Ask me the least glamorous part of clamshell manufacturing and I will say sealing. Yet the seal determines everything: whether the product stays clean, whether the package survives shipping, and whether the customer can open it without a saw. Here are the sealing methods we use u2014 and when.

RF Welding: The Industry Standard

Radio-frequency welding fuses the two shell halves along a flange u2014 strong, clean and tamper-evident. It is our default for clamshell packaging that must survive rough handling, like hardware blisters.

Snap-Lock: Reopenable by Design

Snap-lock clamshells close with a positive click and open with finger pressure u2014 ideal for products customers want to handle and test, like fishing lures and tools. The trade-off is a weaker tamper story.

Ultrasonic Sealing: Precise and Localized

Ultrasonic welding bonds along a narrow seam with no heat damage to the product u2014 perfect for electronics where heat-sensitive components sit close to the seal.

Heat Seal to Card: The Blister Card Classic

Formed cavities heat-sealed to a printed card give the classic peg-able blister card u2014 light, cheap and full of print space. Our auto parts blister cards use precisely controlled heat seal for consistent peel strength.

Choosing the Right Seal

Tamper priority? RF weld. Reopenability priority? Snap or slide. Cost priority? Heat seal to card. We engineer the seal to your product’s lifecycle u2014 and test it with your actual item before production.

Choosing the Right Clamshell Container Sealing Method

The clamshell container sealing method you choose determines tamper strength, reopenability and cost — match it to how the customer will actually use the package.

Related reading: welding methods overview.