I work for a company that manufactures Pharmaceutical Trays. I have noticed that the industry standard for drying buds is a mesh like metal tray on a racking system at least for several of the large Cannabis companies I have spoken with. Is there a specific reason for the mesh like tray. Do you buds require vertical air flow? I have found that most drying rooms have horizontal airflow so I feel the mesh trays are almost unnecessary. I would be very interested in hearing everyone’s feedback and possibly connecting with a grower that would be interested in testing their product with a couple of sample trays.
If you are laying cut flowers down to dry, you would not want them on a non-breathable surface, they will mold. This is true for the hops industry as well. Take a look at hops drying, I think this is where cannabis will be in the near future. Hops is dried on a massive screen/mesh with forced hot air from the bottom (kiln dried). Hops is speed dried, so it won’t be exactly the same, but this bulk handling procedure can be adapted for bulk dried retail cannabis flower. Hops is even run through giant tumble trimmers before drying.
I agree with @Farmer_Dan here in regards to hops. Humulus lupus is in the Cannabacae family…making it the closest relative to cannabis sativa. Large-scale hops cultivation/processing has been happening on an industrial scale for years. Everything from super-fluid cupercritical extraction of essential oils/terpenes for beer production to large scale cultivation and drying methods…let the hops be your guide!
As @Farmer_Dan mentioned, you shouldn’t have any point of contact with a non-breathable surface, regardless of the air flow direction. It allows for drying from all directions, without leaving out the part which is in contact with the tray.
With that said, our customers use DryGair systems not only to dry but also to create air circulation which is vertical as well as horizontal. This type of flow ensures uniformity when drying.
The preferred method we see in the industry, is to hang the harvested flowers on wires strung on mobile carts, or wall to wall. This minimizes mold/mildew. The only time we see trays used for drying in commercial setups, is for flowers that cannot be hung.