Standard our webs are equipped with rods of spring steel class C (DIN 17228). However we can also mount rods of hardened Boron steel, stainless steel or glass fibre reinforced polyester. After consultation with you, we can also use other materials so that the produced web will meet your expectations as good as possible.
Without using rod coverings we can create gaps with a minimum of 5mm. By using rod coverings we can reduce the gaps to 2mm.
Standard rivet rods are available in diameters 6-13 mm and 15mm.
To increase the conveying capacity of a sieve web, we can equip webs with cranked rods. These cranks are available in various heights, both up and down. (An often used construction is 2 down cranked rods, followed by 1 straight rod.)
Kinds of steel.
For use in rough circumstances, for instance in stone separators, we can make the rods out of stronger materials. Here we use special steel
Special steel is harder and tougher than spring steel class C. Further it has all the properties of regular spring steel. Special steel is available in the diameters 10, 11 and 12mm.
Hardened boron steel is even harden and tougher than special steel. An advantage of boron steel is that it can be welded. After welding, the material must be hardened, which makes it impossible to weld on an existing web. Boron steel is available in the diameters 10, 11, 12 and 13mm.
Stainless steel is often used in water. All metals used in the sieve web are then of stainless steel. It is not possible to make a centre flattening in a stainless steel rod. If a centre belt is required, attachment onto the belt will be made with centre clips.
To save weight we can use rods out of glass fibre reinforced polyester. The glass fibres provide great tensile strength. A sieve web with these rods can weigh up to 50% less than a web with steel rods. Another advantage is that these rods don’t rust. Polyester rods are available in the diameters 6, 8 and 10mm.
Twin rods
For the processing of small products, such as flower bulbs, we produce webs with “twin rods”. A twin rod consists of 2 rods, which are clamped together at their ends, by a tube. With the use of rod coverings we can create a gap as small as 2mm. Twin rods are also standard constructed with spring steel rods, though stainless steel or polyester rods are also available.
Square meshes
For oblong products, such as carrots, we produce sieve webs with square pitches. The rods of these webs are made from Boron steel, onto which pins are welded, giving the web square or rectangular gaps.
Vulcanised rods
To protect the product from damage, we can vulcanise a soft rubber layer onto the rods. This rubber has a hardness of 30-35° shore. Because the rod is vulcanised over the total length, including the flattenings, this offers optimal protection. With these rods, the centre belt is attached with OGP.
Hedgehog rods
Hedgehog webs are often used for cleaning the product and the removal of haulm remnants. We can supply hedgehog webs with 3 different types of rods:
E30 (Standard)
This is an arched steel profile, 30mm wide, on which 2 rows of rubber fingers are vulcanised. These fingers are 28mm high and are placed C.T.C. 20mm from each other. These rods are usually attached to 60mm wide traction belts, pitch 40mm. The rods are attached with bolts and welding nuts M6. E30 rods are very stable, therefore allowing for a relatively wide web without using a centre belt.
P30 (Flat)
This is a flat steel profile, 4x30mm, on which 2 rows of rubber fingers are vulcanised. These fingers are 30mm high and are also placed C.T.C. 20mm from each other. Compared to the standard profile these fingers are much thicker and more stable. P30 rods are riveted to the traction belts.
V10 (V-profile)
This is a ø10mm rod, on which the 2 rows of rubber fingers are vulcanised in a V shape. These fingers are app. 25mm high and are asymmetrically placed, also 20mm from each other. A V-profile hedgehog web has the advantage of having sieve capacity. This profile is not available in every width.
Centre belt attachment
Spring steel rods can be attached to a centre belt in 3 different ways:
OGP (rods ø 8, 9, 10, 11, 12, 13 and 15mm)
The rod will be pushed up before flattening. This thickens the material here, so the flattening does not become a weak spot.
Centre clips (rods ø 8, 9, 10, 11, 12 and 13mm)
A centre clip will be slid over the rod. This centre clip will then be riveted to the belt, in order that it is held tightly around the rod. To prevent the centre belt from moving sideways, a rod will be slightly flattened en either side of the clip, at intervals of app. 30cm.
Clamp clips (rods from ø 8mm upwards with star PVC)
A clamp clip will be riveted to the centre belt first. A covered rod will then be placed inside this clip, after which the clip will be squeezed.
Assembling of rods
The rods can be riveted to the belts in different ways. Usually they are riveted with 2 rivets per traction belt. To avoid damaging the product and to prevent the rods from coming loose when the rivet heads wear off, the holes in the rods are made partly conical. This allows the rivet heads on the rods to be almost smoothed away.
Rods with a diameter up to 10mm are riveted with 5mm rivets. For rods ø11mm and up we use 6mm rivets.