Tubular core assemblies for rolls of paper or other sheet material

A tubular core assembly for a roll of paper or other sheet material comprising:

• a hollow cylindrical core member formed by multiple wraps of paperboard material,
• an annular collar within each opposite end portion of the core member, each collar being a rigid body of non-isotropic material and having an outer annular surface glued to the inner annular surface of the core member and an inner annular surface having a configuration complementary to the outer annular surface of a roll supporting chuck so that the chuck is receivable therein with a close fit and
• a pair of plugs insertable into the collars at opposite ends of the tublar core assembly, each plug comprising a body of non-isotropic material with a solid cross-section having an uninterrupted circular outer circumference, each plug having a length substantially equal to the length of the collar, and each plug having an outer annular surface complementary to that of the internal annular surface of the collar so as to be a close fit therein.