Investment in a fully automated system to overhaul a largely manual wet-cast moulding operation results in immediate productivity increases, quality improvements and a significant reduction in running costs for paving and pool coping specialist, Texi-Pave.
After 30 years in the paving and pool coping business, Texi-Pave have seen many changes to the common concrete and brick paver. In today’s sophisticated – and rapidly growing – DIY and renovation market customers insist upon an increasingly wide range of colours and dimensions when selecting pavers and demand for product consistency and finish is high. A technologically advanced production process is the key to eliminating costly product inconsistencies due to air inclusions in wet-cast concrete mouldings and increasing output to meet burgeoning market demand. Identifying their need to maintain an edge in a highly competitive market Texi-Pave made a significant investment in a total automation solution for their existing manual wet-cast operation with major improvements to product quality and output as well as an impressive return on their investment.
Making light work of manual labour
Any manufacturing industry that is heavily reliant on manual production processes faces constant labour, safety and quality control challenges. At Texi-Pave continuous de-stacking of empty trays and transfer of heavy wet-cast concrete moulds onto pallets by hand, along with manual tray lubrication with oil mist spraying equipment were causing serious occupational health and safety issues for the company. By automating the entire wet-cast operation Machinery Automation & Robotics (MAR) successfully integrated electrical, pneumatic and robotic equi pment to eliminate all heavy manual lifting and a fully automated oil mist unit to reduce the potential hazards of manual oil mist spraying. In addition, three fully automated vibration tables were included in the process to effectively remove air inclusions from the concrete cast, replacing the existing manually operated vibration table and ensuring a consistently high quality finished product.
Realising rapid returns on capital investment
The benefits of automating an existing manual system at Texi-Pave proved twofold. A production line previously operating with six staff members in each shift was immediately reduced to a one-man operation significantly alleviating labour costs. The elimination of all manual heavy lifting has minimised costly product damage caused by dropping and knocking trays during transfer and concrete spillage. And for a business averaging a 100% turnover of staff every year, savings in employee training have proved considerable.
Financial savings, however, haven’t been the only benefit. No longer requiring production to stop for mandatory employee work breaks, Texi-Pave operate their automated wet-cast operation continuously throughout the daily shift increasing output without extending operating times. And with robots operating at higher speeds than a manual workforce overall productivity has seen significant increases. Existing capital plant assets, including the mixer and silo storage, have also been more fully utilised. The batching system, where sand, colouring and cement are mixed, and the mixer are better utilised following the introduction of a robot, which transfers more trays onto pallets than were processed manually.
Automation at work
The solution provided for Texi-Pave has automated the production process from the handling of empty trays through the wet-cast moulding process to the transfer of full trays and pallets at completion of the operation. A single forklift operator loads empty trays stacked fifteen high onto the new chain conveyor, designed by MAR to replace an existing antiquated belt system conveyor. The trays are then transferred to a fully automatic de-stacking station where electrical and pneumatic controls handle their separation into individual trays. The operator, who has simple push button control over the conveyor, places the moulds into the trays as they move along the conveyor. The trays then pass through the automated oil mist unit on the inline conveyor to prevent the product from sticking to the mould.
A dosing machine dispenses concrete from the batching system into the moulds. During the dosing process the trays sit on the first of three new vibration tables, which form part of the indexing (transfer) system at the end of the line. The automated vibration action removes air from the concrete as it sets. To ensure the quality of the finished product is consistently high and free of air inclusions the trays then pass over a second and final vibration table before arriving at the robot palletising area.
The robot at the palletising area is capable of picking up three full trays simultaneously and placing them into a single pallet at the loading station. The pallet at the loading station is then stacked with fifteen trays before being dispatched to the unload station where the forklift operator removes the pallet from the system. The pallet stacking station and infeed conveyor supply batches of ten empty pallets to the robot operating area where accumulation of up to twenty empty pallets is possible. The pallets are then transferred one at a time to the loading station conveyor as required.
Adding up the benefits
The transition from a manual operation to an automated one brings with it many changes to any business involving production processes. For Texi-Pave the changes initiated by the introduction of a total automation solution brought with them many benefits. These include:
- A complete automation solution including design, programming, installation and commissioning
- An ROI in less than two years achieved by a reduction in labour costs, an increase in productivity and an improvement in product quality
- Onsite commissioning alongside Texi-Pave’s existing operation with only minimal disruption to production during a one-day installation
- A general robotic training program completed at MAR’s technical facility followed by onsite application-specific training tailored to Texi-pave’s specific needs
- Full compliance with occupational health and safety requirements
Technology at work for Texi-Pave
- The control system features an Allen Bradley CompactLogix PLC and serves as the gateway between the Ethernet and DeviceNet networks
- A single operator controls the line via an Allen Bradley PanelView Plus 600 key colour HMI (Human Machine Interface) running on the Ethernet network
- The entire production line is driven by twelve Allen Bradley Power Flex variable speed drives
- All remote input and output nodes are controlled via the DeviceNet back to the PLC
- The KR 180 PA KUKA robot was selected to undertake all depalletising and palletising tasks, controlled via the DeviceNet and PC driven on a Windows platform
- Three vibrating tables at the end of the production line form part of the indexing (transfer) system a