With the introduction of the SAXM series of suction pads, German vacuum technology provider J. Schmalz is seeking to set new standards in sheet metal processing.

The requirements of the automotive and sheet metal industries are increasing in complexity, due in large part to the fact that increases in efficiency and cost reductions are of critical importance to the competitiveness of a company. Recent servo press generations that handle metal parts using vacuum technology can deliver up to 18 strokes per minute, depending on the type of press and complexity of the component. However, whether you can take maximum advantage of a machine’s efficiency is dependent on the capability of the vacuum system - and particularly the suction pads. The ability of vacuum suction pads to hold the workpiece, absorb lateral forces, adjust to the workpiece and resist wear will ultimately dictate process reliability and transport speed when working with metal sheets.

J. Schmalz, the German manufacturer of vacuum components, has developed a series of suction pads that is superior in both design and construction material to other products currently available on the market. The SAXM series of suction pads features a large stroke that allows them to achieve an optimum position when handling workpieces with complex contours. The suction pad geometry provides all the required features for the highly dynamic handling of metal sheets: minimal pick-up times; high intrinsic stability while suction is applied; and the absorption of extreme holding and lateral forces, especially on oiled surfaces. The pads further use an innovative material that makes them extremely resistant to wear, even when subjected to ozone or aggressive drawing oils.

Improved dynamic handling, decreased costs
Until now, it was a simple rule of three: The faster the press, the more suction pads were required. The more suction pads used, the more tooling work required. The more complicated the tooling work, the heavier and the more expensive the equipment becomes. The design features of SAXM suction pads are set to redefine the laws of sheet metal handling. The special structure of the suction pad interior, together with the additional friction disc, allows SAXM to absorb several times the lateral forces as compared to other available suction pads designed for use with metal sheet. This has a positive effect on the costs and output. On the one hand, the number of suction pads and thus the tooling expenses can be reduced, while maintaining the speed of the press. On the other hand, the speed of the press can be increased while maintaining the number of suction pads. When using a single cavity tool, an increase of just one stroke per minute – when applied to a production year comprising 250 working days with 20 hours of operation and three shifts per day – can result in an increase of 300,000 parts per year.

Adaptability and flexibility
Workpieces such as doors, fenders and valence panels have projecting edges and gaps that restrict the areas that the suction pad can use. This is a point where the advantages of SAXM are two-fold. First, SAXM suction pads provide a stroke that is twice as high as that of common flat suction pads, which allows it to adjust considerably better to the three-dimensional contour of the workpiece Secondly, SAXM suction pads provide a high level of lateral force absorption while keeping the suction pad diameter comparatively small, which allows for more flexible positioning on the contoured metal sheet when space is limited than with common metal suction pads with larger diameters.

Long-lasting and environmentally friendly
Constant exposure to ozone, such as that associated with welding automotive body parts, can cause suction pads to become brittle over time. Contact with aggressive drawing oils, such as those used in forming operations in presses, can cause suction pads to swell. Both can result in vacuum system leakage and increasing energy costs. In a worst case scenario, they can even cause system failure and machine downtime.

SAXM suction pads are made of the innovative Elastodur material, the performance of which is not affected by either ozone or drawing oils. The increased lifetime that the material makes possible results in further advantages. The low amount of wear not only increases the reliability of the system, it also reduces purchase costs and general costs: The extended lifetime of the parts means less machine downtime, where worn suction pads have to removed and new ones installed. SAXM suction pads, which are 100% recyclable, feature a modular design. Individual suction pad elements can be replaced quickly and easily, such as elastomer parts, friction elements and connection elements, which can then be correctly sorted and recycled.

The SAXM series of suction pads made from Elastodur with a Shore hardness of 85 is available in seven sizes with suction areas of 30, 40, 50, 60, 80, 100 and 115mm in diameter. They can be supplied pre-threaded, or as individual parts.