KSRCA0406
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Gauge:
(1) The measure of thickness of the
individual elements making up a rubber
product. (2) A device for measuring. (See
thickness.)
Grain:
The effect on a rubber compound due
to processing it through a tubing machine,
calender, or mill.
Hardness:
Property or extent of being hard.
Measured by extent of failure of the indentor
point of any one of a number of standard
hardness testing instruments to penetrate the
product.
Homogeneity:
Uniformity of composition
throughout the material.
Homogeneous:
Of uniform composition
throughout.
Impression:
Design formed during vulcanization
in the surface of any rubber article by a method
of transfer, such as fabric impression or molded
impression.
Impression, Fabric:
Impression formed during
cure by fabric wrap.
Laminated:
Built up from thinner layers.
Modulus:
In the physical testing of rubber, it is
the ratio of stress to strain; that is, the load in
pounds per square inch or kilograms per square
centimeter of initial cross sectional-area
necessary to produce a stated percentage
elongation. It is a measure of stiffness.
Non-blooming:
The absence of bloom.
Oxidation:
The reaction of oxygen on a rubber
product, usually detected by a change in the
appearance or feel of the surface, or by a
change in physical properties
Ozone Cracking:
Surface cracks, checks or
crazing caused by exposure to an atmosphere
containing ozone. (See also ozone resistant.)
Ozone Resistant:
Withstands the deteriorating
effects of ozone, generally cracking.
Plate Finish (Sheet):
A commercially smooth
surface, the usual result of vulcanization
between press plates (platens).
Ply:
(1) A layer of rubberized fabric. (2) A layer
consisting of multiple strands of cord or wire
close spaced. (3) A single yarn in a composite
yarn. (4) Used in processing as a layer of
unvulcanized rubber compound.
Polymer:
A very long chain of units of mono-
mers, prepared by means of an addition and/or
condensation polymerization. The units may be
the same of different. There are copolymers,
di-polymers, tri or ter polymers, quadri-
polymers, high polymers, etc. Natural rubber is
a polymer of Isoprene.
Press Length:
The length of a product which
can be vulcanized at one time in a press, limited
to the length measurement of the press.
Random Length:
A unit of material which does
not fall into any current classifcation for
standard length.
Relative Humidity:
The ration of the quantity of
water vapor actually present in the atmosphere
to the greatest amount possible at the given
temperature.
Roll:
Sheet rubber and gasket material of a
uniform width rolled up on itself from which
gaskets and other products of lesser
dimensions and various shapes may be cut.
Rubber:
A material that is capable of recovering
from large deformations quickly and forcibly,
and can be, or already is, modifed to a state in
which it is essentially insoluble (but can swell) in
boiling solvent, such as benzene, methyl ethyl
ketone, and ethanol-toluene azeotrope.
Sinks:
A collapsed blister or bubble leaving a
depression in the product.
Slab:
Thick sheet, generally laminated.
Specifc Gravity:
The ratio of the weight of a
given substance to the weight of an equal
volume of water at a specifed temperature.
Tacky (Rubber Surface):
Tending to adhere.
Tensile Strength:
The maximum tensile stress
applied during stretching a specimen to rupture.
Viscosity:
A manifestation of internal friction
opposed to mobility. The property of fuids and
plastic solids by which they resist an instanta-
neous change of shape, i.e., resistant to fow.
Volume Swell:
Increase in physical size caused
by the swelling action of a liquid.
Vulcanization:
Act or process of treating an
elastomer or compound of same to improve its
useful properties, usually accomplished by
application of heat.
Warp:
The yarns that run lengthwise in a woven
fabric.
Waft:
The crosswise threads in a fabric; flling
threads. The threads or yarns running at right
angle to the warp.