The Exilva Blog

To wrap up this corrugated boards application series we finish with a focus on warp. Warp is one of the most common problems that corrugated board manufacturers face. Producing bent or twisted boards results in excessive scrap, waste and reduced production rates. There may be a number of factors that contribute to this problem; leaving out the machinery and focusing on the moisture control in the bonding process, what happens when we add Exilva (Microfibrillar Cellulose, MFC) to the adhesive?

The bonding quality determines the ultimate strength of the corrugated board. In my previous blog post I revealed increased speed results for the production of corrugated boards. In this blog post I have investigated what effect Exilva Microfibrillated Cellulose (MFC) has on bond strength.

Having demonstrated the viscosity stabilizing effect of Exilva in starch adhesives, for this third blog post in the corrugated boards application series, I will focus on the effect on glue ability and production speed.

In a previous blog post, I explained how the new technology of Exilva microfibrillated cellulose may improve the viscosity stability of starch adhesives. Here is the second blog post in the corrugated boards application series, and now I have entered the glue kitchen of a corrugated boards manufacturer to evaluate the robustness and stability effects of Exilva.

Starch is a natural polymer found in many processes either as an adhesive or a thickener. Following paper production, corrugated board is the second largest application of non-food starches globally, where it it used as an adhesive between the fluting and liners. The control of the adhesive viscosity during process and storage is critical. However, despite further developments regarding the formulation of starch adhesives, the viscosity is commonly not stable enough over extended periods of time, in particular over weekend storage. In this first of a series of blog posts with the corrugated boards application as the example, I will give an introduction to this problem, and the new technology of Exilva, a microfibrillated cellulose, to solve it.

The open time, wet edge or lapping of a coating is a measure of how much time an air dry coating takes to reach a stage where it can no longer be applied by brush or roller to the same "wet" coating without leaving an indication on drying that the "wet" and newly applied coating did not quite flow together. Therefore, the advantage of having good open time in a stain would result in better general appearance of the stain.

In my previous blog post, I covered the characteristics of microfibrillated cellulose (MFC) and fumed silica as raw materials used for industrial purposes. I focused on how MFC provides a viable alternative to fumed silica in many applications since they both have large surface areas with similar surface active groups. However, the physical network properties of the two materials differ and may lead to new and exciting discoveries in the end products.

Microfibrillated cellulose (MFC) and fumed silica are both used for controlling the rheology of liquid systems, such as thixotropy and stability, and may be used within the same field of applications giving similar properties. However, there are also profound differences between the two. For example, where MFC is a natural product derived from cellulose-based raw materials, the native hydrophilic fumed silica is an amorphous, colloidal silicon dioxide prepared by a flame hydrolysis process. So why can two such, at first glance, different products be used in similar applications? In this blog post, I will dig more into detail about the two multifunctional additives, and discuss how their similarities and differences may affect application properties.