Composite Materials Flashcards
List the various types of materials that are typically used as reinforcement
Glass, Carbon, Kevlar, Nylon
Rank the following form of glass from thinnest to thickest: strand, filament, yarn,
roving. Draw a schematic to show them
Thinnest to thickest: filament, strand, roving, yarn
[FIND PICTURE FOR THIS CARD]
What is the definition of aerial density? What is the SI unit of aerial density?
Weight of fabric per unit of area. grams / cm2
What does a large value of aerial density for a fabric imply?
A heavy weight fabric with larger yarn and weaves
What is Warp and Fill of a fabric? What is Pick and End?
Warp: bundles of filaments running longitudinally (0°), along the length of the
fabric; perpendicular to the width of the fabric. Fill: bundles of filaments running
in the transverse direction (90°), along the width of the fabric, perpendicular to
the length of the fabric. End: what a warp bundle is called. Pick: what a fill
bundle is called.
Name and identify key characteristics of 3 types of weave patterns?
Plain, Satin, Basket, Leno, Harness, Twill
What is Fiber Sizing?
A chemical that is put on the surface of fibers to accommodate wetting of the
fiber by resin, and create desired adhesion between matrix and reinforcement at
the interface.
What is the molecular weight of a thermoset? Why?
It does not have one for the entire polymer is theoretically on giant piece of
polymer, this does not allow a molecular weight to be obtained
What happens to viscosity of a resin at gelation?
Goes to Infinity
Why do resins shrink when they polymerize?
Less free volume
What are 4 types of thermoset resins?
i. Polyester, contains styrene, free radical polymerization, no by-product
ii. Vinyl ester, contains styrene, free radical polymerization, no by-product
iii. Epoxy, two-part stoichiometric ratio, step polymerization, no by-product
iv. Phenolic, one part resin, step polymerization, water and alcohol as by
produc
