Pulp and paper
Wet strength resins (WSR), such as polyamine epichlorohydrin (PAE), are added to many paper and cardboard products to enhance paper strength under wet conditions. In order to efficiently disperse these pulp fibers during repulping it is necessary to remove the water-resistant WSR from the paper product. This can be notoriously difficult. Oxone™ repulping aid can help.
Oxone™ monopersulfate compound has been used in pulp and paper mills as a WSR repulping aid for over 30 years. It provides a combination of efficient repulping performance and chlorine-free processing in one product, oxidizing PAE without damaging pulp fibers.
The favorable environmental and safety profiles make Oxone™ a sustainable and effective choice for repulping wet strength paper grades. In fact, Oxone™ is the first raw material verified by Green Seal for removal of WSRs in paper repulping.
- Tissue, towel, napkin
- Coffee filter, milk carton
- Wet strength carrier board
- Poly-coated board
- Secondary fiber treatment
Oxone™ chemistry can be used to repulp various different paper types. Our standard repulping conditions are typically used to repulp many types of paper tissue, towel and napkin products. Due to the versatile nature of Oxone™ chemistry, it is possible to optimize repulping conditions for more challenging products. For example, liquid container boards, carrier boards, milk cartons, labels, corrugated liner board, unbleached paper or high PAE-content products.
- No chlorinated (AOX) compounds
- Efficient repulping
- Increased productivity
- High quality pulp
- High fiber yields
- No stainless steel corrosion
- Easier, safer handling
- Green Seal verification
- Reduces reliance on virgin fibers
Recent research published in TAPPI Journal by researchers at the Georgia Institute of Technology1 demonstrated the impressive and selective repulping performance of Oxone™, and the resulting fiber quality characteristics. Oxone™ was found to be “superior to sodium hypochlorite in repulping of PAE-containing paper towel in terms of effectiveness and pulp quality.”
Compared to hypochlorite-repulped paper, hand sheets from Oxone™ repulping had significantly higher physical strength, as measured by tensile, burst, and tear indices in the study published in TAPPI journal1.
Analysis of resultant fiber quality showed that using Oxone™ repulping aid produced a better quality furnish compared to both hypochlorite and caustic-only repulping. Specifically, pulp from Oxone™ repulping yielded 34-47% fewer fines and 24-31% longer average fiber length compared to all other repulping conditions tested.
1Yang, R. and Luettgen, C., Repulping of wet strength paper towel with potassium monopersulfate, TAPPI J. 19(9): 463(2020).
Oxone™ repulping aids offer fast and efficient removal of PAE resin. Other chemistries, including hydrogen peroxide, sodium percarbonate, sodium persulfate (SPS) and caustic soda, are kinetically slower, resulting in significantly longer cycle times.
Laboratory tests show that the rate of disintegration achieved in 30 minutes of repulping with Oxone™ could not be matched by sodium percarbonate, SPS or caustic soda, even after 90 minutes.
The benefits of optimising fiber disintegration by use of Oxone™ chemistry include increased throughput and reduced energy consumption.