Substitution af PVC i plastkort

3. Summary and conclusions

The use of polyvinylchloride (PVC) in various products is undesired from an environmental point of view, due to problematic safety conditions during production of the material and especially due to the negative impact on the environment that accompanies incineration of the used products.

In the present study an investigation was carried out on the possibilities of substituting PVC in plastic cards of credit card format with materials less harmful to the environment. The materials polyethylene terephtalate (PET), acrylonitril-butadiene-styrene (ABS) and polycarbonate (PC) were considered for their potential suitability as substitution materials.

PVC circulation
A survey of the use of plastic cards in Denmark revealed a market in great progress, as the scope of use is widening rapidly. It is estimated that approximately 9 million cards were produced and issued in Denmark in 1995. This is equivalent to 45 tonnes of PVC. In the year 2000, these numbers are expected to reach ca. 15 million cards or 75 tonnes of PVC, if the use of substitution materials is not promoted.

Environmental assay
An environmental assay of PVC and the three alternative plastic materials showed that the use of any of the alternative materials would lead to environmental improvements as opposed to the continued use of PVC. The greatest improvement is expected to accompany the substitution of PVC with PET, as large improvements on the environmental impact as well as reduction of health risks during production would be expected. For substitution with PC or ABS, the reduction in environmental impact is expected to be less than that obtained by use of PET.

The employment of the substitution materials is accompanied by increasing energy requirements for production of raw materials and further processing. This is however, considered to be of secondary importance relative to the potential for improvements of the environment in general and to working environments. In the case of PET also, the increase in energy requirement for production is counteracted fully by an increased release of energy during incineration.

Product requirements
The most important feature of a plastic card is the possibility for electronic data storage. This is an essential requirement for approximately 95% of all plastic cards. Thus, it is imperative that substitution materials should allow function with magnetic strips and/or micro-chip, bar-code, optical coding etc.

Personal identification by photograph/signature, durability and appearance are important features too, while embossing and contact-less communication are less important features for the majority of the plastic card mass.

Alternative materials
Cards of ABS are priced similarly to PVC cards, while PET cards are 10-25 % more expensive. Both ABS and PET are regarded as realistic substitution materials for a large fraction of the PVC card mass. Also, such cards may be produced without considerable changes of technology or machinery. The use of PET however, does not permit laser inscription of photos etc., whereas ABS seems inappropriate for embossing with the existing technology. It seems though, that the joint use of PET and ABS may lead to substitution of a large fraction of the presently used PVC mass.

Cards of PC are approximately 60 % more expensive than cards of PVC, but are more durable and very suitable for laser inscription of photos etc. PC may thus be a very good alternative to PVC for driving licenses and other types of cards of long validity and with high security requirements.

Testing of PET
A test series of 2000 PET cards with magnetic strip for use in the finance sector was produced and tested during a full year. The experience was positive, as only minor adjustments to normal production procedures were necessary in order to produce high quality PET cards, i.e. cards with no reports of function problems during the entire test period.

The appearance of the PET cards, however, is more vulnerable to extensive use than is the case for PVC cards, i.e. more fine lines develop from repetitive use in reading apparatus. These problems are of entirely aesthetic nature and may be reduced through appropriate choice of colours or mat surface finish in order to minimise the visibility of the lines.

A technical examination of PET cards revealed good properties in all respects except the use of laser inscription. Laser inscription of PET cards may possibly be allowed through improvements of PET using new additives. Alternatively, combination materials may be introduced, featuring for example a thin layer of PC to allow laser inscription.

There are tendencies, however, towards a greater extent of electronical safety rather than visual features, especially through the development of new card functions of lower safety requirements. Therefore, the relative need for laser inscription is expected to decrease, whereas the tendency in terms of card numbers is unpredictable at present, mainly due to the importance of decisions in the finance sector on this point.

Testing of ABS
A series of 2 million ABS chip cards was made and issued for use as telephone cards, again without any reports of faults related to the material.

Substitution of PVC
In conclusion, it is expected that a large fraction of the PVC card mass may be substituted by PET, ABS or PC at present, and that almost the entire card mass may potentially be substituted, provided that the will to do so is present, i.e. possible design changes and use of other security systems than laser inscription may have to be accepted. Substitution is considered as preferential to the continued use of PVC, due to the lower environmental impact of the substitution materials.

Continued work into the improvement of PET or development of combination materials to allow laser inscription, or alternatively, development of new substitution materials, may be necessary before PVC can be substituted in a part of the card mass for which a high level of both electronic and visual security is required. This, however, is estimated to be less than 10 % of the total card mass.

The price of cards made from ABS is at present comparable to the price of PVC cards, whereas the prices for PET and PC cards are higher by approximately 10-25 % and 60 %, respectively.

Of the materials in regard, PET causes the lowest environmental impact, and should - from an environmental point of view - be chosen whenever possible.