Spending more to earn more.

“We have always planned ahead and we have always gone for the best machinery available at the time. When you spend more, you earn more” says Mark Woodroffe of Cambridgeshire potato growers Neville Woodroffe and Sons. Their Crowland Fresh Produce Ltd semi-automated grading and packing line, proves the wisdom of this philosophy.

“If you are planning a store it makes sense to consider capacity for expansion, so it is with machinery. Having considered the various automatic palletisers available, we installed one of the first Symach systems in the UK, having first travelled to Holland with David Harrison to see one in operation.”

With the Symach’s potential for stacking 15 sacks a minute, Mark realised that throughput was being limited by their weigher bagger. There were two problem areas. Crowland Fresh Produce bag a lot of ‘Markie’ variety potatoes for chipping. With their unusually large size, two potatoes could become wedged in a weighing bucket. More important however was the limitation of vibrating lanes. While these were OK with dry, clean crops, dirty potatoes lifted from wet or heavy soils would deposit mud on the lanes necessitating regular cleaning stops, after every 2 tons with really dirty crops.

This problem has been addressed by the installation of a 12 bucket Pro-Pack weigher with belt conveyors and X3L buckets. In six months of operation, the belts have been cleaned just once and that was on a quiet day when the whole shed was cleaned!

Moreover the generous X3L buckets are Teflon coated and designed with a bottom flap that leaves a clear passage when opened eliminating blockages. The buckets on Woodroffe’s machine are arranged in 2 facing rows of 6 buckets. Besides facilitating a shorter discharge belt contributing to speedier throughput, the 12 buckets offer the machine’s dynamic weighing system an amazing 900+ combinations to achieve consistent results via as few as just 5 buckets. The computerised system learns how big the potatoes are and calculates the best match every time to achieve an average bag throughput of 12 a minute.

“We can start the system at 7.45 am and bag 50 tons by 11” says Mark “It runs like a dream with no problems and no cleaning. Its phenomenal accuracy means we are giving away just 5 grams on a 25 Kg bag! And we know we can handle up to 120 tons a day when we are under pressure”. 

Photo cell sensors control incoming volumes and a fully adjustable brush spreads the crop across the belts for efficient throughput. Weighing is automatically paused until the holding hoppers are full ensuring that the system works at peak efficiency. Further sensors are installed between the stitching line and the palletiser which adjusts its speed to match the frequency of incoming bags.

In fact the stitching Line has been upgraded with Morray DS9 twin thread equipment to match the high throughput rates and the added security of double stitching.

Further efficiency has been achieved with the Symach palletiser by the installation of a programmable turntable which presents the pallets ‘end on’ or ‘sideways on’ to suit loading requirements and an extended roller conveyor which can hold up to 5 pallets before halting the process. This allows the forklift driver more flexibility. He can now service the box tipper and the hopper with less need to rush back to the palletiser.

The Woodroffe family grow around 125 hectares of potatoes. The speed of the new system allows them to grade all their produce within a much smaller time frame, so taking advantage of favourable market conditions. Furthermore they can offer a grading and packing service to neighbouring growers and have accommodated bulk imports when the exchange rate was favourable.