PVC worldwide is one of the oldest standard plastics. Its consumption for liquid packaging has increased at an annual rate of 8.5% between 1978 and 1983. Penetration of PVC bottles was in replacing glass and cans for packaging of mineral water, cooking oil, detergents, etc. PET has now made inroads replacing traditional packaging material like glass & cans for soft drinks, and PVC for other packaging, currently accounting for approximately 80% of total consumptions. Pharmaceutical blister is another potential area which has been targeted in replacing PVC. Below various properties are compared for PET and PVC.

PVC consists by more than 50% of chlorine derived from electrolytic decomposition of salt or else as a by product from manufacturing of sodalye. Pure PVC is not very stable to heat, has moderate dimensional stability under heat, becomes brittle at low temperatures and ages rapidly, losing its strength and turning yellow. These can be overcome by adding suitable stabilizer but this all adds to the cost of compound. PET is 100% dependent upon hydrocarbon feed stocks, derived from natural gas or petroleum products.

Permeation of carbon dioxide and oxide plus other glass through the wall of a PET container is lower compared to PVC. Moisture vapour transmission rate of PET & PVC are almost similar. Tensile strength of PET & PVC comparable. Impact strength for PET is higher than that of PVC. Flexural creep modulus of the two materials show clearly PET creeps less under load.

Except for its sensitivity to moisture content, and its tendency to generate acetaldehyde, PET is relatively easy and stable polymer to process. On the other hand, while PVC is not quite as moisture sensitive, the polymer is subject to rather rapid heat degradation if allowed to stagnate or remain at elevated temperature encountered during processing.

Visually, PET is more transparent, bright and shiny/glossy than PVC and it is glasslike, while PVC has either a yellowish and bluish tint.

In regard to discussions of PVC and municipal waste, a lot of arguments against PVC are not justified. However, these discussions have led to the fact that the public and environmentalist groups have put PVC under gunfire. PET has benefited from these "discussions" by expanding its applications. In public opinion PET is viewed as a packaging material which is clean and does not have impact on the environment as large as other plastics. Further more, the recycling activities for PET has helped to promote this packaging material.

The major product currently being made from recycled PET bottle material is polyester fiber fill. The empty bottles are collected, compacted into bails for transport purpose and later granulated.

When PET scrap is burnt with municipal waste, it generates heat equivalent to that of low grade coal. Combustion gases (CO2 + H2O) are essentially clean because PET contains no halogens, sulfur, or other difficult to dispose compounds.

PET sheets are penetrating the pharmaceutical industry especially for blister packaging and medical disposable packaging apart from other applications replacing PVC such as toothbrushes, cosmetics, toiletries, food and confectionery etc.

Material PET PVC PMMA ABS

• Absolutely safe for food/medicine contact

• Better barrier properties

• Environment friendly and suitability for re-cycling

• Cost effectiveness due to availability at prices at par with PVC.