or variable denier to reduce elongation use of flame retardant or self extinguishing component in substrate allow for protection of sensitive circuitry in case of catastrophic thermal failure with reference to fig1 therein is illustrated an apparatus for practicing the present method for forming a nonwoven substrate the support substrate of the invention is manufactured in accordance with the techniques disclosed in u s pat no 5 098 764 to drelich hereby incorporated by reference the substrate is formed from a fibrous matrix which typically comprises staple length fibers the fibrous matrix is preferably carded and cross lapped to form a precursor web designated p in a current embodiment the precursor web comprises a majority of cross lap fibers that is most of the fibers of the web have been formed by cross lapping a carded web so that the fibers are oriented at an angle relative to the machine direction of the resultant web fig1 illustrates a hydroentangling apparatus for forming nonwoven substrates in accordance with the present invention the apparatus includes a foraminous forming surface in the form of belt 10 upon which the precursor web p is positioned for pre entangling by entangling manifold 12 pre entangling of the precursor web prior to three dimensional.