GLOSSARY
Dispensing Method:
Choose how the material will be mixed in manufacturing.
Volume per Part:
Provide the estimated amount of material that will be used for
one part. May be specified as grams, kilograms, cubic centimetres, ounces,
pounds, cubic inches etc.
Amount mixed
/ Dispensed at a time:
Specify the amount of material that you wish to mix at one time.
For example: you may want to mix enough material to use on one part only or you
may want to mix enough to pour several parts at a time. Please specify weight or
volume. This has a major impact on the maximum allowable speed of
reaction.
Pot Life:
Pot life is the length of time the material remains pourable
(useable) after mixing the resin and hardener together. Specify how much time
you require to pour or use up all of the mixed material. This is not
applicable to single component materials. Specify in Hours or Minutes.
Gel Time Required:
Gel time is the time required for the material to become firm to
the touch. At this point the component may be handled without causing damage
however, it may not be subjected to any stress or temperature cycling because it
is not fully cured and has not developed full strength. The gel time is less
if the materials were mixed and/or poured at elevated temperatures. Some
products have to be heated for ease of processing. It is therefore necessary to
know both the processing temperature and the desired time for the material to
become firm to the touch at that temperature. Specify the desired time in
Hours or Minutes and the temperature in 0C or 0F (example:
1Hr @ 600C).
Cure Time /
Temperature:
The cure time is the time it takes for the material to solidify
and develop its full strength and cured properties. Some materials are cured at
room temperature while others require the application of heat to react. Many
products will cure faster and develop better properties when cured at elevated
temperatures. There are certain trade-offs involved when products are cured at
other than the specified temperatures and therefore, it is important to know
both the desired time and the cure temperature available. Specify time in
Hours or Minutes and temperature in 0C or 0F (example:
2Hrs@ 1250C).
Mix Ratio By Weight:
The mix ratio by weight represents the weight of component A and
the weight of component B to be mixed together to result in a complete reaction.
The mix ratio is determined by the products chemistry but there may be some
customer requirements that limit processing to certain ratios. Specify this
parameter only if there is such a restriction applicable to the process being
considered. Specify using ratios (100:100) or using weights (100grms:10grms).
Mix Ratio By Volume:
Most commonly applicable if processing by automated dispense
equipment. Many dispense machines have fixed cylinder sizes and therefore the
mix must meet a certain ratio of resin to hardener by volume. Specify
only if a restriction exists. Specify as a ratio (example:1:1).
Viscosity /
Temperature (Resin):
Some resins, especially those that are highly filled, require
heating for easier processing. Certain dispense equipment and/or processing
situations require the resin to be at a certain maximum viscosity when
processed. Specify only if restrictions exist. Specify viscosity in
Centipoises or Pascal-seconds and temperature in 0C or 0F.
Viscosity
/ Temperature (Hardener):
Same as above for the resin. Specify only if restrictions
exist. Specify viscosity in Centipoises or Pascal-seconds and temperature in
0C or 0F.
Viscosity /
Temperature (Mixed):
This is a frequently specified requirement. Certain
applications, such as impregnating, dictate the maximum viscosity. In most
cases, the lower the mixed viscosity the easier it is to de-air the mixed
material and it is able to impregnate porous materials better. Viscosity changes
drastically with temperature. The higher the temperature the lower the viscosity
but the pot life is also reduced. Materials can be formulated to yield low mixed
viscosity at room temperature or can be highly filled and sill yield low
viscosity at elevated temperatures. Specify only if restrictions exist.
Specify viscosity in Centipoises or Pascal-seconds and temperature in 0C
or 0F.
Is Vacuum Available?:
Mixing, especially by hand, introduces air into the material.
This is undesirable from the cosmetic, functional and electrical standpoint.
Materials can be formulated to self de-air (release most of the entrapped air
without assistance) or in some cases must be de-aired under vacuum to completely
remove any entrapped air. Electrical and high voltage electronics applications
are examples where air removal is critical. Select "Yes" or "NO"
Shore Hardness:
Most epoxies and polyurethanes fall into the shore A or shore D
range with some in the very low end of the Rockwell scale. Some applications,
such as rollers, require precise control of the cured hardness. Specify
only if known. Specify the number and select the scale from the dropdown list.
Heat
Deflection Temperature (HDT):
HDT is defined as the temperature at which a standard test bar
with a standard load of 66 or 264psi deflects 0.010". This represents
the point where the cured product begins to soften with the application of heat. Its importance is
application dependent. For example: this property is less important if the material is not weight bearing or there is little force present
while operating beyond its HDT, otherwise it is a critical consideration.
Specify the temperature and select the scale in the dropdown box.
Operating Temperature:
The operating temperature of the finished component in service
is a major consideration in material selection. Specify the continuous
operating temperature and select the temperature scale in the dropdown box.
Indoor or Outdoor
service:
Important from the chemistry standpoint. Select Outdoor if the
material is exposed directly to the elements. Select Indoor if the compound will
not be directly exposed to the elements (example: operates outdoor but
contained in a covered container. Select from the dropdown list box.
Thermal Cycling
Requirements:
Thermal cycling takes place when a component transitions from
hot to cold (or visa versa) temperatures in a gradual manner, passing through
room temperature. Components facing this condition are usually tested and
approved based on having passed a certain number of these cycles. It is
important to know the following:
-
The maximum temperature and the time at that temperature
-
The transition time between the maximum temperature and room
temperature.
-
The transition time between room temperature and cold
temperature.
-
The lowest temperature and time at the lowest temperature.
-
The number of cycles the unit is required to pass for
approval.
Enter the information in the text box.
Thermal Shock:
Thermal shock takes place when a device transitions from hot to
cold (or visa versa) directly without passing through room temperature.
Components are approved having passed a certain number of these shocks. It is
important to know the following:
-
The highest temperature and the time at that temperature.
-
The lowest temperature and the time at that temperature.
-
The number of shocks required for approval.
Enter the information in the text box.
Chemical Resistance:
Products can be formulated to be resistant to certain chemicals
or groups of chemicals in their operating environment. The chemicals present in
high concentrations along with the operating temperature of the device are key
pieces of information for material selection.
In the text box, list all known chemicals expected in the
operating environment.
Moisture Resistance:
Important for components operating in high humidity
environments. Parts are usually tested at a specified temperature, for a
specified number of hours in a certain level of relative humidity for approval.
Need to know:
-
Temperature.
-
Relative Humidity (%)
-
Number of hours required for approval.
Provide the above information in the text box.
Other Known Properties:
List other physical properties required by the application if
known. The following are additional properties that are at times specified:
-
Tensile strength (psi)
-
Elongation (%)
-
Compressive Strength (psi)
-
Compressive Modulus.
-
Colour
Provide the above information in the text box.
Electrical Properties:
List the electrical properties required by the application if
known. The following are the electrical properties that are at times specified:
-
Dielectric Strength (volts/mil)
-
Insulation resistance (ohm-cm)
-
Dissipation Factor (@ frequency Hz)
-
Arc Track Resistance (Minutes)
Provide the above information in the text box.
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