Corrosion-resistant spinneret
US4137032A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 1977 |
| Grant date | Jan 30, 1979 |
| Priority date | — |
| Expiry date | Jun 23, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C48/345
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A corrosion-resistant spinneret, suitable for spinning filaments of poly(p-phenylene terephthalamide) from a viscous solution of the polymer in 98-100 percent sulfuric acid, is prepared from a plate of tantalum alloy or stainless steel which is clad on one face with a layer of pure tantalum. A spinneret blank is formed, counterbores are drilled through the plate and partially into the tantalum layer, the blank is annealed, spinneret capillaries are formed from the counterbores through the tantalum layer to the exit face of the spinneret, the face is polished to remove protrusions, and the face is hardened by heat-treatment in nitrogen. Uniform capillaries having a diameter of about 0.002 inch (0.05 mm) and a length greater than about 0.005 inch (0.13 mm) can be formed in spinnerets without breaking tools used in their production.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.