The poles are produced by pouring concrete into molds fitted with pre-stressed steel wire reinforcements and followed by compacting and curing. The production cycle varies from 6-8 hours depending on the production environment.
The key processes involved in pole production are:
- Mould Preparation: Molds are cleaned and applied with mould release oil for easy lifting of finished poles out of the mould box.
- Pre-Stress Wire Fixing: The steel wires are pre-stressed and passed through mould boxes. The pre-tensioning of wires improves the strength of the poles.
- Concrete Making: Concrete is produced using ‘batching plants’ located within factory premises. The raw materials for concrete are coarse aggregates, fine aggregates, admixture, cement and water.
- Concreting: The concrete is poured into mold boxes.
- Compacting: The mould boxes are vibrated so that concrete gets compacted.
- Steam Generation: Steam is produced using a boiler.
- Steam Curing: The steam is passed over the mould boxes to remove moisture from the concrete.
- Pole Release Preparation: At this stage, the pre-tension wires are cut and hence poles are de-tensioned.
- Lifting: The poles are lifted from mould boxes using gantry cranes and transported to other locations for further processing.
- Water Curing: After lifting from poles, they are stacked inside ponds for further curing and strengthening.
- Stocking: After water curing, poles are stacked at the stockyard as finished goods inventory.
- Delivery: The poles are loaded onto trucks for customer delivery.
The picture given below is the diagrammatic representation of the complete production process.