Transparency with security

Laminated polycarbonate and safety glass

Laminated panes are particularly suitable for this purpose. They are made of single-pane or laminated safety glass on the machine room side and abrasion-resistant coated polycarbonate on the operator side. Modern laminated panes from Hema offer the required retention capacity and therefore comply with the ISO 23125 standard for lathes and ISO 16090-1 for machining centers. They should be used during a retrofit, even if polycarbonate screens were previously used.

The Spinvista side-hung window from Hema is suitable for retrofitting. © Hema machine and equipment protection

Unprotected polycarbonate safety windows not only become optically cloudy and dull due to cooling lubricants and the ongoing production process in the machine, so that their transparency is greatly reduced. They also exhibit a pronounced ageing curve and, as a result, a decreasing retention function. In the first five years of service life, the impact resistance and therefore the retention capacity decreases significantly. Depending on the actual operating conditions, polycarbonate panes without additional protection can lose some or all of their safety retention function after just a few months in use. Studies at the BG Institute for Occupational Safety (BIA) have proven this. In systematic test series, it was found that polycarbonate panes wetted with cooling lubricants exhibit up to 60% less retention force after only nine months of wetting.

Diffusion-tight and resistant to coolants

Hema only uses quality material for its safety windows. The edges of the panes are sealed to be diffusion-tight and resistant to coolants. The polycarbonate panes in thicknesses from 5 to 15 mm are provided with a surface coating that protects the panes from scratches and abrasion. All safety screens are individually configured and manufactured for each machine tool in accordance with the applicable Machinery Directive. Depending on customer requirements, the machine safety screens can be straight or curved. On request, the machine protection experts at Hema can also supply them with a stainless steel frame.

Machine safety screens must be visually inspected at regular intervals by the machine operator's responsible personnel and replaced at the required maintenance intervals. In the event of damage or abnormalities, they should be replaced immediately. Hema offers its customers a replacement service: In an inventory, the machine operator receives a detailed overview of the machine safety windows used in their machines. The replacement period is determined in a professional assessment of the windows. On this basis, the removal and measurement of the panes as well as the construction and safe design of the replacement panes can be tackled. "When replacing machine safety glass, we always aim to minimize machine downtime. We almost always find solutions that allow the machine to be put back into operation quickly, both during the measurement and when installing the new screen," says Marc Arendt. Hema also offers its tried-and-tested Spinvista rotating window as an option when replacing panes. With the help of a rotation mechanism, it removes dirt from the pane caused by chips or cooling lubricants, allowing a clear view into the machine's work area. The rotating window is mounted on the inside of the machine safety screen. Thanks to its low weight, minimal height, modular design and maximum compatibility, Spinvista can generally be easily retrofitted to all machine tools.