The Wet, The Dry, and the PEKK

At Plural, we have been researching a new PEKK material.  It has exceptional strength, chemical resistance, and low outgassing.  It’s appealing for aerospace, automotive, and medical applications.  But, like many thermoplastics, the PEKK is hygroscopic and absorbs water from the atmosphere. Compare dry PEKK (top) and wet PEKK (bottom).

The dry PEKK (top) has a smoother finish than the wet PEKK (bottom) that has bumps and fuzzy threads coming off it.  By keeping the PEKK dry with Plural’s MMS cabinet, the sample came out with a better surface finish.

The next step with PEKK is annealing to fully crystallize the plastic.  The difference is visible as the color shift from tan to off-white as seen below.  From bottom to top, wet PEKK, dry PEKK, and dry annealed PEKK.