22 March 2002

Get to grips with airtight bags for top conservation

MAKING high quality conserved grass while the sun shines is relatively straightforward, but keeping it in tip-top condition is not so easy.

The difficulty lies in keeping the grass completely airtight to prevent aerobic activity and, as a result, spoilage.

Leics-based JB Thorne makes a compressing and bagging machine which, since its introduction last autumn, has received overwhelming interest from farmers and contractors, reports the company.

"The equestrian and racehorse business is now demanding fodder of an increasingly high standard," says John Thorne. "The Swardmaster compresses and bags conserved grass, enabling it to be preserved in an airtight environment for up to 12 months."

Powered by a 7.5kW or 11kW three-phase electric motor, the machine is equipped with a two-stage hydraulic pump, 250-litre reservoir and pair of rams.

In work, an operator places a 60cm (2ft) section of bale in the chamber, before the door is closed and lever operated to start compression.

Exerting no less than a 10t force, a vertical hydraulic ram squeezes the crop, while a second one pushes it through a horizontal chamber.

To maximise workrates, the rams have a "fast approach" which is then slowed during compression.

Pressurising the block of grass pushes two more through the horizontal chamber and when the outer one emerges it is bagged by a second operator.

"The 7.5kW and 11kW machines can fill up to 60 and 100 bags/hour, respectively, which can be increased using a self-loading device," says Mr Thorne. "The bags are then closed by a heat sealing device which we can supply for about £1300."

Weighing 20kg for haylage and 14kg for hay, the sealed bags can be stacked on pallets and then shrink-wrapped to provide further protection.

Price for the Swardmaster is £14,000. &#42