Thermal trimming systems with shape cutters are used in the automotive supplier industry.
They are suitable for efficient, cost-effective cutting of
- flat and shaped motor-vehicle carpeting
- internal motor-vehicle trims
- laminated and in-mould decorated door trims
- A, B and C pillars
- rear shelves
- roof liners
- foam insulation systems for doors
- shaped non-woven elements
- map pockets
- seat coverings and head-rests
- airbag covers.
On airbags, laminated layers of fabric which require thermal cutting or hardening, and fixing, are located around the inlet and outlet openings and around the perforations for fixing of the gas generator.
Thermal trimming with shape cutters is a suitable process in this context. All the cutters for the openings and perforations can be integrated into a combined tool.
The combined tools can be used in an individual machine, or integrated into robot sewing units.
The handling, structure and heating of the shape cutters is identical to that of the cutting lines described above.
Thermal trimming with shape cutters is a more cost-effective, quicker alternative to laser trimming.
Airbag Trimming Tool (Detail)
Hot cutting exploits the thermoplastic properties of the material.
Directly electrically heated cutters are heated to around 600 °C by means of transformers. Thermoplastic material which comes into contact with these cutters melts and is cut. In the case of fabrics, in particular, warp and weft threads tend to flow into one another provided thread thickness is adequate, and thus form a continuous welded edge. Such edges do not fray, and tears and loose threads are prevented.
The cutting line of the straight cutters and shaped cutters is built up of segments of approx. 180 mm. The segments are electrically connected by means of woven Cu tapes.
The cutting segments generally feature 3 to 4 stays, with slider and guides. The outer slider are always movable, in order that expansion can occur toward the cutting line.
Thanks to their low exposure to mechanical loads, the cutters are not subject to wear. Modifications, additions and repairs can be performed quickly and easily by the user after an HSGM works instruction course.
Approx. 12 Volt is required for heating of 1 m of cutting line; a current of approx. 100 A flows.
Safety-type transformers in accordance with VDE 0551 / VDE 0570 / EN 61558 convert the mains voltage (primary side) from 230V or 400 Volt down to the necessary extra-low safety voltage (secondary side).
The secondary side (the cutter-segment circuit) is electrically isolated from the mains. The Voltage is within the safety voltage of AC 42 Volt.
An AC power controller is installed up-circuit the “heating transformers“. Current, and therefore temperature, can be set and adjusted by means of a potentiometer. Current and temperature vary in direct proportion to one another.
Once the current has been set, it is kept constant via the AC power controller, or adjusts to the cutting line. This is particularly important in case of tool changes, if differing cutting lines may be present.
Only the selected current ever flows in the secondary circuit, even in case of a short-circuit or a partial short in the cutting line – an important form of protection for the transformers and the cutting lines and cutting segments.
The cutting line/cutting segments (1) are adjusted to the cutting contour and are mounted by means of slider (2) and guides (3) on an insulating material (4). Aluminium supports (5) provide additional mechanical strength for the overall structure and also assist in adjustment of height to the cutter support frame (6) or the cutter support plate.
The punch mounting (8) with cutting groove (9) is mounted on a further aluminium base (7), and above this, an inner hold-down element (10), possibly with cooling borings (11).
The actual component to be processed (12) is located between the punch mounting (8) and inner hold-down element (10). The projecting part (13) (waste) is generally also restrained by means of hold-down elements (14) during the actual cutting sequence in order that it cannot be drawn into the groove.
In addition to the inner cutting lines and shape cutters, we also construct complete thermal trimming tools.
These tools can be integrated into laminating systems or operated as independent trimming systems.
Trimming tools can be permanently installed in a system or may take the form of interchangeable tools.
Interchangeable Trimming Tools
These systems, including the PLC and OP control systems, are always constructed to individual customer specifications.
We integrate handling equipment and devices into our systems where required.