Process of BOPP Film

Manufacturing Process of BOPP Film: BOPP film is manufactured with the blown method.  Molten resin is extruded from a circular die to form a thick tube. The tube is stretched with air pressure at controlled temperature to achieve transverse orientation and simultaneously pulled by take off nips to achieve machine direction orientation. 

Grading of Polypropylene: 

Trade Names:

1. Haldia Petrochemicals Ltd, India - Halene PP

2. IPCL, India - Koylene 

3. Reliance, India - Repol 

3. Exxon Mobil, US - Escorene 

4. Mitsui petrochemical, Japan - Sunlet PP

5. Mobil Chemical, US - Bicor PP

6. Sumitomo, Japan - Esprene 

7. Mitsubishi , Japan, - Noblen 

Applications: 

1. Automotive: PP is used in bumpers, steering wheel covers, profiles, consoles, door pockets, radiator grills, spoilers, rubbing strips, fenders, wheel arches, truck linings, mud flaps, seat covers, plumbing, integral hinges, accelerator pedals, glove boxes and air- intake noise suppressors.

2. Packaging: PP is used in packaging for goods wrapping, sleeping bags, films for packing tobacco products, candy, cosmetics, contact lens cases, first aid cases, drums and jerry cans, tool boxes, cheese wrap, electrical capacitors, synthetic turf, clothing inner liners, wiping clothes, films for textile goods and medicines.

3. Electrical / Electronics: PP is used in cable connectors and fittings, cable and wire coatings, industrial lights, transformer housings, insulators for electrical fencing, aerial parts, switch gears, radio and TV housings, capacitors, coil forms, control knobs etc.

4. Appliances :PP is used in dish racks, pump housings, door handles, air cleaners and washing machine parts, bleach and detergent dispensing units, agitators, tub liners, housing for appliances, valve and control assemblies, drain tubes, PP silverware baskets. 

5. Household: PP is used in buckets, thermo flask cases, strainers and chairs, baby feeding bottle warmers, microwave oven trays, labels for soft drink bottles, canvass for luggage, air conditioner parts, floor and ceiling pans, dehumidifiers, room humidifiers, knife sharpeners, can openers, hair dryers, coffee makers. 

Modification of Polyolefins:

1. Ethylene-vinyl acetate (EVA) copolymer.

2. Ethylene-ethyl acrylate (EEA) copolymer.

3. Ethylene-methyl acrylate (EMA) copolymer.

4. Ethylene-acrylic/methacrylic acid copolymer.

5. Ethylene-propylene copolymer.

Ethylene–Vinyl acetate (EVA) copolymer:

1. Both filled and unfilled EVA copolymers have good low temperature flexibility and toughness.

2. EVA with 15-20 mol % Vinyl acetate content are rubbery copolymers.

3. About 28% Vinyl acetate content are used in hot–melt adhesives.

4. EVA films are used for liquid packaging, frozen foods, meat wrap, ice bags, drum liner. 

5. Molded and extruded EVA resins are use in flexible toys, bumper pads, hose , gasketing. 

Ethylene–acrylate copolymers:

1. Ethylene–ethyl acrylate (EEA) and ethylene–methyl acrylate (EMA) copolymers with up to 20% weight EA, MA content respectively are commercially available.

2. EEA resins have higher thermal stability and can withstand higher processing temperatures than EVA.

3. EMA resins yield blow film with rubber like limpness and extremely high dart-drop impact strength. They find useful applications in extrusion coating, co-extrusion and laminating applications.

Ethylene–acrylic/methacrylic acid copolymers (EAA/EMa):

1. Copolymers up to 6.5% acrylic acid and 15% by  weight of methacrylic acid are used for melt processing applications. 

2. The acid group promotes excellent adhesion to various substrates and increases abrasion resistance and stress cracking resistance.

3. These resins are extrusion coating onto aluminium foil for pouches, for composite toothpaste tubes, wire and cable applications, blown or extruded films for packaging of food and other products and various lamination applications. 

Ethylene–Propylene Copolymers: 

1. Two main types of ethylene (E) propylene (P) resins are EPM and a terpolymer (EPDM).

2. Rubbers which are rich in either ethylene or propylene have higher tensile strength and elongation at break (%) in the unvulcanized state than those rubbers which contain equal amounts of E and P. 

3. EPM rubbers can be vulcanized only by peroxides or high energy radiation. 

4. In EPDM the third monomer has two double bonds; one enters the polymerization process and the other C=C bond remains as a side chain available for vulcanization with sulphur/accelerator systems.