The world over, efforts are being made for the safe disposal through development of cost-effective technologies to convert fast growing solid waste into useful products. In India, one such solid waste causing concern is the automobile windshield waste. The main sources of waste are automobile windshield manufacturers, dismantlers, recyclers, processors, etc. Automobile windshield waste emanating from various sources is a mixture of glass, PVB, additives, etc. The glass layer is fused with the PVB plastic film. Automobile windshield plastic film cannot be separated and is also not being recycled. At present, the reclaiming of PVB materials from automobile windshield waste is not being carried out in India. It is presently being thrown in dumpsites and land fill sites. It has negative impact both on human health and environment.
TopIntroduction
PVB can be a useful material for making protective primer/peelable coating for wooden and metal surface. The primer and strippable coating made using PVB recovered can be used in paint and coating industry. The use of protective primer and peelable paint made from PVB waste shall have the added advantages:
- ♦
PVB based primer for wooden surface prevent wood from damage by moisture and microbial attack. These primers provide excellent protection when applied prior to paints and top coat of wooden surface. It also ultimately reduces the paint consumption. It will be a good substitute to conventional primers.
- ♦
Protective peelable coating based on PVB can be used for various metal substrates like mild steel, steel, aluminum, zinc, etc. Peelable coating provides protection to metal against corrosion, abrasion and scratch. It can be used for protection of machinery parts, equipment and instruments. After its use, peelable coating can be easily removed by hand or mechanical peeling.
- ♦
An effective management of automobile windshield waste
- ♦
A cheaper replacement of commercially used wooden primer and rubber based peelable coatings
- ♦
Lower production cost while saving the cost of conventional resin (NC/alkyd/PU/epoxy, etc.)
- ♦
To minimize the environmental impact of disposal of automobile windshield waste.
Figure 1. A snapshot of windshield waste
In recent years, many researchers have claimed that the PVB material from various windshield waste and other sources can be reused for making value added products. The PVB can be useful protective coating materials as it has unique properties such as film forming, adhesive, flexibility etc. It has good bonding to various substrates such as metal, glass, wood, ceramic, etc.
A process has been developed for making protective primer and adhesive for wood using recovered PVB. A process has also been optimized for recovery of PVB from automobile windshield waste. The recovered PVB were characterized for solubility, melting point, thermal stability, film forming and adhesiveness. A process has also been developed to make peelable coating using recovered PVB for aluminum and mild steel surfaces. It has good film forming properties and can be easily removed after use.
No effective technologies exist at present within the country for separation of PVB embedded in glass laminates of automobile windshield waste and to make protective primer and peelable coating for wooden and metal surface.
The proposed technology once scaled up will enable to use recovered PVB from automobile windshield waste as a cheap raw material in making protective primer and peelable coating for wooden and metal surfaces. Moreover, it will also replace conventionally used polymer resin at least to some extent in paint industry. Further, this will lead to an effective waste management system for automobile windshield waste generation in huge quantity and making useful protective coatings for wood and metal.
Keeping this in background, a proposal is being submitted so that the PVB and glass waste emanating from automobile windshield manufacturers, dismantlers as well as automobile recycling industry may be reused to make glass articles, protective primer for wooden surface and peelable coating for metal substrate. This will also provide an opportunity to the manufacturers and users of glass, wood, metal and paint industry to have an alternative material PVB recovered from AWW.
SRI and Laxmi Polymers has established an industrial process/knowhow for making protective primer and peelable coating useful for wooden and metal surface using recovered PVB from automobile windshield waste. The infrastructure support for the plant shall be provided by the industrial partner Laxmi Polymer. The industrial scale process would provide and channel the recycle and reuse the materials in an effective manner and solve the solid waste management disposal of windshield waste generated by automotive industry resulting into safe and clean environment.
The main aim of this work is to scale up of the process for separating PVB from glass automobile windshield waste for its use making protective primer and peelable coating useful for wooden and metal substrate.