GLOSSARY PROTECTIVE CANOPY

DEFINITIONS (climate)
Term Definition
± 2%

unit of variation; plus or minus that percentage from the stated value

Wind protection benefits

A well-designed wind-break will not be totally impermeable; but it will reduce the force of the wind, helping to maintain humidity and temperature; and keeping turbulence to a minimum in the sheltered zone – up to a distance of almost ten times the height of the structure.

Wind Load

The pressure on fabric or a structure caused by winds of a certain stated speed

Wind Force

Its full name is the Beaufort wind force scale, although it is a measure of wind speed and not of force in the scientific sense. Wind force is what you feel when you try to stand up in a strong wind. Wind force is what blows the dust, bends the trees etc.

Weft

Yarns running across the fabric.

Warp

Yarns running along the length of the fabric.

Vapour pressure difference

The weight per unit area of the vapour particles in the air.

UV Light

The UltraViolet part of the light spectrum. having or employing wavelengths shorter than light but longer than X-rays; lying outside the visible spectrum at its violet end; “ultraviolet radiation”.

UV Inhibitors / Stabilizers

Chemical additives added at the time of yarn manufacture to prevent the yarns from biodegrading due to the effects of UltraViolet light.

UV Block vs Shade

Shade is the blocking of all light; UV Block only refers to the ultraviolet spectrum of light.

Turbulence

Unstable flow (of a liquid or gas).

Throwover

Net or shadecloth placed over an item or plant for a short-term only; usually there is very little supporting structure other than the item or plant itself. Intended to be easily removed after it has served its purpose.

Tensile Strength

Ultimate strength of the material subjected to tensile loading

Sheltered zone

The lee (down-wind) zone of the windbreak. The level of sheltering depends on the aerodynamic porosity of the windbreak, the local topography, the height and the angle of the windbreak to the wind. In addition, the shelter becomes less with increasing distance away from the windbreak. Fabric porosity also affects the degree of turbulence in the sheltered zone.

Shade-house

A green-house style structure, covered in porous shade-cloth for the sole purpose of provided shade for the contents.

Shade Levels

Shade levels under coloured and white fabrics are measured in PAR (photsynthetically active radiation). This is approximately equivalent to visible radiation; 100% shade is solid.A white fabric will typically have a shade level of about 7/10 of that of a black fabric of the same weave.

Selvedge

The edge of a fabric that is woven so that it will not ravel or fray

Retractable

Able to be pulled inwards, towards a center, or folded into a storable size or shape.

Raschel Warp Knitted

Raschel is a type of knitting machine named after the inventor. Cloth / net knitted on this machine is described as such.

Q-Net

A proprietary term for Netpro’s specific brand of “quad”, “hex” or “hail-net”; net woven in such a fashion as to have any number of single strands crossing over the holes woven in the nets; divides the original hole into smaller holes. The net size is still referred to by the original hole size ie 12mm Qnet means the main hole is 12mm wide from side to side.

Pre-Packaged

Cut and packaged in a pre-determined size; opposite of Cut to Order.

PAR

Photosynthetically Active Radiation; approximately equivalent to visible light radiatio

Pa

Pascal – the International System of Units (SI) unit of pressure, stress, and tensile strength; it is a measure of perpendicular force per unit area; ie equivalent to one Newton per square meter, or one Joule per cubic meter.

Net / Shadecloth

Net refers to a fabric that is woven so as to stretch in one or both directions; Shadecloth is a stable material (does not stretch).

N

Newtons – the International System of Units (SI) unit of force. One DecaNewton (daN, 10N) is roughly equivalent to the non-SI unit of force, kgf (the force exerted on
1kg of mass by standard gravity, 9.80665 m/s2) i.e.1 kgf= 9.80665N