Low Viscosity Polyurethane Gel Casting System

(Product Code: GK-7)

 Prepolymer (Part-A): MPG-023        Curative (Part-B): PNC-157

 

This material is formulated for production of thin polyurethane gel film or parts.  The low viscosity property of the mixed component enables the user to cast this into a thin layer without entrapping a significant amount of air.  This product can be cast in between films, molded in vertical mold, or cast on an open surface to make thin gel sheets.  It is room-temperature-cure liquid castable system that can be processed without use of heat.

 

The suitable applications include custom gel sheets, tack pads, vibration dampening parts, and encapsulation of electric components.  It is also suitable for many other custom applications where flexibility and some strength of the gel sheets or parts are required. 

 

This material is not suitable for pouch filling application.  We recommend MPP-V37A for pouch filling application where the material needs to cure within film encapsulation.

 

GK-7 (Low Viscosity Polyurethane Gel for Films and Sheets)

 

Part-A:

MPG-023

Part-B:

PNC-153

                   

Mixing ratio:

A:B	=	1: 10.00	by volume
A:B	=	1: 9.216	by weight

(This is a variable-ratio system, which the user can change the mixing ratio to control the softness of the material.  Increasing part-B ratio yields a softer gel material.)

 

Processing Temperature:

 

Part-A:	Ambient
Part-B:	Ambient
Mold:	Ambient

Curing Pattern

Pot Life:	8-10 munites
Demolding Time:	8 hours
Complete Cure:	3 - 4days

 (The curing pattern can be modification by use of heat and catalyst variation.)

 

Part-A material has isocyanate material, which is highly moisture sensitive.  Blanket the space in the container with dry nitrogen gas after the containers are opened.  Please refer to the enclosed MSDS for the details on safety and handling the materials.

 

The part-A component material could freeze at temperature slightly below room temperature.  If you see gel-like consistency within the part-A container, the material might have been frozen during the transportation or storage.  Heat part-A to 140 – 160 °F to thaw.  Then the component material should be stored at room temperature 70 – 90°F. 

 

Properties of the components

 

Part-A

Product Code:	MPG-023
Description:	Isocyanate terminated prepolymer extended with polyester polyol
%NCO:	18.6% (+/- 0.5)
Amine Equivalent	225.9
Specific Gravity:	1.112
Physical State at 25 °C ( 77 °F):	Liquid
Viscosity at 25 °C (77 °F):	1200 cps (+/- 200)
Storage:	Store in a dry indoor storage at room temperature.  The material is highly sensitive to moisture.  After using the content, immediately inject dry nitrogen gas or -40° due-point dry air into the container to blanket the material then store.  Heat will accelerate the subsequent reaction within the material and shorten the shelf life of the material. Do not store at an elevated temperature.

 

Part-B

Product Code:	PNC-153
Description:	Curing agent based on a blend of polyols and additives
OH number:	1532
Equivalent Weight:	15 – 1630
Specific Gravity:	1.104
Physical State at 25 °C ( 77 °F):	Liquid with slight haze
Viscosity at 25 °C (77 °F):	900 cps (+/- 300)
Storage:	Store in a dry indoor storage at room temperature.  The material is hygroscopic. For long-term storage, inject dry nitrogen gas or -40° due-point dry air into the container to blanket the material.

 

 

Handling Information:

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 80 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 85 ºF. The moisture contamination of part-B material is reversible.  By heating material to 160 - 180 ºF and vacuuming it at about 29" Hg negative pressure for several hours will reduce the moisture level.

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. 

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.  

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.