Process for metering color concentrates to thermoplastic polymer melts

• US 4,919,872 A
• Filed: 02/16/1989
• Issued: 04/24/1990
• Est. Priority Date: 04/25/1988
• Status: Expired due to Fees

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Fintel, William A.
• Primary Examiner(s): Thurlow, Jeffery
• Application Number:
  US07/311,515
• Time in Patent Office: 432 Days
• Field of Search: 264/210.6, 264/40.1, 264/40.7, 264/103, 264/140, 264/143, 264/211.14, 425/135
• US Class Current: 264/103
• CPC Class Codes: B29B 7/60 for feeding, e.g. end guides for the incoming material B29B7/7615 takes precedence; feeding predetermined amounts for mixing in general B01F35/714
• CPC Class Codes: B29B 7/88 Adding charges , i.e. additives
• CPC Class Codes: B29B 7/90 Fillers or reinforcements , e.g. fibres
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/2888 in band or in strip form, e.g. rubber strips
• CPC Class Codes: B29C 48/29 in liquid form
• CPC Class Codes: B29K 2105/0005 containing compounding ingredients releasing, lubricating or separating agents B29C33/56, fibers B29K2105/08, B29K2105/12; fillers B29K2105/16, recycled material B29K2105/26
• CPC Class Codes: B29K 2105/0032 Pigments, colouring agents or opacifiyng agents
• CPC Class Codes: D01D 7/00 Collecting the newly-spun products D01D5/0076 takes precedence; collecting newly-spun products with the imparting of twist D01H
• CPC Class Codes: D01F 1/04 Pigments

Abstract

Continuous strands of color concentrate are metered into the feed zone of a screw-melter polymer extruder where they are cut into pellets by the shearing action of the flights of a rotating screw against the extruder housing. These pellets are mixed within the extruder with a thermoplastic polymer to be colored and this mixture is then melted and extruded into a useful article, for example, a fiber for textile or carpeting end-use.

Additionally, color concentrates can be first formed into continuous strands and stored conveniently on a spool for subsequent metering into the polymer extruder.

Claims

1. In a process for forming a color concentrate including the steps of compounding a pigment with a thermoplastic polymer melting said compounded material and extruding said melted compounded material as a continuous strand, the improvement comprising:

winding said continuous strand in a constant weight-per-unit-length ratio onto a spool after extrusion.