Stretched polyester foamed sheets and containers obtained therefrom
AssigneeSinco Ricerche S.p.A.
InventorsHussein Al Ghatta, Sandro Cobror, Tonino Severini
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Abstract
Polyester resin foamed sheet, mono e biaxially stretched usable for the production of containers for beverages and foods, having a density lower than 700 kg/m3 and a crystallization rate such that, when the sheet is heated at 120° C. for 5 minutes, the crystallinity does not exceeds 15%. The aromatic polyester resin used for preparing the foamed sheet can be mixed with an aliphatic polyester resin to impart biodegradability and/or compostability to the sheet or with 1-10% by weight of a polyamide.
Claims17
A mono- or biaxially-stretched foamed sheet made from an aromatic polyester resin selected from the group consisting of copolyethylene terephthalates containing from 2 to 20 moles % of isophthalic acid and/or naphthalene dicarboxylic acids, suitable for the production of beverages and food containers, having a density lower than kg/m3 and having creased on it a patter which by folding along creased lines will develop the shape of a container, wherein the crystallization rate of he resin is such that, by heating at 120° C. for 5 minutes, the crystallization does not exceed 15%, said sheet being stretched with a ratio of from 1:1 to 5:1.
The sheet according to any one of claims 1 to 3 in which the polyester resin has melt it strength higher tan 1 cN and melt viscosity higher than 1500 Pa·s with shear rate tending to zero when measured at 280° C.
Dependencies are inferred from the claim text.