Page 69 - Engineering Plastics Handbook

Properties 43

TABLE 3.3 ASTM and ISO Standard Test Methods and
Specifications—Engineering Thermoplastics (Continued)
ASTM ISO

F1876 Standard Specification for PEKEKK Resin for
Surgical Implant Applications
F1855-00 Standard Specification for Polyoxymethylene
(Acetal) for Medical Applications—Medical
Devices, Instrumentation or Components
Thereof
Developed by ASTM Subcommittee F04.11

fatigue crack cycle. DMA is used for research, product development, and
quality control. It is also used to determine viscoelastic properties, such
as elastic modulus (storage modulus G′ or E′), viscous modulus (loss mod-
ulus G′′ or E′′), and damping coefficient (mechanical damping tan δ) as a
function of time, temperature, or frequency. Storage modulus is the ratio
of stress in phase with strain to the amount of strain. Storage modulus is
proportional to the resonant frequency of the plastics. Data are plotted as
G′, G′′, or tan δ versus time, temperature, or frequency. Calculations are
based on the elastic region where the relationship is linear between stress
and strain, and strain returns to zero when an applied load is removed.
A number of materials characterization instrument or testing service
®
companies are available, including Rheologica Instruments AB (Lund,
Sweden), Netzsch Instruments (analyzing and testing headquarters, Selb,
Germany; U.S. sales and service, Burlington, Mass.), Datapoint Labs
(testing services, Ithaca, N.Y.), and TAInstruments. TAInstruments bought

TABLE 3.4 ASTM Standard Specifications for Engineering
Thermoplastics
ASTM Standard specification
Resin Resin Stock shape
Polycarbonate D3935 D6098
Nylon D4066 D5989
PPS D4067
Acetal D4181 D6100
Homopolymer, Polyoxymethylene (POM) D4181
copolymer acetal homopolymer
Polyoxymethylene polyacetals D6778
PPE D4349
Polyesters D4507 D6261
ABS D4673
D5927
PEI D5205
PAEK — D6262