User`s guide

APPENDIX E
Line Parameters Explained
Line parameters control the different aspects of a line dispense command. They need to be set prior to teaching the end of a
continuous path movement including the ARC and CIRCLE instructions. Although the program already has default settings, it
is highly recommended that the User Operator review and set each Line Parameter to obtain the desired application results.
Note that each program can be configured for up to 10 different line types, and each
time-related line parameter is limited to a maximum of 65.535 seconds.
Down Speed
The Down Speed measures how fast the dispensing head lowers to dispense. The units
are in inches/sec or mm/sec. Typically, 2 in/sec or 50.8mm/sec is sufficient.
Dispense Gap
The Dispense Gap is the distance between the needle tip and the substrate during
dispensing operations. This distance is one of the more common adjustments made to
optimize a dispensing program.
Note: dispense gap is only used after a height sense is inserted in a program.
Otherwise, the machine will move to taught Z-position. The units are in either inches or millimeters.
Typically 15 - 20 mils (0.015 - 0.020 in) is sufficient.
Pre-Move Delay
Higher-viscosity fluids do not dispense as quickly as lower-viscosity fluids. The Pre-Move Delay parameter increases the time
that the dispensing head is parked with the valve ON, prior to a programmed move. The delay at the beginning position
insures that a full line is dispensed. The units are in seconds. Typically, 50 ms (0.050 sec) is sufficient for most fluids.
Line Speed
This refers to how fast the dispensing head moves during dispensing. This parameter controls the bead diameter within a
given flow rate. The speed of the dispensing head affects the amount of fluid dispensed.
The units are in inches/second or mm/second. Typical dispense speeds range from 1.0 – 4.0 inches/second
(or 25.4 – 101.6 mm/second), depending upon fluid flow rates and path trajectory.
Shutoff Distance
This parameter controls the point where the valve stops dispensing before the end of the move. Post-extrusion often is
affected by tip size, fluid pressure and material viscosity. Hence, if any changes are made to these factors mid-stream, it is
likely that Shutoff Distance will need to be readjusted.
Note: The shutoff distance cannot be longer than the last line segment e.g. CP Mid to CP End.
72
www.nordsonefd.com [e-mail] USA & Canada 800-556-3484 Europe [phone] Asia [phone]
Sales and service of Nordson EFD dispensing systems are available worldwide.
EFD
®
TT User's Guide
Version 1.2