Method of predicting yarn caterpillar length
US4956902A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 12, 1989 |
| Grant date | Sep 18, 1990 |
| Priority date | — |
| Expiry date | Sep 12, 2009 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD02G1/14
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method of predicting changes in caterpillar length of yarn. The process is used in systems wherein yarn is passed through a set of hot rollers to bulk the fibre and is then contacted with an air jet to pull the yarn away from the rollers and impinge it upon a rotating drum. This drum comprises an endless textured screen forming a cylindrical outer surface of the drum and a frame to support the screen. A caterpillar is thereby formed on the screen. Air is then exhausted from the centre of said drum to draw air through the screen and cool the yarn. The yarn is then pulled off of the screen using take-up rollers. The process for predicting a change in yarn caterpillar length comprises a step of measuring during a given time period: the change in temperature of the exhaust air (dT1), the change in temperature of the yarn (dT2) after it is taken up from the drum and the change in tension of the yarn (dF) after it is taken up from the drum. Caterpillar length change (dL) after this given period of time is then predicted using the correlation: ##EQU1## wherein a,b and c are weighted averages, and a+b+c=1; and wherein: ##EQU2## are all empirically determined constants.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.