Brick Manufacturing

Building Products

Hanson Building Products has automated its brick packing system in order to eliminate manual handling and increase safety. During the process automation commissioning stages, a risk assessment highlighted the need for a new safety network. After analyzing the Kirton sites requirements, a decision was made to employ an ASi Safe system from Siemens Automation & Drives.

Essentially the existing hard-wired safety system did not conform to
BS EN 954-1. Additionally, the safety communication between each machine in the process was not meeting site requirements.

CCK Electrical Services Ltd, specialist system integrators based in Clipstone near Mansfield, identified during the design of the automated shrink-wrapping system, that there were some major safety issues.

The site, which is separated by a set of zones with a complex formulation, is reliant on 'handshaking' between three machines. The shrink wrapper machine, strapping machine and de hacker machine. At the heart of the brickworks wrapping process a Siemens ASi System was installed replacing the redundant under performing existing hard-wired system. Due to the complexity of the existing control and safety network of the three machines, they needed to use a product that would have the flexibility to be programmed to manage communication between all the automated zones. The main component of ASi safe was a master slave system that was interfaced with the shrink wrapper master network.

Robert Holyoake Works Manager at Hanson comments on the speed of the plant retrofit: “Downtime involved in carrying out works on the system was a concerning factor when we embarked on this project. But by using Siemens ASi safe, upgrades were carried out in just two weeks, which would have been impossible using the existing network!”

The packaging of bricks on the automated production line begins with the de-hacker machine that unloads fired bricks from a kiln car haulage system in preparation for packing. The strapping machine then fits plastic bands around the brick packs to hold them together. Finally the shrink wrapper system, takes over to complete the packaging job.

The system required not only the communication network to function with the other machines on the site, but additional safety devices to protect operators working with the automated machine shrink wrapping the bricks.

On the conveyor belt based brick pusher, that links the de hacker machine to the strapping machine, CCK Electrical identified that it was essential to have a light curtain permanently muted by brick packs that could be bi-directional, located between the two machines. In the case of a person crawling through the enclosed conveyor system, the light curtain would detect their presence and stop the hydraulic pack pusher, and send a “dual channel” stop to the strapping machine.

The real risk to operators lay within the shrink wrapper compound, where people are required to manually place plastic bags over strapped bricks for automated shrinking by the gas burner. This part of the process required safe stopping of the conveyors and gas burner. To carry out this function two light curtains were installed.


Richard Kaye system designer from CCK Electrical Services Ltd said: “Apart from increasing the bottom line safety of the brick packing process at Hanson, yet another advantage of the system was the simplicity of slave monitoring via Siemens S7 software allowing easy display on a Siemens HMI.”

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