Quality control system for monitoring and control of contaminants in recycled plastics

• US 6,533,124 B1
• Filed: 02/28/2000
• Issued: 03/18/2003
• Est. Priority Date: 08/19/1998
• Status: Expired due to Fees

• Current Assignee: Plastics Forming Enterprises Incorporated
• Original Assignee: Plastics Forming Enterprises Incorporated
• Inventors: Tacito, Louis D., Marciniszyn, Adam
• Primary Examiner(s): Nguyen, Tuan N.
• Application Number:
  US09/514,841
• Time in Patent Office: 1,114 Days
• Field of Search: 209/3.1, 209/11, 209/913, 341/26, 341/32, 341/79, 422/89, 422/91
• US Class Current: 209/3.1
• CPC Class Codes: B29B 17/02 Separating plastics from other materials
• CPC Class Codes: B29B 2017/0089 Recycling systems, wherein the flow of products between producers, sellers and consumers includes at least a recycling step, e.g. the products being fed back to the sellers or to the producers for recycling purposes
• CPC Class Codes: B29K 2067/003 PET, i.e. poylethylene terephthalate
• CPC Class Codes: B29K 2105/065 containing impurities
• CPC Class Codes: G01N 33/442 Resins, plastics
• CPC Class Codes: Y02W 30/62 Plastics recycling; Rubber recycling
• CPC Class Codes: Y10S 209/913 Screw feed conveyor

Abstract

An apparatus and process for continuously discriminating between a contaminated plastic material containing trapped volatile contaminants and plastic material which contains an acceptable threshold of contaminants including first supplying a continuous source of plastic material wherein the plastic material contains trapped volatile contaminants and feeding a sample of the plastic material to the input section of an auger conveyor. The auger conveyor contains a barrel and a transfer screw positioned within the barrel with flights thereon for conveying the plastic material, the auger also connected to an output section which itself is connected to a detector for detecting trapped volatile contaminants. Plastic material is then conveyed through the auger at a selected rate by rotation of the transfer screw and the auger is also heated to a selected temperature such that trapped volatile contaminants in the plastic material are removed therefrom and remain substantially within the flights and delivered to the detector. The apparatus and process herein is also configured in active communication with a tracking database containing one or a plurality of programmable logic controllers (PLC'"'"'s) which signal, divert and/or isolate contaminated recycled material from plastic material which contains an acceptable threshold of contaminants when the recycled material exceeds preselected contamination levels.

Claims

1. An apparatus for continuously discriminating between a plastic material containing-trapped volatiles and plastic material which contains an acceptable threshold of volatiles, comprising a detector apparatus wherein said detector apparatus comprises a chamber which chamber regulates the temperature of said plastic material in said chamber so that said trapped volatiles in said plastic material are removed from said plastic;

a computer tracking database in communication with said detector apparatus, wherein said tracking database can signal, divert and/or isolate plastic material containing trapped volatiles from plastic material which contains an acceptable threshold of volatiles when said plastic material containing trapped volatiles exceeds preselected volatile levels.

2. An apparatus for continuously discriminating between a plastic material containing trapped volatile contaminants and plastic material without trapped volatiles comprising an auger conveyor wherein said auger conveyor comprises an input hopper and a barrel containing heating elements and a transfer screw with flights thereon positioned within said barrel, said flights for conveying said plastic material, wherein said auger further contains an output section connected to a volatile gas detector for detecting said trapped contaminants wherein said detector is connected to an electronic tracking database containing stored signal responses representative of said volatiles at selected concentrations, wherein said detector is able to generate a signal response characteristic of said volatile contaminant concentration and said tracking database compares said detector signal response to said stored signal responses, and wherein said tracking database identifies said plastic material containing trapped volatiles when said detector signal response meets or exceeds stored signal responses in said tracking database.

3. The apparatus of claim 2 wherein said auger is angled as between said input and output section so that said input and output sections are not horizontally disposed to one another.