In 1931, the No. 2 board mill was set up in Covington in the area formerly occupied by the Robeson Process Plant. Two new cylinder machines with tunnel dryers were installed in 1931 and 1934 and later a third machines was added. It contained the dryers of the original sulphite pulp drying machine with which the mill started in 1900. In Covington, a Gilmore tower was installed which was the first step in converting from the sulphite to soda process in the old No. 1 Pulp Mill. In addition, five acid brick lined sulphite digester were torn out and replaced with smaller, all steel soda digesters.

In 1932, the first Carbon plant was installed at Covington with plant, carbon dryer, sand tables, etc.. Were located in the area of the firing end of #8, 9 and 10 Rotaries.

By 1933, 1500 employees were on the payroll at the Luke mill.

In the early 1930's pressure form the labor movement for unionizaton of industry began to be felt,a nd in 1933 the Employees Protective Association was formed, which had no contract with the company and confined its activities to discussion of grievances. In 1935, the AFL union, the Pulp Sulfite and Paper Mill Workers became the first outside organization to bargain for the hourly employees at Luke, Covington, and Williamsburg. In 1944, the Paper Workers Organizing Committee of the CIO won the right to represent the workers away from the AFL group. The PWOC represented all hourly production and maintenance employees except the electrical workers who joined the IBEW. The PWOC/CIO became the United Paperworker of America (UPA/CIO) in 1946 and in 1947 won the right to represent the electrical workers as well. However, the electrical workers returned to the IBEW in 1950. The year 1958 saw the merger of the AFL and CIO and the local union became the United Papermakers and Paperworkers, AFL/CIO.

In 1935, the Cass woodlands were sold. A research laboratory was started at Luke. W.R. Gingerich convinced the Luke Mill to try pulping a digester of peeled chestnut oak. The oak provided a high yielding, useful pulp. Covington quickly following suit. This was a breakthrough, as the mill was located in a forest that was 80% hardwoods. Also in 1935, an experimental multi-stage bleaching unit (35 tons/day) was begun for specialities made on No. 1 and No. 2 Paper Machines and shortly afterwards the manufacture of cup paper from bleached kraft and hardwood was started on No. 2 and No. 3 Paper Machines.

In 1936, construction started on a new unbleached kraft pulp and paper mill in Charleston, S.C.. Operations began in 1937.

In 1937, the company made 340,000 tons in its five mill (Charleston was just starting up) which was a 42% increase over ten year before. Sales were $30 million and there were 7,000 employees. Covington had a rated capacity of 530 tons per day making a variety of kraft papers, book, magazine and various writings on the seven paper machines and counter and insulating board on the board machines.

In 1937, the Industrial Chemical Company dissolved and the Industrial Chemical Sales Division of the West Virginia Pulp and Paper Company was organized.

An atmospheric semi-chemical cooling installation was built in Covington in 1937-38 to augment the waster filler used on No. 1 Board Machine in the production of linerboard. The continued development and expanded use of the corrugated shipping carton provided the impetus at this time for the addition of a continuous semi-chemical cooker in the No. 1 Pulp Mill for the production of hardwood corrugating medium on No. 6 Paper Machine, a product which the industry was accustomed to making from straw.