What should I watch when using FAS in tissue and specialty papers?

Direct answer

FAS is used differently in tissue and specialty papers than in deinked or mechanical pulp: these grades usually demand high brightness, low basis weight and tight control of odour and food-contact compliance. The focus therefore shifts from whether brightness can be lifted to residue control and compliance: thorough interstage washing, a conservative dose, and confirmation that the finished sheet carries no odour or reversion from residual reducer.

1. Three points needing extra attention

2. Starting conditions

3. Three food-contact considerations

1. Confirm the regulatory scope of the target market first: food-contact paper has explicit requirements for additives, checked against the destination regulations and the customer standard

2. Obtain and file the compliance documents: SDS, applicable declarations and test reports

3. Test the finished product where required: residue and sensory checks per the customer's specification

4. Four notes for specialty papers

• Coloured grades: confirm on a bench trial that the reduction stage does not pull the target shade off
• High-filler grades: filler adsorbs part of the chemical, so dose and washing must be adjusted
• Lightweight sheets: keep both mechanical action and temperature at the lower end to avoid breaks
• Where coating follows: residue from the reduction stage affects coating adhesion, so washing must be reliable

Sources

Starting values are the recommended ranges from our technical materials and published literature. Food-contact and specialty paper requirements must follow the destination regulations and the customer's standard.