a non - metallic element system is provided as part of a downhole tool that can effectively seal or pack - off an annulus under elevated temperatures . the element system can also resist high differential pressures without sacrificing performance or suffering mechanical degradation , and is considerably faster to drill - up than a conventional element system . in one aspect , the composite material comprises an epoxy blend reinforced with glass fibers stacked layer upon layer at about 30 to about 70 degrees . in another aspect , a mandrel is formed of a non - metallic polymeric composite material . a downhole tool , such as a bridge plug , frac - plug , or packer , is also provided . the tool comprises a support ring having one or more wedges , an expansion ring , and a sealing member positioned with the expansion ring .