Smart Safety Solution Helps Grow Capacity and Reliability at Plaster Mill

Winstone Wallboards is New Zealand’s only manufacturer and marketer of gypsum plasterboard, drywall systems, and associated products and services.

Over the last 90 years, Winstone Wallboards has grown from modest beginnings to become New Zealand’s only manufacturer and marketer of gypsum plasterboard, drywall systems, and associated products and services.

Winstone Wallboards has facilities in Auckland, Christchurch and Wellington.  The company is committed to ongoing research and works closely with researchers at universities at New Zealand’s major industrial research and development centres to continually improve its products, systems, and solutions.

A core section of the plant is the joint and finishing compounds area, within the company’s Auckland plaster mill. This is the only production facility capable of producing joint and finishing compounds in New Zealand. As the final step of a complex process, this material handling section seals, conveys, orientates, palletises and wraps finished product.

The material handling equipment for the joints and finishing area was installed in 2002. The installation represented a fundamental leap forward in productivity and technology as the large quantities of manual handling previously required in the area were significantly reduced. However, in the last 15 years, machine safety standards and general expectations on machinery within manufacturing have been substantially updated.

To comply with the latest safety standards and improve reliability, Winstone Wallboards approached NHP Electrical Engineering Products, a distributor for Rockwell Automation products and services, to design and deliver an industry leading solution to meet their palletising requirements and assist with growing the company’s production capacity.

Automated materials handling

The materials handling equipment has the challenging task of handling the two incoming streams – the dry and wet product, packaged in different mediums – simultaneously. The finishing compounds area is divided into three sections; the dry mix section: end user is required to mix the product which is packed in a variety of different sized bags from 5kg to 20kg; the wet mix station: ready to use products are packed in pails of varying sizes from two litres up to 15 litres and also a 14 litre box; the third section merges both the wet and dry mix on the robot palletising system. Safety is therefore a key priority for the system operators.

While reviewing these materials handling zones, Winstone Wallboards had conducted a risk assessment which identified areas of the plant that required updating to meet new standards.

“The initial scope of the project was to replace an aging palletising robot that was no longer meeting capacity,” explained Shaun Sanders, Manufacturing Safety Engineer at Winstone Wallboards. “We decided to upgrade the safety in the joints and finishing area to comply with the standards for palletising cells and implement a new safety system – from control through to devices – in that area,” he said.

Smart safety solution

The functional safety specification helped identify the products and solutions that would best meet Winstone Wallboard’s safety requirements. “We decided to use the full spectrum of Rockwell Automation products to deliver a completely integrated and connected safety system,” said Sanders.

Integrated control and safety for the materials handling equipment was delivered by the Allen-Bradley® GuardLogix® programmable automation controller (PAC). The control system was programmed using Studio 5000® Logix Designer software over Ethernet/IP – for seamless integration and providing time-savings in design, engineering and project development with simplified validation and verification through minimized hardwiring tests.

Given the safety hazards associated with the materials handling equipment at the plant, it was important to provide appropriate guarding between the hazard and operators so the machine could be accessed in safe mode if required. Guardshield® POC Safety Light Curtains provided zone separation for the mill, and the latest Guardmaster® 442G Multifunctional Access Box (MAB) provided an ideal solution for this application. It is an integrated access control and guard locking device which provides a complete safeguarding solution for full body access applications.

The Allen-Bradley 442G Multifunction Access Box installed on safety gate.

Maintaining uptime

“The new solution meets AS/NZ Standard 4024 and provides ease of maintenance and also ease of adjustment. From a maintenance and fault-finding perspective, it has given us great benefits. It is part of a big picture for the plant, moving towards integrated equipment,” said Sanders.

As a result of the solution, downtime due to safety system failure has been reduced. With the old safety system, fault events could take several hours to diagnose; now, with the new Guardlogix based smart safety system, diagnostic information on the state of the safety system is immediately available to the operator and maintenance teams. This facilitates rapid repair and production resumption, resulting in an OEE improvement of 0.3 percent. This means that the safety system provides increased equipment availability to produce for an additional 24 hour period during the year.

Furthermore, the system provides the tools for Winstone Wallboards to drive compliance, while ease of use provides the operator with safe operating procedures whilst enhancing productivity. By incorporating safety information into Environmental Health and Safety management systems, day to day discrepancies between policies and operating procedures can be identified – improving insight into worker behaviour and compliance.

Allen-Bradley, GuardLogix, Guardmaster, GuardShield, Rockwell Automation, Rockwell Software and Studio 5000 are trademarks of Rockwell Automation, Inc.

EtherNet/IP and CIP Safety are trademarks of ODVA.