Dry-ice (CO2) sift and pressing report.
I've been playing about with dry-ice sifting for a year or so, but in small runs. No more - lots of trim, popcorn and entire plants, 5kg of dry ice slabs, a bucket, a 220 micron gauze and a mirror...
I ran two grades of product through, the first was dry trim and popcorn bud from a variety of of my stock plants: Northern Lights, Blues, Skunk, etc.
The second run was an assortment of Attitude freebies, mostly Snowcap, that I won't be cloning.
Using 1,150g of product, I produced 185g of sifted polm, about 155g of it "primo", or first grade, and 30g "secundo".
I could have produced more but I usualy call a halt when there is a noticable darkening of the polm. The residue is usually refluxed in iso to give a 10:1 extraction, so I'll expect up to 100g of dark oil from this too.
I've experimented with pressing the sift with varying results, and several iterations of press and mould later I've built a 10-ton hydraulic press and a stainless steel mould (10mm press plate in a 5mm wall mould) that doesn't buckle under pressure.
(The stainless steel bit is important to me because I process med-grade). I've had good result at about 4 tons pressure with a one-inch square mould (before it warped), but 9 metric tons on a 9cmx9cm plate equals about... enough.
Some primo grade sift was too sticky to push intact from the mould - I rolled some up into a fat tola. Most formed very flexible slabs whether 2 or 10mm thick.. The lower grade "secundo" made a lovely solid passport slate.
Pictures attached: The tolas are sticky primo (Attitude freeby selection), the big and four small squares are another primo (from the NL/skunk trim) and the lighter thin rectangular slab is the secundo. All good stuff.