Apparatus for spiral-boss heterofil spinneret

Plastic article or earthenware shaping or treating: apparatus – Means feeding fluent stock from plural sources to common... – Extrusion shaping means

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C425S382200, C425S464000, C425SDIG002

Reexamination Certificate

active

06554599

ABSTRACT:

BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates to a method and apparatus for spinning bicomponent filaments in a sheath/core polymer configuration. More particularly, the invention relates to a spinneret, used for bicomponent spinning, having a plurality of orifices in a boss.
2) Description of Prior Art
Bicomponent filaments of the sheath/core configuration are well-known and a variety of spinning packs and spinnerets have been employed in the production of such filaments. A conventional spinning assembly involves feeding molten sheath forming material to the spinneret orifices, in a direction perpendicular to the orifices, and injecting molten core forming material into the sheath-forming material as it flows into the spinneret orifices.
As disclosed in U.S. Pat. No. 5,505,889 to Davies, prior art bicomponent spinnerets provide one orifice per boss. Boss spacing, and consequently orifice density, is restricted by a manufacturing requirement of one millimeter spacing between adjacent bosses. An increased orifice density yields a corresponding increase in the number of filaments produced. Accordingly, there is a need for an improved spinneret with an increased orifice density.
SUMMARY OF THE INVENTION
The present invention is directed towards a spinneret assembly and method for spinning bicomponent filaments. According to the present invention, the spinneret assembly includes a distributor and a spinneret. The distributor is provided with inner openings near the center of the distributor and with outer openings further from the center. The inner openings convey molten sheath polymer to the spinneret and the outer openings convey molten core polymer to the spinneret. The spinneret is provided with an integral boss having a plurality of orifices for receiving core polymer which coaxially align with the distributor outer openings for receiving core polymer. By providing the spinneret with an integral boss having multiple orifices, orifice density is increased over prior art spinnerets which contain one orifice per boss. Orifices on the same boss can be manufactured closer to each other than orifices on adjacent bosses. The spinneret is also provided with a plurality of openings and recessed pathways adjacent to the boss for conveying sheath polymer to the orifices.
According to another aspect of the present invention, the bosses are curvilinear. Still further aspects of the present invention include spiral, semi-circular or linear bosses.
According to another aspect of the present invention, a method is provided for making a bicomponent filament. The method includes providing a distributor having an inner flow passage and outer flow passages, providing a spinneret beneath the distributor having a plurality of bosses which have a plurality of orifices aligning with the outer flow passages, forcing core polymer through the outer flow passages and the spinneret openings, forcing sheath polymer through the inner flow passage and onto recessed pathways provided adjacent to the boss, and forcing the sheath polymer through the recessed pathways, over the bosses, then through the spinneret openings to form a sheath about the core polymer.


REFERENCES:
patent: 3716317 (1973-02-01), Williams, Jr. et al.
patent: 4376743 (1983-03-01), Dees
patent: 4411852 (1983-10-01), Bromley et al.
patent: 5256050 (1993-10-01), Davies
patent: 5393219 (1995-02-01), Hagen et al.
patent: 5505889 (1996-04-01), Davies
patent: 5624754 (1997-04-01), Choe et al.
patent: 5654097 (1997-08-01), Choe et al.
patent: 5773144 (1998-06-01), Choe et al.
patent: 0 514 084 (1992-11-01), None

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Apparatus for spiral-boss heterofil spinneret does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Apparatus for spiral-boss heterofil spinneret, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for spiral-boss heterofil spinneret will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3031198

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.