Sglossary
Seam
Joint consisting of a line formed by joining two pieces
Secant
A straight line that intersects a curve at two or more points
Secant Modulus
Slope of a line drawn from the origin to a point on the stress / strain curve
Shear
A force acting perpendicular to the longitudinal axis of a SAMPLE
Shear Rate
Shear rate is a measure of the rate of shear deformation
Shear Strength
Maximum shear stress that can be sustained by a material before rupture
Shear Stress
Normal stress is perpendicular to the designated plane, shear stress is parallel to the plane
Snap Off
Used in the testing of container lids, the action of removing the lid that exhibits a sharp drop in
Snap On
Used in the testing of container lids, the action of fitting the lid that exhibits a sharp drop in force
SPC
Statistical Process Control
Springiness
The elasticity of a material that can be stretched and returns to its original length
Stiffness
Stiffness is the resistance of an elastic body to deflection by an applied force
Strain
The amount of deformation a material experiences per unit of original length in response to stress
Strain Energy
Measure of energy absorption characteristics of a material under load up to fracture
Strain Hardening Exponent
An increase in hardness and strength caused by plastic deformation at temperatures below the recrystallization range
Strain Rate
Deformation of a specimen height or length per time
Strength
The of stress an object can endure before it breaks
Stress
Force that a material is subjected to per unit of original area
Stress Ratio
The algebraic ratio of two specified stress values in a stress cycle
Stress Relaxation
A stress-strain condition in which the stress reduces as the strain remains constant
Stringiness
The property of an adhesive which causes it to form filaments, threads, etc., when the applicator is removed from the adherend, or when transfer surfaces are separated
T
Tack Test
Applicable to adhesives. Two surfaces are contacted together at a set speed for a set duration and the force required to pull them apart is recorded
Tangent Modulus
The instantaneous slope at any point on the stress-strain curve
Tear Resistance
Resistance of a material to a force acting to initiate and then propagate a failure
Tear Strength
The force required to tear an sample divided by the sample thickness
Tenacity
Strength of fibre or yarn in terms of the ratio of breaking load and linear density
Tensile Strength
The stress in force per unit area required to break a specimen
Tension Set
Extent to which vulcanized rubber is permanently deformed after being stretched a specified amount for a short time
Tex
A unit for linear density equal to the mass in grams per 1000M
Toughness
The ability of a material to absorb energy and deform plastically before fracturing
TPA
Texture Profile Analysis. A simulation of a two bite action
True Strain
Instantaneous percentage change in specimen length. It is equal to the natural log of the ratio of length at any instant to original length
True Stress
Load divided by the area of the sample. The constant changing area is used during the test
V
Viscosity
The thickness or resistance to flow of a liquid
W
Warp
Lengthwise yarns in a fabric
Weft
Crossways yarns in a fabric
Wet Strength
Breaking force of paper when wet
Y
Yield
The stress at which a material exhibits a specified deviation from proportionality of stress and strain
Young's Modulus
The Young's Modulus result is calculated as being the gradient of the modulus line on a stress vs. strain graph
U
Ultimate Strength
The highest force developed in a sample before break
Upper Yield
An upper yield is defined as the first maxima to occur above a specified load threshold, that persists for not less than a specified duration
Upper Yield Strength
Upper yield strength is calculated as being the reading on the stress axis at the point of the upper yield