US Patent 9718065 Method of plant resin separation and extraction

A process for trichome separation from plant matter deploys water slurry agitation and/or dry sieving to produce a mixture of solid trichomes and similar sized plant debris. The plant debris in each separate fraction is then removed by gravity filtration in a dense inert liquid, which is preferably a salt or brine solution. The desirable trichomes or trichome glands float on the dense liquid, while the undesirable vegetative matter sinks to the bottom of the brine containing vessel. The trichomes are readily removed and washed before further processing.