A few questions about dust collectors for metal and plastic dust

I'm researching dust collectors for my shop. I work with a variety of materials, but mostly plastics, phenolic and steel.


I do some surface grinding of steels, but not a lot.
My biggest source of dust and debris is from plastics. I do many different operations with plastics which include cutting on a table saw, machining, welding, and even some grinding / deburring with a flex shaft grinder (done inside of a bead blasting cabinet).

I'm looking for a dust collector that can filter out very small particles. The cheap import type bag dust collectors are out of the question, unless someone makes a reasonable quality canister filter unit.
I'm looking more at two stage cyclones or the Torit type units.

Is it possible to use the same collector for the plastic and metal dust, or will I need separate units?
Is a two stage cyclone better, or the "baghouse" type Torit units that are very common?
Is there something else that I should be looking at?

Any input would be greatly appreciated!


btm

If your surface grinding produces sparks, you very much want a stand alone unit for that. Any spark getting into the plastic bin and igniting will burn very fast, hot, and very toxic with a forced air supply.
Most sparks may go out long before getting to the bin, but the OOPS! FAAK! spark may not. Same goes for any all plastic bins. Spark from tool crash could be a problem.

Grizzly, Powermatic, and others make bag collectors with big cartridge filters on top.
Cyclones excel at cleaning the air and very little gets to the after filter. Unless you forget to empty the main barrel. Main barrel gets full and ALL goes into the after filter.
A pic of chips and type of plastic(s) will help. Type of table saw would help too. Some do not have an extractor setup at the blade, just a cabinet port.
Jet and Powermatic also make air cleaners that you can hang from the ceiling if you want. Turn on with a wireless unit. I have 2 of them mounted inside one of my mills for mist extraction. Makes the difference between coughing up a whole alternate universe the next day, or not.

Scruffy887 said:

If your surface grinding produces sparks, you very much want a stand alone unit for that. Any spark getting into the plastic bin and igniting will burn very fast, hot, and very toxic with a forced air supply.
Most sparks may go out long before getting to the bin, but the OOPS! FAAK! spark may not. Same goes for any all plastic bins. Spark from tool crash could be a problem.

Click to expand...

For grinding or anything that may generate hot chips, including aggressive milling, a water trap is likely the best way. This can be as simple as a 5-gallon pail with water at the bottom and a metal standpipe through the lid and metal-lined flex hose. A flange type port from any of the woodworking suppliers can be bolted to the other side of the lid for connection to the dust collector or vacuum. The ports are available in 2-1/2" and 4", and mount with four screws.

I use a similar setup in my home shop to collect oily chips. I use the apparently now discontinued Bucket Max unit instead of the lid and keep about 2 inches of water mixed with non-foaming dishwasher detergent in the bottom of the bucket. The standpipe almost touches the water.

I use the Gore-Tex Cleanstream filters in all my dry vacs and maybe you could glue a stack together to replace the bag where you are worried about dust coming through. I discovered how poor a job stock filters do while vacuuming up some fine silt residue that washed onto my driveway from a nearby construction site. It left a light colored haze on the black Shop-Vac and when I switched to the Cleanstream filter it no longer happened.

Your best bet would be to simply call these people.

Oneida Air Systems - The Industry Leader in Dust Collection

Steve

Actually there are 2 or 3 other vendors worth calling - Dust Collectors | Fume Extractors | Downdraft Tables | Micro Air being one I've used.

many plastic strings and dust is very difficult to handle due to static electricity. This can make it hard to duct and even to empty out of the collection bin.
Bill D

Full disclosure, I work for oneida air systems. Check out our cyclones. We make small ones for wet and dry vacs. All the way up to 20 hp systems. Plastic dusts separate just fine..ideally you use a static conductive model.

Thank you for the input.

Most of the plastic dust is smaller chips and fine dust. However, several times a year I produce some parts from 2-1/2" thick UHMW Polyethylene. I rough cut the material on the table saw. I've tried using a typical bag type dust collector with this material, but it produces long stringy chips that get caught up in the impeller.

Looking at the cyclone type collectors, it appears that on most models the material does not initially pass directly through the impeller. So this design may work better for my plastic dust.

The Oneida systems look great. They're a little more money than I wanted to spend, but if they can handle the long stringy UHMW, it may be worth it.

Currently, I cant run any dust collector with the UHMW, so I spend a great deal of time on cleanup.




btm

Long stringy whatever are always a challenge because the cross over to the outlet. However it will still be effective. Thecfinw dust and chips are not a problem.
This goes back to to outlet sizes and your budget.
If you already have a single stage collector you may add a super dust deputy which will separate out 99 %of the material before it reaches the impeller and filter.

I'm going to beg ignorance to what some high end dust collection systems or technologies can do.

I read a paper some years back about dust collection that talked about how many of them do more harm the good. Especially if you're trying to get rid of the finer particles that will actually hurt you and your lungs. Your basic fan box with a few filters installed comes to mind. I own one. No longer use it for its intended purpose. What was said is these fan filter units can't actually trap the finer particles and mostly work to keep them suspended in air far longer then they would be if you were to just let them settle out. Meaning they work counter to their intended purpose. Granted they work fine for some of the large stuff, but the large stuff is not as dangerous.

The details and finer specifics of the article eludes me, but I remember it all made perfect sense. I offer it here to the pieces of advise pile.

If you want the best at collecting fine dust from air, look at Aerospace America air scrubbers, these are what the asbestos abatement companies use. I have no affiliation to this company, I'm just a happy customer, iirc they filter to .3 microns.
Aerospace America - Air Filtration - Bay City, MI - Mike Alley

It's always more effective to capture dust at its source. Once it is floating around you are fighting a loosing battle