Blister Defect

Blisters are raised surface defects that appear as bumps or irregularities on a molded plastic part. Blisters occur when trapped gas or moisture expands beneath the surface of the plastic during molding or cooling.

Blisters are often associated with trapped air, poor venting, excessive moisture, material contamination or processing conditions that prevent gases from escaping the mold cavity. Because blisters appear on the surface of a part, they can negatively impact appearance.

M. Holland helps customers identify material and processing solutions that improve molding consistency and reduce common manufacturing defects.