Formosa TAISOX® EVA

TAISOX® EVA resin is an ethylene-vinyl acetate copolymer produced by Formosa Plastics Corporation. By incorporating vinyl acetate (VA) into the polyethylene molecular chain, the resin achieves greater flexibility and polarity than conventional polyethylene. This structure provides a balanced combination of elasticity, impact resistance, transparency, and processing performance.

The TAISOX® range offers multiple grades with different VA contents and melt flow characteristics to meet diverse processing requirements. Depending on the selected grade, the resin can support applications such as footwear, cross-linked foam sheets, shock-absorbing materials, hot melt adhesives, flexible components, and photovoltaic encapsulation films.

Representative TAISOX® EVA Resin Grades

Grade	VA Content	Melt Index*	Typical Applications
7140F	14%	0.7 g/10 min	Greenhouse films, agricultural films, sanitary applications
7240M	15%	1.5 g/10 min	Foamed footwear, cross-linked foam sheets
7320M	9%	4.0 g/10 min	Flexible products, foam sheets
7340M	14%	2.5 g/10 min	Flexible products, cross-linked foam
7350M	18%	2.5 g/10 min	Foamed footwear, cushioning materials
7360M	21%	2.5 g/10 min	Foamed footwear, cushioning materials
7470M	26%	7.5 g/10 min	Foam sheets, cushioning materials, building materials
7760H	28%	25 g/10 min	Hot melt processing
7670S	28%	10 g/10 min	Photovoltaic encapsulation films
7760S	27%	27.5 g/10 min	Photovoltaic encapsulation films

Major Applications

Footwear and Shoe Components. Formosa TAISOX® EVA resin provides flexibility, resilience, and cushioning properties for midsoles, outsoles, slippers, sports footwear, and other lightweight shoe components.
Cross-Linked Foam Products. Selected grades support cross-linked foaming processes and can produce lightweight foam with controlled hardness, elasticity, and cushioning performance. These materials serve packaging, sports, construction, and protective applications.
Cushioning and Shock Absorption. EVA foam can absorb impact and provide cushioning for protective pads, sports products, packaging inserts, and industrial components.
Flexible Products. Selected grades offer the softness and flexibility required for sheets, seals, gaskets, and other flexible molded or extruded products.
Hot Melt Adhesives. High-VA grades with suitable melt flow characteristics can serve as base polymers for hot melt adhesive formulations, providing flexibility and adhesion for various substrates.
Photovoltaic Encapsulation Films. Specialized TAISOX® EVA grades support photovoltaic encapsulation film production. They provide suitable adhesion, transparency, and lamination performance for solar module manufacturing.

How to Select the Right EVA Grade

Choosing an appropriate EVA grade requires more than simply comparing VA content. Processors should consider the complete material specification together with the manufacturing method and final product requirements.

(1) Consider VA Content

Lower VA content generally provides a comparatively firmer material with higher crystallinity and can suit applications that require a balance between flexibility and structural rigidity.
Medium VA content offers a practical combination of softness, elasticity, and processability, making these grades suitable for many foaming and footwear applications.
Higher VA content generally produces greater flexibility and polarity. Such grades can be considered for applications that require enhanced softness, adhesion, or optical performance, including hot melt adhesive systems and photovoltaic encapsulation films.

(2) Consider Melt Flow. The melt index provides an indication of how readily the molten resin flows under a specified test condition.

Lower melt flow: useful when the process requires greater melt strength and shape retention.
Medium melt flow: suitable for many conventional molding and foaming processes.
Higher melt flow: supports applications that require easier melt movement and faster processing.