Wahlforss repatriated and got employed as main chemist at A. Ahlström Oy Varkaus factory in 1937. In 1941 he became Executive Director in Wärtsilä Selluloosa Oy Äänekoski Pulp Mill and in the following year he was appointed managing director. At the time, the Chief Executive of Wärtsilä Group was his older brother Wilhelm Wahlforss. 92% of the Äänekoski production was newsprint. The times were difficult due to the prevailing war and the company's paper machine was down most of the time. Later the company built a chemical factory, which produced spirits, vinegar, yeast, weed control agent and detergent. Eric Wahlforss led the plant until he died in 1951.