Ethylene-vinyl acetate is made by combining polyethylene and vinyl acetate. The outcome is rubbery. EVA is a slightly less common blend included under polyolefins. Vinyl renders the material rubber-like, yet reasonable strength is maintained. In some cases, EVA can be a viable alternative to TPE. The material properties depend on the mixing ratio.
Why choose it?
- You want more clarity and elasticity than PE-LD can offer.
- Better stress-cracking and UV properties than with PE-LD.
Why not choose it?
- The product has a mild natural smell due to its vinyl content.
- Protective mechanical joint housings
- Bath slides (possibly partly foamed)
By examining the Plasticprop sample made of EVA, you can draw for example the following conclusions:
- Compared with LDPE, EVA feels more rubbery.
- In case of harder EVA grades, the glossy mould surface is replicated well, but the sample gives only a vague promise of this. The specified sample material hardness is Shore A 94, which would be approximately equivalent to the value Shore D 44. Presuming that the actual hardness complies with the values specified by the material supplier, even though LDPE is clearly stiffer than EVA, it is also a little softer than EVA. Stiffness and hardness do not necessarily go hand in hand.
- The sample is reasonably neat and straight.
- Comparison between PE samples suggests that EVA shrinks somewhat less than HD-PE and LD-PE.
- Some of the EVA samples are slightly pinkish. LDPE residues that have remained after the preceding run cause the colouration. White colours are typically problematic. In some production plants, there are injection moulding machines dedicated to only white products.