Control of tubular film size
US4243363A · kind A · utility
22Cited by
4References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 12, 1979 |
| Grant date | Jan 6, 1981 |
| Priority date | — |
| Expiry date | Mar 12, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2948/92923
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A blown-film system, for producing plastic tubing, in which the rate of flow of air, into or out of the tube, is made directly dependent upon the deviation in position of the tube wall and in which stability in tube size is achieved by providing a control system that feeds back both tube circumference and air valve position to drive a valve motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.