Process Equipment

Powder is messy but is an essential state for mixing and applying materials. Sometimes powder is mixed with a fluid so that is can be poured like a viscous liquid, but a lot of applications require powder to stay dry for the whole operation. It is actually easier to move powder than fluid in many cases, and process equipment has been designed just to work with dry powder. 

Extra information about process equipment 

The most basic piece of equipment is a grinder that reduces raw material to a fine powder. This step is called milling and takes several steps to first break down and then separate the finest grains from the thicker bits that must be removed or reprocessed. Most of this is done automatically in a factory, as handling powder by hand is time-consuming. The raw material is easier to handle before it is shredded and sifted.

In fact, powder is so difficult and messy to work with that the rest of the process is enclosed in tubes. By definition, a powder is able to suspend in the air because it is so fine. This creates a breathing and handling problem, so it is more efficient just to keep powder inside a system without ever exposing it to the outside air.

This is perfectly fine because factory process equipment is available that can safely move powder like it is a fluid. Forced air moves powder through long pipes, and spiral conveyors can move large amounts of powder at a slower pace. It can actually be easier to handle dry transit systems because there is no fluid to create adherence. A powder can actually be moved more easily than a liquid, so any liquid phase is more likely to happen near the end of the system.

Process equipment does always have to be designed for the material. If the powder is of a heavy material such as sand or metal, then the equipment must be designed to withstand any sandblast effect from using forced air to move fine particles like a fluid. This is seldom a problem for organic particles, but heavier materials pack a kinetic punch even as fine dust. If this issue can be anticipated, then consider using a slower conveyor system.

What happens at the end of a cycle depends on the material and the application. Powder is easier to move than its molten form, but melting might be the end application. Decide if buying powder is the right solution over melting solid blocks. Some plastics are sold as a powder so that different polymers and pigments can be easily mixed. As a general rule, powder is more expensive, and avoiding having a local mill can save a lot of money.

Powder is chosen when it is applied raw to the end product. This might be dry paint that is then cured to form a durable surface. It might also be a sugar for dusting confections. Yet another powder is fine sand that might be applied to sheets to create sandpaper. For a niche application, it often takes an engineer to create the most efficient solution. Factories are precise by definition, so invest as much as possible into finding the best solutions from the startup.