Sonoco Increases Prices on Plastics Used in Adhesives and Sealants Packaging 29/08/2008 06:44:15 Sonoco, one of the largest diversified global packaging companies, has announced a 10 percent price increase on the plastic cartridges and plungers it supplies into the adhesives and sealants marketplace. The increase went into effect Aug. 15. Sonoco, one of the largest diversified global packaging companies, has announced a 10 percent price increase on the plastic cartridges and plungers it supplies into the adhesives and sealants marketplace. The increase went into effect Aug. 15. "The adjustment in price is a direct reflection of the escalating costs in resins, energy, freight and converting," said Bob Puechl, division vice president and general manager - Rigid Plastics.