Method for controlling the discharge of granules from a nozzle onto a coated sheet
US5520889A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1994 |
| Grant date | May 28, 1996 |
| Priority date | — |
| Expiry date | Aug 15, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB05D2401/32
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for applying granules to a coated sheet, and in particular a coated asphaltic sheet for use in the manufacture of roofing, comprises controlling a fluid (e.g., pneumatic) counterflow through the discharge opening of a nozzle which holds an accumulation of granules therein to rapidly stop or otherwise modify the flow rate of granules onto the sheet. A buffer chamber is in communication with the granule accumulation in the nozzle, and an apparatus modifies the pressure in the buffer chamber to generate the desired fluid flow through the nozzle opening. A vacuum source provides a negative pressure for a pneumatic counterflow, and a positive pressure source is utilized to increase pressure in the buffer chamber to act as a discharge assistant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.