Abstract: A smooth, plastic-lined corrugated pipe having an intermediate layer of plastic foam. The pipe is made by internally coating a corrugated pipe with a foaming mixture and pressing an expandable cylinder of plastic sheet liner against the foaming mixture until the foam solidifies. An expandable mandrel apparatus presses the plastic sheet liner into position.

Abstract: A smooth, plastic-lined corrugated pipe having an intermediate layer of plastic foam. The pipe is made by internally coating a corrugated pipe with a foaming mixture and pressing an expandable cylinder of plastic sheet liner against the foaming mixture until the foam solidifies. An expandable mandrel apparatus presses the plastic sheet liner into position. The apparatus comprises a hollow cylinder, an elastomeric cylinder fitted on the outside of the hollow cylinder defining an annular space therebetween and a fluid conducting means communicating with the annular space.

Abstract: A compartmented container made of pliable film material includes a first compartment formed by looping the film material and attaching one edge of the film material to itself to form a first seam intermediate of the edges of said film material and substantially parallel to the longitudinal axis of said package. A second compartment is formed with said film material by attaching the second edge of the film material to the first compartment to form a second seam adjacent to the first seam and substantially parallel to the longitudinal axis of said package. Reactive components are loaded within the first and second compartments and the compartments are closed at opposite ends to form a unitary container.