Title of Invention

"A PROCESS FOR THE PREPARATION OF MINWOOL FIBRE REINFORCED THERMOPLASTIC/ THERMOPLASTIC BLEND COMPOSITES"

Abstract This invention relates to process for the preparation of minwool fibre reinforced thermoplastic /thermoplastic blend composites. This invention particularly relates to making of minwool fibre reinforced thermoplastic/thermoplastic blend composites by melt blending. Minwool fibre mixed polymer composites can be used for moulding to make utility items such as tubes, profiles, bars, containers, boxes, cabinets, building materials, electrical insulations items and the like. Process steps are: drying the thermoplastic polymer/blends 1 to 95 wt % and minwool fibre 1-95 wt % of polymer in an oven at 70° C, mixing the said mixture of thermoplastic polymer and minwool in a single screw extruder at 220° C at rotation speed of screw being 20 rpm to obtain the product.
Full Text This invention relates to process for the preparation of minwool fibre reinforced thermoplastic composite.
This invention particularly relates to making of minwool fibre reinforced thermoplastic/thermoplastic blend composites by melt blending. Minwool fibre mixed polymer composites can be used for moulding to make utility items such as tubes, profiles, bars, containers, boxes, cabinets, building materials, electrical insulations items and the like.
Minwool is added in polymers to improve the properties of polymer in order to achieve desirable properties such as high temperature stability, and better electrical insulations etc.
In most of the polymers such as Polypropylene, polyethylene, Nylon-6, polystyrene, polycarbonate and poly vinyl chloride etc. different types of fillers and reinforcements such as CaC03, glass fibres have been added in the past by melt mixing technique.
Many companies and researches have incorporated different size glass fibres in different polymers to improve their mechanical strengths by using melt mixing methods. Glass fibre is costlier as compared to most of the polymers. Process of preparation of glass fibre surface and dimensionp is very costly and difficult.
A common method of mixing is known as melt mixing. Melt mixing is carried out either by extruder, kneader, banbury mixer

or by tow roll mixing mill at elevated temperature (above melting temperature of polymer) and then cooled to room temperature for making utility items mentioned above.
The main object of the present invention is to provide a process for the preparation of minwool fibre reinforced thermoplastic/thermoplastic blend composites.
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Accordingly the present invention provides a process for the preparation of minwool reinforced thermoplastic/thermoplastic blend composites which comprises: drying the thermoplastic polymer/blends 1 to 95 wt % and minwool fibre 1-95 wt % of polymer an oven at 70° C, mixing the said mixture of thermoplastic polymer and minwool i single screw extruder at 220° C at rotation speed of screw being 20 rpm to obtain the product.
The thermoplastic polymer used may be such as polypropylene, polyethylene, polyvinyl chloride, polymethyl methacrylate, polycarbonate, polyamides and crystalline polymers or mixtures thereof.
The ratio of polymers used for blending may be in the range from 1 to 95% by weight. The amount of minwool fibres used may be in the range of 1 to 95 wt % of polymer.
The present invention provides a simple process for minwool fibre reinforced which comprises heating of the mixture to its softening temperature; mixing in a single screw extruder until uniform compositions is obtained.
Apart from minwool several other mineral particles like calcium carbonate, talc, silica, etc. Can be used along with minwool fibres in this process. These particles are fine.

Addition of this fibre, increases the thermal stability of the system and reduces the rate of crystallization of high melting temperature polymer. Addition of minwool fibres in the polymers/polymer blends will improve thermal stability alongwith other properties.
In case of blend composites two different polymers alongwith weighed amount of minerwool (Minwool) fibres is mixed mechanically, this mix is then melted and mixed through single screw extruder and extrudate were cut in to 2-4 mm. length.
The invention is described with the help of the following examples and should not, therefore be construed as limiting the scope of the invention.
Example 1
160 gms. polypropylene, 40 gms. low density polyethylene and 20 gms. minwool fibres were kept in air circulating oven at 70°C to dry the materials. These materials were mixed at 220°C in a single screw extruder. The rotation speed of screw was 20rpm. These extrudate were cut into the granules using a cutter. Tensile strength of this PP/LDPE/MW composite was 23.38 MPa.
Example 2
In this case 160 gms. polypropylene, 40 gms. high density polyethylene and 20 gms. minwool fibres were kept in air circulating oven at 70°C to dry the materials. These materials were mixed at 220°C on a single screw extruder. The rotation speed of screw was 20rpm. These extrudate were cut into the granules using a cutter. Tensile strength of this PP/HDPE/MW composite was 22.15 MPa.

ADVANTAGES OF THE PRESENT INVENTION
1) This invention provides new compositions based on polymers/
polymer blends with minwool fibres having improved thermal
stability.
2) This provides homogeneous mix minwool reinforced
polymers/blends composites.
3) These new polymer/ polymer blend based compositions can be
used for molding purpose for various electrical/ structural/
building applications.





We Claim:
1. A process for the preparation of minwool reinforced thermoplastic /thermoplastic
blend composites which comprises: drying the thermoplastic polymer/blends 1 to 95
wt % and minwool fibre 1-95 wt % of polymer in an oven at 70° C, mixing the said
mixture of thermoplastic polymer and minwool in a single screw extruder at 220° C
at rotation speed of screw being 20 rpm to obtain the product.
2. A process as claimed in claim 1, wherein the thermoplastic polymer used is selected
from polypropylene, polyethylene, polyvinyl chloride, polymethyl methacrylate,
poly-carbonate, polyamides and crystalline polymers or mixtures thereof.
3. A process as claimed in claim 1, wherein minwool fibers is optionally mixed with
mineral particles such as calcium carbonate, talc, silica.
4. A process as claimed in claim 1 wherein the mixing is effected under constant
rotation in a single screw extruder.
5. A process for the preparation of minwool reinforced thermoplastic/thermoplastic
blend composites substantially as herein described with reference to the examples.


Documents:

1111-del-1998-abstract.pdf

1111-del-1998-claims.pdf

1111-del-1998-correspondence-others.pdf

1111-del-1998-correspondence-po.pdf

1111-del-1998-description (complete).pdf

1111-del-1998-form-1.pdf

1111-del-1998-form-19.pdf

1111-del-1998-form-2.pdf

1111-del-1998-form-3.pdf


Patent Number 215610
Indian Patent Application Number 1111/DEL/1998
PG Journal Number 11/2008
Publication Date 14-Mar-2008
Grant Date 28-Feb-2008
Date of Filing 27-Apr-1998
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI - 110 001, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 NAVIN CHAND REGIONAL RESEARCH LABORATORY (CSIR)HOSHNGABAD ROAD, BHOPAL, INDIA
2 S. VASHISHTHA REGIONAL RESEARCH LABORATORY (CSIR)HOSHNGABAD ROAD, BHOPAL, INDIA
PCT International Classification Number C08L 23/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA