EVA welding

Frequently asked questions about eva welding

Well-known for its use as a food film, Vinyl Acetate Ethylene is also used in the production of flexible gloves and hot-melt adhesives. This copolymer is used either pure or mixed with thermoplastics or paraffinic hydrocarbons, for applications in a wide range of sectors. EVA welding can be used to finish certain products and to manufacture or seal packaging.

What is Ethylene Vinyl Acetate?

Ethylene Vinyl Acetate is a resin derived from the copolymerization of ethylene (80%) and vinyl acetate (20%). The presence of the latter in the EVA copolymer reduces its rigidity (increasing its elastomer character) and therefore improves its impact resistance, whatever the ambient temperature. In addition, ethylene vinyl acetate-based materials have a high coefficient of friction and good heat adhesion. They are also highly flexible in low-temperature conditions, and highly resistant to impact. Certified for food contact, EVA is one of the substances authorized by European regulations (CE 1935/2004) for contact with foodstuffs. As a result, ethylene vinyl acetate is frequently used as a packaging film in the food industry.

What welding technologies are used for EVA?

Like all thermoplastic materials used in packaging, Vinyl Acetate Ethylene can be assembled by ultrasonic and high-frequency welding.

Ultrasonic welding is a process used in particular for welding small parts, based on mechanical vibrations emitted at a frequency of 16 kHz by an electromagnetic transducer or generator. Amplified and transmitted by a sonotrode, these ultrasounds cause molecular agitation on the “lips” of the parts to be welded, resulting in heat emission and softening of the materials thus brought into contact.

This technology is used by a wide range of industries that use thermoplastics for packaging (document covers, etc.), protection (phone covers, etc.) and packaging (bottles, food films, etc.).

High-frequency welding is a welding technology based on the use of an electric field at a frequency of 27.12 MHz to join thermoplastic parts, sheets or films. This welding technique is particularly interesting for assembling Vinyl Acetate Ethylene material, because its polarity facilitates molecular agitation and heat release.

High-frequency welding offers numerous advantages. It can be used to assemble parts with complex shapes, and to produce watertight, airtight and gastight welds. What’s more, assembly is fast, and welding results are uniform and not visible to the naked eye.

What can Vinyl Acetate Ethylene be used for?

A resin used in the manufacture of hot-melt adhesives, stretch films and flexible gloves, EVA is also used in the agricultural, automotive, construction, packaging and medical equipment industries…

Vinyl Ethylene Acetate is also used in the manufacture of products with a flexible structure (greenhouse films, food films, adhesives, flexible hoses, protective covers, etc.) and products with a rigid structure (door handles, vacuum cleaner covers, telephone shells, protective and transport cases, etc.).

EVA is also used in the glass industry, as it is indispensable for the manufacture of laminated glass and for building insulation.