| 摘要 |
Apparatus and methods for producing intermittent, discrete patterns of foam coating material, onto discrete substrates or substrate areas, where the patterns have sharp, square leading and trailing edges, as well as side edges. A slot nozzle die has elongated air slots along the slot extrusion opening. Air flow is initiated from both air slots prior to the initiation of the foam flow. Also, the air flow is continued beyond that point in time when the foam flow ceases. The delays between the operations of the air flow and the foam coating flow are on the order of micro seconds. Alternatively, the lead and lag air start and stop times on each side of the foam coating material are different to control the exact disposition of the square cut-on and square cut-off coating edge on the substrate. |
