EVAL™ Properties / Durability

Durability

Long-Term Thermal Stability of EVAL™ Resins

When properly selected, EVAL™ resins will offer a good ageing resistance even when exposed to relatively high temperatures. This long-term and thermal stability of EVAL™ can be increased by adding anti-oxidants or thermal stabilisers.

Tests conducted in Kuraray's R&D centre have given the following results:

UV-Resistance

UV radiation affects the properties of polymers and influences their mechanical and optical behaviour. Kuraray R&D centre has studied the UV resistance or weatherability of EVAL™ films in comparison with other polymers.

The following properties were examined:

The results indicate that EVAL™ resins display excellent UV-resistance. Even when exposed to outdoor conditions, the polymer retains its colour. It will not turn yellow or become opaque. Mechanical property changes are minimal, demonstrating an overall high resistance to weather effects.

 

Radiation Resistance

The effects of radiation on most polymers range from discoloration to loss of physical properties. This deterioration can take place at irradiation levels as low as mega rads with Gamma rays and becomes extremely pronounced at the five mega rad level.
Various stabiliser systems must be used to protect polymers from the irradiation effects. Some of these systems are not approved by the Food packaging Regulations.

EVAL™ resins however, maintain their physical properties after being radiated and show no discoloration.