265ProFlow.pdf - 第39页

TECHNI CAL REFEREN CE SEQUEN CES Chapter Issue 8 Dec 02 ProFlow Manual 1.35 5. A load of 5kg is applied to the ProFlow unit. 6. The ProFlow unit is moved at 30mm/sec to the outer edge of t he shake-of f envelope. 7. The …

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TECHNICAL REFERENCE
SEQUENCES
1.34 ProFlow Manual Chapter Issue 8 Dec 02
ProFlow
Placement
This sequence is designed to move the ProFlow unit from the home or zero
height position onto the stencil, at contact height, when one of the following
occurs:
• When Run is selected.
• When Knead Paste is selected.
• When Prime ProFlow is selected
• When Refill ProFlow is selected.
Raise ProFlow This sequence is designed to move the ProFlow unit from the stencil to the
home or zero height position when one of the following occurs:
• When the machine is initialized.
• When Change ProFlow is selected.
• When Change Screen is selected.
• When Change Tooling is selected.
• When Raise ProFlow is selected.
The ProFlow unit is raised by one of the following methods:
• 'Shake-off' ProFlow
• 'Lift-off' ProFlow
Shake-off is the preferred method of raising the ProFlow unit. Lift-off is only
carried out if the ProFlow unit is not in a shake-off envelope or the stencil
protection parameter in the board file is set to ON.
The shake-off envelope is the portion of stencil required by the ProFlow transfer
head when performing the shake-off or knead over rail function. Depending on
the stencil, it’s justification and the board width, a particular product may have
none, one or two shake-off envelopes. If the unit is not in a shake-off envelope
a lift-off is carried out.
Shake-off ProFlow This sequence is designed to raise the ProFlow unit clear of the stencil without
leaving a print medium deposit on the stencil. Pre-conditions exist prior to any
shake-off procedure, these are:
• The ProFlow unit is on the stencil at contact height.
• The pressure on the transfer material is at Idle Paste Pressure or else it is
released.
• The ProFlow unit is inside a valid shake-off envelope.
• The printers cover is closed.
• The stencil protection parameter in the board file is set to OFF.
The following sequence occurs when shake-off is initiated:
1. The machine cover is secured while the shake-off is carried out.
2. Any pressure on the transfer material is released.
3. The board clamps are closed.
4. The camera is driven home and the rising table is raised to print height.
TECHNICAL REFERENCE
SEQUENCES
Chapter Issue 8 Dec 02 ProFlow Manual 1.35
5. A load of 5kg is applied to the ProFlow unit.
6. The ProFlow unit is moved at 30mm/sec to the outer edge of the shake-off
envelope.
7. The ProFlow unit is moved the full extent of the shake-off envelope, in each
direction, at 30mm/sec. This cycle is repeated twice.
This cycle is repeated twice more while at the same time the unit is raised
at 2mm/sec.
8. The ProFlow unit is raised at full speed to the zero height position.
Lift-off This sequence is designed to raise the ProFlow unit straight up off the stencil,
without any movement in the horizontal plane. A print medium deposit may be
left on the stencil.
The preconditions for a ‘Lift-off’ to be initiated are:
• The ProFlow unit is on the stencil at contact height.
• The printers cover is closed.
• The ProFlow unit is in a turnaround envelope, not a shake-off envelope or
the stencil protection parameter in the board file is set to On.
• The pressure on the transfer material is at Idle Paste Pressure or else it is
released.
The turnaround envelope is where the printer has evaluated the position in
which the ProFlow unit has come to rest and calculated that there is only enough
room for the ProFlow unit to print back across the image or do a lift off.
The following sequence occurs when lift-off is initiated:
1. Any pressure on the transfer material is released.
2. The user is prompted to confirm that the ProFlow unit’s base cover has been
fitted.
3. The ProFlow unit is raised straight up from the stencil to the zero height
position, without any movement in the horizontal plane.
Knead Paste Print material changes it’s characteristics (viscosity) through lack of use, caus-
ing poor print quality. To overcome this a knead paste sequence is available
and is initiated by one of the following:
• The elapsed time since a board was printed has exceeded the value of the
paste knead period parameter.
• When Knead Paste is selected.
• A print stroke is about to be applied and there is a deferred request for a
paste knead.
• The amount of boards printed, since the last paste knead equals the value
of the knead before printing parameter, (only valid if the knead off-image
parameter is set to enabled).
When a paste knead sequence is initiated the message ‘Automatic paste
knead activated’ is displayed.
Two types of knead operation may be carried out:
TECHNICAL REFERENCE
SEQUENCES
1.36 ProFlow Manual Chapter Issue 8 Dec 02
a. Knead off image
b. Knead over a board
Knead Off Image This operation is carried out off the stencil image. If the ProFlow unit is not in
a shake-off envelope the paste knead is deferred until it is.
The preconditions for a knead off image to be initiated are:
• The stencil protection parameter in the board file is set to OFF.
• The ProFlow unit is on the stencil at contact height.
• The ProFlow unit is in a shake-off envelope.
• The pressure on the transfer material is at Idle Paste Pressure or else it is
released.
• The machine cover is closed.
The following sequence occurs when a knead off image is initiated:
1. The machine cover is secured while the knead off image is carried out.
2. The board clamps are closed.
3. The camera is driven home and the rising table is raised to print height.
4. ProFlow is lowered to ProFlow print height, as set by System Pressure and
Knead Paste Pressure is applied to the system.
5. The ProFlow unit moves away from the stencil image, at the appropriate
print speed, to the edge of the shake-off envelope.
6. The ProFlow unit traverses the full extent of the shake-off envelope, the
number of times set by the current value of the knead deposits parameter,
before it is returned to the position from which it started.
7. Upon completion Knead Paste Pressure (piston pressure) is changed to Idle
Paste Pressure and ProFlow raises to the contact height position.
Knead Over a Board This operation is carried out over the stencil image, with a board in place.
The preconditions for a knead over a board to be initiated are:
• The stencil protection parameter in the board file is set to OFF.
• The ProFlow unit is on the stencil at contact height.
• The pressure on the transfer material is at Idle Paste Pressure or else it is
released.
• The machine cover is closed.
The following sequence occurs when a knead over a board is initiated:
1. ProFlow is lowered to ProFlow print height, as set by System Pressure and
Knead Paste Pressure is applied to the system.
2. The ProFlow unit is driven backwards and forwards over the loaded board
the number of times set by the current value of the knead deposits param-
eter.
3. Upon completion Knead Paste Pressure (piston pressure) is changed to Idle
Paste Pressure and ProFlow raises to the contact height position.