Moisture-Cure Particle Bonding Agent with Variable Flexibility
(For Recycled Foam Bonding and Other Particle Bonding Applications)
MPA-221/MNB-013
Technical Data Sheet
This two-part moisture-cure polyurethane adhesive system is designed
to be used with recycled ground rubber, polymer foam, polymer beads,
as well as other particles such as cork granules, wood and pulp
fiber/particles/powder to make various recycled foam and other
bonded particle products.
By
changing the blending ratio, the user can vary the flexibility of
the end product. A higher amount of MPA-221 will produce a more
flexible product. A higher amount of MNB-013 will produce a more
rigid product.
For
example, "MPA-221: MNB-013 = 95: 5" ratio can be used to make
flexible floor covering mats for exercising/playing room using
recycled/ground EPDM particles. With the same EPDM particles,
"MPA-221: MNB-013 = 20: 80" ratio can produce semi-rigid products
such as soft foam stools/tables and custom positioning/supporting
parts for wheel chairs. The users can try different blending ratios
to find the optimum blend for their applications. This formulation
system can be used in a wide range of crumb/particle bonding
applications.
The
material cures with moisture. There is no solvent in this system.
Curing rate can be controlled by addition of catalyst. Heat may
also be used to accelerate curing.
Designations
MPA-221 (MDI Based Prepolymer to Produce Softer Film)
MNB-013 (Polymeric MDI to Produce Harder Film)
Ratio Recommendations
The
ratios below are references for starting point blending ratios, and
are
MPA-221: MNB-013
respectively by weight. The blending ratios can be varied for the
optimum result for the intended application. The user can test to
find the optimum ratio.
95:
5 for Soft Flexible Film
70:
30 for Firmer Flexible Film
20: 80 for Semi-Rigid
Film
0: 100 for Rigid Film
Processing Recommendations
Blend MPA-221 and MNB-013 at the desired ratio using a mechanical
mixing tool. If a larger batch is made, powered mixing tools can be
used.
If
blending is difficult due to the high viscosity of MPA-221, heat
MPA-221 to the 100 – 160 ˚F range to reduce the viscosity. If heat
is used, be sure to circulate and ventilate the working area with
fans and/or other dynamic air moving apparatus.
If
the blend needs to be stored for a long time, the blend must be
stored in an air-tight container. The head space must be purged and
blanked with dry nitrogen or argon gas.
In
a blending vessel, load the particles such as recycled foam crumbs
first, and pour the bonding agent blend gradually as the contents
are agitated with a powered mixer.
After the particles and bonding agent are blended well, the mixture
can be poured into a mold and mechanically compressed until the
bonding agent cures to solid/dry consistency.
Curing Pattern
The
curing time varies depending on the air moisture content,
temperature, catalyst level, and other factors. Higher temperature
and catalyst (amine/base catalyst) will increase the curing rate.
This product is not tested for bonding applications at uncontrolled
conditions such as outdoor made-in-place applications. However, it
is likely that outdoor application is possible with addition of
catalyst at the installation site.
Bonding Agent Concentration
The
loading ratio of bonding agent to the particle media needs to be
tested for the required strength for the application. We recommend
20% to 40% bonding agent ratio by weight as the starting point for
your tests. You may reduce/increase the bonding agent ratio
according to your tests. Compressing the part in mold will improve
the bonding capacity, and you may use a smaller amount of bonding
agent.
Component Material Properties (Typical/Theoretical Values)
MPA-221 (Soft/Flexible Component)
General Description: Isocyanate Terminated Prepolymer based on MDI
and polyether polyol
NCO: 1.9%
Equivalent Weight: 2206
Specific Gravity (at 77 ˚F): 1.043 grams/cm3
Viscosity: 10,000 cps at 100 ˚F, > 40,000 cps at 72 ˚F
Storage/Handling: Store indoor at room temperature between 72 ˚F
and 90 ˚F. The container head space must be purged to blanket the
material with dry nitrogen gas or argon gas.
MNB-013 (Hard/Rigid Component)
General Description: Polymeric MDI
NCO: 31.5%
Equivalent Weight: 133
Specific Gravity (at 77 ˚F): 1.235 grams/cm3
Viscosity: 200 cps at 77 ˚F
Storage/Handling: Store indoor at room temperature between 72 ˚F
and 90 ˚F. The container head space must be purged to blanket the
material with dry nitrogen gas or argon gas.
Other Notes
When the material is reacting with moisture, CO2 gas is also
created. The gas can expand the part in mold if the mold is not a
closed-mold with capacity to withhold the expansion pressure. The
open-molded parts molded in a heated mold also have higher shrinkage
after the part is cooled due to the CO2 gas expansion and shrinkage.
After the optimum blending ratio is found for the intended
application, Northstar Polymers may be able to custom blend MPA-221
and MNB-013 for large consumption demands. Please consult Northstar
Polymers for the details.
The
film thickness of this bonding material is limited up to about 1/16”
to 3/32” (3 to 5 millimeters). If a thicker film thickness is
required, different formulations will be recommended.
These materials are industrial grade isocyanate based materials,
which need to be handled carefully according to the
safety/handling/storage recommendations. When you are handling
these materials, please operate in a large area with good air
circulation or well-ventilated area. The operator must wear rubber
gloves, long sleeves, and protective eyewear to avoid skin/eye
contact of these materials until it is cured to the solid state.
Please refer to the “Handling Information” section in this document
and the Safety Data Sheet for each material for the details.
Northstar Polymers does not guarantee the fitness of its products to
any application. The producers/marketers of the end products are
responsible for testing the functionality, safety, regulatory
conformance, marketability, and all other relevant aspects to
confirm the fitness of their raw materials, including these
materials from Northstar Polymers, used in their end products.
Standard Packages:
5-gallon pails (40 pounds per pail)
55-gallon drums (450 pounds per drum for MPA-221, 500 pounds per
drum for MNB-013)
Handling
Information
Storage/Handling Information for the Component Materials
Storage:
These
component materials contain isocyanate components, which are highly
sensitive to moisture. If it is left in air, the material will
react with atmospheric moisture and will be ruined. This reaction
is non-reversible. Soon after opening the container to dispense the
content, dry nitrogen gas or argon gas needs to be injected to the
container to purge and blanket the head space. Please consult
Northstar Polymers for nitrogen gas set-up information.
For gravity
feeding system from a 55-gallon, silica gel or calcium chloride
desiccant filter(s) should be installed to the vent-hole of the
drum. A valve to inject dry nitrogen gas can be installed instead.
Store the
containers a dry indoor storage within the temperature range between
72 and 90 ºF. Avoid direct sunlight.
If a large
amount of water mixes with a large amount of isocyanate base
materials, the chemical reaction may produce a large amount of CO2
gas and heat to create a hazardous condition. Keep the storage area
free of water.
Under a
certain combination of heat, catalyst (basic chemicals), amounts of
reactive materials, and some other favorable conditions for the
reaction, the water (or alcohol/glycol/amine) to isocyanate reaction
can reach a dangerous state of accelerated reaction. The
accelerated reaction may create a very high temperature condition.
The thermal decomposition of isocyanate based material by extremely
high temperature or fire can produce toxic gasses and smokes. Please
be sure that the containers are stored in dry indoor storage, away
from source of large amount of water.
If a leak
is found in a drum, please place the drum in such a position that
the leaking part is at the highest part of drum so that the content
no longer leaks out. Cover the leaking area with dry towel to
prevent air from entering. If possible, transfer the material into
new container(s) with nitrogen purge. If moisture enters into an
isocyanate container from a small leakage, CO2 gas may be produced
to gradually pressurize the container. If pressure built up is
suspected, open the bung (or cap) very slowly to release the
pressure before you change the drum position.
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 handle these materials need to read
the Safety Data Sheet (SDS) for detail information on safety and
handling of the material. The SDS 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, 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.
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 SDS for each component for the detailed health
information.
For any
questions, please contact Northstar Polymers.
Tel:
612-721-2911 Ext 119
Fax:
612-721-1009
Web Site:
http://www.northstarpolymers.com
E-Mail: info@northstarpolymers.com