New equipment & information
For many sound reasons, architects today are rapidly changing the way buildings look by incorporating glass as a distinctive or important feature of their design. This modernistic approach is an ideal construction solution in terms of cost reduction, energy conservation, and meeting environmental concerns. Aesthetic appeal no longer stops at the exterior but has also found its way into interiors as a resourceful partner, both as a breathtaking decorative source and superb means for partitioning.
Once considered as exotic from an architectural standpoint, the use of printed or color coated glass is almost endless and is incorporated in the most prestigious building projects today. More and more exterior/interior doors, showers/bath enclosures, vanity tops, shelving, mirrors, partitioning, walls, skylights, ceiling canopies, elevators, balustrades, stair treads, table stops and floor tiles are fast becoming the popular glass-made items receiving color, pattern or textured finishes.
Regardless of its function, size or color, all architectural glass—as opposed to automotive and appliance glass—that is either printed or roller coated shares one commonality: the need to manufacture in a clean environment. While screen printing has tremendous versatility to give a full flood—monolithic—or selective 5 percent to 100 percent pattern tints to solids, textured and multicolor, the printing machines must be of robust construction to overcome the limitation of the screening process with large-format glass panels.
It is important to realize this need because, unlike automotive glass printing, where only about 10 percent of the glass surface is printed, architectural glass mostly requires some coverage on 100 percent of the glass. Then there are the size, glass thickness and weight factors to consider. All together, the mechanical stress and demand from the process are much greater than those experienced elsewhere with other glass printing applications.
It is not unusual to have both coating systems, screen printing and roller coating, working together as part of the process to create the image conceived by the architects.
Details of a typical large format architectural glass decorating line:
Glass panels are first washed and dried in a washer, a prerequisite to obtaining a blemish-free print, or coated image if roller coated.
1a. Just before the cleaned glass panel exits the washer, it enters the clean room.
Optional pre-squaring unit to pre-position any size, shape or thickness, mostly used with larger runs of the same part.
2a. Quick adjustable pre-register stops.
2b. Robust transportation conveyor system built into the table.
Fully automatic in-line large format architectural glass screen printing machine: Semiautomatic models also available where glass can be manually fed onto the printer and manually registered, plus 3⁄4-automatic models where glass is automatically transported to the print table and then manually registered.
3a. Operator friendly LCD display control panel on a moveable stand to custom suit any operator, stores recipes for quick setup recall.
3b. Heavy-duty constructed print head for superior print quality and complete peace of mind.
3c. Strong, non-flexing, squeegee assembly unit to permit full and uniform print on the entire sheet of glass. Anti-drop system to prevent ink from dripping off the floodbar onto the screen or image.
3d. Perfectly flat print table for uniform printing on thin glass. Fleischle, for example, provides a special construction with patented solvent-resistant surface for scratch-free handling.
3e. Numerous built-in features for fast setups such as laser alignment, adjustable stops, pneumatic screen clamping—ideal for quick changeovers between custom and short job lots.
3f. Main control cabinet built to UL508, CSA and NEC2006 codes.
3g. Equipment compact in size to free up valuable floor space.
Inspection area on conveyor to check print quality before it goes into the dryer.
Reverse roll coater applies flood coat color directly on un-coated glass or over a screen printed image. Powered infeed and outfeed conveyors interface with other system components.
5a. Rubber covered coating roll is grooved to handle ceramic, silicone based and other ink types.
5b. Doctor roll regulates the amount of ink transferred to the glass.
Drying/curing oven with a combination of medium wavelength infrared and convection for maximum flexibility. Suitable for water miscible ceramic, silicone based, epoxy and other decorative inks.
6a. Insulated enclosure with accessibility to the interior for maintenance.
6b. Clean out provisions for broken glass.
6c. A conveyor that will safely transport and track the glass through the oven. Shown is a driven roll conveyor with spiral wrap Kevlar rope.
6d. Combination medium wavelength, electric infrared and convection to efficiently transfer energy to the ink/coating while scrubbing away the evaporated materials from the coating surface. System should have the ability to run IR only and combination of IR with convection. Controls should be closed loop for repeatability.
6e. Exhaust system to remove evaporated byproducts from the system.
Above all, a successful operation is built around the people who run it. Cleanliness, equipment maintenance, controlled conditions for repeatability and defined process procedures all contribute to producing a quality product.