Agrifac produces two lines of crop sprayers. One type is large and self-propelled; the other, the more compact trailed crop protection sprayer, is the source of this challenge.
The trailed sprayer is hailed as one of the most innovative sprayers in the world, and the only trailed machine on the market with self-propelled sprayer technology. When shrinking technology but nevertheless trying to retain efficiencies, however, there is a need to adapt and alter some of the component parts.
In this instance, the adaptation lay with the spray nozzle that is positioned on the boom at strategic points to ensure that every drop of spray arrives in the right moment, in the right size, exactly where it is needed.
On the trailed Milan model, the nozzle is angled slightly differently, and the aperture is slightly smaller than on a self-propelled sprayer. This device also needs to withstand the demands of the spray, as well as its removal and replacement when the farmer needs to make adjustments.
“We’re an innovative company,” says Jarno Habing, Product Manager for the Milan range. “R&D is 20% of our company. We’re driven by technology revolution and we’re almost always first to market. Our research showed that the most efficient and economical way to produce these nozzles was to 3D print them. 3D printing allowed us to trial the different dimensions, as well as move to the low volume manufacturing required to keep our farmers in the field spraying.”
Despite the range of resins available, however, more traditional 3D printing methods proved not to be the economic option Agrifac sought. Constant exposure to chemicals, the weather and the need for removal and adjustment, combined with the need for developing fine apertures and even finer but nevertheless robust screw threads, were typically too much for most resins used in laser sintering or stereolithography printing. Agrifac noted that they were sending out at least five replacement nozzles a week to every farmer using the sprayer.
Determined to find an additive manufacturing solution, it appeared there could be one further possibility. Carbon’s Digital Light Synthesis process utilised some tough resins. It promised parts with functionality, durability, repeatability and, most importantly, very quick delivery.
Agrifac approached their nearest Carbon production partner, Paragon Rapid Technologies in the UK, with the problem. Together, the two companies set about determining the most appropriate resin to deliver on all the required attributes.
The Carbon produced rigid polyurethane resin, RPU70 is tough, durable and heat resistant and seemed ideal for the job. With high tensile strength and very little water absorption, it would not only allow for the fine detailing on the nozzle, it would also mean there would be less clogging and therefore easier cleaning of the finished part.