ADDITIVE MANUFACTURE

Exhaust system for fume and dust  suitable for additive manufacturing.

What is additive manufacturing (additively manufactured cellular metallic  structures, additive processes by powder injector or in powder bed).

Additive manufacture ranges from data processing (new design tools, data formats), simulation, materials (ceramic, metals, polymers, composites, biomaterials and multi-materials), microstructure development, new AM processes or combination of processes (e.g. additive and subtractive, hybrid, multi-steps), parameter and process optimization, new testing methods for AM parts and process monitoring.

Additive manufacturing materials can be divided into two main families:  polymers and metals.

A turnaround compared with  traditional production technology from the solid made, for example with milling or turning metalworking.

If necessary, the parts obtained can be subjected to post-production treatments, by chemical and heat treatments and  finishing processes on machine tools,too.

The main categories of processes used for metallic materials.

Powder bed fusion (PBF)
Additive manufacturing is currently the most promising technology of metals, as it allows the creation of high-performance structural parts. The process is very simple: multi-steps of metal powders are subsequently solidified by a laser beam, oriented by moving mirrors.

The micro-casting produced by a a laser powder-bed fusion additive , returns a very uniform material. For this reason the properties of these metal alloys are even superior than by mechanical technologies. Many metal alloys, from aluminum to titanium, can be processed with complex geometries, however the machines work on very small surfaces and with very high costs. Furthermore, this type of processing does not require supports, because the powder of previous steps performs this function.

Laser metal deposition / Laser cladding

Laser cladding is realized either as wire (laser hot wire cladding) or powder cladding. The laser beam creates a molten pool at the workpiece surface, to which is simultaneously added the laser coating material (wire or powder) molten by the laser. The exposure time is short, which creates only a short delay as the cooling is quick. The result is a layer that is connected with the basic material metallurgically. It is tougher than those coatings created by thermal spraying, and compared to hard chromium plating, for example, it is harmless to health, too.
This type of processing adds material to existing solids, it is  possible to carry out repairs or additions, of one or more different materials and it can be added to processes as laser cutting or milling metal working. 
The processing point is often flooded with inert gas to avoid oxidation or other reactions of the locally melted material. Thanks its peculiarities, this technology allows a rapid transition from one material to another (just switch to a different powder or wire) and a great contribution of volumetric construction when compared with other additive technologies. 
The supply of material with high properties only at strategic points allows the creation of highly performing parts for  naval, aeronautical, oil & gas sectors, saving money.

The additive technologies products have correntely a very high quality, for example  the quality of  microcasting by bed powder fusion . 
For this reason they are increasingly used not only for prototypes, such as  production structural parts. 

The processable polymers have increasingly higher characteristics of heat-resistance and from mechanical and chemical stress. Obviously, additive technologies do not yet present the possibility of producing aesthetic details without any subsequent treatment. 
The resolution obtained, however, has reached very high levels, ranging from tenths of a millimeter of FFF technology, to hundredths of stereolithography, to microns of powder bed casting, dictated by the dimensions of dust metallic grain.

These are important informations must be taken seriously into consideration whenever you are going to purchase a mist collector for your machine tool.

Depending on the type of production and working processes required, it is presumed that particular types of pollutants will arise during  metal working and consequently a suitable exhaust fan must be suggested.

 The mainly found pollutant during  ADDITIVE MANUFACTURING, beyond powders, are fumes, due to the increase in temperatures of laser processing.

The problem of fume exhalation and smells not treated.

The volatility of polluting particles such as fumes,exhalations and odors entails and creates various problems in the workshops, to operators and machine tools.

Firstly they negatively affect the health of the air and the health and hygiene conditions of the operators, in particular at the respiratory level, since the particles smaller than 0.3 microns can reach the pulmonary alveoli, compromising the respiratory tract. Not only that, in contact with the epidermis they create skin irritations, dermatitis and redness.

From production point, pollution in the workshop considerably reduces the productivity of the plant and in particular the efficiency of the machine tools, since the stratification of pollutants invalidates the precision and tolerance of the measuring instruments, with the onerous consequence of having to increase maintenance on the most delicate components.

Without forgetting any possible fines deriving from current regulations, which impose a concentration limit for oily mists in the workplace.

The best system for the abatement of fumes, exhalations and odors is an active carbon stage preceded by a very high efficiency pre-filtration H13 / 14.