In addition to preventing bird and animal damage to silage sheets, protective silage covers should also:

  1. Be flexible enough to follow the contours of the silage surface holding silage sheets in place to prevent aerobic spoilage
  2. Prevent wind lifting the silage sheet There are two main types of material used to make protective silage covers, woven or knitted high density polyethylene (HDPE). Woven material is made of monofilaments which run straight, horizontally and vertically.

However, in Secure Covers knitted material the monofilament follows a complex looped path (Fig 1).

Because there is no single straight line of monofilament, Secure Covers material is inherently more flexible than woven material. The stiffness properties of fabrics, bending length and flexural rigidity, can be measured using a fixed-angle flexometer. Results confirm that Secure Covers
material is more flexible than woven material (Table 1).


Therefore Secure Covers material will follow the contours of the silage surface more effectively that woven material. This will result in less surface waste.

A summary of the results show that:

1. Secure Covers are more flexible (Bending Length and Flexural Rigidity) than woven covers. Which means Secure Covers follow the contours of the silage clamp better than woven covers


2.Secure Covers have a greater wind diffusing effect resulting in a greater resistance to ‘wind lift’, keeping the silage sheet in place even on windy days. This effect is due to a combination of:-

a) The 3-dimensional structure of knitted Secure Covers  which is much more complex than a woven silage cover

b) Secure Covers are rougher than woven covers (Mean Roughness Depth and Mean Peak Width)

c) Secure Covers have a greater Void Volume

Secure Covers are protected by patent application GB1704218.5

For more information on Secure Covers® please ask in your local store or visit www.wynnstayagriculture.co.uk to request a quote.