|Monthly Tech-Tip |
A shipment EP Kaolin has arrived for use in production of porcelain and stoneware bodies. Of course, this needs to be tested before being put into product. But how? The first step is to create a new recipe record in my Insight-Live account, and find their production date code stamp on the bag. Hmmm. It does not have one! OK, then I need to record the date on which we received it. We need to save a bag on every pallet and sieve 50 grams through 100 mesh (to spot contamination). Then we'll make test bars (of all the samples mixed) to fire across a range of temperatures (to compare fired maturity with past shipments). We do a drying performance disk also, it also shows soluble salts.
Pouring the EPK powder into water to make a slurry
We measure 50 or 100 grams of powder, mix it in water and then wash it through sieves of varying openings. The finer particles go through, we dry and weigh the coarser ones that do not.
Washing material through screens (while testing EPK particle size).
Screens drying after washing EPK powder through.
Weighing oversize on screen during EPK particle size test.
Slurrying EPK to prepare for dewatering.
EPK slurry has been poured onto plaster batt for dewatering.
EPK slurry has been dewatered on the plaster, ready for removal and kneading.
Plastic EPK slab ready for cutting into test bars.
EPK test bars and drying disk have been made from the plastic material.
A 10cm mark is made in the plastic bar during preparation. It is well formed and has clean edges because we dip the ends of the marker-tool into talc powder, as a parting agent. These bars are made from the same clay, they are part of a mutli-temperature test whose data is stored in a recipe record in insight-live (each bar is measured dry, fired at its assigned temperature and measured again). As these numbers enter the recipe record, Insight-live is able to calculate more of the drying and fired shrinkages.