A Delaware federal judge on Thursday confirmed a $50.3 million infringement verdict against Ardagh Glass Inc. for infringing a patent held by a small Pennsylvania-based glass company.

In a 28-page memorandum opinion, U.S. District Judge Gregory M. Sleet of the District of Delaware turned away Ardagh’s attack on a Wilmington jury’s finding last April that an American subsidiary of the European glass manufacturer willfully infringed Green Mountain Glass’ patent, which covers technology used to recycle glass in the manufacturing process.