DeFelsko ATM50A, Full Manual

Page: 5 / 22

4
Analysis of Test Results
Glue failures typically occur when the glue is improperly mixed or
the coated surface has not been adequately prepared (see pg.2).
Upon completion of the pull-off test, the dolly and coated surface
should be examined. In addition to pull-off force, many National
and International standards such as ASTM D4541 and ISO 4624
require the nature of the fracture to be recorded.
The PosiTest AT-A model provides an interface to document the
nature of the fracture for each pull-off test (see pg. 11). Fracture
results are included in test reports.
Glue failure: visible separation of the glue from itself,
the coating or dolly (no coating visible on the dolly face).
Dolly Face Coated Surface
Dolly
Glue
Cohesive fracture
(within a layer)
Adhesive fracture
(between layers)
Glue failure
(coating/glue)
Substrate
Adhesive fracture:
fracture occurs at the interface
between layers (coating on
dolly face differs from surface).
Cohesive fracture:
fracture occurs within a coating
layer (same coating on dolly
face and coated surface).
www.
GlobalTestSupply
.com
Find Quality Products Online at: sales@GlobalTestSupply.com