Customized Expanded Metal Mesh For Decoration / Filters / Protection

Process Details

During the process of turning metal sheet into expanded metal products, manufacturers start with the expansion, then go into the shaping and forming of the sheet to custom specifications. For more detail, read on.

1. expansion

The start of the manufacturing process for regular and flattened metals is exactly the same. First, manufacturers feed metal sheets into a machine that presses and expands them. These days, this is usually all controlled by an automated process, as it offers better efficiency.

2. die pierces

After expansion, a die pierces the sheet over and over again in an even pattern. Most often, this is a diamond shape pattern. However, manufacturers can cut and form custom shapes and patterns.

3. hot rolling press

Next, manufacturers feed the sheet through a hot rolling press. The hot rolling press causes the metal to expand and become thinner and flattened. If the original metal sheet is very thick, they will have to apply extra heat and pressure to expand and cut it.

4. annealing

After this, if they so choose, manufacturers can finish the expanded metal product with annealing to promote corrosion resistance, veneers (such as those derived from paint or PVC), galvanization (to make galvanized steel), or anodization. Protective coatings that manufacturers add after the metal is formed are usually a spray or dip. Manufacturers can employ these coating methods not only to improve the properties of the metal, but also to change the colors of the surface.

Once this is done, manufacturers consider the piece to be a finished metal grid or mesh.

Machinery Used

Manufacturers use a number of different machines and tools in order to perform the metal expansion process and subsequent parts forming procedure. These include expansion presses, flattening presses, dies, and hot rolling presses.

1. Expansion presses push metal outward using a stretcher bar as they cut slits into the metal using mechanical knives. Manufacturers may use either manual expansion presses or automated CNC expansion presses, though they most often use the latter.

2. Flattening presses do just what their name suggests–they flatten and smooth metal sheet. They come into play after perforation and expansion. They cold roll metal using parallel cylinders that squeeze the metal as it passes in between the cylinders.

3. Dies are special manufacturing tools used in conjunction with presses and other forming machines. Typically made from metal, these tools are designed in the shape of a product to be produced. When material is forced through them, or in this case, when they press into material, they cut and shape it.

4. Hot rolling presses are presses featuring rollers to flatten metal. They are different than cold rollers because they work the metal above its recrystallization temperature.

Variations and Similar Processes

Similar to expanded metals are perforated metals. Manufacturers make perforated metals by punching holes into solid metal sheet (without expanding it). Expanded sheet metal is more flexible and weighs less than perforated metal sheet.