Peelable packaging: the conflicting demands of product safety and consumer convenience
The use of peelable packaging is gaining ground not only in the food sector but also in the field of medicinal products. It simplifies product handling and thereby minimizes the risk of contamination, particularly with sterile products. To ensure that easy-to-open packaging is both safe and consumer friendly, it needs to be openable with minimal force while remaining tightly and hygienically sealed during storage and transport. Moreover, it is important that no cracking or so-called angel hair should appear in the packaging as it is being opened.
Influence of key parameters on openability
A host of parameters influence the openability of peelable packaging. These include:
- Material properties
- Sealing parameters
- Location and direction of applied force
- Packaging design
To facilitate the efficient design of safe and easy-to-open packaging, it was therefore necessary to develop a tool that calculates in advance the ideal opening force while taking these key parameters into account.
Development of the PeelForceCalculator
This calculation is based on a description of the initiation and propagation of cracking in the sealed seam during the opening process as a function of the composition of the packaging film (carrier and peel layer). The sealing conditions and seam formation were also taken into account. Structure-property correlations were drawn up on the basis of peel tests and structural analyses. These enabled a description of the relationship between the polymer structure, the adhesion mechanisms and the resulting crack-formation processes. In addition, the geometrical conditions during peeling (length of peel line, direction of opening) were also investigated using real packaging and then compared with classic tests on plastic film stripn.
The PeelForceCalculator provides an pre-calculation of the force required to open peelable packaging. This tool will be used during the design and development phase together with CAD data of the sealed seam contour. It will therefore minimize costs and reduce the use of material.
Tool as a smart service
The PeelForceCalculator tool was developed in the course of the EasyReliablePeel project. It has been available for use in conjunction with development orders from industry as of the end of 2020. There are also plans underway to offer the tool online as a smart service.