MPS-M09A
9 Pound-per-cubic-foot Semi-Rigid Foam
Used in hand-mix/cast-in-place, and low pressure machine casting
operations
This foam polyurethane formulation is designed to yield structural
foam by either hand-mixing or machine casting method. The pot-life
of this material is much longer than ordinary rigid foam formulations to
allow enough handling time in a hand-mixing operation or a
low-pressure meter-mixing machine to cast larger parts. Whereas standard rigid foam
formulation has pot life of about 30 to 60 seconds, this formulation
has 5 minutes pot life, which allows easier handling for a
cast-in-place operation.
Unlike common rigid foam
formulation, the semi-rigid foam structure of MPS-M09A resists
cracking and chipping from impact force by slight flexibility. This
combination of features makes MPS-M09A ideal for cat-in-place
insulation, molding compound for structural parts, and many other
custom applications.
The components are liquid at room temperature. For a small quantity,
this can be batched manually using hand tools. This can also be cast with a
multi-component meter-mixing/dispensing machine. The free-rise
density of the foam is 9 pounds-per-cubic-foot, the cell structure
is closed-cell (>90%).
Typical Properties
of the Components
| |
Prepolymer (A) |
Curing Agent (B) |
|
Product Code: |
MSA-018 |
PPX-008 |
|
Specific Gravity: |
1.183 |
1.075 |
|
Equivalent Weight: |
183 |
85 |
|
%NCO |
23% |
n/a |
Mixing
Ratio:
| |
Part-A |
:Part-B |
|
Volume Ratio: |
2.000 |
:1.000 |
|
Weight Ratio: |
1.000 |
:0.446 |
Stoichiometry NCO/OH = 1.000/0.962
NCO Index: 1.039
*Mixing ratio can vary within 3-5 %. Higher ratio of part-B will
make it slightly more flexible. Be sure to calibrate your meter mixing
equipment before use.
Processing Temperature:
|
Part-A: |
Ambient |
|
Part-B: |
Ambient |
|
Mold/Substrate: |
Ambient |
|
Post Cure Oven: |
100 -120°F (If needed) |
* The ideal temperature for the mold and substrate is 100 - 110 ºF.
However, if you are using plastic mold, the mold may not need to be
heated. For all metal molds, the temperature needs to be between 100
to 110 ºF.
Cure Pattern:
|
Mixing time |
30 - 60 seconds by hand batch |
|
Pot life (pour within) |
5 minutes |
|
Demolding time |
6-
8 hours with mold temperature 70 - 110 °F* |
|
Complete Cure Cycle: |
2 - 3 days at room temperature |
Stoichiometry NCO/OH: 1.000 0.962
NCO Index 1.039 1.000
Recommended Processing:
I recommend testing small amounts to see how the material behaves,
then develop your casting method accordingly. When you do test
batch, please be sure to operate in a well-ventilated area or large
open area, wear rubber gloves, long sleeves, and protective
eyeglasses to avoid skin/eye contact. Read the enclosed Material
Safety Data Sheet for details on the safety and handling.
*Before you start your test, there is a chance the materials being
frozen during the transportation. This may cause separation within
the components. If in such case, you need to agitate the components
in the cans. Do not open the can for part-A (MSA-018) until you are
ready to use as it is a moisture sensitive material. Shake the
unopened can to agitate. You can open the can for part-B (PPX-008)
and use a metal spatula or knife (or something dry, strong, and
clean) to agitate. Do not use wooden paint stick as it has moisture
within, it may contaminate the material. After agitating the
components, keep them at a room temperature above 70 ºF. These
materials will not freeze at room temperature.
Pre-heat the mold and substrate to between 100 and 110 ºF if needed.
Apply mold release into the mold if needed. Do not use silicone-base
mold release as it destroys the foam surface.
Calculate the total inside volume of the mold (or the finished part
volume) in cubic feet. Divide it by the density (9 in this case).
This will give you the weight of the component mixture at the
free-rise density. Multiply by 1.1 for 10 % compression rate. (See
below for compression molding). This will give you the total weight
for the two components.
Take the correct ratio of part-A and part-B into a mixing cup. Mix
well with a steel or plastic stir stick for at least 30 seconds.
Agitate vigorously and thoroughly. Scrape the material off the side
and bottom of the cup as you mix. This material has a long pot-life
for ease of process.
Cast the mixture into the mold. The mold should be between 100 and
110 ºF if using a metal mold. The material may not cure properly if
mold is too cold. For a higher production rate, we can modify the
formulation to cure faster.
Cure in the mold for 6 to 8 hours before demolding. Please check the
strength of the foam surface before demolding. Larger parts may
demold faster.
The foam cures at room temperature gradually for about 2 to 3 days
to yield the final physical properties that are OK to be used in a
lord bearing application.
Compression Molding
Foam needs to fill the mold space by put slightly larger amount of
foam into the mold. The expansion pressure of the foam sends the
foam material to fill the mold. The mold therefore needs to be a
close mold and has to have some capacity to retain the expansion
pressure. The simplest mold will be just an open-top box with a lid.
The lid then needs to be clamped hold the pressure. The air trapped
on the top side of the mold could make a large void if it is not
released. For this purpose, you need to have a very small vent (hair
vent) to let the trapped air escape from the mold.
The mold material can be metal, plastic, or elastomeric material.
Mold surface needs to be slick as foam could stick to any porous
surface. Metal molds tend to absorb the heat. Heat created from the
chemical reaction is required for foam to cure. If mold is cold,
this heat is absorbed and the foam does not cure properly. The mold
needs to be heat to 100 to 110 ºF in case of metal molds if metal
mold. If your mold is plastic or elastomeric mold, this may not be
necessary as those materials retain heat better than metal molds.
Compression rate indicates how much more of component material is
put into the mold. The rate indicates the percentage of excess
amount of material to the amount in which to fill the mold using the
foam’s free-rise density. Typically, about 10 % compression should
give enough pressure to distribute the foam within the mold. Using
higher rate makes the foam denser and stronger.
Applications requires fire-retardant property
This foam is not fire-retardant foam, and it is not recommended for
applications, which require or should be using fire-retardant grade
materials. The applications such as automotive interior, building
material, and components for some electronic parts often require
fire-retardant grade materials by law. It is the user's
responsibility to conform to the applicable regulations. We also do
not recommend this foam to be used to the applications in which the
foam can be exposed to high temperature or being near an ignition
source.
By adding fire retardant additives, this foam may be modified to
fire-retardant grade foam. The user must test the foam modified with
the fire retardant additives for the fire-retardant property and the
conformance to the applicable regulations. Contact Northstar
Polymers for source information.
Deflection Temperature
All semi-rigid foams soften as operating temperature rises. If load
bearing capacity is required at an elevated temperature, test the
structural integrity of the foam parts at the expected operating
temperature for the application.
Handling Information for the Component Materials
Storage:
Part-A component (prepolymer) contains isocyanate component, which
is very much sensitive to moisture. If it is left in air, part-A
will react with atmospheric moisture and will be ruined. This
reaction is non-reversible. Soon after opening a can and dispensing
the content, nitrogen gas or negative-40-degree-due-point dry air
needs to be injected to the can to blanket the material. Silica gel
or calcium chloride desiccant filter should be installed to 55
gallon drum-vent for your drum feeding system. The storage
temperature should be at a room temperature between 70 and 100 ºF.
Part-B component is hygroscopic. If the material is exposed to
ambient air, it may absorb moisture. Moisture contaminated part-B
material may become source of degradation or excessive bubbles in
the product. Avoid exposure of the material to air. Purging the
empty space in the container with nitrogen gas or
negative-40-degree-due-point dry air is also recommended to prevent
moisture contamination of part-B as well; however most of the cases,
keeping in an airtight container will be sufficient. Store it in a
dry indoor storage at a room temperature between 65 and 80 ºF.
Safety:
The component materials are industrial-grade chemicals. Please keep
them in a secure place and prevent access from any unauthorized
individual. The personnel who handles these materials needs to read
the Material Safety Data Sheet (MSDS) for detail information on
safety and handling of the material. The MSDS for each component is
sent with the shipment of the material.
When using this material, be sure to operate in a wide-open area
with good air movement, or in a well-ventilated area. Wear rubber
gloves, long sleeves, and protective eyeglasses to prevent skin/eye
contact of the material. When your operation involves heating or
spraying of the material, we recommend, in addition to the above,
installation of a proper ventilation system and/or using an
appropriate type of respirator to prevent inhalation of the fume.
Direct contact of polyurethane raw materials to skin/eye, as well as
ingestion may lead to health problems. No eating or smoking should
be permitted at the working area. The operator should wash hands
well with soap and water after handling the materials and follow the
other procedures of the Standard Industrial Hygiene Practices.
Please refer to the MSDS for each component for the detailed health
information.
For any questions, please contact Northstar Polymers.
Notice: All of the statements, recommendations,
suggestions, and data concerning the subject material are based on
our laboratory results, and although we believe the same to be
reliable, we expressly do not represent, warrant, or guarantee the
accuracy, completeness, or reliability of same, or the material or
the results to be obtained from the use thereof, neither do we
warrant that any such use, either alone or in combination with other
materials, shall be free of the rightful claim of any third party by
way of INFRINGEMENT or the like, and NORTHSTAR POLYMERS DISCLAIMS
ALL WARRANTIES, EXPRESS OR IMPLIED, OF MERCHANTABILITY and FITNESS
FOR A PARTICULAR PURPOSE.
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