MPP-R06C is one of our polyurethane foam formulations. It is closed-cell foam with a good structural integrity and an enhanced skin quality. Unlike polyurethane rigid foams, the physical properties of a cured product have slight flexibility so it resists cracking and chipping-off upon an impact. The application of this foam includes backing structure for flexible concrete molds, parts production by compression molding, and other specialty applications.

Since the liquid mixture does not fill the mold, the foam needs to fill the mold space with its expansion pressure. By slightly larger amount of foam into a closed mold, you can obtain a better resolution from the mold. The expansion pressure of the foam sends the foam material to fill the mold to the expected shape.

The mold therefore needs to be close mold with a capacity to retain the internal pressure. A simplest compression mold will be an open-top box with a lid. The lid needs to be clamped by c-clamps or furniture clamps to hold the pressure. The air trapped in the mold could make large voids if it is not let out. For this purpose, you need to have very small vent holes to let the trapped air escape from the mold. You may need to actually try foaming the material to see what parts of the mold have tendency to trap air; then create vents to those places.

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 urethane reaction is required for foam to cure properly. If mold is cold, this heat is absorbed and the foam does not cure properly. The mold needs to be heat to 100 to 120 ºF in case of metal molds. If your mold is made of a plastic or elastomeric material, such as silicone rubber, epoxy, and urethane, this may not be necessary. Please test and determine the optimal temperature for your mold. You may need to machine off the small amount of material squeezing out from the vent holes.

Compression rate is the rate in which 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. This means you need to add 10% more of the material than the volume free-risen foam would fill. Using higher rate makes the foam denser and stronger.

If you see many small voids in the foam, this may be because the material is cast in while the mixture is creaming and loosing its flow. If creamed material is mechanically stirred, it may trap air and make those bubbles. To prevent this, try casting the material within the pot life or before the material is too thick.

In case the mold is thin and it is placed in a vertical position, if the material touches the side wall of the mold and starts to cream/foam from the side wall, this could create many small air pockets as well. If the compression rate is high, these small voids may be shrunk to invisible sizes. Try not to get the material on the side wall when you are pouring the material in the mold. Changing the position of the mold may help alleviating this problem.

Applications that 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.

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 65 and 90 ºF.

Part-B component may be 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. The storage temperature should be at a room temperature between 65 and 90 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 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.

Whenever using this material, please 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 using a half-face respirator recommended for the use 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. 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.

Revised January 2, 2006