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Flexible packaging has become increasingly popular in various industries due to its versatility and cost-effectiveness. It is used for packaging a wide range of products, including food, pharmaceuticals, electronics, and more. It includes materials like pouches, bags, sachets, and wraps made from materials such as plastic, foil, paper, and laminates. Flexible packaging offers several advantages, such as being lightweight, space-efficient, and customizable in terms of design.

Flexible package seal integrity testing is of paramount importance due to its direct impact on product quality, safety, and consumer satisfaction. A secure and intact seal serves as the primary defense against external factors that could compromise the contents of the packaging. This includes preventing the ingress of moisture, oxygen, and other contaminants, all of which can adversely affect the product's shelf life, flavor, texture, and overall quality. A compromised seal not only risks the product's integrity but also raises concerns related to food safety and hygiene. In industries such as food and pharmaceuticals, maintaining seal integrity is vital to prevent potential health hazards and economic losses.

Furthermore, a strong focus on flexible package seal integrity testing is crucial for businesses aiming to uphold their brand reputation and avoid costly recalls. Products with compromised seals could lead to customer dissatisfaction. By implementing rigorous seal integrity testing protocols, manufacturers can ensure that their products remain fresh, safe, and free from contaminants, thereby safeguarding their brand's image and preserving customer loyalty.

Package seal quality inspection using Airborne Ultrasound Technology

PTI's Airborne ultrasound technology is a non-destructive, non-invasive method for seal integrity testing of flexible packages. It is a deterministic, quantitative test method and also an ASTM Test Method F3004-13. It is based on the principle that ultrasound waves are reflected at different rates depending on the density of the material they are traveling through. When ultrasound waves are transmitted through a package seal, any defects in the seal will cause the signal waves to be reflected differently, resulting in a change in the signal strength.

Airborne ultrasound technology is a versatile and reliable method for testing seals on a wide variety of flexible packaging materials, including films, foils, laminates, and pouches. It is also capable of testing seals on a variety of product types, including food and beverage products, pharmaceutical products, and medical device products.

PTI offers two configurations of Airborne ultrasound testing technology: Seal-Scan and Seal-Sensor. Seal-Scan is a high-resolution method that inspects and analyzes pouch seals non-destructively offline. Seal-Sensor is designed for 100% online pouch seal inspection.

Benefits of Airborne Ultrasound Technology

• Non-destructive and non-invasive
• Deterministic, quantitative test results
• ASTM Test Method F3004-13 compliant
• Capable of testing a wide range of flexible packaging materials
• Detects a variety of seal defects, including leaks, misaligned seals, incomplete seals, missing seals, channel defects, pin holes, and porosity
• High-speed inspection capabilities
• Easy to integrate into production lines

The science behind perfecting flexible package seal integrity is a multidimensional approach that combines technological advancements with a commitment to product quality, safety, and brand reputation. Airborne ultrasound technology is just one example of how innovative methods are used to ensure that the seals on flexible packages remain strong, secure, and reliable.

Tyvek is a highly durable and lightweight material that is commonly used in the medical industry for the packaging and sterilization of medical devices and equipment. It is a non-woven material made from high-density polyethylene fibers that are bonded together using heat and pressure. Medical device manufacturers and packaging professionals prefer Tyvek packaging because it is a sterile barrier that protects against bacteria and other contaminants. Tyvek is also breathable, allowing for sterilization methods such as ethylene oxide and gamma irradiation to be used effectively.

Tyvek packaging is used in a variety of medical applications, including surgical gowns, drapes, and covers, as well as in medical device packaging such as catheters, implants, and instruments. Its use in the medical industry is regulated by government agencies such as the FDA to ensure that it meets the necessary standards for safety, sterility and efficacy.

What are the Challenges Associated with Tyvek Package Testing?

Leak testing of Tyvek packages is a critical step in ensuring the integrity of the package and the safety of its contents. However, there are several challenges associated with leak testing Tyvek packages, including:

• Sensitivity of the test method: The sensitivity of the leak testing method can impact the ability to detect leaks in Tyvek packages. For example, some testing methods may not be able to detect very small leaks or may be impacted by the size or shape of the package.
• Environmental conditions: Environmental factors, such as temperature, humidity, and pressure, can impact the results of the leak test. For example, changes in temperature can cause the package to expand or contract, which can impact the tightness of the seal and the results of the test.
• Interference with product properties: Some leak testing methods may use test gases or liquids that can interact with the product inside the package. For example, the test gas may cause the product to degrade or impact its efficacy, which can affect the overall performance of the package.

In summary, leak testing of Tyvek packages requires careful consideration of the test method, the packaging process, and the environmental conditions to ensure accurate and reliable results.

Testing Tyvek Packages Using Airborne Ultrasound Technology

With today’s sensory technology advancements, Tyvek packages can be tested using Airborne Ultrasound technology. Airborne Ultrasound technology is a seal quality testing method that uses airborne ultrasound to evaluate seals for flaws and defects non-destructively. It is an ASTM Test Method F3004 for testing the seal quality and a recognized FDA standard for seal quality inspection. These tests are mostly carried out to improve seal quality inspection of pouches, flexible packaging, and tray seals. Tyvek, paper, foil, film, aluminum, plastic, and poly are just a few of the packaging materials that may be used with Airborne Ultrasound technology to enable thorough seal quality evaluations.

In this method, sound waves are reflected as ultrasonic waves are transmitted through the packaging seal. If there is a leak or flaw, the signal intensity is decreased or lost. To find the leak, these differences are closely monitored. Most leak test techniques encounter the problem of being unable to identify non-leaking defects. By using Airborne Ultrasound technology, users may recognize a variety of seal faults, including visible and invisible, leaking and non-leaking, process-related and random. Airborne ultrasound can be applied in the laboratory for offline in-depth seal quality analysis as well as for 100% online seal quality inspection on the production line.

Benefits of Airborne Ultrasound Technology

• Non-destructive, non-subjective, no sample preparation.
• Deterministic inspection method producing quantitative results.
• Can be integrated for 100% online defect detection of the final pouch seal.
• Repeatable and reliable results.
• Eliminates subjective manual vision inspection methods.
• Characterizes overall quality and uniformity of the seal.
• Economical cost-effective solution for seal integrity testing the final pouch seal.

The method used for leak testing Tyvek packages will depend on the specific requirements of the medical device or equipment being packaged and the regulations set forth by regulatory agencies such as the FDA. It is important to use a validated and appropriate method for leak testing to ensure the safety and effectiveness of the packaged medical devices or equipment. Airborne Ultrasound is one such technique.

For sterile medical devices, seal integrity testing ensures product efficacy, shelf-life stability, and microbial sterility. Common defects that can threaten the integrity of the seal include voids, wrinkles, dust or other random particles. Hence, inspecting seals after they have been formed is important. Earlier, visual inspection or other destructive testing methods were used for seal quality inspection. However, they lacked accuracy and reliability in test results. But technology is changing. Today, the market offers a range of non-destructive inspection techniques that ensure highly sensitive and reliable seal quality inspection. Even then, the suitability depends on the type of packaging and the size of defect that needs to be inspected.

Relevance of Airborne Ultrasound Technology in Seal Quality Inspection

Airborne Ultrasound technology is a non-destructive container closure integrity testing method, capable of examining seal quality for defects. Such tests are mainly conducted to provide enhanced seal quality inspection of pouches, flexible packages and tray seals. Airborne Ultrasound technology ensures in-depth seal quality analyses and is applicable for multiple packaging materials Tyvek, paper, foil, film, aluminium, plastic and poly. It is an ASTM Test Method F3004 and FDA recognized standard for seal quality testing. According to Oliver Stauffer, CEO of PTI-Packaging Technologies & Inspection, “Ultrasound is one of the only technologies that are telling us what the quality of that physical bonded nature of the seal materials are.”

Under this technology, ultrasound waves are passed through the package seal which causes reflections of sound waves. The signal strength is reduced or eliminated in the presence of a leak/ defect. Such variations are closely observed to identify the leak. Inability to detect non-leak defects is a common challenge faced by most leak test methods. However, with Airborne Ultrasound technology users can identify various types of seal defects; visible and invisible, leaking and non-leaking, process-related and random.

Latest improvements in Airborne Ultrasound Technology are in the form of Seal Scan (Offline) and Seal-Sensor. Both these technologies utilize non-contact airborne ultrasonic testing technology. Seal-Scan® technology has been proven in the field by several online and offline units installed. With the advancements in form of Seal Scan and Seal-Sensor, Airborne Ultrasound technology has been proven to be the most effective method for non-destructive seal integrity testing.

Benefits of Airborne Ultrasound technology

• Deterministic seal quality inspection technique that assures quantitative and reliable results.
• Applicable for multiple material types and combinations regardless of color, transparency, print, surface finish or porosity.
• Eliminates subjective manual inspection methods.
• Non-destructive, non-subjective, no sample preparation
• Technology can be integrated for 100% online defect detection of the final pouch seal.

Over the last two decades, pharmaceutical industry has seen tremendous growth in the form of technological advancements and drug delivery system innovations. However, such innovations have increased quality assurance challenges for drug manufactures. For this reason, drug product manufacturers give at most importance to their quality control procedures as well as package integrity tests. All packaging forms, whether pouches constructed of porous or nonporous material, rigid thermoformed trays with Tyvek or film lids, bottles with induction-welded seals, or blister packs, need verification that their sterile-barrier characteristics are not compromised. Previously, only sterility testing was conducted on pharmaceutical packaging. However, when it was realized that sterility testing alone is not sufficient to hold the integrity of the medical products, the US FDA published Guidance for Industry for Submission Documentation for Sterilization Process Validation in Applications for Human and Veterinary Drug Products. This emphasized the importance of verification of microbial barrier properties of a pharmaceutical product package (i.e., CCI).

Relevance of CCIT in pharmaceutical package testing

Container Closure Integrity Testing is an assay to evaluate whether container closure systems can maintain sterile barriers against potential damage. Even a minute defect in the container can cause external elements to enter the product, thereby reducing its shelf life. Common threats that can pass through a defected container closure system include microorganisms, reactive gases, and other substances. Considering the ability of such threat to deteriorate product quality, undertaking appropriate CCI tests are beyond crucial. However, it should be noted that CCI is not a one-time process, rather an integral and comprehensive approach. It is evaluated throughout the manufacturing lifecycle of a sterile drug product -from primary package development until the products are dispatched.

Container closure systems are made up of primary packaging components and secondary packaging components. Components like vials or syringes that are in direct contact with the product are called primary packaging components. Although there are multiple CCI techniques available in the market today, regulatory guidelines have broadly classified methods into probabilistic and deterministic test methods. Under a probabilistic test method, results are generated through a series of events, each with a respective probability distribution. Thus, the accuracy of the results cannot be assured. In contrast to a probabilistic method, deterministic test methods assure quantitative results with higher level of accuracy and reliability. The United States Pharmacopeia in 2016 issued new guidelines stating that deterministic methods are preferred over probabilistic test methods. Container closure integrity testing can be performed in many different ways. All the testing methods have pros and cons. Given below is a list of non-destructive Container Closure Integrity test methods:

• Airborne Ultrasound technology
• Vacuum Decay technology
• Microcurrent HVLD technology
• Helium Leak Detection
• Pressure Decay leak testing
• Force Decay leak testing

Talking about medical devices, ensuring seal quality or seal strength of sterile medical device packaging are extremely crucial as well as highly regulated. Medical device package seal contains a flexible barrier which is joined to the rigid container through an advanced adhesive. A defect in the seal such as an incomplete or weak seal can initiate leaks, contaminating the product and reducing its shelf life. Hence, for quality control purposes, seal quality inspection of medical device packages is mandatory.

Historically, manual inspection was the most popular method used to inspect seal defects. Although this is covered by an ASTM method (ASTM F1886), it lacked accuracy and reliability in terms of test results. “There is a huge shift in the industry towards deterministic and quantitative test methods,” comments Oliver Stauffer, Chief Executive Officer at PTI - Packaging Technologies & Inspection. “This includes Vacuum Decay and Airborne Ultrasound for medical device applications. The industry is currently moving away from dye ingress and manual visual inspection because there are so many blind spots in applying them and there’s a huge false sense of assurance.”

Airborne Ultrasound technology is a non-destructive seal integrity test method capable of advanced seal quality inspection of pouches and flexible packaging. Seal defects can be of two types- leak defects and non- leak defects. While it is easier to detect a leak defect, detecting non-leak defects can be a challenge for manufacturers. However, Airborne Ultrasound technology allows non-destructive Container Closure Integrity testing of multiple seal defects including visible and invisible, leaking and non-leaking, process-related and random- making it a practical solution for medical device seal quality inspection.

Technology overview

Airborne Ultrasound technology utilizes ultrasound waves to detect defects in package seals. Ultrasound waves are passed through the material as the package seal moves along the sensor head. This causes reflections of sound waves. In the presence of a leak, the signal strength is either eliminated or reduced. Such variations in signal strength are analyzed to identify the defects. Seal scan testing is a practical solution to recognize defects, such as inconsistent seals or areas of seals that fail to meet minimum width requirement. Seal-Scan® and Seal-Sensor utilize non-contact airborne ultrasonic testing technology for advanced seal quality inspection. Seal-Scan® technology has been proven in the field by several online and offline units installed.

Benefits of Airborne Ultrasound technology

• Deterministic seal quality inspection method that produces quantitative results.
• This method works for any material type and combinations regardless of color, transparency, print, surface finish or porosity.  
• Non-destructive and non-subjective test method that requires no sample preparation.
• Technology can be integrated for 100% online defect detection of the final pouch seal.
• Repeatable, reproducible and reliable results for seal quality inspection.
• Cost-effective solution for seal integrity testing and seal analysis that characterizes overall quality and uniformity of the seal.