F.D. Sims Limited: Polyurethane 130 Solderable Enamel Round Wire Technical Page

Polyurethane 130 Solderable Enamel Round Wire is covered with a modified polyurethane resin which was introduced to combine excellent dielectric strength with the advantage of soldering without prior removal of the enamel from the wire. This factor makes it most useful for multi-connection windings as it eliminates costly stripping operations, especially on finer wires.

Specification

Solderable 130 Wire has a very low power factor which shows little change at high frequencies or under humid conditions and, whilst its abrasion resistance is not quite as good as that of PVA 120 it possesses equal flexibility and adhesion. Its windability, due to careful selection and processing of the copper, is excellent.

Health and Safety Note

In common with all polyurethane enamels, Solderable 130 may produce minute quantities of highly toxic gas, Tolune Di-Isocyanate (T.D.I.) on soldering. As the maximum allowable concentration of this gas is 0.005 parts per million, it is strongly recommended that fume extraction equipment be installed in the area where soldering is carried out. (For the method of measuring T.D.I. concentration see HSE Publication MDHS 25 Methods for the Determination of Hazardous Substances - Organic Isocyanates in Air).

Chemical Properties

Prolonged contact with aggressive polar solvents e.g. alcohol and acetone, will cause temporary softening of the enamel but Solderable 130 will withstand the normal solvent combinations used in the majority of impregnating varnishes.

Temperature Classification

Solderable 130 Wire is suitable for use in Class B Systems provided that a suitable and correctly applied impregnating varnish is used and that all other associated insulating materials are of the same classifications.
However, as is well established, this classification is dependent on other factors, especially the nature of the operating environment. When evaluated in accordance with the procedures laid down in I.E.C. Publication 172 this covering can be damaged by overload temperatures which exceed 220°C.