Raised vs Flattened Expanded Metal: Which Type Is Right for Walkways, Guards and Facades?
Choosing Between Raised and Flattened Expanded Metal for Industrial Applications
Choosing the right material for an industrial application can be difficult at times. In deciding between the two types of materials, raised vs flattened expanded metal, there is usually a requirement to evaluate strength, safety, feel, and aesthetics. Both materials are made through the same process, but the end product is totally different.
When it comes to designing industrial pathways or safety barriers, choosing the right material is key for both safety and cost efficiency.
What Is Expanded Metal?
Expanded metal is a very flexible sheet material made by both cutting and stretching metal at the same time. This process starts with either a sheet of solid metal or metal coils. The metal then goes through an expansion machine.
Since there is no material wastage during expansion while making cuts, the product is highly economical compared to traditional Perforated Sheets. The Expanded Metal sheets form one-piece sheets without any joints and hence have a high strength-to-weight ratio.
What Is Raised Expanded Metal?
When a sheet leaves the expansion press, it is in its normal form. The normal form is referred to as the raised expanded metal. At this stage, the strands and bonds are oriented at a constant angle relative to the original plane of the sheet.
Key features of raised expanded metal mesh include:
- High Traction: Angled edges of the strands ensure high traction and very good slip resistance, which is especially useful in a wet or oily environment.
- Maximum Rigidity: The three-dimensional structure provides maximum rigidity without extra weight.
- Open Area Efficiency: Angled openings enable 60-70% open area, ensuring free passage of light, air, and water.
Because of these features, raised expanded metal is the preferred material for heavy-duty industrial applications, as well as outdoor catwalks, stairs, and grates.
What Is Flattened Expanded Metal?
To manufacture flattened expanded metal, another stage of the manufacturing process is needed for the raised sheet. The raised sheet undergoes cold rolling in the cold rolling mill.
The huge roller compacts the sheet by bringing the strands and bonds into one flat surface again.
Key features of flattened expanded metal mesh include:
- Smooth Surface: It removes any bumps from the material, providing a smooth surface that is safe to touch.
- Reduced Thickness: This process reduces the total thickness of the sheet to around 40%-50%, increasing its length.
- Easy Handling: It gives a smooth finish that does not snag any fabric or skin.
Therefore, flattened expanded metal is very suitable for interior partitions, retail displays, vent covers, and close-proximity enclosures.
Mesh Opening Size and Safety Guard Selection
While designing a machine guard or safety enclosure, choosing the right mesh opening is essential for worker safety. Safety standards for occupational safety provide safe distances according to the size of the mesh openings:
- Small Mesh Openings (under 1/2 inch): Keep fingers away from dangerous spots close to gears, belts, and rotating blades.
- Medium Mesh Openings (1 to 1.5 inches): Prevent hands or tools from accidentally touching dangerous machinery while still allowing airflow.
Flattened expanded metal meshes should be used for close-contact safety barriers, as the workers would not get hurt if they run into the barrier.
Raised vs Flattened Facade Mesh: Visual Comparison
The visual effect of raised or flattened expanded metal in architectural facades is highly dependent on lighting, angle of view, and depth.
Understanding SWD, LWD, SWO and LWO
For a precise description of expanded metal, engineers use 5 fundamental dimensions:
- SWD (Short Way of Diamond): The measurement taken between the centers of two consecutive bonds on the short axis of the diamond.
- LWD (Long Way of Diamond): The measurement taken center-to-center on the long axis of the diamond.
- SWO (Short Way of Opening): The actual open clearance width within the diamond formation.
- LWO (Long Way of Opening): The actual open clearance length within the diamond formation.
- Strand and Knuckle: The strand is the single metal strip that forms the diamond shape, while the knuckle or bond is the intersection of two strands.
How Surface Finishes Affect Expanded Metal Performance
Raw steel sheets can rust when exposed to water or other strong chemicals used in an industrial setting. Choosing the right material grade and finish guarantees longevity:
- Stainless Steel (SS304): Has high corrosion resistance and is suitable for chemical process applications, food applications, and coastal areas.
- Hot Dip Galvanizing: This process provides a protective coating of zinc to prevent rusting of carbon steel for more than 25 years when used outside.
- Powder Coating: Provides color customization options along with a protective coating.
How to Choose Between Raised and Flattened Expanded Metal
Here is an easy-to-use decision matrix for choosing between raised and flattened expanded metal mesh:
- Prioritize Safety: Choose raised metal mesh for walkways and areas with heavy foot traffic, since the angle of its strands offers superior safety in the presence of rain, oil, or snow.
- Choose Smooth Surfaces: Use flattened expanded metal mesh for railings, cabinets, and partitions that will be touched repeatedly by hand.
- Consider Facades: Use raised mesh to create dynamic shadows and ever-changing light. Use flattened mesh to maintain a consistent appearance.
- Check Thickness: Cold rolling may lower sheet thickness, so make sure that the flattened sheet will fit in your frame.
- Analyze the Load: Raised mesh normally provides more strength when handling large point loads.
Final Verdict: Raised or Flattened Expanded Metal?
The decision on whether to use raised or flattened expanded metal will depend mostly on the application. Raised expanded metal is ideal for applications such as walkways, steps, and platforms. Flattened mesh is usually preferred for facades, partitions, and where an even surface is required.
The choice between raised and flat expanded metal also depends on opening dimensions, loading considerations, materials, finishes, maintenance, and installation. Alongside expanded metal, buyers can also consider products like woven wire mesh, vibrating screen mesh, welded wire mesh, and perforated sheets.
The production process can involve slitting, stretching, and cold rolling for certain products to ensure that the right shape is attained. Other features influence the structure, including the knuckle, strand, and bond.
For effective industrial wire mesh and metal solutions, Banaraswala can assist clients in choosing appropriate products for industrial, architectural, and commercial uses. As an experienced supplier and manufacturer, the company can provide solutions based on material type, mesh, size, finishes, and usage.
