| 摘要 |
Fuel system components for vehicles may be made from polyethylene components which are typically blow molded. To inhibit fuel vapour permeation, the polyethylene is often co-extruded into a parison with the parison comprising a barrier layer. Upon trimming flash or in the mold closure itself, the barrier layer may be ruptured. Sealing of areas of discontinuity in the fuel system component to inhibit hydrocarbon vapour pass through is achieved by sealing the area of barrier discontinuity with a sealing bead which has the necessary barrier properties. The barrier properties may be inherent in the sealing bead material or in a barrier layer extruded into the sealing bead.
|
