That's all styrofoam — or so you thought. We hate to break it to you, but a lot of the things that people think are made of styrofoam are actually made of polystyrene. Styrofoam is a trademarked brand of closed-cell extruded polystyrene foam, or XPS.
Three major types of polystyrene include polystyrene foam, regular polystyrene plastic, and polystyrene film. Amongst the different types of foam are expanded polystyrene (EPS) and extruded polystyrene (XPS). EPS includes the most well-known and common types of polystyrene to include styrofoam and packing peanuts.
There are two primary types of PS foam, which include expanded polystyrene and extruded polystyrene, abbreviated as EPS and XPS respectively. EPS is more commonly used in everyday applications, such as in Styrofoam cups and in packing peanuts used in shipping.
The key difference between polystyrene and Styrofoam is that the polystyrene is a form of synthetic aromatic hydrocarbon polymer whereas the styrofoam is a commercial brand of polystyrene.
The major difference between Styrofoam and EPS foam blocks is that Styrofoam is made from extruded polystyrene (XPS) while EPS foam blocks are made of expanded polystyrene.
Duramate™ Plus is a Styrofoam™ Brand extruded polystyrene (XPS) foam insulation, designed for residential home construction. It is DuPont's strongest XPS foam insulated sheathing, with proprietary extra-tough plastic on both sides.
Both are manufactured using the same process and contain similar chemical components. The two products also have the same insulating power. However, blue foam boards are manufactured by Dow Chemical Co. whereas the pink foam boards are manufactured by Owens Corning company.
As we said, Styrofoam™ is a Dow trade, blue in color, and is an extruded polystyrene (XPS) foam made for thermal insulation, construction and craft applications. EPS is an expanded polystyrene available in various densities for insulation, construction and craft applications and so much more.
It is not safe to microwave this most-common type of Styrofoam. During normal use, the material remains stable. But at high temperatures, it begins to melt or break down. Even if there's no visible damage on the foam, a microwave oven may cause the toxic chemical styrene (among other chemicals) to leach into your food.
XPS is manufactured in a continuous extrusion process that produces a closed cell form of foam insulation. EPS, on the other hand, is manufactured by expanding spherical beads in a mold and then using heat and pressure to fuse the beads together. Each product has proponents claiming one out performs the other.
Polystyrene is identified by the #6 resin identification code. Resin identificiation codes are used to identify plastics for recycling purposes.
Styrofoam is a trademarked brand of closed-cell extruded polystyrene foam, or XPS. This foam is also referred to as “Blue Board” and is used for building insulation, thermal insulation and water barriers.
Closed-cell EVA foam.
Popular for cosplay creations, EVA foam is our top-recommended crafting foam. EVA foam is thin and lightweight, making it easy for children to use. We recommend using this type of foam to create costumes, shapes, letters of the alphabet, cards and stickers.
Styrofoam is made from expanded polystyrene, and it does not withstand heat well. It will start to soften at 212 °F, and it will melt at 464 °F. You can use styrofoam containers to preserve food in the fridge, but you can never reheat it or cook it in the oven.
The word Styrofoam™ is often used to describe expanded polystyrene (EPS) foam; however, 'Styrofoam' is actually a trademarked term for closed-cell extruded polystyrene foam made for thermal insulation and craft applications. EPS foam is the correct term for any form of expanded polystyrene.
Food-use styrofoam containers, made from expanded polystyrene, are not oven safe. These styrofoam containers will begin to soften at 212 degrees Fahrenheit and actually melt at 464 degrees. They are, however, safe to use for storing food in the refrigerator but never to cook or reheat in the oven.
Unlike PET, styrofoam is particularly unsafe when heated or used with hot liquid. In contact with heat, it will start to melt or break down, causing the chemicals — dioxin, benzene and styrene — to seep into the liquid or foods.
These are similar to the rigorous standards established by the US Food and Drug Administration (FDA) for styrene-based food packaging materials. So far, test results indicate that styrofoam containers are safe for use, when used appropriately.
Choose the right type of rigid foam for your needs
Polyisocyanurate: Known as polyiso for short, polyisocyanurate foam has the highest R-value per inch (R-6.5 to R-6.8) of any rigid insulation. This type of rigid foam usually comes with a reflective foil facing on both sides, so it can also serve as a radiant barrier.
Extruded polystyrene insulation (XPS) is manufactured using a process of extrusion. This continuous process results in a closed cell structure with a smooth skin on the top and bottom of the board.
Closed cell foam is the best choice for robust insulating where space is an issue, as it can achieve 2x the R-Value of open cell inside a standard wall. Its rigid nature also adds to the structural integrity of the building and E84 fire rated versions are available.
A wall utilizing STYROFOAM T-MASS Technology with a 2-inch exterior layer and a 4-inch interior layer of concrete along with a 2-inch layer of STYROFOAM extruded polystyrene insulation would result in a material R-value of approximately 11.33.
DuPont Styrofoam™ Insulation (Blue Board) is a nonstructural, rigid board insulation manufactured of Extruded Polystyrene Foam (XPS). Blue Board can be used both on exterior and interior walls to give you a continuous insulation barrier that can increase effective R-value of the wall by up to 20%.
This foam board insulation is the rigid pink or blue panels that can be found at home centers in many different thicknesses. It is denser than EPS and provides more R-Value with a rating of 5 per inch of thickness.