Abstract: A continuous process for making a thermoplastic article comprises extruding a sheet of thermoplastic and contacting the sheet with a mold surface while the sheet is in a substantially non-oriented state. The mold surface is selectively heated and/or cooled during thermoforming to maintain the sheet in a molten or thermoformable state. A stripper plate adjacent to the mold surface is maintained at different temperature for inducing a predetermined degree of crystallinity to the sheet, for increasing web stiffness and improving web alignment, and optionally for assisting in the separation of the articles from the mold. A continuous apparatus for making thermoformed articles has co-extruders for extruding at least two distinct layers, which can have dissimilar properties (e.g., polar and non-polar), and a temperature controlled molding surface. Preferred thermoplastic compositions of the present invention have improved toughness and retained intrinsic viscosity.
Abstract: A continuous process for making a thermoplastic article comprises extruding a sheet of thermoplastic and contacting the sheet with a mold surface while the sheet is in a substantially non-oriented state. The mold surface is selectively heated and/or cooled during thermoforming to maintain the sheet in a molten or thermoformable state. A stripper plate adjacent to the mold surface is maintained at different temperature for inducing a predetermined degree of crystallinity to the sheet, for increasing web stiffness and improving web alignment, and optionally for assisting in the separation of the articles from the mold. A continuous apparatus for making thermoformed articles has co-extruders for extruding at least two distinct layers, which can have dissimilar properties (e.g., polar and non-polar), and a temperature controlled molding surface. Preferred thermoplastic compositions of the present invention have improved toughness and retained intrinsic viscosity.
Abstract: A thermoplastic container, which is particularly useful for packaging meat, comprises a first polymeric layer, a second intermediate or tie layer, and a third polymeric layer. The first layer comprises an alkylene terephthalate or naphthalate polymer such as polyethylene terephthalate (PET). The first layer can include, in whole or in part, one or more homo-polymers, co-polymers, recycled polymers, or reprocessed polymers. The third layer comprises a non-polar thermoplastic such as high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or a blend thereof. The intermediate layer primarily functions as an adhesive and as a compatibilizer/emulsifier/surfactant (CES), and comprises a grafted or backbone-based co-polymer or ter-polymer of ethylene, glycidyl acrylate or maleic anhydride, and optionally an acrylate co-monomer.