Power Point Presentation SUBJECT CODE & NAME 20AG105PE STORAGE AND PACKING TECHNOLOGY UNIT – 4 FOOD PACKAGING MATERIALS AND TESTING Prepared by, Dr. P. Dineshkumar M.E., Ph.D., Assistant Professor, Department of Agricultural Engineering, Kongunadu College of Engineering and Technology. Dr. P. Dineshkumar / AP / AGE / KNCET 1 INTRODUCTION • Food packaging materials are essential components in the food industry, serving multiple purposes ranging from preserving and protecting food products to providing information and branding opportunities . • Food packaging materials serve as a crucial barrier, shielding food products from external factors that can compromise their quality and safety. • By creating a protective environment, packaging materials help extend the shelf life of perishable foods, prevent spoilage, and maintain product freshness. • Plastics, such as polyethylene, polypropylene, and polystyrene, are widely used due to their versatility, lightweight nature, and cost-effectiveness • Paper and cardboard are commonly used for packaging dry goods and are often preferred for their recyclability and eco-friendliness • Chemical analysis is conducted to determine the composition of the materials and to identify the presence of hazardous substances such as heavy metals, phthalates, and volatile organic compounds (VOCs) • Tensile strength tests measure the material's ability to resist deformation or breakage under tension, simulating stresses experienced during handling, transportation, and storage • Other mechanical tests such as impact resistance and compression strength evaluate the material's ability to withstand external forces and protect the contents • In conclusion, food packaging materials play a crucial role in preserving, protecting, and presenting food products to consumers • Through rigorous testing, these materials are evaluated for safety, quality, and performance to ensure they meet regulatory requirements and maintain the integrity of the packaged food PAPER & PAPER BOARDS Paper and paperboards are widely used in the food packaging industry due to their versatility, eco-friendliness, and cost-effectiveness. These materials are derived from plant fibers, primarily wood pulp, and offer various advantages for packaging applications. • Versatility: Paper and paperboards can be easily shaped, folded, and formed into different packaging formats such as boxes, cartons, trays, bags, and sleeves. They provide flexibility in design, allowing for customization and branding opportunities • Eco-Friendliness: Paper and paperboards are renewable and recyclable materials, making them a sustainable choice for food packaging. They have a lower carbon footprint compared to materials like plastics and metals. • Printability: Paper and paperboards offer excellent printability, allowing for vibrant graphics, branding, and product information. This enhances product visibility and consumer appeal • Safety: Paper and paperboards used in food packaging undergo rigorous testing to ensure they are safe and do not pose any health risks • Absorbency: Paper has absorbent properties, which can be advantageous for certain, food products. It can absorb excess moisture, helping to maintain product quality and reduce surface oiliness • Limited Barrier Properties: While paper and paperboards can provide some level of protection against light, they have limited barrier properties compared to materials like plastics and metals • Storage Considerations: Paper-based packaging materials may have limitations in terms of resistance to moisture and physical damage. Careful consideration should be given to storage conditions to avoid deterioration or loss of functionality • Types of Paper and Paperboards :Some common types include kraft paper, folding carton board, solid bleached sulfate (SBS) board, and recycled paperboard. These materials vary in terms of strength, thickness, surface finish, and printing capabilities, allowing for diverse packaging solutions • Sustainability and Recyclability: Paper and paperboards are considered environmentally friendly packaging materials due to their renewability and recyclability • Coatings and Laminations: To enhance the performance of paper and paperboards in food packaging, they can be coated or laminated with various materials. Coatings such as polyethylene (PE) or polypropylene (PP) can improve moisture resistance • Direct Food Contact: Paper and paperboards used in food packaging must comply with regulations for direct food contact. They are required to meet specific safety standards and undergo testing to ensure they do not transfer harmful substances into the packaged food • Applications: Paper and paperboards are utilized in a wide range of food packaging applications. They are commonly used for packaging dry goods like cereals, snacks, and baked goods. Additionally, they are employed for beverage cartons, fast-food packaging, takeout containers, and foodservice trays • Sustainability Certifications: Various certification programs, such as the Forest Stewardship Council (FSC) and the Sustainable Forestry Initiative (SFI), provide assurance that the paper and paperboards used in food packaging come from responsibly managed forests • Barrier Enhancement Techniques: While paper and paperboards have inherent limitations in terms of barrier properties, manufacturers employ techniques to enhance their resistance to moisture, grease, and other contaminants. This includes incorporating barrier coatings, laminations, or using specialized grades of paper with improved barrier characteristics. FLEXIBLE FOOD PACKAGING MATERIALS • Types of Materials: Flexible food packaging materials encompass a wide range of materials, including plastics, films, and laminates. Common plastic materials used include polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and polyvinyl chloride (PVC) • Barrier Properties: Flexible packaging materials are designed to provide specific barrier properties to protect the food product from external factors. These properties include moisture resistance, oxygen barrier, light protection, aroma barrier, and grease resistance • Versatility and Convenience: Flexible packaging materials offer versatility in terms of shape, size, and functionality. They can be easily formed into various formats such as pouches, bags, wraps, and sachets, providing convenience for consumers • Printability and Branding: Flexible packaging materials provide excellent printability, allowing for vibrant graphics, product information, and branding opportunities • Shelf Appeal and Product Visibility: Transparent or semi-transparent flexible packaging materials, such as clear films and laminates, enable visibility of the packaged food product • Packaging Efficiency: Flexible packaging materials offer advantages in terms of packaging efficiency. They often require less material compared to rigid packaging alternatives, leading to reduced packaging waste and transportation costs • Sustainability Considerations: While flexible packaging materials provide numerous benefits, their environmental impact is a growing concern. Efforts are being made to improve the sustainability of flexible packaging through initiatives such as utilizing recyclable materials, incorporating bio-based and compostable films, and implementing recycling programs for these materials PLASTICS • Types of Plastics: There are various types of plastics used in food packaging, including polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), and polyvinyl chloride (PVC) • Barrier Properties: Plastics offer excellent barrier properties, providing protection against moisture, oxygen, light, and other external factors that can degrade food quality • Versatility and Design Flexibility: Plastics are highly versatile, allowing for a wide range of packaging designs and formats. This versatility enables customization and branding opportunities, enhancing product visibility and consumer appeal • Lightweight and Portability: Plastics are lightweight materials, making them ideal for packaging products that require portability and convenience. Lightweight plastic packaging also improves consumer convenience by reducing the overall weight of the packaged product • Printability and Labeling: Plastics provide excellent printability, enabling high-quality graphics, labeling, and product information to be applied directly onto the packaging surface • Safety and Hygiene: Plastics used in food packaging undergo rigorous testing and must meet strict safety regulations to ensure they do not pose health risks to consumers. Food-grade plastics are designed to be non-toxic, resistant to chemical leaching, and suitable for direct food contact • Recyclability and Sustainability: The environmental impact of plastics has become a significant concern. Efforts are being made to improve the sustainability of plastic food packaging materials through initiatives such as using recyclable plastics, increasing the use of post-consumer recycled content, and exploring alternative bio-based or biodegradable plastics GLASS CONTAINERS • Preservation and Protection: Glass containers provide excellent preservation and protection for food products. Glass also protects food from light exposure, which can be detrimental to certain products • Non-reactive and Safe: Glass is a non-reactive material, meaning it does not interact with or impart any flavors or odors to the food contents. This makes it an ideal choice for preserving the natural taste and quality of food • Transparency and Visibility: Glass containers offer excellent transparency, allowing consumers to see the product inside. This transparency enhances product visibility, showcases the product's quality, color, and freshness, and builds consumer trust • Recyclability and Sustainability: Glass is a highly recyclable material. Glass containers can be recycled indefinitely without loss of quality, making them a sustainable packaging choice • Versatility and Reusability: Glass containers come in various shapes and sizes, offering versatility in packaging options. They can be used for a wide range of food products, including sauces, condiments, beverages, preserves, and more • Heat Resistance: Glass containers have excellent thermal properties and can withstand high temperatures. This makes them suitable for hot-fill applications, such as sauces or soups, and allows for pasteurization and sterilization processes during food processing • Prestige and Branding: Glass containers convey a sense of quality and prestige, making them a preferred choice for premium or specialty food products • Shelf Life Extension: Glass containers help extend the shelf life of food products by providing an effective barrier against oxygen. This is particularly beneficial for products that are sensitive to oxidation, such as oils, spices, and certain beverages • Purity and Hygiene: Glass is an inert material that does not leach chemicals into the food contents, ensuring the purity and hygiene of the packaged products. It does not retain flavors or odors, which makes it suitable for a wide range of food items • Heat Resistance and Microwave Compatibility: Glass containers can withstand high temperatures, making them suitable for various heat processing methods. They can be safely used for hot-fill or hot-processed foods, such as sauces, soups, and baby food • Environmental Considerations: Glass is a sustainable packaging material. It is made from abundant raw materials such as silica, soda ash, and limestone, and can be recycled endlessly without any loss in quality. Recycling glass helps conserve resources, reduce landfill waste, and lower carbon emissions. • Tamper Resistance: Glass containers offer inherent tamper resistance due to their rigidity and breakable nature. Any tampering attempts are easily visible, providing consumers with a sense of security and ensuring product integrity • Chemical Compatibility: Glass is compatible with a wide range of food and beverage formulations. It does not react with acidic or alkaline substances, making it suitable for packaging acidic juices, sauces, and pickled products • Aesthetic Appeal and Premium Image: Glass containers have a timeless and elegant appearance that adds value to food products. The transparency and clarity of glass showcase the natural colors and textures of the contents, contributing to an enticing visual presentation CANS • Protection and Preservation: Cans provide excellent protection for food products. They are designed to be airtight and provide a barrier against oxygen, light, moisture, and contaminants, which helps to preserve the quality, flavor, and nutritional value of the packaged food • Shelf Stability: Canned food products have a long shelf life due to the protective nature of the can. This allows consumers to store and use the products over an extended period without compromising quality or safety • Durability and Protection: Cans are rigid and provide physical protection to the food contents. They are resistant to impact, puncture, and breakage, which ensures the integrity of the package during handling, transportation, and storage • Heat Resistance: Cans are heat-resistant and can withstand high-temperature processing, including retorting and sterilization. This allows for the safe packaging of products that require thermal treatment to ensure food safety and shelf stability • Recyclability: Cans are highly recyclable. Steel cans and aluminum cans are both recyclable materials. Recycling cans helps conserve resources, reduce energy consumption, and minimize waste. The recycling process for cans is well-established and can be carried out efficiently. • Convenience and Portability: Cans are lightweight and portable, making them convenient for on-the-go consumption • Branding and Shelf Appeal: Cans offer ample space for branding, labeling, and product information. They can be decorated with eye-catching graphics, logos, and nutritional information to enhance shelf appeal and attract consumers • Sustainability Considerations: While cans offer recyclability, there are some considerations regarding their environmental impact. The production of cans requires energy and natural resources, and recycling rates may vary by region ALUMINIUM FOILS • Barrier Properties: Aluminum foil provides excellent barrier properties, acting as an effective barrier against moisture, oxygen, light, and other contaminants. It helps to prevent the spoilage and degradation of food products, maintaining their freshness, flavor, and nutritional value • Heat Conductivity: Aluminum foil has high thermal conductivity, allowing for efficient heat transfer. It is commonly used in heat-sealing applications where the foil is sealed to the container or closure, ensuring a secure and airtight packaging • Flexibility and Conformity: Aluminum foil is a highly flexible material that can easily conform to various shapes and sizes of food products.The ability to conform to the shape of the product helps to create a tight seal and maintain the integrity of the package • Lightweight and Portability: Aluminum foil is lightweight, making it convenient for food packaging applications. Its lightweight nature reduces the overall weight of the package, leading to cost savings in transportation and minimizing the environmental impact • Hygiene and Safety: Aluminum foil is a hygienic material that ensures the safety and cleanliness of food products. Aluminum foil is also resistant to grease, oils, and moisture, which helps to maintain food quality and prevents leakage or cross-contamination • Versatility: Aluminum foil is suitable for a wide range of food packaging applications. It is used for wrapping and covering food items, as well as for forming containers, trays, and pouches • Recyclability: Aluminum foil is highly recyclable and can be reused multiple times without any loss in quality. Recycling aluminum foil helps conserve resources, reduce energy consumption, and minimize waste. It is important to ensure that aluminum foil is clean and free from food residues before recycling • Light Protection: Aluminum foil provides excellent light protection, preventing the penetration of ultraviolet (UV) light and other sources of light that can degrade the quality and nutritional value of food products • Retains Moisture: Aluminum foil can help retain moisture in food products, preventing them from drying out. This is especially useful for baked goods, meats, and other perishable items that require moisture retention to maintain their texture and taste • Freezing and Cold Storage: Aluminum foil is commonly used for packaging food products intended for freezing or cold storage. It acts as a barrier against moisture vapor and helps prevent freezer burn, preserving the quality and taste of frozen food over an extended period • Heat Sealing and Cooking: Aluminum foil is suitable for heat sealing applications, allowing for the creation of a secure and airtight package. It is also used for cooking and baking, providing a protective barrier while allowing heat to be evenly distributed • Portion Control and Convenience: Aluminum foil can be easily shaped and formed to create individual portions or compartments within a package. This allows for portion control and convenient serving sizes, particularly for ready-to-eat meals or pre-packaged food items • Cost-Effectiveness: Aluminum foil is a cost-effective packaging option due to its availability and affordability. It provides an economical solution for food packaging needs, especially for products that require a high level of protection • Extended Shelf Life: The barrier properties of aluminum foil help extend the shelf life of food products by preventing the entry of oxygen, moisture, and other contaminants • Compatibility with Different Food Types: Aluminum foil is compatible with a wide range of food types, including acidic, alkaline, and fatty foods. It does not react with or transfer flavors to the food, preserving the taste and quality of the packaged products • Environmental Considerations: Aluminum foil is a recyclable material and can be recycled repeatedly without losing its properties. Recycling aluminum foil helps conserve energy, reduce greenhouse gas emissions, and minimize the need for primary aluminum production PACKAGE MATERIAL TESTING • Material Selection: The first step is to identify and select the appropriate packaging material for the intended application. Factors to consider include the type of product being packaged, shelf life requirements, transportation conditions, regulatory compliance, and customer specifications • Sample Preparation: Once the packaging material is chosen, representative samples are prepared for testing. Samples may be obtained directly from suppliers or created in-house using appropriate methods • Test Plan Development: A test plan is developed to outline the specific tests to be conducted based on the requirements and objectives of the packaging material. The plan defines the test methods, equipment, acceptance criteria, and any applicable industry standards or regulations PHYSICAL AND MECHANICAL TESTS Tensile Strength: Measures the maximum tensile force a material can withstand before breaking or deforming Tear Resistance: Evaluates the material's ability to resist tearing or propagation of a tear Burst Strength: Determines the resistance of the material to burst or rupture under pressure Compression Strength: Measures the material's ability to withstand compressive forces Impact Resistance: Assesses the material's resistance to impact or shock BARRIER PROPERTY TESTS Moisture Vapor Transmission Rate (MVTR): Measures the rate at which water vapor passes through the material Oxygen Transmission Rate (OTR): Determines the rate at which oxygen permeates through the material Ultraviolet (UV) Transmission: Evaluates the material's ability to block UV light transmission TENSILE STRENGTH • Tensile strength refers to the maximum stress or load that a material can withstand before breaking or deforming under tension • Tensile strength is an essential mechanical property used to evaluate the strength and performance of materials in various applications • Tensile strength is typically measured in units of force per unit area, such as pounds per square inch (psi) or megapascals (MPa) • The higher the tensile strength value, the greater the resistance of the material to breaking under tension • The tensile strength of a material is determined through standardized testing procedures, such as the tensile test or the pull test • Sample Preparation: Samples of the packaging material are prepared for testing. The samples should be representative of the material's composition, thickness, and manufacturing process • Test Equipment: Tensile strength testing requires a universal testing machine, also known as a tensile tester. This machine consists of a load cell, grips or clamps to secure the sample, and a movable crosshead that applies tension to the sample • Test Procedure: The prepared sample is securely clamped between the grips of the testing machine. The grips are positioned to ensure that the load is applied evenly along the length of the sample • Data Collection: During the test, the universal testing machine measures and records the force or load applied to the sample, as well as the elongation or displacement of the material. This data is typically collected at regular intervals or continuously throughout the test until the sample breaks • Calculation of Tensile Strength: Once the test is completed, the tensile strength of the packaging material is calculated. Tensile strength is typically expressed in units of force per unit area, such as pounds per square inch (psi) or megapascals (MPa). It is calculated by dividing the maximum force or load applied to the sample by the cross-sectional area of the sample • Data Analysis and Reporting: The test data is analyzed to determine the material's tensile strength, yield point, elongation, and other relevant mechanical properties. Statistical analysis may be performed to evaluate the consistency and variability of the test results PROCEDURES Sample Preparation: • Prepare representative samples of the packaging material according to the relevant testing standards or specifications • The samples should be of appropriate dimensions and thickness, typically in the form of dumbbell-shaped specimens or strips • Ensure that the samples are free from defects, contaminants, or any irregularities that may affect the test results • The clamping mechanism should firmly grip the sample without causing damage or slippage during the test • Preload :Apply a small initial load, known as a preload, to the sample . The preload typically ranges from 2% to 10% of the anticipated maximum load to be applied during the test • Test Speed: Set the test speed or rate of grip separation for the tensile test. The rate of grip separation determines how quickly the sample will be stretched. Common testing speeds range from 1 to 500 mm/min • Start the Test: Initiate the test by starting the universal testing machine. The machine will begin applying tension or pulling force to the sample at the specified test speed • Data Collection: Throughout the test, the universal testing machine will measure and record the load or force applied to the sample, as well as the corresponding elongation or displacement of the material • Test Completion: The test continues until the sample breaks or reaches the desired deformation point, as per the testing requirements. The universal testing machine will automatically stop once the test is completed • Data Analysis: After the test, the collected data, including load and displacement measurements, is analyzed. The data can be used to calculate various mechanical properties, such as tensile strength, yield strength, modulus of elasticity, elongation, and other relevant parameters • Reporting: Generate a test report summarizing the test procedure, relevant specifications, test results, and any additional observations or remarks. The report should include details such as the applied load, elongation, and calculations of tensile strength and other mechanical properties FORMULA • The formula for calculating tensile strength is: Tensile Strength = Maximum Load (Force) / Cross-sectional Area • In this formula: The Maximum Load (Force) is the maximum force applied to the material during the tensile test. The Cross-sectional Area is the area of the material perpendicular to the direction of the applied force. It is typically measured in square units, such as square inches or square millimeters • To calculate the tensile strength, divide the maximum load by the cross-sectional area of the sample • The resulting value will be expressed in units of force per unit area, such as pounds per square inch (psi) or megapascals (MPa) EXAMPLE • Using the formula for tensile strength: Tensile Strength = Maximum Load / Cross-sectional Area Tensile Strength = 500 pounds / 2 square inches Tensile Strength = 250 pounds per square inch (psi) • Therefore, the tensile strength of the packaging material in this example is 250 psi • This means that the material can withstand a maximum tensile load of 250 pounds per square inch before breaking or deforming under tension • The higher the tensile strength, the stronger the material is in resisting tensile forces BURSTING STRENGTH • Bursting strength refers to the measure of the maximum pressure or force that a packaging material can withstand before it ruptures or bursts • It is an important parameter used to assess the strength and durability of materials, particularly in applications where the material may experience internal or external pressure • The bursting strength of a packaging material is determined through standardized testing procedures, such as the Mullen Burst Test or the Bursting Strength Test • Bursting strength testing is conducted to determine the maximum resistance of a packaging material to the application of a steadily increasing internal or external pressure • This test is crucial in assessing the ability of a material to withstand pressure and prevent rupture or bursting • Sample Preparation: Prepare representative samples of the packaging material for testing. The samples are typically circular or rectangular in shape, depending on the specific requirements of the testing standard or specification • Bursting Strength Test Equipment: The primary equipment used for bursting strength testing is a bursting strength tester, also known as a Mullen tester • Mounting the Sample: Place the sample securely between the clamping mechanisms of the bursting strength tester. The sample should be evenly aligned and centered within the clamps to ensure uniform pressure distribution during the test • Test Medium Selection: Depending on the testing requirements and standards, the bursting strength test may be conducted with either water or air as the test medium. Water-based tests are common for materials intended to come into contact with liquids, while air-based tests are suitable for general packaging materials • Calibration: Before performing the test, calibrate the bursting strength tester to ensure accurate pressure measurement. This involves verifying the accuracy of the pressure gauge or transducer against a certified reference • Preloading: Apply a preload to the sample to remove any slack or looseness and ensure proper contact between the sample and the diaphragm. The preload is typically a small initial pressure applied to the sample before the actual test begins • Test Execution: Start the test by gradually increasing the pressure, either through the application of water or air. The pressure is steadily increased until the sample bursts or ruptures. The pressure at which the sample bursts is recorded as the bursting strength • Data Collection: During the test, the bursting strength tester measures and records the pressure or force applied to the sample. The pressure is typically displayed on the pressure gauge or recorded by a data acquisition system connected to the testing equipment • Calculation of Bursting Strength: After the test, the recorded pressure is converted to bursting strength using the appropriate units, such as pounds per square inch (psi) or kilopascals (kPa). • Data Analysis and Reporting: Analyze the test data to determine the bursting strength of the packaging material. Assess the results against relevant standards, specifications, or customer requirements. Generate a test report summarizing the test procedure, results, and any additional observations or remarks FORMULA 1.Mullen Burst Test: Burst Strength = Bursting Pressure × Conversion Factor • In the Mullen Burst Test, the bursting pressure is measured in pounds per square inch (psi) or kilopascals (kPa) • The conversion factor is used to convert the bursting pressure to the desired unit of measurement for burst strength • The conversion factor depends on the specific unit of measurement used and can vary between testing standards 2.Diaphragm Burst Test: Burst Strength = Maximum Load / Sample Area • In the diaphragm burst test, the burst strength is determined by dividing the maximum load applied to the sample by the cross-sectional area of the sample • The maximum load is usually measured in pounds or newtons, while the sample area is typically measured in square inches or square centimeters • It is important to note that the specific formula and units of measurement may vary depending on the testing standards and specifications followed • It is recommended to refer to the relevant testing standard or consult the specific testing guidelines for accurate and consistent burst strength calculations for packaging materials TEAR STRENGTH • Tear strength refers to the resistance of a material against tearing or the force required to initiate or propagate a tear in the material • It is an important property that determines the durability and integrity of various materials, particularly those used in packaging, textiles, and other applications where tear resistance is crucial • Tear strength is typically measured using standardized testing methods, such as the Elmendorf tear test or the trouser tear test • These tests involve applying a controlled force or initiating a cut in the material and measuring the force required to propagate the tear or the distance the tear propagates before stopping • The tear strength is usually reported in units such as Newtons or pounds-force FORMULA 1. Elmendorf Tear Test: Tear Strength = Tear Force / Sample Thickness • In the Elmendorf Tear Test, the tear force is typically measured in grams or newtons, and the sample thickness is measured in millimeters or inches • The tear strength is calculated by dividing the tear force by the sample thickness 2. Trapezoid Tear Test: Tear Strength = Tear Force / Sample Width • In the Trapezoid Tear Test, the tear force is also measured in grams or newtons, while the sample width is measured in millimeters or inches • The tear strength is calculated by dividing the tear force by the sample width • Tear Resistance: Tear strength is an important characteristic for packaging materials, especially those that may undergo stress or potential tearing during handling, transportation, or opening • Tear Test Methods: The tear strength of packaging materials is typically determined using standardized test methods, such as the Elmendorf Tear Test, Trapezoid Tear Test, or the Grab Test • Material Composition: The tear strength of a packaging material is influenced by its composition, including the type of polymer, additives, fillers, and reinforcing materials present • Thickness and Orientation: The tear strength of a material can also be influenced by its thickness and orientation. Thicker materials generally have higher tear strength, as they provide more resistance to tearing forces • Material Testing: Testing laboratories or manufacturers often conduct tear strength testing to ensure compliance with industry standards and customer requirements • Applications: Tear strength is a critical consideration for packaging materials used in various industries, including food and beverages, pharmaceuticals, consumer goods, and industrial products • Quality Control: Manufacturers use tear strength testing as part of quality control measures to ensure consistent product quality and performance. By maintaining specified tear strength values, they can ensure the packaging materials meet the required standards and customer expectations • Material Optimization: Tear strength data can be used to optimize packaging material formulations and designs. It helps in selecting appropriate materials and adjusting the material composition or reinforcement to improve tear resistance and enhance overall packaging performance
