Customer Background

A supplier of aviation electronic systems, providing housings for the flight data recorder of a business jet avionics upgrade project. Required to produce 5 prototype housings for environmental testing (-55°C to +85°C, random vibration of 20g) and installation coordination.

Challenges

• Special material: required to use PEI (Ultem 9085), which is flame retardant, heat resistant, and dimensionally stable, but difficult to machine.
• Strict precision: the housing needs to be waterproof sealed, with a flange face flatness requirement of 0.05mm, and a thread hole position tolerance of ±0.1mm.
• Surface identification: the housing requires screen-printed characters and warning symbols, which need to be solvent-resistant.
• Documentation requirements: need to provide material certification, dimensional inspection report, and processing records.

Solutions

• Machining: use high-speed CNC and special tools to machine PEI, controlling feed and speed to avoid material melting.
• Post-processing: sandblast (glass beads) after grinding to remove tool marks.
• Screen printing: use aerospace-grade ink, which is resistant to alcohol and aviation kerosene after curing.
• Documentation: provide original material certificate, coordinate measuring machine report, and processing date records with the goods.

Results

• Delivered 5 housings on day 10, and the customer completed assembly and sent them to a third-party laboratory for testing.
• Successfully passed the -55°C to +85°C temperature cycle and 20g random vibration tests without cracking or deformation.
• Screen-printed labels showed no peeling after wiping tests.
• The customer passed the acceptance, and placed an order for 20 more units for small-batch installation.

"Yiruida's PEI machining quality and document integrity fully met the aerospace requirements."