It was only a matter of time before industrial cannabis regained its place as an important crop in American agriculture. Whereas plants – including hemp – have long been used to provide raw materials for industry throughout human history, hemp had a bad rap in the past century, particularly in the United States. 

Re-Igniting the Industrial Cannabis Industry  

The 20th century saw Prohibition increase for various plant-derived substances, including opium, cocaine, and an ill-fated 1920s era alcohol ban. Where cannabis was concerned, the reasons for this are many and varied. Speculation about US cannabis Prohibition during the 20th-century range from racism against refugees from Mexico's 1910 revolution and black jazz musicians who smoked its flowers to conspiracy theories about business interests – particularly the paper, petroleum, and pharmaceutical industries – providing support for the ban. The reason: the plant's fibers were providing competition for products they produced. 

Whatever the reasoning behind the US cannabis ban put in place by the Marihuana Tax Act of 1938, cannabis made a massive comeback in the 21st century, beginning when California legalized medical marijuana in 1996. For farmers and manufacturers of hemp processing equipment, it took a bit longer. Though a brief respite occurred for hemp farmers and supporting industries during World War 2, when legal options for alternatives were cut off, farmers were dissuaded from growing hemp afterward. From 1945 onwards, the US hemp processing industry essentially went dormant. 

It took until 2014 for an agricultural bill to introduce a pilot program that allowed research into hemp's many uses. The new law allowed state agriculture departments and "institutions of higher education" to cultivate the plant, so long as state laws permitted. Though a step forward, it kept production under the Drug Enforcement Administration (DEA). 

A later farm bill passed in 2018 that allowed increased hemp production and processing of hemp as an agricultural commodity, though it did not remove the plant and its derivatives from the DEA's list of controlled substances. 

While the medical marijuana industry has concentrated on legalizing the cannabis plant's flowers for medicinal and recreational purposes, the fibers in the plant's stalks primarily excite the hemp industry and those who make hemp processing equipment. Hurdles still exist for those entering the industry. Still, it looks increasingly certain that industrial cannabis production will overcome these challenges and that hemp processing equipment will soon be back in vogue. 

Dissecting the Cannabis Plant: A Glossary of Terms

Here are some of the more important terms to know about the plant:

  • Commercial Cannabis: Comes from the female species, which have long skinny stems and iconic fan leaves.
  • Cola: The plant is trimmed down into buds, which come together in a cola at the stem's top. 
  • Trichomes: a blanket of crystal resin coating the cannabis plant.
  • Terpenes: within the trichomes, terpenes are organic essential oils that give the plants a distinctive aroma and flavor. 
  • Cannabinoids: within the trichomes, cannabinoids are the major active chemical in the cannabis plant. The two most well-known cannabinoids are THC and CBD (which also occur in the largest volume).
  • Delta-9-tetrahydrocannabinol (THC): known to cause psychoactive effects or the "high" felt from cannabis.
  • Cannabidiol (CBD): lacks nearly any psychoactive effect, making it preferred as a medicine. 

How the Industry is Using the Whole Cannabis Plant

Every part of the cannabis plant can be used, from the roots to the flowers. 

  • Seeds can be eaten raw or ground into a meal and the plant's roots for making powdered health supplements
  • Hemp seeds can be pressed and made into oil for salad dressings, paint, ink, or a core ingredient in body care products. 
  • The hemp plant's stalks become clothing, construction material, and paper. Raw hemp hurds – the coarse parts of the plant that adhere to the fibers – are processed to use as insulation, paper, and even cement. 
  • Processed hurds become pulp for biodegradable plastics. Even waste material from cannabis plants can be fermented and utilized to make hemp-based biofuel.

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Preparing Hemp for Processing

The type of hemp processing equipment needed depends on the end product, with specific machinery suiting different parts of the process. Before processing, the hemp plant must be cleaned before decortication – removing the outer layer of hemp from its fibrous core – and retting – a method for separating the plant's long bast fibers. 

Usually dried first before decortication and retting, new technologies in development allow hemp to be harvested while wet; therefore, producers rely less on the weather during harvest time. It also helps those within the supply chain to access raw hemp with more ease. Wet processing is often done when making hemp into insulation materials, fiberboards, or other fibrous material reinforced with hemp. 

Hemp Processing Equipment for Threshing & Separating Seeds

After cleaning and drying, the hemp is then threshed to remove the seeds from the rest of the dried plant material. This process involves breaking up the flowers, stems, and leaves. Though threshing hemp has traditionally been done by hand, at scale hemp processing equipment is necessary for this task. Threshing also involves breaking down the remaining plant material. The dried buds are being rubbed or crushed to release more seeds. 

Meanwhile, separating hemp seeds for planting involves combining gravity and blowing air, typically using an air/screen cleaner to remove finer or lighter material on the first pass. This also helps with cleaning the husks off the seeds. Using screens with variously sized holes, it separates seeds by size. As one of the oldest techniques for separating seeds, blowing air carries off the lighter seeds while dropping the heavier ones, which are much more likely to germinate. This crop seed passes through the screen to be collected, or the smaller sized seeds pass through to a container where they are discarded. 

Often there are multiple screens, the first retaining the chaff, the next retaining the seed, and the smallest one allowing smaller seeds and debris to pass through it. One problem with hemp is that the smaller stems and sticks frequently pass through the screens with the seed. One of the more effective types of hemp processing equipment is a type of grading machine that uses small pockets on a cylindrical device to collect the round seeds as the cylinder rotates. Stems and sticks won't fit into these small round pockets, which slide down the cylinder and drop off into a container while the seeds discharge into a separate bin for further processing. 

Hemp processing equipment that combines the air/screen cleaner with this seed separator offers even greater efficiency, as it combines two pieces of equipment into one. Threshing hemp and separating seeds from it often involves vibrating deck screeners, some with multiple decks to catch the seeds, or rotary screens, which offer greater capacity than conventional screening methods. The vibrations act in conjunction with gravity and centrifugal force to separate seeds and heavier materials from the rest of the plant. Once separated, the seeds can then be further processed for food or oil, while the plant's flowers and fibrous parts continue through processing.

Other Hemp Processing Equipment

A range of other equipment dries, sifts, screens, and extracts plant material to make it into a wide array of hemp-based products. This includes drying machines like belt and rotary dryers to prepare hemp for processing, lump breakers to break down biomass, air classifiers to separate hemp material by weight or size, and machines used for pre-roll preparation for extracting CBD. 

When used as hemp processing equipment, particulate-reducing machinery such as hammermills and lump breakers plays a significant role in breaking down the plant material into useful material. Such size reduction equipment helps manufacturers to grind the fibrous hemp stalks to maximize CBD extraction. These mills can crush without reducing the plant to its basic fibers while handling the tough hemp fibers along a production line. 

Reducing machinery also helps break longer hemp fibers down into shorter fibers, a stage of the process known as carding. This can happen in single or multiple stages and involve breaking down the long fibers and splitting, untangling, and opening lumped fiber to remove remaining dirt and form slivers. This fundamental practice works, strips and doffs the hemp so it can be used to make cloth and fabrics. 

Studies have shown CBD to be promising for: 

  • Alleviating cancer symptoms
  • Anti-psychotic properties
  • Assisting in treating neurological disorders
  • Lowering blood pressure
  • Pain relief
  • Reducing the spread of some cancers
  • Reducing symptoms of depression and anxiety
  • Reducing the chance of developing diabetes
  • Treating acne and other skin conditions 
  • Treating substance abuse

Reducing machinery also helps break longer hemp fibers down into shorter fibers, a stage of the process known as carding. This can happen in single or multiple stages and involve breaking down the long fibers and splitting, untangling, and opening lumped fiber to remove remaining dirt and form slivers. This fundamental practice works, strips and doffs the hemp so it can be used to make cloth and fabrics. 

Other types of equipment used for processing hemp include: 

  • Air classifying mills used to grind defatted hemp protein meal into flour.
  • Aspirators separate hemp seeds from flowers.
  • Dehulling machines clean, dehull, separate and recycle the shells around the hemp seeds.
  • Filters and filtration systems remove finer hemp particles when extracting CBD from plants. 
  • Fine grinders grind free-flowing, dry material with extremely narrow ranges of particle sizes, including heat-sensitive cannabis resins. 
  • Hammermills for grinding biomass ahead of CBD extraction.
  • Industrial herb grinders free seeds from flowers and strip remnants of buds from the stalks.
  • Multi-aspirators screen material to separate seeds from flowers by using blowing air. 
  • Rotary drum screeners sift out larger material for reduction. 

As time goes on, new types of hemp processing equipment will be developed by partners of the emerging hemp industry, increasing all hemp processing systems' efficiency. 

Prater Hemp Processing Equipment

Prater Industries can repurpose its deck screeners, grinders, lump breakers, hammermills, and other machinery to process hemp. Depending on applications and end products, Prater is especially adept at designing whole systems for processing hemp. Additionally, the company's willingness to collaborate with producers, both big and small – including entrepreneurs and startups – makes it a valuable partner to those looking to capitalize on the nascent industry. In the end, it's Prater's technical expertise that will offer hemp processing companies an edge over their competition.