VG Paper Blog


Testing the Hollander Beater

In testing the beater I found the leak points, the weak points, and the capacities and items that need to be improved…

So when I was designing and planning the beater, I did some calculations (see Hollander Beater Math) and found the depth, width and etc. to get me the volume I wanted. First I just added water, about 7 gallons. It leaked under the backfall mounting and the left (looking from back to front) bearing shaft slot. The backfall leak was easy to fix with a little silicon in the holes that were leaking and put the hold-down screws back in. The slot leak was kinda fixed by leveling the beater (back to front and left to right). OK time for a test run! (Sorry about the antique phone quality.)

Refilled the beater with 7 gallons of water. I weighed out 3 lbs. of fibre (shredded waste paper and a sheet of cotton linter). I turned on the beater with the drum at a higher position, and added the shred slowly. Remember the "waterfall effect" from a previous post? Well this is where the waterfall shield came into play. Every 15 minutes, I dropped the height 1 full turn of the height bolts. After about 3 hours, it was close to being done. The test is a mason jar (1/2 pint) filled with water and 1 Tbs. of the pulp in the beater. Shake the jar vigorously. Hold it up to a light source (like the sun) and see what the pulp looks like. If it is free of big chunks and threads and looks like a smooth mixture, it's done! If not keep beating with the drum at its lowest point checking every 15 minutes.

When it tests good, lift the drum with the height screws up, so it is at its original starting point (hydration stage), and add your sizing, if desired. Originally since I was making an original medieval type of pulp, I used liquid laundry starch for sizing (1/2 cup in a qt. of water, shaken and added to the pulp). I had people watercoloring on it, painting, markering, inking and such. There were a couple of people who were heavy handed with their high-flow fountain pen. They needed more sizing. So I changed to a professional, modern sizing AKD (Alkyl Ketone Dimer from Twinrocker paper). You use less and it makes a harder sheet but still good for watercolor and paint. Great for inking.

Additional Notes: - Since I have been using this beater for about four years and I made some improvements to the baseplate/drum relationship, the time has been drastically reduced. Plus I am using less shred. 6.5 gal. of water to start. 2.5 - 2.7 lbs. of shred boiled for an hour or (easier) soaked in a 5 gal bucket overnight. 15 minutes of hydration stage (drum up), 15 minutes with the drum almost at the lowest point (first pass), 15 minutes lump, lump (the lowest point of the drum and thats the sound that it makes). Test and if good, raise the drum up, add the sizing and run for 15 more minutes. About an hour. To keep things flowing well you may have to add another half to full gallon of water over the course of the hour. The pulp really absorbs the water. You can get 8.5 to 10 gals. of pulp (half-stuff).