Effect of metallocene blending on critical film properties of LLDPE stretch films

Critical film properties of LLDPE stretch films for on-pallet wrap include stretchability, puncture resistance, load retention, tear resistance and cling. Stretchability and puncture resistance of LLDPE can be influenced by suitable modification/selection of Melt Index (i.e., molecular weight) and/or addition of LDPE, but there is usually an inverse relation between stretchability and puncture resistance. Blending of metallocenes (mLLDPE) into LLDPE can improve puncture resistance without sacrificing stretchability, as the present work will show. Experimental results of on-pallet stretch film testing and results of ASTM-type testing are also presented.