Why I chose a Kliklok Folding Mechanism for the SPCs?

When I designed the Sustainable Produce Containers as an alternative to plastic clamshells, I was looking for something that could compete on price and was easy to recycle - but could also be accessible to small, medium and large growers alike. Created in 1945 by American carton genius Reg Miller and still going strong, the Kliklok interlocking carton design using corner locks was the choice.

1. No Glue Required (Lower Cost & More Sustainable)

Kliklok designs rely on interlocking paperboard tabs, not adhesive.
This means:

Reduced material costs compete with plastic at high volumes
No glue application equipment needed
Faster setup and fewer production issues
Fully recyclable and more EPR-friendly because there’s no adhesive contamination

2. Fast to Assemble (Hand or Machine)

Kliklok-style cartons are engineered for (and can be folded using):

High-speed automation (Kliklok/Bosch/BluePrint closers)
Medium-speed automation (FoldBot Folding Robot)
Low-skill manual packing (Folding Fixture)

The tabs are shaped to self-locate and lock quickly, cutting labor time and boosting throughput.

3. Very Secure Closure

The mechanism creates a positive “click” lock that resists:

Pop-opens during shipping
Pressure from products inside
Vibration on conveyor belts
Moisture-related swelling (important for produce and perishables)

This is why it’s used so often in retail food packaging.

4. Built-In Tamper Evidence

While not a full tamper-evident system, the design:

Shows visible damage if opened
Cannot be discreetly reassembled once torn
Provides shoppers with confidence that the box hasn’t been accessed

5. Clean Exterior Panels for Branding

Because there’s no glue seam and fewer exposed flaps:

Panels stay flat and rigid
Graphics print cleanly (see examples: CUSTOM PRINTING)
Structural design supports high-quality shelf presentation

Brands like the professional, crisp look of Kliklok closures.

6. Strong Under Compression

The interlocking tabs support the top load of:

Stacked cases
Display trays
Cold-chain distribution (common for produce)

This keeps the box from opening when stacked or jostled.

7. Compatible With Sustainable Barriers

Because closure strength doesn’t depend on glue:

Coated paperboard (compostable or recyclable) still locks reliably
Plant-based coatings don’t interfere with the closure
Works well for EPR-compliant mono-material packaging

Where Kliklok Mechanisms Are Commonly Used

Fresh produce (mushrooms, berries, tomatoes)
Bakery goods
Frozen foods
Snacks and confectionery
Meal kits
Ready-to-eat items
Any product replacing a plastic clamshell with paperboard

Locked In