The corrugated industry has seen a rapid transformation in the last century. One of the major development was in the field of adhesives which resulted in achieving remarkable production targets. The history of these developments will help us understand how these transformations assisted the corrugated industry and what are the further required steps for modifications.
At the start of the 20th-century corrugated adhesive used to have high water content as compared to starch. The water to starch ratio was 15:1. These adhesives made a good bond but they had a high water content which was a limiting factor, due to which production speed was restricted to 15-25 feet per minute.
In the second decade of the 20th century, most corrugators switched from starch/flour to silicate soda-based adhesives. These adhesives can be made on corrugator location as well as it could be purchased in ready liquid form. The main benefit of silicate-based adhesives was that they required minimum heat to make a bond. It also assisted in better print quality on corrugated sheets. A major downside to this adhesive is that it increases the wear and tear of corrugating rolls. Another disadvantage is that it increases the weight of the overall corrugated sheet. Still, silicate remained the most used corrugated adhesive for nearly 15-20 years. until 1934, when an individual from the Stein-Hall company named as Jordan C. Bauer introduced a starch-based adhesive that could match performance with speed.
Baurer used a small portion of cooked starch as a carrier to rest the remaining starch suspended. Baurer added some more ingredients such as Borax and caustic soda to control the viscosity and Gel temperature of adhesives. Some Modifications have been made in this process but this starch adhesive is still used in modern corrugators. There have been efforts to introduce cold set and hot melt adhesives corrugated industry but it didn’t prove to be a productive option.
As Corrugators in today’s world run at high speed, it requires a large number of adhesives in a speedy manner. A common practice is to make adhesive on site of operation, this enables timely delivery of adhesive to corrugator.
As a corrugator Engineer, I always maintain the adhesive level on all units of the corrugator. I retain the viscosity and gel point of adhesive because it can lead to serious production loss if any of these parameters is disturbed. I also do iodine tests on my running jobs so that I can ensure the right amount of application on the medium. We also use resin which is a water-resistant solution for some water-resistant corrugated boxes.
-Haseeb Qausim Shift Engineer RPL