December 11, 2025
It was in the 1300’s that a new recycling industry was started. It was then, in Europe, that ragmen started collecting old clothing so that the cotton fiber could be recycled. The pulp was made into paper.
This industry continued strong until the early 1900’s, when it became more economical to produce paper from wood chips.
One of the survivors is a Vincent customer. Founded in 1924, Cheney Pulp & Paper in Franklin, Ohio produces high-quality specialty pulps, primarily for the paper industry. The main focus is on cotton fiber or “rag pulp”, although other non-wood pulps are manufactured. The pulp is used chiefly by securities papers and industrial papers manufacturers. There is a chance that you have paper currency in your wallet that contains fiber processed by Cheney.
Most of Cheney’s furnish is scrap cut-outs from cotton clothing manufacturers and fabric processors.
Their use of the Vincent press is a typical paper mill application. Reject and waste fiber, mostly fines, from the plant wastewater DAF system is dewatered in the press.
Today programs are underway which might resurrect the rag industry. The goal is not to make paper from scrap fabric and discarded clothing, but rather to produce more valuable byproducts. Vincent works actively with three companies, one in the States and two in Europe, which are advancing the technology in the field.
The rags are soaked in solvent and the screw press is used to recover as much solvent as possible. Consequently, screw presses for this market must be designed and built to explosion-proof standards.
Vincent has run a number of trials with sample material, both polyester and cotton. In the process we have learned that the application requires a much more robust screw press than normal. Wet cotton fiber is tough, and it has high freeness. The liquid used in washing the fiber squeezes out rapidly, leaving a very tough and compact mass of fiber in the press. The press cake moisture content is typically in the range of 40% to 55%.
These characteristics have led to press configurations with double-thickness flights; continuous flighted screws; and short L/D’s (length of screen divided by diameter of the screw). A significant difference has been found between press operation (and damage) depending on whether the soaking step is done with water or solvent. It is easier to test with water, but we have had more success testing with solvent.
ISSUE #362