MATERIALS FOR FOOD PACKAGING
Learning outcomes of the course unit
KNOWLEDGE AND ABILITY TO UNDERSTAND
At the end of the course, the student shall have acquired the main knowledge related to the skills in testing and characterization of packaging components.
The student shall be able to make informed choices in the selection of the many packaging options available today. The student shall be able to use the acquired knowledge to analyse and process numerical data, to support the relative decision-making choices.
AUTONOMY OF JUDGMENT
Upon passing the exam, the student should have developed the ability to critically evaluate the analytical data of the mechanical behaviour of a material to predict its behaviour on site, as well as the ability to interpret the data of acceptance controls of a material to be employed.
Upon passing the exam, the student should have gained enough ownership of language, at least as far as the specific technical and chemical terminology of the teaching is concerned.
The students who have attended the course will be able to deepen their knowledge of food packaging materials, through the autonomous consultation of specialized texts, scientific or popular magazines, even outside of the topics dealt with strictly in class. The possible final seminar activities will have the aim of introducing the student to the most recent developments in terms of research in the field of materials applied to food packaging: the student should have acquired the basic knowledge and skills of the discipline to face, in the future, an autonomous deepening of these aspects.
Knowledge of Chemistry and Applied Chemistry Technology are useful bases for a successful course management.
Course contents summary
INTRODUCTION. Terminology. Purposes and characteristics of the conditioning operation.
CHEMICAL PROPERTIES. Chemical structure, characteristics and resistance of materials.
PHYSICAL PROPERTIES. Thermal properties. Optical properties. The behavior of a material to ionizing radiation. The behavior of a material to microwave radiation. Mechanical properties.
PACKAGING MATERIALS. Glass. Ceramics. Cellulosic materials. Paper and cardboard. Cellophane - Regenerated Cellulose. Plastics.
INTRODUCTION. Terminology. Purpose and characteristics of the packaging: containment, protection, communication. Chemical properties of packaging materials. Chemical structure and material characteristics. Atomic constituents. Ties between atoms. Molecular bonds. Molecular organization.
CHEMICAL PROPERTIES OF INTEREST FOR PACKAGING MATERIALS. Resistance to oils and fats. Stress cracking resistance. Combustion behaviour. Biodegradability, biodeterioration, biotoxicity, biofilm formation.
PHYSICAL PROPERTIES OF PACKAGING MATERIALS. Surface, thermal, mechanical and electromagnetic properties. Surface properties. Surface tension, wettability and adhesiveness. Measurement methods of surface properties. Relationship between contact angle and surface energy. Surface energy modification.
THERMAL PROPERTIES: Thermal conductivity. Thermal capacity and specific heat. Thermal expansion coefficients. Useful temperature range (range of use). Calorific value and energy content. Transition temperatures.
MECHANICAL PROPERTIES: Slide resistance (friction). Mechanical resistance. Properties related to dynamic stresses. Cushioning properties.
ELECTROMAGNETIC PROPERTIES: Interactions between electromagnetic radiation and matter. Electromagnetic properties of packaging materials in the ultraviolet and visible regions. Behaviour of a material subjected to ionizing radiation. Behaviour of a radiated microwave material. Density and relative properties. Density. Weight.
GLASS AND GLASS PACKAGING. Chemical structure of the glass. Glass production. Physical and chemical properties of glass. Mechanical properties. Thermal properties. Optical properties. Chemical reactivity. Glass container production technologies. Press and blow process. Blow and Blow process. Annealing. Quality control. Glass container strengthening techniques. Ceramics and other terracottas.
METALLIC MATERIALS FOR PACKAGING. Steel and aluminium. Tinplate and tin-free steel.
CELLULOSE MATERIALS AND PACKAGING. Morphological structure of cellulosic fibres. Chemical structure of cellulosic fibres. Lignin. Hemicellulose. Cellulose. Paper and cardboard. Raw materials for the production of paper and cardboard. Production technologies. Additives used in the production of paper and cardboard. Special papers. Properties of paper. Corrugated cardboard. Stretched cardboard. Patinated cardboard. Moulded cellulose. Pulp of cellulose. Cellophane. Regenerated cellulose. Envelopes and paper bags. Folding cases. Corrugated cardboard boxes.
PLASTIC MATERIALS AND PACKAGING. Structure and properties of plastic materials. Nature of raw materials. Polymerization mechanism. Tacticity. Molecular weight. Heat behaviour. Glass transition temperature. Morphology. Structural organization. Polymer blends (blends) and polymeric alloys (alloys). Structural modifications of plastics. Orientation. Heat shrinking. Main polymers used in food packaging. Most common polymers. Soldering polymers. Polymers with a high gas barrier. Less common polymers. Symbols and abbreviations of polymers and some of their characteristics. Packaging materials and plastic packaging. Additives of plastics. Movie. Biodegradable polymeric materials for packaging: types and characteristics. Mater-Bi. The PLA.
Luciano Piergiovanni, Sara Limbo “Food Packaging Materials” (SpringerBriefs in Molecular Science) (English Edition), 2016
G. L. Robertson “Food Packaging ans Shelf life: A practical Guide”. CRC Press / Taylor & Francis Group, 2009.
Oral lessons with the support of Power Point. Educational visits consistent with the availability of the Companies.
Assessment methods and criteria
Written exam consisting of 5 questions to each of which up to 6 points are awarded. The student who has taken at least 18/30 in the written test can ask to take an oral supplement. The vote of the written exam together with the vote of an oral presentation on a topic of choice (related to the course) will allow to reach the final grade.