|
|
 |
|
News / Innovations
Full-automatic production for rail pads realized
|
In its capacity as complete system supplier of injection moulding technology, DESMA has developed and realized a full-automatic plant for the production of rail pads for the line of rail infrastructure.
 These rubber sheets called rail pads serve as vibration absorber between rails and sleepers in the construction of track systems and thus contribute to protect the superstructure. They are mainly used on bridges, in tunnels, close to shock-sensitive buildings and for ballast-less construction.
Basis of the production of these 150 g heavy parts made of a natural rubber compound is the tried and tested horizontal DESMA machine D 969.560 Z with a clamping force of 5,600 kN. The rigid clamping unit in 4-tie bar design stands for minimum deflections and the precise guiding of platens and hydraulic lifting devices.
Since being equipped with the retractable injection unit FIFO B, which is fitted with 2,500 cm³ and 2,810 bar, deformations within the mould area do virtually not occur. Apart from an extremely small through hole in the platen, this is also ensured by the additional contact force of the injection unit. The FIFO principle guarantees an even residence time of the compound in the injection unit with the stock pressure being constant. So the stock temperature can be correspondingly set to a high value during the complete plasticizing process. As a result, cure time is reduced.
The used 2-deck mould with integrated ejectors was produced in the DESMA-owned mould shop. With a FlowControl CRB it is directly injected into the center of the articles. The runner-free production by using this innovative cold runner system offers two advantages at the same time: Material loss because of runner waste is eliminated and any kind of rework such as runner separation is superfluous, which on the other hand reduces cycle time. And that is not the only reason why this procedure has to be regarded as very efficient.
A servo-electrically driven brushing unit with gripper plate and vacuum grippers takes over the full-automatic demoulding of the parts. The article and tear-trims separation is already made during cure time.
The vulcanized articles are cooled down to room temperature by being conveyed through a 4 m long cooling section, before a piling device piles the finished products up to 20 pieces each ready for packing. The plant produces more than a million rail pads every year.
|
| |
| [back to overview] |
|
 Print page (change to landscape please) |
|
|
|
