Paper Chemistry for New Markets: An Overview

martin a. hubbe

The versatility of papermaking can be an asset when addressing the needs of new potential customers who have new requirements. Much of that versatility can be achieved by use of chemical additives to the papermaking process.


Among the thousands of available chemical additives, papermakers can place most of them into two categories. Some of them get categorized as “process additives.” Examples include defoamers, slimacides, retention aids, and stickies-control agents. They help the papermakers maintain runnability and production. But when a potential customer has a new set of requirements, the papermaker can turn to a category called “functional additives.” Examples of these include hydrophobic sizing agents, superabsorbent polymers, strength agents, and colorants, among many others.

Innovations often come to the paper industry in two forms. The most familiar are the evolutionary innovations, in which companies gradually adjust their recipes of chemical additives to fine-tune their paper products to better meet the needs of existing customers. For example, they may upgrade the process control aspects of applying hydrophobic agents to a board product, thereby more reliably meeting the water hold-out needs without interfering with expectations for friction or gluability.

The other kind of innovation is the disruptive kind. One of the best examples, which occurred in the 1980s and 1990s, was the widespread switch from clay to calcium carbonate fillers in printing papers. A motivating factor for the switch was lower costs to achieve brightness goals. The switch was enabled by technology developments in precipitated calcium carbonate (PCC) and in hydrophobic sizing agents such as alkenylsuccinic anhydride (ASA) and alkylketene dimer (AKD). The change in sizing additives was made necessary by the fact that calcium carbonate requires alkaline pH and would dissolve when exposed to the acidic conditions needed for conventional rosin sizing.

Another important innovation in paper chemistry involved the use of mineral microparticles or nanoparticles to enhance dewatering during papermaking. As in the case of alkaline papermaking, these programs (which use bentonite or colloidal silica, etc., in sequential addition with cationic polymers) seemed like an oddity at first, but they became widespread once their advantages became well known. More recently, the category of enzyme-based additives for papermaking processes has become used more and more. Due to their bio-based nature, enzymes are inherently biodegradable. They are being used for such things as freeness enhancement, deposit control, and quality aspects of tissue products.


New market opportunities are emerging due to increasing emphasis on environmental aspects of packaging products. The public, as well as legislators, are objecting to non-biodegradable packaging materials, which often end up as wind-blown or water-borne contaminants. On the one hand, paper products have achieved positive recognition due to their inherent biodegradability and the high percentages of recovery and recycling. But there are increasing efforts to prepare paper products that can take over the jobs previously done by plastics. That includes the plastic laminates that are used in beverage cartons. The challenge is to come up with surface treatments for paper that provide barriers to oxygen and greases. An even greater challenge is to match the water-resistant nature of plastic layers in packaging products. In addition, the papermaker wants to achieve all of those goals without hurting the biodegradability and recyclability of their products.

The word “leveraging” can describe the strategy that papermakers are employing when they utilize functional additives to change the performance attributes of their products. In many cases the substantial investments in building a pulp mill, installing a paper machine, and in establishing pulp supply logistics already have been established at the mill site. The added investment needed to achieve different requirements for such things as water absorbency or water hold-out of a new product is often low by comparison.


Future innovations in paper chemistry will require both effort and skill. Over time, many paper producers have tended to become specialized. While there can be practical advantages in focusing on a narrow range of products, especially at a given mill site, there may be a lack of the needed skill and experience when a need arises to produce different paper products at that mill. Where will the skilled input come from? Can the needed developmental work be farmed out? Can some current employees become tomorrow’s experts in the emerging product lines?

In many cases, the chemical additives that can make a new paper product possible at a mill site already exist, and it is just a matter of optimizing the process on existing paper machines and converting equipment. From the mill’s perspective, it can be an advantage to have local expertise. That helps when focusing on customer needs, aiming for high reliability, optimization of paper properties relative to your customer’s operations, and essentially “tuning” your paper products by effective usage of chemical additives.


When making plans for a needed innovation involving papermaking additives, a manager should not underestimate the need for testing and optimization. The fact that a paper product or a chemical additive has been demonstrated on one paper machine does not mean that the same recipes and procedures will succeed on another one. Issues such as levels of hydrodynamic shear, the time delay between different points of addition, and details related to the local fiber attributes are likely to differ for different mills and even for adjacent paper machines. Support will be needed from analytical chemists when new forms or locations of deposits on papermaking equipment are experienced. The local production team, often in collaboration with chemical suppliers, will need to conduct trials at the production level, often supplemented by lab-scale testing.

Truly important and disruptive innovations in any field often start small. As in the case of the smart phone, there was no way to predict whether people would buy and use such things. Not every innovation related to applications of paper chemicals can be expected to take fire in the way smart phones did. But many of them will be highly appreciated by new or existing customers.

Martin A. Hubbe is a professor and Buckman Distinguished Scientist at North Carolina State University, teaching and conducting research related to the colloidal chemistry of cellulosic materials, with a particular focus on papermaking wet-end chemistry. A TAPPI Fellow, he serves on the Paper and Board Division’s Paper Additives Committee and is co-editor of several books from TAPPI Press (see sidebar.)