Foamed Insert Tray Compound (PLA/PBAT)

About This Product

The grade is a pellet compound of polylactic acid and polybutylene adipate terephthalate formulated for foam extrusion and forming rather than for film. PLA, an aliphatic polyester from the ring-opening polymerisation of lactide, gives the set cell walls their stiffness; PBAT, an aliphatic-aromatic copolyester, gives the melt the extensibility a growing cell needs. Foam extrusion is governed by melt strength. As the blowing gas comes out of solution at the die the cell walls stretch biaxially and must stiffen as they thin, or a wall ruptures, neighbouring cells coalesce and the structure collapses into a coarse, open, weak foam. Neat PLA is a linear polyester with little melt strength and almost no strain hardening, so it foams poorly alone; the PBAT fraction raises melt viscosity and extensibility so the wall resists thinning long enough for the cell to set. Foam density is set against the protection required, a lower density absorbing more energy per unit mass but yielding at a lower stress. Insert trays are usually expanded polystyrene or vacuum-formed PVC, both awkward at end of life for a consumer unpacking at home; a biodegradable foam lets the whole pack go into one waste stream. It is used in product insert trays, retail packaging, electronics packs and cosmetics packs. Bio Green Chem supplies the foamed insert tray compound to specification on foam density, wall section, cushioning target and tool geometry, as a raw material for processing on the buyer's own line; we do not produce finished articles.