EPS foam block – How is it manufactured & Molded
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Posted On :
Mar-09-2010
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Article Word Count :
529
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EPS foam, what we call "white foam" starts out in a sand-like texture, similar to sand, called polystyrene. The raw material is called Styrene, made of small beads. Then the beads are blown in an expander to a larger size. This process is done using 2 main blowing agents. Lastly, the material is molded either in a block machine or a shape machine into EPS Foam.
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EPS foam starts at very small beads similar to sand in texture, called polystyrene. The raw material is called Styrene. Styrene can be found nearly everywhere, in your local food store and the local electronics stores.
The plastic utensils are all made of Styrene, such as CD cases and cloth hangers.
EPS, which means Expanded Polystyrene, starts as the small beads.
The next step in the process is to "blow" these small beads into larger beads about 50 times its original
size. Depending on the density required, the beads are blown using steam in a machine called "expander"
The expander can be a simple machine that a worker places the raw material, and then turns on the steam, or an automatic machine where the material is weighed automatically Steam, then is enables (automatically) and then stopped.
At this stage, the beads are up to 50 times their original size.
Continuous pre- expanders are operated without pressure and are equipped with an open- top agitator tank in which raw material is continuously fed from the bottom by an adjustable screw conveyor.. Steam is "also fed continuously into the pre- expanding room through openings that are positioned shortly above the tank bottom. An agitator and fixed breaker rods make it more difficult for bead clusters to develop; they keep the beads in motion and make sure that al ready pre-expanded beads of lower density move to the top of the bead bulk and fall into a shaft through a height- adjustable discharge opening.
Pre- expanders for the so- called "second pass expansion" of already expanded materials are equipped with an especially large feed screw in order to transport the already expanded material to be steamed again. All pre- expanders have in common that the completely expanded beads trickle into a so- called fluid bed dryer where they are dried and stabilized before they are transported into the storage silos.
The two most common blowing agents used are pentane and carbon dioxide. Neither of them contains CFCs. This process, which is called polymerization, fills the polystyrene with millions of air pockets. These help it to expand and also give it a low thermal conductivity. During expansion, the product can be molded into a variety of shapes and sizes.
The final product is 90% air, but amazingly, EPS can have a compressed strength up to 40 psi.
The last step in the process is the mold machine. Mold machine are divided into two main categories
Block molds and shape mold machines.
Block mold machines create a block of foam - from 3' x 2' x 8' up to 5' x 5' x 24'
Block Mold can be done manually or automatically. If manually, once the molding process is done
The workers need to open the doors of the mold in order to remove the block from the mold.
On the machine above, this process is done manually. Molding can also be done with an automatic EPS block mold machine
Shape mold machines create different shapes - bicycle helmets, surfboards, RC planes, packing foam
food packing and any shape imaginable that is not a block.
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Article Source :
http://www.articleseen.com/Article_EPS foam block – How is it manufactured & Molded_12911.aspx
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Author Resource :
Tal is an electrical and software engineer with over 20 years of expertise with hardware, software, mechanical and motion control. Owner of Foamlinx, designing, manufacturing and distributing cnc hot wire foam cutters www.foamlinx.com and providing foam cutting services www.wecutfoam.com
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Keywords :
Eps, foam, foam block, beads, polystyrene, styrene, expander, blowing agent, mold, molding, machining, foam cutter, hot wire,
Category :
Business
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Small Business
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