For the third time this year, major polyethylene film makers are seeking non-resin price increases for their products.

AEP Industries Inc., Sigma Plastics Group and Berry Plastics Corp. each recently have sent letters to customers indicating price increases effective Dec. 1. Hackensack, N.J.-based AEP and Lyndhurst, N.J. each are seeking increases of 4 percent. The increase amount cited by Evansville, Ind.-based Berry is 3-5 percent.

In the AEP letter, Chairman and CEO Brendan Barba said that continued rising price pressure on freight, energy, healthcare and other non-resin-related costs “have been unprecedented.”

“While AEP continues to make huge strides in manufacturing efficiencies to offset these cost increases, it’s not always possible to achieve when those costs are significant and mount up quickly,” he said.

Similar increase attempts in May and September met with mixed results. PE film makers also are dealing with a steady rise in PE resin prices. Since late 2012, North American PE resin prices have seen six price increases — totaling 23 cents per pound — without a single decrease. That’s different from historical pricing patterns where increases would be partially offset by decreases in the course of a typical year.

AEP, Sigma and Berry each rank among North America’s 10 largest film and sheet makers, according to Plastics News’ recent ranking.