EVA resins

Equistar Chemicals L. D. Polyethylene, high pressure autoclave LDPE and EVA resins Ethylene, vinyl acetate Proven reliable resin production for film, injection molding and wire and cable grades. VA content up to 30% film, adhesives, etc. 10 1988... 

EVA copolymers with vinyl acetate (VA) contents ranging from 5 to 50% are commercially available. For most food applications, VA ranging from 5 to 20% is recommended. EVA resins are mainly recognized for their flexibility, toughness, and heat sealability. 

The outdoor stability of EVA resins is superior to that of LDPE by virtue of their greater flexibility. Addition of UV stabilizers can extend the outdoor life of clear compounds to three to five years, depending on the degree of exposure. Outdoor life expectancy is also enhanced by the addition of carbon black. 

With increasing VA content, EVA resin properties range from those of LDPE to those of highly plasticized PVC. High VA resins are soft and flexible, with excellent toughness and good stress-crack resistance. With EVA resins these properties are permanent and do not dissipate with time because of the loss of the liquid plasticizer. EVAs also have exceptional low temperature toughness and flexibflity. 

Uses Tackifier in pressure-sensitive and hot-melt adhesives, tapes, paint vehicles, rubber compds. modifier for EVA resins and waxes waterproofing resin for textile sizing in sealants, printing inks FDA cleared for use in closures with sealing gaskets for food containers, etc. Features Thermoplastic Regulatory FDA compliance... 

Chem. Descrip. Aliphatic hydrocarbon resin emulsions Uses Resin emulsion used in combination with other aq. thermoplastic and/or elastomeric systems to produce coatings, paints, and adhesives extender, tackifier for NR, SR waterproof finishes for paper, textiles esp. suitable for use in high-styrene SBR, EVA resin, and polyacrylic-based latex paints, and in adhesives for bonding films, fibers, and granular materials food-pkg. and processing operations Properties Gardner 9 (50% in toluene) liq. dens. 0.97 kg/l vise. 3000 cps soften, pt. (R B) 63 C pH 8.5 anionic 50% aq. disp. 

Uses Tackifier for natural rubber, polyisoprene, and SIS rubbers in pressure-sensitive adhesives modifier for waxes in lost-wax investment casting operations and in EVA resin/wax/low m.w. polyethylene hot-melts, for use in paints/coatings... 

Uses Resin in hot-melts, adhesives, rubber compding., specialty paints and lacquers, petrol. wax EVA resin-based, hot-melt form-and fill coatings, forfood-pkg. and -processing... 

Figure 7. Hot-tack strength ofAFFINITY POP and EVA resins as a function of seal-bar temperature. Nylon/EAA/Sealant (I/I/1.5 mil) blown co-ex film was used. (Reproduced with permission from reference 25. Copyright 2002 Taylor and Francis Group, LLC.)...

Ehnax, Stainless mold steel, Uddeholm EHesol, Catalysts, Albright Wilson Americas Elvaloy, Ethylene/ester/CO terpolymers, DuPont Elvamide, Nylon multipolymer resins, DuPont Elvanol, Polyvinyl alcohol, DuPont Elvax, EVA resins, DuPont Emamelt, Electromagnetic hot melts, Emabond Systems, Ashland Chemical Co. 

Lennite, Lennite XL, Ultra-high-molecular-weight polyethylene, Westlake Plastics Co. Leucopure EGM, Fluorescent whitener for polymers, Clariant Corp., BU Additives Levapren, EVA resins, Bayer Corp., Fibers, Additives Rubber Div. 

Attempts to bind aerogels similar to traditional composites have yielded little success. Dry binding systems such as epoxy and EVA resins are some of the commonly used binders for composites leveraging on the tackiness of the binding... 

Elvax EVA resins, DuPont Emi-X EMI attenuated thermoplastic composites, LNP... 

Ethylene vinyl acetate. The properties of ethylene vinyl acetate (EVA), a random copolymer of ethylene and vinyl acetate, depend on the content of vinyl acetate. EVA resins show better flexibility, toughness, and heat sealability than LDPE. The content of vinyl acetate (VA) in the copolymer ranges from 5 to 50 percent. For optimal food packaging applications, VA content should range from 5 to 20 percent. 

For both resins, gel permeation chromatography (GPC) was employed to measure variation in molecular weight and molecular weight distributions. For the EVA resin, samples were dissolved in tetrahydrofuran (THF) and analysed using a Viscotek TDA GPC instrument calibrated against EasiCal poly(styrene) standards. The peaks observed from the EVA samples were within the range covered by the EasiCal poly(styrene) calibration standards used within this study. 

Fig. 10.3 Acidity of the uncured EVA resin (emulsion) monitored as a function of time and at a number of different temperatures. The slope of the linear regression fit to the data was used to...

Fig. 10.4 Arrhenius plot of the rate of change in EVA resin acidity as a function of temperature. This plot allows the rate of change in acidity at temperatures representative of typical resin storage conditions ( 20 °C)...

Fig. 10.5 Vinamul 3161 EVA resin molecular weight as a function of resin storage temperature (over 4 months) as measured by GPC. The weight average and number average trends fit a power law relationship with accelerated ageing, inducing a gradual reduction in molecular weight through oxidative chain scission chemistry...

Metallocene polyethylene (mPE) plastomers 0.900-0.915 Coextrusion, heat seal layers Ethylene-vinyl acetate (EVA) resins with 9% vinyl acetate, ultra low density polyethylene (ULDPE), very low density polyethylene (VLDPE)... 

Case sealing adhesives based on EVA resins are often a blend of several ingredients. A typical formulation is listed in Table 7. 

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