HEATER FOR USE IN THE MANUFACTURE OF PLASTICS FILAMENTS

• US 3,741,716 A
• Filed: 03/28/1972
• Issued: 06/26/1973
• Est. Priority Date: 03/30/1971
• Status: Expired due to Term

• Current Assignee: Max Bechter, Rudolf Johne
• Original Assignee: Max Bechter, Rudolf Johne
• Inventors: Johne, Rudolf, Bechter, Max
• Primary Examiner(s): Camby, John J.
• Application Number:
  US05/238,846
• Time in Patent Office: 455 Days
• Field of Search: 432/8,59,64 165/133
• US Class Current: 432/59
• CPC Class Codes: D01D 5/084 Heating filaments, threads or the like, leaving the spinnerettes

Abstract

A heater for use in the manufacture of spun plastics filaments which comprises two portions each having a truncated right polygonal pyramidal or truncated right conical internal surface that is open ended, the internal surface of one of the portions is heated while the internal surface of the other portion is thermally reflective and at the smaller end of the heated portion a screen is arranged to reduce the effective area of the said smaller opening. With the use of the heater spun filaments can be produced having a low degree of preorientation and a satisfactory uniformity.

Claims

1. A heater for use in the manufacture of spun plastics filaments which comprises two portions each of which has a truncated right polygonal pyramidal or truncated right conical internal surface that is open ended, the perimeters of the larger ends of the internal surfaces being congruent and the two portions meeting at their larger ends with the perimeters of the larger ends of the internal surfaces in register with one another, wherein the internal surface of one of the portions is heated and the internal surface of the other portion is thermally reflective.

2. A heater as claimed in claim 1, wherein there is provided at the smaller end of the said one portion a screen arranged to reduce the effective area of the said smaller opening.

3. A heater as claimed in claim 1, wherein the internal surface of each of the said portions is a truncated right conical surface.

4. A heater as claimed in claim 1, wherein the largest cross sectional area is at least twice the cross sectional area of the bundle of filaments.

5. A heater as claimed in claim 1, wherein the diameter d4 of the smaller opening in the said other portion is in the range of from 0.4 to 1.0 times the total height L, of the heater.

6. A heater as claimed in claim 1, wherein the length H of the internal surface of the said one portion and the apex angle phi are such that a perpendicular drawn from the said point of the internal surface of the said one portion meets the internal surface of the said other portion, and arcsin H/2d3 <

phi /2 <

arcsin (H/2 Cube Root (d3 + d4/2)2 + L12) + arccot d3+d4/2L1 where;

L1 is the total height of the heater, d3 is the largest diameter of the heater taken at right angles to the axis, and d4 is the diameter of the smaller opening in the said other portion.

7. A heater as claimed in claim 1, wherein the internal surface of the said other portion is highly polished or coated with a reflective foil.