Rijk Zwaan homogenises fragile vegetable seeds using Lindor technology

It seemed an ambitious project: homogenising large quantities of fragile, high-quality vegetable seeds by machine without causing any damage to the seeds. Nevertheless, in collaboration with Rijk Zwaan, a global player in vegetable breeding, Lindor successfully developed a mixer which homogenises and blends seeds and fruit crops while maintaining a consistent quality. “Cucumber seed is very fragile which, once damaged, you can’t sell. Lindor’s gentle touch technology is a perfect match for our products”, says René Hendriks, team leader of Operations Support at Rijk Zwaan.

Continuous innovation is essential if, as an international player, you want to deliver top quality and participate in the development of new varieties, a company philosophy that Rijk Zwaan embraces. However, it becomes a lot more challenging when you’re dealing with a delicate product that also has to be packed precisely to the gram. “We pack spinach seeds by the million, about 12 grams per 1000 seeds, which is about 12.2 kilos for a million seeds. Due to variable weather conditions, the shape and size of a delivered batch of spinach seeds can be rather erratic. If the seeds are coarse, the customer will receive far fewer seeds than ordered. For that reason, we homogenise spinach seeds manually”, Hendriks explains. A time-consuming, labour-intensive and rather inefficient process, in his opinion: every box had to be sampled individually to be able to label boxes of seeds with a similar TGW (thousand grain weight) as one batch. This is how the desire arose to homogenise large batches by machine.

Homogenisation with consistent quality
A previous introduction to Lindor’s customised mixers at a trade fair brought the two innovation-minded parties together. “The objective of Rijk Zwaan’s project was to homogenise one delivered batch of spinach seeds and guarantee consistent quality”, says Michael van der Knaap, project engineer at Lindor, about the L25000 that has been installed. With a diameter of 3.6 metres and a length of 9 metres, this is also Lindor’s largest machine. Capable of mixing 25,000 litres in one operation which, in this case, is 12 tonnes or over a billion spinach seeds. That’s a lot of spinach!

Rijk Zwaan has also installed a smaller L200 drum mixer for homogenising and mixing paprika, aubergine and cucumber seeds. According to the project engineer, it is beyond dispute that Lindor’s technology makes all the difference here too: “Gravity ensures that all seeds, large and small, tumble and mix extremely well. Due to the shape of the mixing drum and the vanes, the seeds follow a trajectory, and the required homogeneity is achieved in a very short time. During this process there is almost no friction between the seeds, so they remain undamaged.”

Optimised production process
The excellent cooperation between Rijk Zwaan and Lindor has resulted in an optimised production process, which ensures a more consistent quality and less fluctuation of the TGW, an indicator of the average weight of a seed. Hendriks: “We empty all the boxes from one single batch into the mixer, which then homogenises 12 tonnes of spinach seed within five minutes.” According to the team leader of Operations Support, the new production process not only saves employees time, but the automated process also contributes to an improvement in quality.

In short: a successful project, according to Hendriks, as a result of which Rijk Zwaan is now able to supply customers with just one batch of a homogeneous product of a consistent quality, instead of several batches of manually selected seeds based on TGW. “The implementation ran very smoothly! Including the attention we received from Lindor during the test phase, their engagement and flexible attitude: our entire collaboration process was extremely satisfactory!” concludes Hendriks.