Oversized, Jumbo or Regular?

Key fabrication factors to consider when moving to large sizes
Jack Van Meerbeeck
October 4, 2018

lifting equipment from Barbaric
Lifting equipment becomes essential with oversized and jumbo glasses. Pictured is the Jumbo Glass Lifter from Barbaric. Photo courtesy of Matodi.

The use of glass over the last decade has grown tremendously, not only in quantity, but also in the size of glass used. Architects favor larger and more energy-efficient glass types for a number of reasons, including aesthetic and optical needs. 

The largest oversized glass products need to be imported into North America. Specialized companies such as Sedak can process glass overseas up to 49 feet by almost 11 feet. In North America, several companies are producing jumbo glass in sizes of 130 inches by 230 and even 300 inches. Jumbo coated glass can also be domestically sourced. 

The large glass market offers benefits to fabricators. It can be processed on equipment with a reasonable investment. And, depending on the optimization and mix, a fabricator might see 2-4 percent yield savings on glass, which can be huge when considering products such as commercial insulating glass. 

However, with bigger glass comes a bigger, more complex set of practicalities and issues associated with it. Consider the following:

1. Jumbo and oversized glass manufacturer locations

Two float manufacturers recently opened jumbo sized float plants with an associated coater in North America: Guardian Glass, in Carleton, Michigan, and Vitro Architectural Glass (formerly PPG), in Wichita Falls, Texas.

This is welcome news. Finally, soft coats, domestic, in jumbo size 130 by 204 inches, will be available. Even larger sizes can be obtained from European or Asian float plants, with all the associated costs and practices in terms of shipping, packing and handling. Note that this route can prove to be extremely expensive, given the special care requirements for these products.

2. Structural integrity and bearing loads

Bigger or thicker does not necessarily mean stronger, but it definitely means heavier. Consider what processes will be utilized on an oversized piece of glass: tempering, edging, laminating, bending, etc. A tempered laminate is not safer than an annealed laminate, although it has better bearing characteristics. Fabricators must study and prepare for every process when dealing with larger sizes.

3. Pre-processing transport limitations

Regular glass is transported in North America on specialized trailers with a maximum limitation of 44,000 pounds, which corresponds to about 11 stoce packs. Jumbo glass transport necessitates lowboy trailers, with usually four stoce packs to a trailer. These trailer types are defined by the width of the glass packs (130 inches for jumbo, which equals the width of the ribbon coming off the float), transported at a 4-degree angle, allowing tractor trailers to pass under regular bridges. 

Larger than jumbo glass requires special transport, which may not always be possible due to existing road infrastructure, and it carries a tremendous price tag associated with it. Shipping from overseas may involve on-deck shipping.

4. Packing and handling

Serious attention should be given to the crating, loading and unloading process, including storage and lifting systems. Similar issues apply after processing the glass, if the size remains nearly the same.

5. Equipment limitations

Processing capabilities will be limited by equipment. Fabricators must consider the size of tempering furnaces, autoclaves, etc. The laminating process also can be limited by the maximum width of the interlayer. Some interlayer roles are available in 130-inch widths, while others are available up to 99 inches wide. There are tricks to process two layers next to each other, but this can come at the detriment of optical quality.

6. Limitations on handling during installation

Do glazier customers have the equipment to install these oversized lites? Huge lites on very tall buildings require careful planning in many areas such as safety, lifting and cranes, to name a few.

7. Market advancements

Facts, figures and requirements are constantly changing in the glass industry, particularly when it comes to the oversized glass market. Fabricators should keep an eye on the innovations to come involving oversized glass. 

Jack Van Meerbeeck is co-founder of machine and tool supplier Matodi. He can be reached at jack@matodi.biz.