Model Muse

Dec

by admin

Model Muse

Whats the difference between a Bern Muse Hardhat, or an EPS helment?

I was looking at the Bern Muse model. You can get it with 'Brock foam' or as an 'EPS helmet'. What are the differences? Do they look any different? PLEASE HELP

No difference in appearance, just quality..

Brock Foam, Brock USA has a proprietary multi-impact foam formulation using expanded polypropylene or polyethylene beads held together by an elastic adhesive that produces a closed-cell foam that is still porous. Brock Foam is made by fusing the round foam beads together just touching at their tangent points. The result is a resilient foam that allows moisture and air to pass through it. Depending on the size, roughness and pre-compression of the beads, they will compress under the force of a blow in various ways. Brock Foam can be made in cross-linked polyethylene for durability and softness, or in polypropylene for strength. The foam is used for many different products besides helmets, and until late 2005 we had not actually seen a helmet made with it, although we knew that some manufacturers have experimented with it. For the 2006 model year, Bern Unlimited introduced several new helmets made with Brock foam. They have the hard shells characteristic of Brock foam helmets. Some of them meet the US CPSC bike helmet standard. There are many more interesting details in the patent, including a lot of information on how the beads behave in an impact. Brock Foam is manufactured in Shenzen, China and Butler, Pennsylvania.

EPS, Expanded PolyStyrene is one of the most widespread foams used in our society. It is the white picnic cooler foam that you see eggs and stereo gear packed in. It is the peanuts in your mail order package. It is the white food carton or drink cup you get at a carry-out. It is cheap to manufacture, light, and has almost ideal crush characteristics with no bounce-back to make the impact more severe. It can be reliably manufactured with reasonable quality control procedures. EPS is formed by placing polystyrene beads (granules) about the size of table salt in a pressure mold shaped like the helmet liner and expanding the bead from 2 to 50 times with a blowing agent like pentane under pressure and heat. The beads expand to form the cells and fill the mold. The cells are tightly bonded--under ideal conditions. Under poor conditions the steam/pentane temperature is not just right or the pressure is off a little and the foaming may not be uniform, or there may be hidden recesses where the granules did not expand correctly. (A helmet liner with such a recess "rattles" with unexpanded beads inside when shaken.) The foaming is often done by a "foam shop" outside the manufacturer's plant, and the challenge for helmet quality control programs is to design testing that will catch any problem liners. Foam density is measured by weighing the liner, then placing it in water and weighing the amount of water displaced, and comparing the two weights.

Hope this helps!
Happy shredding!