Test for coating shrinkage

Objectives:

Determine the shrinkage of a coating on a substrate.

Materials:

Prepared substrates on aluminum foil from the coatings preparationactivity and the impact tester which consists of:

• Saran wrap
• Selected liquid coatings
• A paper template with a 6 cm x 6 cm square cut in the middle of an approximate 20cm x 20 cm piece of heavy paper
  ( folders cut to these specifications could be used.)

Safety:

Wear protective eye wear, gloves, and lab coat during this activity.

Procedures:

1. Carefully spread a sheet of Saran wrap in an undisturbed place.
2. Lay precut templates on the sheet.
3. Cover the exposed square with the coating applying it directly to the Saran Wrap.
4. Remove the template after applying the coating to the Saran Wrap.
5. Continue with steps 3 and 4 until all coatings have been applied.
6. After coatings have completely dried measure the dimensions of the painted square.

Analysis:
Record the shrinkage of each coating and report theresults to the class.

Conclusions:
Summarize findings and determine which coating and substrate would be bestfor certain applications.