How a Powder Production Line Works
Metal powders are the building blocks of a wide range of products. They require special handling to achieve their desired properties.
The first step is to mix and blend the powders with binders and lubricants. This is done with specialized equipment that can vary depending on the type of product.
Raw Material Storage
Raw materials are the building blocks of a business’s finished goods inventory. They’re procured from suppliers and transformed by manufacturing technology into work-in-progress inventory (or WIP) before being sent to customers. In the meantime, a company must Powder Production Line manage and store its raw materials inventory in storage facilities.
The right storage system is a key component in the efficient operation of any plant. It should provide a safe and secure location for storage bins, barrels or piles of raw materials, as well as a conveyor system that can quickly and accurately move them to and from production areas. In addition, the warehouse should have processes in place to help control and minimize allergen cross-contact.
Many of the challenges in designing a storage and conveyance system are related to material flow properties, which are often difficult to determine from a data sheet. Therefore, a prudent engineering team will consult with operations, quality assurance and maintenance personnel during the design process to gain unique insights into their issues, constraints and past experience. This knowledge is critical in developing a proper basis of design.
The first step in a powder production line is to grind raw materials down into fine powders using crushing technology. This is necessary because the granular metals and alloys used in PM must be able to withstand extreme heat, friction and pressure, often at high temperatures.
A variety of crushing techniques are available, including mechanical grinding, sand blasting and laser cladding. Depending on the application, the resulting powder may be dry or wet and can be combined with binders and lubricants.
Once the material has been crushed into a fine powder, a rotary screen is used to separate out unqualified products for further pulverizing. This produces powders with a finer grain size and lower moisture content.
Once the powders are mixed and consolidated, they can be compacted under great pressure to create dense, metallic parts with precisely defined dimensional tolerances. This process is used to manufacture a wide range of special products, including iron powder compacts coated with very thin oxide layers for improved refraction and the linings of friction brakes; cams and gears that can be made in almost any form; and valves and manifolds that must withstand harsh oil and gas exploration environments.
Powder mixing is a key step in filling machinery the process of creating a consolidated metal part. There are many different types of mixing technologies, from simple convective mixing to plasma-based atomization and more. The type of mixing technology used depends on the characteristics of the material being mixed, the desired particle size distribution and the final use of the resulting part.
For example, very fine and agglomerated materials such as titanium dioxide pigments cannot be mixed in liquid with traditional mixers. This is because the particles are too small to be suspended in the turbulent eddies of a liquid, and the differences in their shape and density create drag forces that can cause segregation.
In-line powder blending systems that combine a continuous conveyor belt and tableting are becoming increasingly popular for the production of metal parts, as they can reduce manufacturing times and improve yields. These systems can be equipped with an NIR probe to monitor the powder blend’s content uniformity in real time. A sample thief can also be used to extract a sample of the powder blend, but care must be taken as the thief could disturb the blend in-situ or the particles may flow preferentially towards the thief cavity.
Sintering & Compaction
The metal powder mix is then compressed into a shape by intense pressure, which reduces potential voids and increases the product’s overall density. This is a necessary step for some metals, like carbon, tungsten and tanatalum, which have very high melting points and can be dangerous to work with in their unconsolidated form. It also allows for efficient stacking of the ware in the furnace, reducing damage to surfaces & maximizing the amount of material processed per batch.
The green compacts formed in the compaction process are then sintered. This converts the mechanical bonds into metallurgical ones, which provides the particle-based metal part with its primary functional properties. The sintering process is done in an atmosphere controlled environment, and the parts are then cooled.
A special form of this method is called injection molding. This uses a different kind of powder, with a binder that makes it moldable. This is the technique used for making engine blocks, light bulb filaments & many other complex products. The parts made in this manner can be repressed, impregnated, machined, tumbled or plated to give them additional functionality, and they are generally ready for use after sintering.
Milk powder processing line consists of raw milk acceptance system, milk homogenization tank, milk sterilization, milk skimming (to produce sugared full fat milk powder), vacuum concentration and spray drying. It can produce full-fat sugared milk, skimmed milk, flavored milk powder etc according to the customer’s demand.
Powder metal technology allows for a higher degree of customization, better surface finish and more repetitive accuracy than traditional casting or wrought processes. Its benefits include lower production costs and more versatility, especially with high-volume orders. Examples of special products made using powder metallurgy are Al2O3 whiskers coated with thin oxide layers for improved refraction; iron compacts that resist high-temperature creep; and metal glasses used in spacecraft reentry heat shields.
The ingredients are put into one of two machines in the Powder Production Line, a tumble blender or a ribbon blender. The machine turns and shakes the tumbling blender to mix the components, and the ribbon blender uses blades to scrape and combine them. The mixed milk powder is then packaged into bags and shipped. The bags can be sealed with different methods: back seal, three sides seal, four side seal.