Dukane SVB031, Руководство пользователя

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Spin Welder User’s Manual Section 9 – Troubleshooting
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Dukane Manual Part Number 403-547-03 Dukane Manual Part Number 403-547-03
Welding Process
Material Choices
A family of thermoplastics is usually compatible
with its own type and sometimes with other types.
Characteristics to consider are the melting point and
coefficient of linear expansion. Even members of
the same family may cause problems due to differ-
ences in the manufacturing process. For example,
an extruded Polyethylene (PE) piece may not weld
as well to an injection molded PE piece as it would
to another extruded PE piece.
Parameter Effects
Surface Velocity
Insufficient surface velocity may not allow the
plastic to reach its melting temperature. Instead,
it may simply erode away part of the material and
stick by a clawing effect. The surface velocity is
determined by both the weld joint diameter and the
motor speed.
Axial Pressure
In conjunction with surface velocity, axial pressure
determines whether the plastic reaches the melting
temperature. Both speed and pressure are needed
to produce sufficient frictional heating. Excessive
pressure may cause one part to scrape away part of
the surface and produce a lot of flash but insufficient
melt volume.
Weld Time
Insufficient welding time may not allow the melt
to propagate far enough into the plastic to achieve
the necessary melt volume and the required weld
strength.
Hold Time
Insufficient holding time may not allow the plastic
enough time to solidify and form a strong perma-
nent bond.