Matt Durkin-Jones, who joined the board for an initial six-month term last January, will leave the specialist manufacturer on December 17 so a search for his successor is underway.
In a separate statement, the firm posted an 11% decrease in revenue to GBP49mln while underlying profit before tax slumped 79% to GBP437,000 for the six months to September 30. Net debt at period-end was GBP24mln.
Performance was slightly ahead of expectations although both the Technical Plastics and Aerospace divisions were behind those of the prior period due to COVID-19 related disruption to non-medical diagnostics customer demand and business interruption caused by local lockdowns.
The second half is expected to see a marginally stronger underlying operating profit performance, reflecting higher anticipated Technical Plastic product sales from its existing customer base alongside revenues from two new tooling agreements for COVID-19 test components which were entered into during the period with a new medical customer.
This is expected to offset a weaker performance in the Aerospace division during the second half due to lower customer demand.
Shares slipped 15% to 15.05p early on Friday.