PVC-Free Polymer Sealing Insert for Fat-Containing Food Closures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vessel closures with larger inner diameters face challenges in providing PVC-free sealing inserts that comply with migration regulations, maintain sealing properties, and withstand sterilization conditions, especially when used for fatty or oily foods.
Innovation Solution
A PVC-free sealing insert is developed using a polymer compound comprising a polymeric component with an olefin block copolymer and random copolymer, with minimal or no liquid components, no plasticizers, and specific additives like antioxidants and lubricants, processed to ensure low migration and effective sealing across various temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PVC-containing compounds are used for sealing inserts in vessel closures with larger inner diameters, then sufficient flowability during production and sealing properties are achieved, but migration of chemical components into food exceeds legal limits and harmful substances are released
Solution Approach 1:
The invention extracts and removes PVC and plasticizers from the sealing compound formulation, replacing them with alternative polymers (polyethylene, polypropylene, elastomers) that provide equivalent sealing properties without the harmful migration issues. This extraction of harmful components while maintaining functional performance directly resolves the contradiction between reliable sealing and chemical safety.
Solution Approach 2:
The invention uses composite materials consisting of multiple polymer components (polyethylene, polypropylene, elastomers, and other additives) to replace the single-component PVC system. This composite approach allows optimization of each component for specific functions (flowability, sealing, elasticity) while ensuring none of the components migrate harmful substances, thus achieving both reliable sealing and chemical safety.
2Object-affected harmful factors
If PVC-free compounds are used to eliminate migration issues, then chemical safety is improved, but achieving sufficient flowability and sealing properties for larger vessel diameters becomes difficult
Solution Approach 1:
The invention changes the physical and chemical parameters of the sealing compound by selecting polymers with appropriate melting points, viscosities, and flow characteristics. The multi-component polymer system is formulated to exhibit optimal flowability at processing temperatures while maintaining chemical safety, thus resolving the contradiction between manufacturability and chemical safety.
3Adaptability or versatility
If sealing inserts are designed for vessels with larger inner diameters, then applicability to various vessel sizes is improved, but the amount of material increases leading to higher migration risk
Solution Approach 1:
By removing PVC and plasticizers from the formulation, the invention eliminates the primary migrating substances from the sealing compound. This extraction ensures that even when larger amounts of material are used for larger vessel diameters, the migration risk remains minimal because the harmful components have been removed entirely, thus resolving the contradiction between versatility and migration risk.
Data Source
AI summary
The invention relates to a polymer compound for a sealing insert for a container closure, in particular for fat-containing filling materials, which has a composition such that the migration of constituents of the compound into the filling material is reduced, characterised in that the Shore A hardness of the polymer compound is between 45 and 95 and in the compressive deformation test analogous to ASTM D395-97 Method B at 70 °C the polymer compound exhibits a compression set of 30-90%.