How many microns is mdf dust

It can therefore be suggested that the existence of the resin in MDF not only influences the physiochemical properties of MDF sanding dust, but also extends the lowest limit of particle size.

A small quantity 1. Mass-weighted size distribution of MDF sanding dust determined by flatbed scanning image analysis histogram: differential size distribution, line: cumulative size distribution. The shape analysis showed that the MDF sanding dust samples had a pretty low aspect ratio as a whole, and the mean AR value was 0. This coincided with the visual observation of SEM pictures Fig.

But elongated or fibrous particles also existed. Larger particles presented a wider AR distribution. But for smaller particles, a much less AR variation was found Fig. This seems to be a general trend for bio-based particles and has been repeatedly reported [ 23 , 34 , 35 ].

Figure 7 illustrates how particle shape varies with size reduction. The big particles shown in Fig. It can also be found that big particles inherit the anisotropic nature of wood. The length of the particles is parallel to the longitudinal direction of wood fibers, which makes the particle orientation an important factor influencing its handling properties.

On the contrary, when the particle size is similar to the fiber cell wall thickness, almost no anatomical characteristics of wood can be found, indicating a homogeneous handling behavior totally different from that of big particles. Contrary to AR, solidity analysis revealed a very narrow distribution with a RS value of only 0. The mean and 50th percentile solidity values were 0.

The high solidity means less concave positions on MDF sanding dust surfaces, which can thereby be characterized as flat or smooth surface.

The AR and solidity values demonstrated that full breakage and surface erosion of wood fibers occurred during the sanding of the MDF panels. The wood fibers were subject to the interactions with the sanding belt grits, the panel surface and other particles, which broke the fibers and eroded small irregularities on particle surfaces, resulting in smaller, shorter and smoother particles discovered in this study.

Several factors contribute to the statistical difference between IA and SA. For the fibrous particles, it is possible to fall through millimeter-wide apertures after sufficient vibration. Besides shape characteristics, factors like the impact forces between the particles during sieve vibration and the cohesion of small particles all contribute to the retaining of particles on the sieves.

Compared to SA, IA obviously provided a better insight into the morphological characteristics of MDF sanding dust by providing detailed information down to the sub-micrometer level. SA did not present enough information on the fine particles due to the limit of mesh size, which makes it more suitable for the analysis of coarse particles from sawing or milling processes.

The morphology of MDF sanding dust was investigated by sieve analysis, scanning electron microscopy and flatbed scanning image analysis. Moreover, other chemical components were found in the dust samples, which influences not only the size distribution, but also physiochemical properties of MDF sanding dust. The relative span of particle size was wide. Bigger particles showed a wider distribution of aspect ratio, while smaller ones exhibited homogeneous appearance.

Only the surface texture was uniform and could be characterized as smooth surface. Taken together, MDF sanding dust might pose a considerable occupational health risk and imply quite complex handling behaviors as well.

For the MDF industry, care should be taken when the sanding dust is handled. Frequent inspections are suggested to be made where the particles are easy to accumulate and filtering materials with higher efficiency are recommended to separate them from the air. The sieve analysis presented particle size distribution comparable to the image analysis, but it failed to provide detailed information on fine fractions of the sample. It is suggested to be applied for homogeneous or coarse particles ready to settle down in the air.

The image analysis demonstrated itself a robust particle morphology analysis technology by offering detailed results of both size and shape distribution and their correlations. It deserves further exploration for the better application in the field of bio-particle analysis.

Most data analyzed during this study are included in this published article. The supplementary information is available from the corresponding author on reasonable request.

FAO, Geneva. ISBN Google Scholar. Int J LCA — Zhang B Operating principles of wide belt sanding machine for wood-based panel industry continued. China Wood Panels —31 In Chinese. International Agency for Research on Cancer IARC monographs on the evaluation of carcinogenic risks to humans volume 62, wood dust and formaldehyde.

World health organization, Geneva. Mazumder MK Aerodynamic properties and respiratory deposition characteristics of formaldehyde impregnated medium-density fiberboard particles. Part Sci Technol — J Occup Environ Hyg — Article Google Scholar. Int J Environ Health Re — Ann Occup Hyg — Powder Technol — Eckhoff RK Understanding dust explosions.

The role of powder science and technology. J Loss Prev Process Ind — Particuology — Appl Math Model — Biosyst Eng — J Food Eng — Fuel Process Technol — EN standard Solid biofuels—determination of particle size distribution—part 1: oscillating screen method using sieve apertures of 1 mm and above.

EN standard Solid biofuels. Determination of particle size distribution. Vibrating screen method using sieve apertures of 3. Effects of particle shape and size for poplar and corn stover. Fuel — Chaloupkova V, Ivanova T, Havrland B Sieve analysis of biomass: accurate method for determination of particle size distribution.

Comput Electron Agr — Benthien JT, Heldner S, Ohlmeyer M Size distribution of wood particles for extruded particleboard production determined by sieve analysis and image analysis-based particle size measurement. The cell counts and cytokine levels of the nasal lavage fluid samples did not show statistically significant differences between the workers exposed to MDF board dust and those exposed to other wood dusts.

Nevertheless, two MDF-exposed workers had a considerable increase in the proportion of eosinophils and cytokine levels. Several workers exposed to MDF and wood dusts experienced nasal, eye, and skin symptoms at the end of a work shift. This allows the air flow to change direction in two small steps rather than one large one. For smaller shops, an easy way to reduce lots of bends near the collector is to build a platform that raises the unit as high off the floor as the ceiling will allow.

Choosing the right collector requires quite a bit of thought. For larger shops, the best answer is perhaps to employ a consultant or a knowledgeable salesperson from a reputable company. For small- and medium-sized shops, the process can be broken into two stages — design the system and then go shopping.

Knowing exactly what is needed is essential, before looking at shiny new toys. Oneida Air Systems offers a very handy flowchart, walking a shop owner through the various choices, at www. One should also take a look at aftermarket filter bags. On a lot of smaller dust collectors, efficiency can be greatly improved by swapping out the factory filter for a custom bag that either increases the air volume or air flow.

The actual fabric material plays a big role, too. American Fabric Filter www. It also customizes products with inlets, outlets, flanges, support hardware, windows and other options, such as maybe adding a few loops so you can hang the bag from a ceiling hook. Machinery is always evolving and sometimes two technologies combine to create a new and better one. Manufacturers have understood for a long time that a cyclone system can separate fine and gross particles, allowing filter bags to do a better job.

And filter manufacturers have been steadily working on the problem of catching smaller particles while still allowing air to flow freely. Recently, Grizzly introduced a new line of dual-filtration, HEPA filter, cyclone-style dust collectors. What HEPA does for a filtering system is that it catches those very small particles that escape our natural defenses and cause harm over time.

The Grizzly models have a primary filter efficiency of That is, they can catch particles that are less than a micron in size and do so more than 99 percent of the time. A new approach to dust control is being pioneered by Servair. That means heating and cooling costs are no longer major issues. Previously, booths that evacuated dust outside also eliminated pre-cooled or warmed shop air, and running a furnace or AC unit to compensate for that was expensive. The new booths are quiet less than 80dB , the filters self-clean, and each unit comes with filter monitoring gauges.

Sanding booths can be even more effective if the task is being done on a downdraft table. Marrying these two technologies can potentially remove all volatile particles from the sanding process. Companies such as Sandman Products www. When a downdraft table is in place, much less dust makes it to the booth filters, so they can go a lot longer between cleanings. The idea of collecting dust at the source the point where it is generated has been raised to a fine art by engineers at Festool www.

The more dust control that happens at the tool, the less needs to be handled by a large central vac system. The filters clean themselves and these little machines even have two-stage collection, which helps them last a long time. They can also be fitted with a HEPA exhaust filter that captures Then, every time a board is moved or an employee walks by, those particles are again propelled into the breathable air in the shop.

The only way to tackle this problem is to scrub the air. Among the most robust is the CI from General International www. It also comes with a remote control, so employees can turn on this ceiling-mounted unit when it is hung higher than their heads maximum distance is 49 feet.

Several manufacturers also tackle the ago-old problem of woodworkers forgetting to close blast gates.