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Plastics
Design Resources
Injection
Molding Manufacturing and Services
Alloys - is a way to create custom
variations in plastics. I general alloys are combinations of polymers that are
physically mixed.
Brittleness - is the lack of a
material to with stand impact. Typically, brittle materials have lower impact
and higher stiffness properties.
Density - of any material is a
measure of the mass per unit volume.
Ductility - is the ability of a
material to be stretched, pulled, or rolled into shape with destroying the
integrity of the material.
Elasticity - is the ability of a
material to return to its original size and shape after being deformed. Most
plastic materials have limited elasticity.
Elastomers - A material which at
selected temperatures stretches under low stress and returns back to the
original length upon release of stress.
Notch Sensitivity - is a measure
of the ease with which a crack propagates through a material from a
pre-existing notch, crack or sharp corner.
Plasticity - is the inverse of
elasticity. A material that tends to stay in the shape or size to which it is
deformed has high plasticity.
Specific Gravity - is the ratio of
the mass of a given volume of material compared to the mass of the same volume
of water, as measured at 23 degrees centigrade.
Thermosets - are plastics that
undergo chemical change during processing to become permanently insoluble and
infusible. Thermoset material will undergo or has undergone a chemical reaction
by the action of heat, catalysts, ultra-violet light, etc., leading to a
relatively infusible state. Typical of the plastics in the thermosetting family
are the aminos (melamine and urea), most polyesters, alkyds, epoxies, and
phenolics.
Thermoplastics - are resins that
repeatedly soften when heated and harden when cooled. This characteristic
facilitates the forming of the material into desired shape when the
thermoplastic is placed within a die or fixture of the desired final geometry.
This process is referred to as
Thermoforming
.
Water Absorption - is the
materials tendency or lack of to absorb water.
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