PET Clamshells Now Successfully Sealed Using RF Welding, Ultrasonics and Heat
Arnold, MO – November 3, 2024 – VisiPak, a Sinclair & Rush brand, proudly announces a breakthrough in packaging technology with a new PET material (recycle code 1) 
that can be sealed using existing RF Welding equipment. This innovation reintroduces the option of securely sealing clamshells utilizing RF sealing technology, which was previously only feasible using PVC (recycle code 3) 
or PETG (recycle code 7) 
packaging options which are very difficult to recycle given current technologies. This often led to the use of trapped blister packages which were cost-prohibitive. In addition, trapped blisters are not easily recyclable due to the application of adhesives to secure the paper cards to the plastic PET blisters.
The need for secure packaging in retail environments is critical to prevent theft and tampering, which poses a significant loss for retailers. Major retailers have been requiring a switch from PVC or PETG packaging to PET . The challenge of sealing PET clamshells with automated processes has forced brand managers to switch to less effective packaging options. Welding is a common method for sealing a package, and PET is increasingly popular due to its recyclability. VisiPak, aware of the challenges in sealing clamshells with RF, heat, and ultrasonic welding, collaborated with material suppliers to find a solution. VisiPak, has developed an industry-first solution allowing PET clamshells to be sealed using already available sealing equipment.
Extensive testing has shown that the new material creates a robust seal, making it impossible to pull apart and does not cause the PET plastic to become brittle when subjected to RF sealing, heat sealing, or ultrasonic sealing. The stress of heat and friction is the common failure point when attempting to seal alternative PET options. This advancement allows manufacturers to automate the packaging process efficiently.
Tests on existing sealing equipment and tooling formerly used for PVC and PETG clamshells in various wall thicknesses, temperatures, and sealing cycles have consistently produced secure packages. While exact sealing parameters may vary based on individual customer conditions, the new PET material has proven to be highly effective with a wide operating window.
Jeff Barket, Director of Sales & Marketing for Sinclair & Rush, stated, “For brand managers seeking a tamper-proof, durable seal with PET clear plastic (recycling code 1), this is a game changer. Before VisiPak introduced this option at Pack Expo 2024, the only RF sealable clear packaging options were PVC or PETG, which did not meet major retailers’ sustainability requirements. Other PET materials either failed to seal or created weak bonds that were brittle and easy to break.”