EPP

I assume they are pre-expanded? Which means that then you process them, depending on several factors, you will have a foamed part. Which may be OK depending on the application.

Cost of a used molder, depending on capacity could be anything from a few thousand $USD to many thousands. Check some of the used equipment web-sites.

Tooling is the killer. A typical steel mold to produce a single part can cost $50,000.00USD

I see lots of trial and error in your future if you try this.

Maybe "bean-bag" chairs?

Do they have insulative qualities?

Maybe they could be used as a form of blow in insulation?

Too dense. Pre-expanded beads are mostly solid. They would have to be expanded into foam, but, even then too dense.

It floats in water, if that gives you any ideas. Maybe dump it in your lake to retard evaporation?

Could they be used as an additive to soil to increase drainage?

My instinct says no. They are very light compared to dirt. Imagine a plastic BB. Nothing to grab anything. I think they would migrate to the surface.

Environmentalists might not cotton to the idea of plowing plastic into the ground, either.

Unfortunately no, they'll dissolve in the oil. However, they will float on water, so if you pack several large Ø PE pipes full of them and seal the pipes, the pipes will float even if there are minor leaks in them, because not enough water will seep inside to sink them. You can then hang large sheets of chamois leather, which will allow water but not oil to pass through them on the pipes and deploy them in the Gulf region as a short of makeshift oil screen. In this way, you can allow the seawater to pass through the screen while trapping the oil so that it would be easier to skim it up. Just remember to hang weights on the ends of the chamois leather so that they'll hang suspended in the water instead of floating on the surface.

When I worked with the forest service they had their own nursery to grow pine and spruce trees. These type of beads were mixed into the planting medium. Perhaps check with a plant nursery or tree farm.

Sounds like the ideal material for making a geodesic dome: Umm if you need one.

But then of course you'd need to make the tooling which as Lyn pointed out will cost too much.

Most things have a calorific value....

What we have done with them is disolve them in solvent and use as a roof sealant. Most of the roofs here are tin, but it seals well.

DCGYS,

What solvent is used to dissolve polypropylene?

Hexane, but you don't want to go there.

OK your probably right, but tell me about it.

Polyolefins (PE/PP)are essentially ultrahigh molecular weight waxes. Their chemical resistance is well known. If crosslinked, they are virtually insoluable in common solvents. They are difficult to dissolve in any form and I don't know why one would want to.

eps also dissolves in acetone

Remember, EPS and EPP are totally different materials and have vastly different properties, including solvent resistance.

We have muddled the issue, but you can always make ice chests and coffee cups from pre-expanded styrene.

Bruce,

Are you sure these are expanded polypropelene EPP? (Maybe Polystyrene?).

Usually, EPS is used to make insulation panels by pressing them and gluing them in a mould. I think that EPP could be used as a thermal insulator the same way. PP is also a good electrical insulator.

Why were they ordered or why you received them? Was there a purpose for them ...?

This is EPP, I am also getting EPS from the same source. It is a recycling center that has the stuff and can't afford to ship it because of the bulk and distance to a user.

I am trying to figure out a way to use the stuff but am not a plastics person and need ideas. It seems that all production systems are made for high output and I need to find something that will allow me to produce products on a small scale.

bean bag style furniture

I have docks at my cottage that are made with expanded polystyrene foam in a roto moulded polyethylene shell. If the shell gets puncutured, it doen't effect the flotation. Check out Shoremaster

Could they be melted down and formed into blocks or sheets to reduce shipping size?

Don't know the market for this product, but maybe....

No, injection molders and extruders that use these materials both require pellets about the size of BB's.

In their present form they are introduced into a cavity and heated with steam which causes them to expand and fill the mold with a foam, usually with a skin on the outside. The term "pre-expanded" is somewhat misleading.

My EPP IS pre-expanded bb's.

There are too many variations of material properties to consider.

Do you have a data sheet? Or at least a MSDS?

EPS sheets and boards are used extensively in the advertising and architectural industries. They're used for making models and mock-ups.

Could they be used in a "cartridge" form as a filter? Not fine particle but large chunks?

I'm not sure of the size of these, but PP is used extensively in the filtration industry.

So, I guess you could use them in a filter/as a filter.

EPP typically usually comes from the manufacturer already expanded. The beads are molded into parts with a density range of 1 to 10 pounds per cubic foot. EPP has good properties for energy management and its resiliency makes it ideal for repeated impacts. It is used largely for automotive applications such as headliner and side door impact parts, bumper fascia liners and some seating. Many cars use molded EPP as a carrier for jack parts. It is also used for dunnage and as a liner for racing helmets.

The beads are steamchest molded and setting up a molding operation is not something done in your garage, unless you have a large garage and checkbook to match. If you have a supply of beads you can use them for soil amendment, bead bag furniture or in a flotation application. They will not succumb to oil in the water like most flotation foam, being largely impervious to most solvents. One of the most unique applications I have heard of is as a mosquito barrier in third world water supplies.

Where are you located and do you have a steady supply?