Attached to the uprights, backs, and sides of individual industrial steel pallet racks and vertical storage systems, steel mesh containment panels contain items stored overhead. Their presence reduces the chance of equipment or inventory falling. Also known as rack safety panels, rack guarding, or rack back, these panels (when properly secured) minimize the risk of pedestrians or equipment to be struck from an item falling off a pallet rack. They also often guard and secure both products and moving automated components when installed within the racking integrated in shuttle- and crane-based automated storage and retrieval systems (AS/RS).

Specification for Steel Mesh Containment Panels

The purpose of steel mesh containment panels is to protect personnel, products, and property. Therefore, it is critical to verify that their engineering and construction will allow the panels to perform their job reliably and effectively. That’s why the members of the Protective Guarding Manufacturers Association (ProGMA), offer the standard, “ANSI MH31.1 – Steel Mesh Containment Panels Used In Vertical Storage System Applications: Performance and Testing Requirements.”

Available for purchase, this specification provides guidance and information about design, operating, and testing practices. It also outlines performance criteria and operational requirements. Its purpose is to help owners, users, designers, purchasers, or specifiers of these types of products as they are determining the optimal way to use these panels in their operations.

How Steel Mesh Containment Panels Work

In addition to preventing items from falling into pedestrian aisleways and work cells, steel mesh containment panels can also be installed floor-to-ceiling. This includes extending above rack columns where the height of the uppermost store pallet load is taller than the rack structure to secure loose, non-unitized loads. They also protect structural features and utility lines — including electrical, plumbing, and sprinkler systems — from impact by a load or pallet placed too far back in the rack by a forklift operator.

ANSI MH31.1 Testing Confirms Impact Resistance, Containment Potential

To ascertain the amount of deflection (the degree to which the impact load displaces the mesh structure) and deformation (any changes in the shape of the mesh as a result of the impact), the ANSI MH31.1 standard establishes parameters for testing steel mesh containment panels. The goal of the recommended testing process “is to apply a quantifiable impact load at both the geometric center and an offset quadrant of a steel wire mesh containment panel and indicate wire or weld failure, if they occur. Deflection of the mesh during impact is also quantifiable in a risk assessment.”

To achieve this objective, the testing procedure specifies the dimensions of the panel for evaluation, as well as the use of a pendulum to apply an impact force at both the center of the panel and in an offset location. Replication of the resulting amount of deflection and deformation must occur at least twice.

What the Testing Results Show

Testing results can determine one (or more) of the following in a field installation:

• If the maximum dynamic deflection from the impact load could cause the mesh panel to encroach into an aisle to such a degree that it exceeds the maximum aisle safety width.
• If actual impact conditions — such as sustained energy, materials other than steel, or impacts to areas outside the panel’s center — might produce different results.
• If the resulting maximum dynamic deflection of a containment panel could come into contact with the containment panel of an adjacent rack in a back-to-back rack installation.
• If the impact could cause the panel’s mounting hardware to become disconnected or disengaged from the rack, the panel, or both.

ANSI MH31.1 also offers guidance for considering the results of the testing in accordance with the National Fire Protection Association’s NFPA 13, Standard for the Installation of Sprinkler Systems. This standard details requirements for a horizontal gap between the back sides of back-to-back rack and shelving systems.

Looking to install steel mesh containment panels in your facility’s pallet rack?

Learn more about the ANSI MH31.1 standard and other key considerations when specifying these rack accessories, here.