PVC is one of the monta key backing materials to be used in the production of self-adhesive packaging tapes. Over 60% of the monta production is related to PVC products. Worldwide approximately 30,000t of PVC film is produced for the tape industry and quantities continue to be stable. PVC film coated with a natural rubber adhesive remains a high-quality product and the requirement to use PVC in printing and hand roll applications is unrivalled. The main advantages PVC offers are the easy and direct printability, the low noise and smooth unwinding, the low elongation and the hand tearability, just to mention a few.
The negative discussion about the commodity PVC in general and its environmental effect in the early 90s has slowed down significantly in the last years – and justifiably so. The positive characteristics of PVC have been more and more emphasized in the meanwhile and are almost overbalancing the critical points. Nevertheless only an ecobalance/lifecycle assessment would bring light to the whole discussion.
We would like to take the opportunity to provide some more background about the commodity of PVC in general and in connection with self-adhesive packaging.
Gallazzi, one of the leading producers of PVC film for the tape industry describes the material PVC (polyvinyl chloride) generally as follows:
PVC holds a main position amongst the plastics we encounter every day. It was one of the earliest developed commodities and is still the most widely used one. PVC is non-flammable, robust and durable, it is impermeable and does not deteriorate. It is easy to maintain and gives excellent value for money. Its physical and mechanical characteristics make it ideal for many different uses.
Looking at the origins of PVC, we are right back at the sea. Salt (57%) and oil (43%), both natural resources, form the basic elements for PVC. Through a polymerization process a fine white powder (vinyl chloride polymer) is achieved which will be mixed with several additives such as:
- Stabilizers to allow the PVC resin to be processed without thermal degradation during moulding, extrusion or calandering and to give good heat resistance to the final product
- Additives to give PVC great mechanical properties
- Pigments to be able to also produce coloured PVC
The process when PVC resins and additives are homogeneously mixed in high-speed mixers is called ‘blending’. The PVC blend achieved from this process is then led into a heated cylinder, known as an extruder. The result from the extruder process, a ‘hot homogeneous PVC dough’, is then fed in a so-called calander to transform the PVC compound into a rigid PVC film. This rigid PVC film is used for the production of PVC packaging tapes. It is available in various thicknesses and colours and also in an embossed version.
In connection with PVC the media often talks about phthalates, i.e. plasticizers to make vinyl more flexible. The PVC film used in self-adhesive packaging tapes is a rigid emulsion PVC film which is DEHP (Diethylhexylphthalate) and phthalate free.
PVC products when separated correctly can be burned in specially equipped incinerators and transformed partially in energy. Nowadays PVC can also be mechanically recycled. This means that the waste is directly converted in a different product with a new lifecycle. This only makes sense ecologically and economically where sufficient quantities of homogeneous, separated and sorted waste are available.
Please contact us at our website to find out more about our PVC packaging tape range.
(This article is based on an intensive exchange of information with Gallazzi, Italy.)