9 Pound-per-cubic-foot "Slow Cure"
polyurethane formulation is designed yield structural foam by either
hand-mixing or machine casting method. The pot-life of this
material is set longer than ordinary rigid foam formulations to
allow enough handling time in a hand-mixing operation. Unlike
common rigid foam formulation, the semi-rigid foam structure of MPP-M09D resists cracking and chipping from impact force by slight
flexibility. This combination of features makes
MPP-M09A ideal for
cat-in-place foam application, molding compound for short-run parts,
and many other custom applications.
The components are
liquid at room temperature. This can be batched manually by hand
tools, and 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.
Prepolymer (A) Curing Agent (B)
Mixing Ratio (A)
* The ideal temperature for the mold and substrate is
100 - 110 ºF. However, if you are using plastic mold, this may not
be necessary. For all metal molds, the temperature needs to be
between 100 to 110 ºF. If a cold substrate must be used, you may
yield a better result if the material is poured when the exothermic
heat raised the temperature to above 90 °F.
life (pour within) 5 - 6 minute
(pour after 4-minute point if possible)
Demolding time 2 - 4 hours
(thicker parts demold faster)
Complete Cure Cycle: 2 days at room
Rise Density: 8.2 – 8.5 pounds per
Compressed density: 9.0 pounds per cubic
We recommend testing this material 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
Agitate part-B component before
dispensing out to ensure homogeneous blend within the part-B.
Part-B component is made of several different chemical constituents,
which are not completely compatible to each other. Use a bung mixer
to agitate it for 20 to 30 minutes for 55-gallon drum package. Use
a paint mixer or spatula to agitate for a few minutes for 5-gallon
pail and smaller packages.
Pre-heat the mold and substrate
to between 100 and 110 ºF in needed.
Apply mold release into the mold
when needed. Do not use mold release with a high concentration of
silicone 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. Use this
total weight to calculate the weight ratio of 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 use.
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
smaller batch size or the material needs to be cast on a cold
substrate, do not pour until the blended mixture is starting to be
slightly creamy and warm (this will happen at about the 4- to 5
minute point from the beginning of agitating part-A/B blend).
Cure in the mold for 2 to 4
hours before demolding. Please check the strength of the foam
surface before demolding. Larger parts can 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
Note: You may see non-foamed area at the bottom of
the cured foam. When the foam is cured in compression mold, or cast
on cold substrate, the foam may create non-foam, solid areas. If
this is an issue, heating the mold or the substrate can alleviate.
Increasing the catalyst level may also reduce this tendency; however
pot life will become shorter. Holding the blended mixture in the
cup until the material is creamy and warm may also help.
Polyurethane foam needs to fill the mold space by the
expansion pressure of the foam sending the foaming material to fill
the mold. The mold therefore needs to be 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 hard lid. The lid then needs to
be clamped hold the pressure.
The air trapped in the mold could make a large void
if it is not let out. For this purpose, you need to have very small
vents to let the trapped air escape from the mold. You need to
plan where in the mold the in-mold air is cornered by determining
the position of the mold and cast point, and then drill small holes
where you see the air traps.
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 (or exothermic heat) 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 is the rate of how much more
material you would put in to create the pressure. Typically, about
10 % compression should give enough pressure to distribute the foam
within the mold. Using higher rate makes the foam denser and
If you have any questions, please feel free to call
Northstar Polymers at 612-721-2911.
Applications requiring fire-retardant grade
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 a 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.
All semi-rigid foams
soften as the temperature rises. If load bearing capacity is
required at an elevated temperature, test the structural integrity
of the foam parts at the expected entire operating temperature range
for the application.
Handling Information for the Component Materials
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 argon gas 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 65 and 80 ºF.
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.
component materials are industrial-grade chemicals. Please keep
them in a secure place and prevent access from any unauthorized
individual. The personnel who handle these materials need 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.
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, and if you expect the isocyanate content level in the
work place atmosphere may become above the threshold regulated by
OSHA or by other appropriate working place safety standard, we
recommend, in addition to the above, installation of a proper hooded
dynamic ventilation system and/or using an appropriate type of
respirator (such as a full-face respirator equipped with OSHA
approved HEPA filters for particulate and organic vapor) to prevent
inhalation of the fume.
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
3444 Dight Avenue
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.
Back to Foam Index
Back To Product Index
Back to Main Page