comprises cleaning by known methods, a mould made of highly rigid material, treating the cleaned moult! with a known mould release agent, sealing the treated mould, pouring the epoxy concrete, compacting the epoxy concrete so poured to remove voids, repeating till the mould is completely filled and allowing it to stand for curing for a period in the range of 12 to 48 hours followed by demoulding and fine finishing, il roqu i r • The mould material may be wood, aluminium, wood with aluminium sheathing, etc for a temporary mould and a highly rigid material such as mild steel, spheroidal graphite iron, special steel, etc for a permanent mould.
The mould release agent used may be such as silicone grease, wax polish, ordinary grease.
The compaction of the epoxy concrete may be effected using means such as a vibrator, pressure, combination of pressure arid v j bra tor.

The sealing of the mould before pouring may be effected using plasticine, modelling clay, rubber/plastic sheet, soap.
The casting process of the present invention consists of preparation of mould made of wood, aluminium, mild steel, spheroidal graphite or any highly rigid material which may be called special purpose steel when the mould is having the surface finish of 0.15 to 0.95 micro meter and when the maximum aggregate or the filler size to the minimum thickness of finished product of epoxy concrete casting ratio is 0.15 to 0.5. The epoxy concrete prepared for casting is poured continuously or in batches into the properly clamped mould treated with mould release agent and compacted until the mould is completely filled up and left for curing for 12 to 48 hours.
The properly weighed raw materials, namely the resin the hardener and the filler materials in the proportions given in the statement above are mixed thoroughly in a suitable mixer and poured inside the mould made of materials and having requisite surface finish. The mould is surface treated with the mould release agent and the mould is sealed before the casting material is compacted suitably, say, through a vibrator/pressure or by other type of compactor with which the mould is rigidly clamped until the mould is completely filled up and allowed to remain for the duration

of curing time and taken out through demoulding and fine finish ing is done, if needed, to get the finished product.
The following examples are given by way of illustration of the present invention and should not be construed to limit the scope of the present invention :
Example 1
l.Epoxy Concrete Surface Grinder Bed-Ingredients used are stone chips, sand, cement & graphite powder, epoxy resin and hardener. Filler/binder ratio is 3.2 to 9.0. Weight of the casting is 360kg.
Example 2
2.Epoxy Concrete Lathe Machine Bed - Fillers are stone chips, sand & cement and binder is epoxy resin & hardener. Filler/binder ratio is 2.5 to 9.0. Weight of the bed is 132kg.
Example 3
3.Epoxy Concrete Centrifugal Pump - Fillers are gravel, sand, silica flour & cement and binder is epoxy resin & hardener. Weight of the casting is 45kg.
Example 4
4.Epoxy Concrete High Voltage Disc Insulator - Ingredients are stone dust, graphite powder, sand, epoxy resin and hardener. Filler/binder ratio is 3.5. Weight of the casting is 5.6kg.
Exaple 5
5.Epoxy Concrete Cylindrical Grinding Machine Bed - Fillers are stone chips, sand & stone dust and binder is epoxy resin & hardener. Filler/binder ratio is 3.2 to 7.5. Weight of the casting is 1200kg.

Example 6
6.Epoxy Concrete Non-corrosive Tank - Fillers are gravel, sand & stone chips dust and binder is epoxy resin & hardener. Filler-binder ratio is 10.0. Weight of the tank is 15kg.
The main advantages of the present invention are :
1.Excellent damping characteristics ( 4 to 8 times better to that of cast iron ).
2.Low cost ( in an average Rs.30-35 per kg as 1997 ).
3.Excellent dimensional accuracy of the cast parts, even with metallic inserts requires much less final machining.
4.Capital investment is low.
5.High dynamic stiffness.
S.Anti corrosive against a wide range of chemicals.
7.Easily repairable.
8.Excellent sound absorber.
9.Excellent surface finish.
10.Pleasing aesthetics.



We Claim:
1. A process for the preparation of epoxy concrete useful for making molded parts
which comprises:
i) cleaning and drying stone chips/gravel/granite, sand/silica flour and stone dust/cement/graphite powder/chalk dust by known methods, mixing the said cleaned and dried stone chips/gravel/granite, sand/silica flour and stone dust/cement/graphite powder/chalk dust in a ratio in the range of 2 to 4.5: 1 to 3: 1 by weight respectively to obtain an aggregate;
ii) mixing epoxy resin and hardener in a ratio in the range of 100 : 6 to 10 by weight to obtain a binder;
iii) mixing thoroughly the aggregate and binder, so obtained, in a ratio in the range of 3.2 to 10.5 : 1 by weight to obtain epoxy concrete.
2. A process as claimed in claim 1 wherein the stone chips/gravel/granite used is of
size in the range of (1.4-2.0) to (2!5-40) mm.
3. A process as claimed in claim 1 wherein the epoxy resin and hardener used is such
as thermosetting resin and amines, both aliphatic & aromatic, respectively.
4. A process for the preparation of epoxy concrete useful for making moulded parts
substantially as herein described with reference to the examples.


Documents:

498-del-1998-abstract.pdf

498-del-1998-claims.pdf

498-del-1998-correspondence-others.pdf

498-del-1998-correspondence-po.pdf

498-del-1998-description (complete).pdf

498-del-1998-form-1.pdf

498-del-1998-form-19.pdf

498-del-1998-form-2.pdf


Patent Number 216259
Indian Patent Application Number 498/DEL/1998
PG Journal Number 13/2008
Publication Date 28-Mar-2008
Grant Date 11-Mar-2008
Date of Filing 26-Feb-1998
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI 110001, INDIA
Inventors:
# Inventor's Name Inventor's Address
1 RAMESH CHANDRA BISHNU CENTRAL MECHANICAL ENGINEERING RESEARCH INSTITUTE, DURGAPUR
2 KRISHNAPADA ROYSARKAR CENTRAL MECHANICAL ENGINEERING RESEARCH INSTITUTE, DURGAPUR
PCT International Classification Number C04 B41/63
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA