What causes microcracks in plastics? Causes, risks, and prevention
What causes micro-cracking in plastic sheets?
Micro-cracks in plastic sheets are usually caused by a combination of internal stress in the material and additional strain during processing or use. When laser cutting, this is especially noticeable around cut edges, holes, sharp corners, and narrow details.
Common causes include:
- residual stress in the sheet from production, storage, or previous processing
- excessive heat input during laser cutting
- mechanical stress from clamping, bending, lifting, or stacking
- temperature fluctuations
- unsuitable storage or rough handling
This is a well-known point of attention, especially with acrylic. Not every sheet reacts the same way, so always test your settings on the exact material variant and thickness. For example, check out the Acrylic collection or compare options via All sheet materials and thicknesses.
How to reduce the risk
- make a test cut in the same material
- avoid unnecessarily sharp inner corners
- prevent excessive heat build-up in small details
- store sheets flat and stable
- handle parts carefully after cutting
Leave a suitable protective layer in place for as long as possible, for example using protective film for laser use.
In short: micro-cracks are rarely caused by a single factor. Usually, it is the combination of material stress, laser settings, and handling.
For additional selection and safety context, also read the Knowledge base on sheet materials.