A PETG blister card is three parts pretending to be one product: a formed cavity, a printed card and a seal that has to survive a pegboard, a carton and a customer opening it in a car park.
A hardware brand moved 40 SKUs to blister cards. The first shipment arrived with 8 percent of blisters detached, all from a batch sealed with a coating that did not match the PETG film.
PETG blister card thickness and seal window
- Small hardware: 0.5 mm
- Cosmetics: 0.4 mm
- Seal flange: 6 to 8 mm minimum
- Euro hole: reinforced, 8 mm above the card top edge
The seal flange is a width decision. Six mm of clean flange gives a continuous seal; a 3 mm flange leaves the seal running over the formed transition, where thickness varies and the seal is weakest.
Card stock, curl and hanging
Card curl is a humidity problem, not a printing problem. An uncoated card absorbs moisture in a warm warehouse and bows away from the blister; a coated card stays flat and keeps the seal intact.
The euro hole carries the whole weight on a peg. Without a reinforced patch the card tears upward from the hole, and the product ends up on the shelf floor with no card.
For the food-contact paperwork on the base film, see PETG FDA compliance, and for forming parameters on thin sheet, PETG thermoforming.
Send your product outline, card artwork and seal method to oversales@rpplexiglass.com for a blister quote.
Frequently Asked Questions
What thickness PETG for a blister card?
0.4 to 0.6 mm for small hardware and cosmetics. The blister needs enough stiffness to hold shape on a pegboard, and enough thinness to form without thinning the corners.
How is the blister sealed to the card?
By heat seal, radio frequency or adhesive, depending on the coating on the card. A PETG blister needs a compatible coating or the seal peels in a cold warehouse.
Why does a card curl on the peg?
Moisture uptake in an uncoated card stock. A coated or poly-lined card stays flat, and the euro hole position has to be reinforced or the card tears at the peg.