Page 310 - Engineering Plastics Handbook

270 Engineering Plastics

Metal aircraft parts are easily converted to parts composed of polyamide-
imide, because of the metal-like coefficient of thermal expansion of the
filled compounds. The high modulus and low creep of polyamide-imides
provide outstanding thread-holding ability for nonmetallic and thermally-
isolating aerospace fastener mounts [20].

Clip nuts. Clip nuts for aircraft are configured to slide over an edge of
a panel and align a screw and nut with a hole in the panel. They are used
to mount devices to that panel and for attaching panels together. They
require durability and high load capability, in addition to excellent cor-
rosion resistance, a common pitfall of metal clip nuts. Clip nuts
manufactured by the injection molding of a polyamide-imide resin
enable a cost-effective and weight-saving metal replacement solution
[21] (Fig. 12.15).

Semiconductors
Semiconductor manufacturing has some of the toughest material
requirements of any industry. Materials used to hold and process wafers
and the final IC chips during the manufacturing process are required
to endure high plasma-etch temperatures and harsh chemical envi-
ronments. The materials themselves must not introduce impurities
into the manufacturing environment through outgassing or leaching of
ionic molecules. Polyamide-imides, along with a number of other high-
performance polymers, are utilized in this manufacturing segment
because they are the only materials that can handle the difficult

Figure 12.15 Clip nuts.