	US 12,343,910 B2
	Method for producing an rPET plastic material for use in a thin-wall injection molding method and containers, such as cups, bowls, trays or multi-compartment packagings produced by the thin-wall injection molding method
Robert Siegl, Dornbirn (AT); and Benjamin Haas, Lauterach (AT)
Assigned to ALPLA WERKE ALWIN LEHNER GMBH & CO. KG, Hard (AT)
Appl. No. 18/858,237
Filed by ALPLA WERKE ALWIN LEHNER GMBH & CO. KG, Hard (AT)
PCT Filed Apr. 21, 2023, PCT No. PCT/EP2023/060430 § 371(c)(1), (2) Date Oct. 18, 2024, PCT Pub. No. WO2023/203194, PCT Pub. Date Oct. 26, 2023.
Claims priority of application No. CH 000468/2022 (CH), filed on Apr. 22, 2022.
Prior Publication US 2025/0108543 A1, Apr. 3, 2025
Int. Cl. B29C 45/00 (2006.01); B29B 9/06 (2006.01); B29B 17/04 (2006.01); B29K 67/00 (2006.01); B29K 105/00 (2006.01); B29K 105/26 (2006.01); B29L 31/00 (2006.01); B65D 1/26 (2006.01); B65D 1/36 (2006.01)

CPC B29C 45/0001 (2013.01) [B29B 9/06 (2013.01); B29B 17/0412 (2013.01); B29K 2067/003 (2013.01); B29K 2105/0094 (2013.01); B29K 2105/26 (2013.01); B29L 2031/712 (2013.01); B65D 1/265 (2013.01); B65D 1/36 (2013.01)]

33 Claims

1. A method for producing an rPET plastic material for use in a thin-wall injection-molding method, with a ratio of wall thickness (L) to flow path (D) of 1 to 50 to 1 to 500 for thin-wall injection-molding, in which method

a) post-consumer PET articles-mostly PET bottles produced by an ISBM process—the PET material of which has an intrinsic viscosity between 0.72 dL/g and 0.86 dL/g according to ASTM D4603, are sorted, washed, and comminuted,

b) impurities, such as metal or paper, are removed before, simultaneously with, or after method step a),

c) the comminuted PET material is subsequently dried,

d) the comminuted and dried PET material is subsequently melted and then granulated, and

e) a thin-walled injection-molded article is produced from the PET material in an injection-molding method,

wherein

f) in method step e), a low-viscosity virgin PET, hereinafter referred to as “vPET”, is added to the granulated material, and the resulting mixture of granules and vPET is extruded and injected directly into an injection mold,

wherein the process is carried out in such a manner that the intrinsic viscosity of the injection-molded article is lowered to 0.5 dL/g to 0.7 dL/g during the extrusion.