On the other hand, when very sensitive medications are on the line, a coldform blister should be the first choice. Why? Because it is time for a change of perspective in this area, and the comparison with thermoformed materials is often reduced to just the blister size. However: Coldform foil offers a 100% barrier against oxygen, water vapor and light.
Thermoformed materials do not offer this complete protection. Furthermore, the barrier properties of coldform foil are not changed by the forming process. To put it another way: The barrier is independent from the thickness of the aluminum. For plastics, the barrier also depends on the thickness of the plastic layer. This means that a formed cavity has lower barrier properties than the unformed film. Plus: Coldform foil can be inspected on the blister packaging line using light detection units to spot holes and cracks – this is still not possible with transparent thermoformed blisters. In other words, it is not possible to detect the number of defects after thermoforming. With coldform foil, things are different since one can easily ensure that the coldform laminate will still possess the required barrier properties after forming. In the area of efficiency, coldform foil also leads the way, especially when high demands are placed on the water vapor barrier. For this reason alone high barrier thermoformed laminates are so expensive that coldform foil is the more economical alternative. If you have questions about the many advantages of CONSTANTIA Coldform, our experts are ready to assist you. Just send an email to Wilhelm.Zuser(at)patz.cflex.com.