Control of tubular film size
US4377540A · kind A · utility
15Cited by
19References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1981 |
| Grant date | Mar 22, 1983 |
| Priority date | — |
| Expiry date | Aug 24, 2001 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2948/92923
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An internally cooled blown film system, for producing a plastic tube, in which the flow rate of the continuous flow of cooling air through the tube is made directly dependent upon deviation of the tube circumference as determined by transmission and detection of ultrasonic waves from the surface of the tube.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.