Starch-Based vs. Synthetic Adhesives for Corrugation

In the corrugated board industry, the choice of adhesive technology is a foundational decision that impacts cost, performance, and operational complexity. For decades, the undisputed king has been starch-based adhesive. Made primarily from corn or wheat starch mixed with water and caustic soda, it is inexpensive, readily available, and effective. However, a new class of synthetic polymer-based adhesives is challenging this dominance, offering significant performance advantages that can, in many cases, justify their higher upfront cost. Understanding the trade-offs between these two chemistries is essential for any modern corrugating plant looking to optimize its operations.

Starch-based adhesive, typically made on-site in a 'starch kitchen,' is the industry's workhorse. Its biggest advantage is cost. Starch is an agricultural commodity, and the raw materials are significantly cheaper than synthetic polymers. This makes it a very attractive option, especially for high-volume production of standard board grades. However, it has several operational drawbacks. The performance of starch adhesive is highly sensitive to variables like temperature, water quality, and batch-to-batch consistency. It requires careful management of viscosity and gel temperature, and the process of making and handling it can be messy and labor-intensive. Furthermore, it introduces a large amount of water into the board, which can contribute to warp and requires significant energy to dry.

Synthetic adhesives, like Kubron's Aquatack Plus CS, represent a different approach. These are highly engineered formulations based on specialized co-polymers, delivered ready-to-use. The primary advantage of synthetics is consistency and performance. Because they are manufactured under precise laboratory conditions, their quality and performance are predictable and repeatable, eliminating the variability of on-site mixing. They typically have a much higher solids content, which means less water is introduced into the board. This leads to faster setting times, higher machine speeds, and significantly flatter board with less energy consumption for drying. They also offer superior adhesion to difficult substrates like coated liners, where traditional starch can struggle.

The decision between starch and synthetic often comes down to a total cost of ownership (TCO) analysis. While the per-kilogram cost of a synthetic adhesive is higher, its benefits can lead to substantial savings elsewhere. For example, increased machine speeds of 10-20% can dramatically increase a plant's total output and revenue. Reduced energy consumption in the drying section lowers utility bills. A lower rate of warped or rejected board reduces waste and improves profitability. For plants producing high-value, complex, or specialty board, the performance benefits of a synthetic adhesive often provide a clear and rapid return on investment. At Kubron, we work with our clients to perform this TCO analysis, helping them determine which adhesive technology is the right strategic choice for their specific business goals.