ETHYLENE VINYL ALCOHOL COPOLYMER PELLET, METHOD FOR EXTRUSION OF THE PELLET AND EXTRUSION MOLDED FILM PRODUCED THEREBY

• Main Authors: Chang, Huan Ming, Liang, Chih Chieh, Lin, Weng Shing, Hsu, Chia Hao
• Format: Patent
• Language: English
• Published: 09.01.2020
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; MAKING GRANULES OR PREFORMS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PREPARATION OR PRETREATMENT OF THE MATERIAL TO BESHAPED; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIALCONTAINING PLASTICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

Extruded films comprising ethylene vinyl alcohol copolymer (EVOH) with substantially no blow holes therein, are formed by using a pellet feed to the extruder wherein 90-100 wt. % of the pellets pass through an ASTM size 5 sieve and 0-10 wt. % of the pellets are finer than a number 10 mesh (ASTM Sieve size). Uniform feeding to and through the extruder with a lack of bridging of the EVOH pellet feed have been observed.