why perforated metal sheet hole have more and more shape

First of all,the shape of the hole of perforated metal sheet are mainly include:rectangular hole, square hole, diamond-shaped hole, round hole, hexagonal hole, cross hole, triangular hole, five-pointed star hole,etc,so why just a few years has appeared so many shapes of the hole?

In fact,at the beginning,perforated metal sheet mainly used in railways,highways and other transport facilities to carry out noise and environmental protection,and later used in the factory to sound-absorbing.Of course,many times we can also see the perforated metal sheet on the computer host,the effect is for heat dissipation.Recently,perforated metal sheet mainly used in decorative aspects,such as decorations and home improvement.

People to enjoy the requirements,resulting in perforated metal sheet appeared many shapes of the hole to meet the demands of the market.