Immiscible - Descriptive
of two or more fluids which are not mutually soluble.
Impact Bar (specimen) -
A test specimen of specified dimensions which is utilized
to determine the relative resistance of a plastic to
fracture by shock.
Impact Resistance - Relative
susceptibility of plastics to fracture by shock, e.g.,
as indicated by the energy expended by a standard pendulum
type impact machine in breaking a standard specimen
in one blow.
Impact Strength - (1) The
ability of a material to withstand shock loading. (2)
The work done in fracturing, under shock loading, a
specified test specimen in a specified manner.
Impregnation - The process
of thoroughly soaking a material such as wood, paper
or fabric, with a synthetic resin so that the resin
gets within the body of the material. The process is
usually carried out in an impregnator.
Impulse Sealing - A heat
sealing technique in which a pulse of intense thermal
energy is applied to the sealing area for a very short
time, followed immediately by cooling. It is usually
accomplished by using an RF heated metal bar which is
cored for water cooling or is of such a mass that it
will cool rapidly at ambient temperatures.
Infra-red - Part of the
electromagnetic spectrum between the visible light range
and the radar range. Radiant heat is in this range,
and infra-red heaters are used in sheet thermoforming.
Inhibitor - A substance
that slows down chemical reaction. Inhibitors are sometimes
used in certain types of monomers and resins to prolong
storage life.
Injection Blow Molding -
A blow molding process in which the parison to be blown
is formed by injection molding.
Injection Mold - A mold
into which a plasticated material is introduced from
an exterior heating cylinder.
Injection Molding - A molding
procedure whereby a heat-softened plastic material is
forced from a cylinder into a relatively cool cavity
which gives the article the desired shape.
Injection Molding Cycle - The complete time cycle of operation utilized in injection
molding of an object including injection; die close
and die open time.
Injection Pressure - The
pressure on the face of the injection ram at which molding
material is injected into a mold. It is usually expressed
in psi.
Injection Ram - The ram
which applies pressure to the plunger in the process
of injection molding or transfer molding.
Insert - An integral part
of a plastics molding consisting of metal or other material
which may be molded into position or may be pressed
into the molding after the molding is completed.
Instron - An instrument
utilized to determine the tensile and compressive properties
of material.
Insulation - A coating of
a dielectric or essentially non-conducting material
whose purpose it is to prevent the transmission of electricity.
Insulation Resistance -
The electrical resistance of an insulating material
to a direct voltage. It is determined by measuring the
leakage of current which flows through the insulation.
Intrinsic Viscosity - The
intrinsic viscosity of a polymer is the limiting value
of infinite dilution of the ratio at the specific viscosity
of the polymer solution to its concentrate on moles
per liter.
Ionomer Resins - A polymer
which has ethylene as its major component, but containing
both covalent and ionic bonds. The polymer exhibits
very strong interaction ionic forces. The anions hang
from the hydrocarbon chain and the reactions are metallic
- sodium, potassium, magnesium. These resins have many
of the same features as polyethylene plus high transparency,
tenacity, resilience, and increased resistance to oils,
greases and solvents. Fabrication is carried out as
with polyethylene.
ISO - International Organization
of Standardization.
Izod Impact Test - A test
designed to determine the resistance of a plastics material
to a shock loading. It involves the notching of a specimen,
which is then placed in the jaws of the machine and
struck with a weighted pendulum. See also Impact Strength. |