How to Prevent Bubbles, Cracks and Burn Marks When Bending Plastic

Bubbles and burn marks usually indicate excessive surface heat or unsuitable material conditions. Cracks often come from insufficient or uneven heating, a radius that is too tight, or damaged edges.

1.Why it matters

Different defects point to different causes, so changing every setting at once makes troubleshooting harder. Inspect where the defect starts, then adjust one variable and compare the cooled sample.

2.Practical checklist

· Lower or stabilize heat when the surface bubbles or discolors.

· Increase heating depth or bend radius when the inside face cracks.

· Check edges and protective film before blaming the machine.

3.Which machine fits?

Precise control and adjustable heating width help both models manage sensitive materials, but safe processing limits must follow the sheet supplier.

Frequently asked question

Why is only one end of the bend defective?

Check lane alignment, sheet support, heating-wire condition and airflow across the working length.

Always test a small offcut and follow the machine manual, material safety information and local rules.

Need help choosing a machine? Send us your material, thickness, maximum bend length and daily output.