Fortron PPS Product Brochure (B240) - Hi Polymers

Fortron ®
Polyphenylene sulphide (PPS)
The design and geometry of the joint must be appropriate
to the welding method used. The processing
and specific welding characteristics of Fortron should
be taken into account. The choice of method for the
particular application will be governed by:
– joint shape and design,
– Fortron grade,
– part requirement profile.
The following points should be taken into account in
welding Fortron.
Ultrasonic welding
Fortron mouldings can be joined by the usual ultrasonic
assembly methods (welding, riveting) [3]. Joints
produced by ultrasonic welding have high strength.
Ultrasonic welding machines can be integrated
smoothly and efficiently into mass production processes.
Ultrasonic assembly offers the advantage of
the shortest cycle times of all the welding methods
used for Fortron.
contact pressures and rotational speeds, will depend
on the Fortron grade and part geometry and must be
determined by optimizing trials.
Vibration welding
This method should preferably be used when short
cycle times are required and an alternative to ultrasonic
or spin welding is necessary because of part
geometry or size.
Hot-plate welding
This method is preferably employed for joints exposed
to mechanical stress in service, large joint surfaces
or part geometries that preclude the use of other
welding methods. It is important to ensure that the
hot tools used are designed for the high temperatures
required.
Fig. 52 · Load bearing capacity of ultrasonically
welded test specimens produced from
various Fortron grades
Fortron is suitable for both near- and far-field ultrasonic
welding. However, because of the relatively
brittle-hard behaviour of the material, it should be
borne in mind that the alternating strains which have
to be absorbed by the parts being joined can lead to
localized damage. To avoid, special precautions need
to be taken in terms of correct component design for
the material and weld and correspondingly optimized
machine settings (amplitude, welding time, welding
pressure etc).
0.05–0.1 mm
not welded
a
30–45°
min.
0.05 mm
welded
R
melt
Pinch-off welds are the most suitable for this method
of welding, employing a frequency of 20 to 40 kHz.
Tapered pinch welds with a welding distance of over
1 mm can be made gas-tight.
Additions of up to 40% reinforcing materials still
permit good welding results. Under mechanical load
fracture usually occurs outside the weld (fig. 52). With
higher additions, however, weldability deteriorates.
Spin welding
For Fortron mouldings with rotationally symmetrical
joint faces, spin welding is a suitable assembly method
to obtain gas-tight, high-strength joints. The most
suitable welding conditions, such as surface speed,
Breaking stress
6,000
N
5,000
4,000
3,000
2,000
1,000
0
1130L4 1040L4 6165A4
1040L6 6165A6
Frequency 20 kHz Welding time 0.8 s
Amplitude 30 µm Weld design single pinch weld
Welding force 400 N Generator output 700 W
40