An undersized shrink tunnel is one of the most common (and avoidable) equipment mistakes. Get the sizing wrong and you'll either bottleneck your line or pay for capacity you'll never use. Here's how to size a tunnel correctly the first time.
Start With Your Largest Product
Always size a tunnel to your biggest product, not your average one. Measure height, width, and length of the largest item you'll ever run through it — a tunnel that fits your average product but not your outliers will force you to hand-finish those items separately.
Tunnel Opening vs. Product Clearance
Leave clearance beyond your product's exact dimensions — product that touches the tunnel walls won't shrink evenly and can scorch or distort. As a rule of thumb, more clearance on width and height gives more consistent results than a tight fit.
Match Tunnel Length to Line Speed
A shorter tunnel needs a slower conveyor speed to give film enough dwell time to shrink fully; a longer tunnel can run faster while still achieving a clean shrink. If your target output per minute is high, tunnel length becomes just as important as opening size.
Plan for Growth, Not Just Today
If you're expecting to add larger SKUs or scale volume in the next year or two, size with that in mind. Replacing an undersized tunnel a year after buying it costs far more than sizing correctly upfront.
Not Sure What Size You Need?
Send us your largest product's dimensions and target output, and we'll recommend the right tunnel size. Browse our shrink wrapping equipment or contact our team for a free sizing recommendation.
