Method for producing shrink films

A process for producing a shrink film comprising

• A) from 45 to 70% by weight of a biodegradable, aliphatic-aromatic polyester obtainable via condensation of:
• i) from 40 to 70 mol %, based on components i to ii, of one or more dicarboxylic acid derivatives or dicarboxylic acids selected from the group consisting of:
• succinic acid, adipic acid, sebacic acid, azelaic acid, and brassylic acid;
• ii) from 60 to 30 mol %, based on components i to ii, of a terephthalic acid derivative;
• iii) 98 to 102 mol %, based on components i to ii, of a C2-C8 alkylenediol or C2-C6 oxyalkylenediol;
• iv) from 0.00 to 2% by weight, based on the total weight of components i to iii, of a chain extender and/or crosslinking agent selected from the group consisting of:
• a di- or polyfunctional isocyanate, isocyanurate, oxazoline, epoxide, and carboxylic anhydride, and/or an at least trihydric alcohol, or an at least tribasic carboxylic acid;
• v) from 0.00 to 50% by weight, based on the total weight of components i to iv, of an organic filler selected from the group consisting of:
• native or plastified starch,
• natural fibers,
• wood flour,
• an inorganic filler selected from the group consisting of:
• chalk, precipitated calcium carbonate, graphite, gypsum, conductive carbon black, iron oxide, calcium chloride, dolomite, kaolin, silicon dioxide (quartz), sodium carbonate, titanium dioxide, silicate, wollastonite, mica, montmorillonite, talc, glass fibers, and mineral fibers, and
• a mixture thereof
• vi) from 0.00 to 2% by weight, based on the total weight of components i to iv, of at least one stabilizer, nucleating agent, lubricant and release agent, surfactant, wax, antistatic agent, antifogging agent, dye, pigment, UV absorber, UV stabilizer, or other plastics additive;
• and
• B) from 30 to 55% by weight of polylactic acid and
• C) from 0 to 2% by weight of a compatibilizer,
• wherein a blow-up ratio smaller than or equal to 4:1 is selected.