A reel or spool package has opposing sidewalls or flanges formed of the specified or appropriate substrate and connected by a core formed of a flowable material which sets or cures to harden, such as a two part expandable polyurethane foam. The foam is applied into a partition, which may be a paper ring, by an injection and metering device. The chemistry of the flowable material may be altered to change density, rigidity and flexibility as required by package stresses. The polyurethane foam is an effective adhesive medium, thereby forming the core and connecting the sidewalls to form the package.