Linear sensors help stretch bath manufacturers' profits.
Penny & Giles sensors are fitted to a new machine that is helping
bath and shower tray manufacturers save thousands of pounds in
material cost.
Preston Associates of Kincardine in conjunction with Dundee
based Marcoh Engineering, are revolutionising bath and shower
tray manufacturing with their new Stretch-Form vacuum forming
machine, which produces material savings of up to 50% by
stretching acrylic sheets in two planes prior to manufacture.
Explains Ron MacDonald of Marcoh Engineering: “Using conventional
vacuum forming machines, manufacturers can waste significant
amounts of expensive acrylic because they have to cut standard
bath or shower tray-sized pieces from the large sheets supplied
by the material suppliers.
“With Stretch-Form, manufacturers can cut the large acrylic sheet
into equal portions with no waste and stretch the material to suit
standard bath and shower tray sizes. Another benefit of the process
is that stretching increases the strength-to-weight ratio of the acrylic.”
The Stretch-Form is fitted with Penny & Giles SLS320 sealed
linear sensors on all three of its axes to provide accurate position
feedback for the stretching and forming processes. The X and Y
axes ensure that the correct amount of ‘stretch’ is applied for
each bath or tray size, allowing the machine to be accurately
programmed to process the acrylic sheet from pre-stretched
to post-stretched state. Another SLS320 is fitted to the Z-axis,
which controls the ‘draw’ that determines the rim size of the bath
or shower tray.
Marcoh Engineering also manufactures a range of ovens and
trimming machines used in the manufacture of acrylic baths
and shower trays. The ovens are used to heat acrylic sheets
to 180ºC ready for vacuum forming.
After forming, baths and shower trays are reinforced by spraying
with GRP, cured and then finished on the trimming machines.
Trimming machines are fitted with a Penny & Giles SLS190
sensor. Feedback from this sensor is used to verify the position
of the cutter relative to a revolving trimming table.
Commenting on the choice of sensors Ron MacDonald says:
“We had used Penny & Giles rotary encoders until the new SLS
sensors were introduced. SLS320s are ideally suited to the
working environment of our machines, which is why they were
specified for the new Stretch-Form.” He adds that the units are
very competitively priced and Penny & Giles provides excellent
product support and service.
The SLS320 features IP66 sealing as standard and is supplied
with an industry standard connector that enables it to be easily
designed into existing and new equipment.
It has also successfully completed almost 106 million strokes
as part of a life cycle test. Each test cycle comprised two
strokes - 25mm out, 25mm back - and the 52,891,471 cycles
covered by the test was the equivalent of more than 2600
kilometres - approximately the distance from London to Istanbul!
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For more information contact:-
Penny & Giles Controls Ltd.
Tel: +44(0) 1202 409409
E-mail: mike.iles@pgcontrols.com
Website: www.pgcontrols.com
September 2001
