Clamping Equipment for Metal and Plastic Processing

Vacuum clamping technology is particularly well-suited for large-surface-area, thin-walled, dimensionally unstable, or scratch-sensitive workpieces.

The even distribution of force via atmospheric vacuum prevents warping or deflection during machining. This allows components to be clamped with virtually no distortion, without creating local pressure marks or deformations caused by conventional mechanical clamping equipment.

Optimal materials in practice:

• Metals: Aluminum, non-ferrous metals (NF metals) such as copper or brass.
• Plastics: Technical plastics, acrylic glass, and delicate coated sheets.

Yes, absolutely. Vacuum clamping technology is ideal for delicate, thin-walled, or easily deformable workpieces.

Since the holding force is applied evenly across the entire surface via atmospheric vacuum, localized clamping peaks caused by mechanical clamps or vises are completely avoided. This ensures that no pressure marks or scratches occur, especially on thin-walled aluminum components, coated sheet metal, or workpieces with sensitive visible surfaces. At the same time, the sides of the workpiece remain largely accessible, enabling complex machining operations to be performed in a single setup.

Yes. Vacuum clamping systems are ideal for both 5-axis and 6-axis machining.

Since the workpiece is clamped across its entire surface from the bottom, there is no need for obstructive mechanical clamping claws. This offers the major advantage of completely unobstructed access. As a result, complex machining operations can often be performed on five sides in a single setup, without the need for additional re-clamping operations. At the same time, thin-walled components are clamped in a way that is gentle on the material and prevents warping.

Important requirements for the process:

• During machining, the clamping fixture must remain permanently connected to the vacuum generator to prevent the vacuum from collapsing.
• Particularly with rotating and swiveling machine tables, it must be ensured that vacuum hoses are routed safely and do not create interfering contours in the work area.

Schmalz offers specific solutions for each of the various production stages:

• Single-component and small-batch production: Maximum flexibility is key here. Standardized clamping equipment such as Matrix-Plates (MPL) or vacuum block suction cups (CMB) are well-suited for this purpose. They enable cost-effective clamping of a wide variety of geometries without the need for complex custom fixtures.
• High-volume production: For production runs of larger sizes, the focus is on cycle time and absolute process reliability. Specialized clamping fixtures, specifically tailored to the workpiece and the machining process, are frequently used here. Schmalz offers both individual components for integration into customer-specific designs and support in the design of custom clamping fixtures.

There is no one-size-fits-all solution for CNC vacuum clamping; rather, there are two primary approaches that differ depending on the part geometry and milling forces:

• Vacuum block suction cups: These are the go-to solution for plastics and sheet metal. They offer a simple, cost-effective entry-level solution and can be set up in a matter of seconds. They are particularly well-suited for recurring workpiece geometries that require material-friendly, distortion-free clamping.
• Modular clamping systems (vacuum grid plates): The all-rounder for maximum flexibility. The clamping surface can be individually adapted with a sealing gasket and expanded with accessories (such as Innospann suction cups ISBL-HD or elastomer mats SFM). This makes them perfectly suited for machining complex metal and plastic components with varying dimensions, irregular contours, or very high machining forces.

Yes. In many cases, a vacuum clamping system can be easily retrofitted to existing CNC machining centers—regardless of the machine manufacturer. Such an upgrade is generally much more cost-effective than investing in a new machine.

All common machine table systems are supported. On smooth tables or T-slot sheets, the vacuum attachment module or grid plate is simply secured mechanically or via a zero-point clamping system.

When selecting the right vacuum generator for metal and plastic processing, you must primarily ensure a high vacuum level for maximum clamping forces, as well as intelligent energy and fluid management. Since CNC processes for these materials depend significantly on the type of workpiece (porous or dense) and are usually air-tight, Schmalz application experts generally recommend high-performance, oil-lubricated vacuum pumps.

When making your selection, pay attention to the following key features:

• Energy efficiency: Since metal and plastic machining often involves air-tight applications, a system with an integrated automatic energy-saving feature is highly recommended to lower operating costs.
• Process reliability: Continuous monitoring of the vacuum level via appropriate warning devices, as well as a direct interface to the machine control system, are essential for maintaining a safe grip.
• Fluid management: If coolant (KSS) is used in the machining process, an integrated system for the reliable separation and recirculation of fluids is absolutely essential.

Depending on the application, CNC clamping systems use either electric vacuum pumps or pneumatic vacuum generators. The key factors in selecting the appropriate system are primarily workpiece size, leakage rate, machining process, and the required holding force:

• Airtight materials (high vacuum level): For dense materials such as aluminum, plastics, or coated sheets, vacuum generators capable of producing high vacuum are often used to achieve maximum holding forces.
• Porous areas (high flow rate): In applications with higher leakage rates, high suction capacity or a higher flow rate is required to continuously compensate for the loss.

In addition, intelligent functions such as vacuum monitoring, liquid separation, or energy-saving controls play a crucial role in ensuring process reliability and energy efficiency in automated manufacturing.