MIL-I-24768

Abstract

This specification covers thermosetting plastic laminated insulation materials for mechanical and electrical military applications. <br>The form and type of insulation shall be as specified in the applicable specification sheet (see <a>3.1</a> and <a>6.2.1</a>). <br>The types of insulation grouped according to the base material used, shall be as follows: <br>a. Cotton Fabric Base, Phenolic-Resin Binder </span><pre> FBE - Cotton Fabric Base, Phenolic-Resin, Electrical Grade FBG - Cotton Fabric Base, Phenolic-Resin, General Purpose FBI - Cotton Fabric Base, Phenolic-Resin, Machining Applications FBM - Cotton Fabric Base, Phenolic-Resin, Mechanical Grade</pre> <br> <strong>Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, Naval Sea Systems Command, SEA 55Z3, Department of the Navy, Washington, DC 20362-5101 by using a self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.</strong> <br>b. Glass Fabric, Base, Epoxy-Resin Binder <pre> GEE - Glass Fabric Base, Epoxy-Resin, Electrical Grade GEB - Glass Fabric Base, Epoxy-Resin, High Temperature Electrical Grade GEE-F - Glass Fabric Base, Epoxy-Resin, Flame Resistant, Electrical Grade GEB-F - Glass Fabric Base, Epoxy-Resin, High Temperature, Flame Resistant, Electrical Grade</pre> <br> <br>c. Glass Fabric Base, Melamine-Resin Binder <pre> GME - Glass Fabric Base, Melamine-Resin, Electrical Grade GMG - Glass Fabric Base, Melamine-Resin, General Purpose</pre> <br> <br>d. Glass Mat Base, Polyester-Resin Binder <pre> GPO N-1 - Glass Mat Base, Polyester-Resin, Mechanical Grade GPO N-2 - Glass Mat Base, Polyester-Resin, Low Flammability and Self-extinguishing Properties, General Purpose GPO N-3 - Glass Mat Base, Polyester-Resin, Track Resistance, Low Flammability and Self-extinguishing Properties, General Purpose GPO N-1P - Glass Mat Base, Polyester-Resin, Mechanical Grade, Punching Characteristics GPO N-2P - Glass Mat Base, Polyester-Resin, Low Flammability, Self-extinguishing Properties, Punching Characteristics GPO N-3P - Glass Mat Base, Polyester-Resin, Track Resistance, Low Flammability, Self-extinguishing Properties, Punching Characteristics</pre> <br> <br>e. Glass Fabric Base, Silicone-Resin Binder <pre> GSG - Glass Fabric Base, Silicone-Resin, General Purpose</pre> <br> <br>f. Glass Fabric Base, Polytetrafluoroethylene-Resin Binder <pre> GTE - Glass Fabric Base, Polytetrafluoroethylene-Resin, Electrical Grade</pre> <br> <br>g. Glass Fabric Base, Phenolic-Resin Binder <pre> GPG - Glass Fabric Base, Phenolic-Resin, General Purpose</pre> <br> <br>h. Nylon Fabric Base, Phenolic-Resin Binder <pre> NPG - Nylon Fabric Base, Phenolic-Resin, General Purpose</pre> <br> <br>i. Paper Base, Phenolic-Resin Binder <pre> PBE - Paper Base, Phenolic-Resin, Electrical Grade PBG - Paper Base, Phenolic-Resin, General Purpose PBM - Paper Base, Phenolic-Resin, Mechanical Grade PBM-P - Paper Base, Phenolic-Resin, Hot Punching Stock, Mechanical Grade PBM-PC - Paper Base, Phenolic-Resin, Cold Punching and Shearing Stock, Mechanical Grade PBG-P - Paper Base, Phenolic-Resin, Hot Punching Stock, General Purpose PBE-P - Paper Base, Phenolic-Resin, Hot Punching Stock, Electrical Grade PBE-PC - Paper Base, Phenolic-Resin, Cold Punching Stock, Electrical Grade PBM-PF - Paper Base, Phenolic-Resin, Hot Punching Stock, Flame Resistant, Mechanical Grade PBE-PCF - Paper Base, Phenolic-Resin, Cold Punching Stock, Flame Resistant, Electrical Grade</pre> <br> <br>j. Paper Base, Epoxy-Resin Binder <pre> PEE - Paper Base, Epoxy-Resin, Flame Resistant, Electrical Grade</pre> <br> <br>k. Continuous Filament Glass Cloth, Epoxy-Resin Binder <pre> CEM-1 - Glass Cloth Base, Epoxy-Resin, Cellulose Core CEM-3 - Glass Cloth Base, Epoxy-Resin, Nonwoven Core</pre> <br> <br>The insulation forms shall be as follows: <pre> Form R - Rods Form S - Sheets Form TRR Tubes, rolled, round Form TMR Tubes, molded, round.</pre> <br> <br>The sizes of insulation shall be as specified in the individual specification sheets (see <a>3.1</a>). <br><b><u>Intended Use:</u></b> The laminated insulation covered by this specification is intended for the following applications of electrical usage. Laminated sheets are generally used as terminal boards, spacers, voltage barriers, motor and generator slot wedges and slot fillers, and circuit boards. Laminated rods are intended for a variety of applications such as insulating screws, bolts, and small bushings or spacers where electrical stress is not severe. Rolled tubes are intended for application in coil forms, insulating bushings, bearing retainers, and so forth, where excellent concentricity and good physical and electrical characteristics are required. Molded tubes are intended for use in coil forms, insulating bushings, bearing retainers, and so forth, where higher density, lower water absorption, and better dimensional stability are required. <br>