What is tray sealing?
Tray sealing is a packaging process that binds a flexible, die-cut lid to a pre-formed, rigid tray that contains whatever it is that needs to be packaged. Usually, the lid is made from thin material such as Tyvek, laminated foil, paper, or film, and the tray is made from a rigid or semi-rigid plastic such as PETG.
Tray sealing is commonly used for packaging medical devices, particularly when clamshell packaging or blister sealing are not applicable. Tray sealing prevents products from moving in the tray during shipping and creates a hermetic seal so that products can be stored and shipped under sterile conditions.
Types of materials used for tray sealing
Tray and lid materials are carefully selected based on their inherent properties and the specific needs of the products being packaged. For medical tray sealing, the most common lid stock is Tyvek, and the most common tray material is PETG—because both of these materials are well-suited for sterilization. Alternative tray materials may be used for products requiring specific vapor transmission rates or other internal atmospheric conditions ( e.g., HDPE offers a higher vapor barrier than PETG).
Likewise, some products may be light sensitive and require an opaque tray material, while others may need more protection during shipping and therefore may be best packaged in materials that can resist cracking if dropped. For lids, a manufacturer might opt for foil rather than Tyvek if the sterilization process is not a concern and there is a need for additional puncture resistance, more moisture control, or a light barrier.
Products shipped and stored in sealed trays
Tray sealing is commonly used in the medical device industry to package products that need to be shipped and stored under sterile conditions. These types of medical devices cannot be packaged using clamshells because clamshells rely on snap closures and cannot be hermetically sealed. By contrast, tray sealing completely bonds the lid to the tray, enabling a hermetic seal. In addition, these products are typically high-value medical devices, such as joint replacements and implants, that need to be packaged so that they are immobilized and yet readily accessible and presentable in medical settings. It is easiest to do this using a tray, rather than a flexible pouch. Sealed trays also provide better puncture resistance than clamshells or pouches.