Live Stress Check from Constantia Flexibles Measures Strain on Coldform Foil
CONSTANTIA Live Stress Check determines the level of strain applied to coldform foil.
Constantia Flexibles, a global corporation that develops, manufactures and supplies flexible packaging solutions for the pharmaceutical, healthcare, home and personal care, food and beverage markets, has introduced the new Live Stress Check for its CONSTANTIA Coldform, one of the most popular pharmaceutical packaging solutions on the market.
CONSTANTIA Live Stress Check is an innovative tool that determines the strain level applied to coldform foil and the quality of the forming process when running on blister lines. Results are used to optimize the manufacturing process by uncovering improvements that can be made concerning forming plug designs, plug materials, and process setup.
To perform the stress check, a pattern of high-resolution dots is printed on the Coldform laminate which, when stretched, changes. The Live Stress Check sample, with cavities that were formed under production conditions, is inspected with a camera system and special software to determine these distortions. Afterwards, an automatically-generated 3D-image illustrates the degree of strain at various areas of the blister — valuable information that allows for significant improvements to both the overall process and the cavity shaping steps in particular.
A related service offered by Constantia Flexibles is a simulation of the so-called cross-permeation in coldform blister packs. This concerns the moisture that permeates into a blister cavity in very small quantities along the inner layers of the blister’s punched edge (moisture permeation is only possible along the punched edge, because the base foil’s aluminum creates a 100 percent barrier against water and oxygen).
Such cross-permeation can be controlled using laminates whose plastic layers provide a higher barrier to water vapor on the coldform laminate’s inside layer. For example, polyvinyl chloride films can be substituted by polypropylene films for added protection. Cross-permeation can also be influenced by the blister’s design. Often, correcting this sort of systemic flaw involves adjusting the sealing area or eliminating blister perforations altogether.
Constantia Flexibles’ simulation assesses the effect of using various plastics and/or making design changes to address cross-permeation. The effective early-stage test can significantly improve product shelf life while avoiding expensive mid-process reiterations. The result is increased speed to market, reduced materials waste, and an uptick in overall productivity.
CONSTANTIA Coldform is a key point of focus for Constantia Flexibles, as it offers superior barrier properties that help ensure drugs reach patients in best-possible condition, unsullied by moisture, light or oxygen. Unlike other blister packs, CONSTANTIA Coldform is not thermoformed, but brought into shape mechanically, creating a 100 percent barrier against the environment while increasing stability and extending product lifecycles.
