Method and apparatus for producing multilayer plastic articles

• US 5,628,950 A
• Filed: 09/30/1994
• Issued: 05/13/1997
• Est. Priority Date: 12/26/1989
• Status: Expired due to Term

• Current Assignee: The Dow Chemical Company (Dow, Inc.)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Ayres, Ralph E., Bremmer, Jeffrey N., Roehrs, Herbert C., Barger, Mark A., Schrenk, Walter J., Shastri, Ranganath K.
• Primary Examiner(s): TIMM, CATHERINE
• Application Number:
  US08/315,374
• Time in Patent Office: 956 Days
• Field of Search: 264/73, 264/75, 264/241, 264/245, 264/255, 264/297.2, 264/328.8, 264/328.12, 264/513, 425/130, 425/132, 425/133.1, 425/133.5, 425/525, 425/533, 425/588
• US Class Current: 264/241
• CPC Class Codes: B29C 2043/3433 using dispensing heads, e.g. extruders, placed over or apart from the moulds
• CPC Class Codes: B29C 2043/3618 plurality of counteracting elements
• CPC Class Codes: B29C 43/16 Forging
• CPC Class Codes: B29C 43/203 Making multilayered articles
• CPC Class Codes: B29C 43/361 with pressing members independently movable of the parts for opening or closing the mould, e.g. movable pistons transfer moulding B29C45/02; injection-compression moulding B29C45/561
• CPC Class Codes: B29C 45/16 Making multilayered or multicoloured articles B29C45/0062 takes precedence; feeding colouring materials into the injection unit B29C45/1816
• CPC Class Codes: B29C 48/07 Flat, e.g. panels
• CPC Class Codes: B29C 48/10 flexible, e.g. blown foils
• CPC Class Codes: B29C 48/12 Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• CPC Class Codes: B29C 48/18 the components being layers
• CPC Class Codes: B29C 48/21 the layers being joined at their surfaces
• CPC Class Codes: B29C 48/71 for layer multiplication extrusion of multi-component articles B29C48/16
• CPC Class Codes: B29C 49/22 using multilayered preforms or parisons
• CPC Class Codes: B29C 51/14 using multilayered preforms or sheets
• CPC Class Codes: B29C 69/001 a shaping technique combined with cutting, e.g. in parts or slices combined with rearranging and joining the cut parts for reinforced material B29C70/545; B29C49/4278, B29C51/268 take precedence
• CPC Class Codes: B29C 69/02 of moulding techniques only
• CPC Class Codes: B29K 2105/26 Scrap or recycled material
• CPC Class Codes: B29K 2995/0067 non-permeable
• CPC Class Codes: B29L 2031/565 for containers
• CPC Class Codes: B32B 37/153 at least one layer is extruded and immediately laminated while in semi-molten state

Abstract

Methods and apparatus are provided for making multilayer plastic articles. Initially, two or more streams of diverse thermoplastic materials are provided. Layers are formed from these streams and are arranged in a layered first composite stream. The first composite stream may be directly formed into a desired configuration by a molding process or may be manipulated to form a second composite stream having an increased number of layers before being formed into the desired configuration. The resulting articles are comprised of a number of discrete and substantially continuous layers.

Claims

1. A method of making a multilayer plastic article comprising the steps of:

providing first and second diverse thermoplastic materials;

coextruding via a coextrusion feedblock device a first composite stream comprised of discrete, generally planar and parallel layers of said first and second diverse thermoplastic materials;

manipulating via one or more interfacial surface generators said first composite stream to form a second composite stream having an increased number of layers of substantially uniform thickness; and

directly injection molding said second composite stream into an article having a desired configuration so as to form said multilayer plastic article.