WEB EXCLUSIVE: Supply of conventional LDPE is very tight, and LLDPE does not have the melt strength some processors need for foams, blown film, extrusion coating, and thermoforming. Fortunately, E-Beam Services, Inc., Cranbury, N.J., has an answer. Electron-beam irradiation of LLDPE pellets reportedly can induce long-chain branching that provides processability similar to that of LDPE while retaining the superior mechanical properties of LLDPE. According to independent consultant Edward M. Phillips, Elkton, Md., who is developing this market with E-Beam Services, irradiation increases the molecular weight, adding melt strength. The long-chain branching makes the resin more shear sensitive; and at very low melt indexes, excessive extrusion pressures and shear heating can be avoided. E-Beam Services is doing truckload business now with film and foam processors who can’t get enough LDPE and supply LLDPE for toll radiation processing. E-Beam Services can provide different levels of treatment, depending on the customer’s needs. For example, a higher dose can be provided to create, in essence, a masterbatch form of melt-strength modifier. E-Beam has facilities in Cranbury, N.J.; Lebanon, Ohio; and Lafayette, Ind.
According to Phillips, e-beam processing could also improve the processability of PLA biopolymer and engineering resins with poor melt strength.