2737 



23-7 CHEMICAL ADDITIVES 2771 



SIZING OF FIBERBOARD 2771 



Rosin size 2771 



Wax size 2772 



Asphalt size 2772 



FIBERBOARD BINDERS 2774 



FIRE RETARDANT AND 



PRESERVATIVE TREATMENTS 2775 



Fire retardants 2775 



Preservative treatments 2776 



PROCESS COMPARISONS AND 



INDUSTRIAL PRACTICE 2776 



Wet processes y general 2776 



Insulation board 2777 



SIS wet-process fiberboard 2778 



S2S wet-process fiberboard 2778 



Dry-formed hardboard and medium-density fiberboard . 2779 



23-8 WET-PROCESS FIBERBOARD MANUFACTURE 2781 



CONSISTENCY AND WATER CONSUMPTION 2782 



FORMING MACHINES 2783 



Batch-type sheet mold 2784 



Cylinder forming machines 2786 



Fourdrinier forming machines 2789 



Board surface modification on a Fourdrinier 2792 



Fourdriniers for SIS hardboard compared to those for 



insulation board and S2S hardboard 2793 



Wet press 2793 



Trimming of wet fiber mat 2797 



DRYING MATS FOR INSULATION AND S2S BOARDS 2798 



Dryer construction 2798 



Heating and circulation 2799 



Feeding and transporting 2799 



Dryer performance 2800 



Safety 2800 



HOT PRESSES, TYPES AND CONSTRUCTION 2801 



PRESSING S2S HARDBOARD 2806 



Mat handling 2806 



Pre-drying 2806 



Press loading 2807 



Press cycle 2807 



Thickness tolerances 2808 



Density distribution 2809 



