Part Defects

Shrink Line

8min

Shrink Line



Lines on the part surface corresponding to changes in geometry.

Lines on the outside of the part correspond to ribs on the inside
Lines on the outside of the part correspond to ribs on the inside


How to Identify

Shrink lines can be diagnosed as follows:

  • Lines correspond to a feature change in the geometry.
  • Lines can appear in any direction relative to the build platform.
  • Lines do not have a sharp edge.
  • Lines can often be seen but not felt.
    Cosmetic only



Troubleshooting



Print Preparation or Part Design Adjustments

The following solutions will address print or part-related causes of the defects. Choose among the suggested actions below and select the best approach for your application. Usually only one type of adjustment is needed.

If problems persist, please reach out to Carbon Support.

Explanation & Causes

Explanation

  • The process of polymerization produces heat as each slice cures.
    • Slices cool after initial cure.
    • Cooling rate is determined by cross section.
  • When cross section changes due to a feature change in the geometry, cooling will occur at different rates where the geometry changes.
    • Smaller cross sections cool more quickly than larger cross sections.
Document image


Causes



Root Issue

Problem

Why Defect Presents

Cross Section

Cross section changes suddenly

Smaller cross sections cool more quickly than larger cross sections. When a sudden change in cross section occurs between slices, the change in cooling can manifest in a surface finish difference.