1. What is Expanded Polystyrene? (EPS)
Expanded Polystyrene or EPS for short; is a lightweight, rigid, plastic foam material produced from solid beads of polystyrene. A cost-effective, easy-to-use and process material, it performs as an acoustic and thermal insulator, is moisture resistant, recyclable and environmentally sound. Expanded Polystyrene (EPS) Panels are made of dense polystyrene or more commonly named Styrofoam. They can be made as large as desired however the most useful and common is 1.2 m to 7.3m wide and 2.4m or 2.7 high made in standard thicknesses of 0.1m to 0.2m although a thickness of up to 0.3m may be used if desired. The result is an engineered panel that provides structural framing, insulation, and exterior sheathing in a solid, one piece component.
2. How is EPS made?
It is produced when pentane is dissolved in a polystyrene base material, which is then steam-heated to form EPS beads. Expansion is achieved by virtue of small amounts of pentane gas dissolved into the polystyrene base material during production. The gas expands under the action of heat, applied as steam, to form perfectly closed cells of EPS. These cells occupy approximately 40 times the volume of the original polystyrene bead. The EPS beads are then molded into appropriate forms suited to their application such as insulation boards, blocks or customized shapes for the building and packaging industry.
Read all about EPS and the MEGA Green Process.
3. Who needs EPS?
EPS is one of the best insulation and building materials for what concerns the respect of the environment. EPS does not and has never used CFCs or HCFCs in its manufacturing process. Therefore it does not damage the ozone layer. The environmental effects of the manufacture of EPS raw material (expandable polystyrene bead) and its conversion to EPS insulation material are small. Over the life cycle of EPS buildings and insulation, the main environmental effects are those of substances released into the atmosphere, principally when the raw EPS is made and when the insulation board is delivered to users. The main substance is pentane (used as blowing agent), which is released during the conversion of the raw material to insulating board, has a minimal global-warming potential making only a slight contribution to the greenhouse effect. Once EPS is installed in a building, emission levels are negligible, due in part to the fact that its volume consists of 98% air. EPS is an inert, stable closed cell plastic which has superior insulating qualities. Unlike many other foam products, EPS is “Ozone-Friendly” and contains no CFCs or formaldehyde. The EPS Core material retains its shape indefinitely. It will not shrink, decompose or disintegrate due to age or adverse weather conditions.
• Thermal Stability – EPS does not lose its insulation values with time.
• Toxicity – EPS is formaldehyde-free.
• Low Water Absorption – EPS is a closed cell foam. EPS absorbs little moisture which does not affect its insulation values significantly.
• Permanence – EPS is an inert material. It provides no nutrition to plants, insects, animals or micro-organisms. EPS will not decompose and is highly resistant to mildew.
5. Can EPS be recycled?
EPS can be recycled if it is recovered without contamination from other materials. EPS waste can be ground and mixed with fresh EPS to make new foamed products. Alternatively EPS can be melted and extruded to make compact polystyrene, for items such as plant pots, coat hangers and wood substitutes or medium toughened polystyrene, for products from which sheet or thermo-formed articles such as trays can be made. As part of a mixed plastic waste, EPS can be recycled to make, for example, fence posts and road signs, ensuring the plastic waste has a long and useful new life. Globally, EPS production and total recycling use very little energy in comparison to other insulation materials.
6. How does EPS behave in case of a fire?
Like practically all organic building materials polystyrene foam is combustible. However in practice its burning behavior depends on the conditions under which it is used, as well as the inherent properties of the material. These inherent properties differ depending on whether the cellular material is made from EPS with or without a fire retardant additive. The bonding of other materials to cellular polystyrene also considerably affects its burning behavior.
For example, foil-faced products have an improved surface spread of flame performance. When installed correctly, expanded polystyrene products do not present an undue fire hazard. It is strongly recommended that expanded polystyrene should always be protected by a facing material, or by complete encapsulation – As in the case of the MEGA Building System. When burning, expanded polystyrene behaves like other hydrocarbons such as wood, paper etc.
The products of combustion are basically carbon monoxide and styrene: during a fire, the styrene may be further decomposed, giving off oxides of carbon, water and a certain amount of soot (smoke). EPS is produced in two types: the standard quality and the fire-retardant modified quality, designated by the code ‘SE’. Flame retarded or SE grades, which make the expanded material much more difficult to ignite, considerably reduce rates of spread of flame. Some countries, such as those in Scandinavia, only use the standard grade, whereas others, Germany for example, only use the SE grade. However, in many European countries, both grades are used. If EPS is exposed to temperatures above 100° C, it begins to soften, to contract and finally to melt. At higher temperatures, gaseous combustible products are formed by decomposition of the melt.
Whether or not these can be ignited by a flame or spark depends largely on the temperature, duration of exposure to contribution to the propagation of fire-retardants. The presence of fire retardant additives in SE grades leads to significant improvements in the fire behavior of EPS. While the complexity of a real fire situation makes it very difficult to predict overall fire performance from laboratory tests, there are several small-scale tests which clearly show that it is much more difficult to ignite EPS made from grades with a fire retardant additive than standard grades.
7. Architectual Information
Choosing an architect should enjoy the same degree of investigation that you would apply when choosing a broker to invest the same amount of money on the stock exchange. The return on that investment is directly proportional to the experience that the broker has to offer and to the amount of effort that they choose to put into managing your portfolio. It is the same with your architect. You will be investing a lot of money in your building project and you need to be assured of the best possible return on that investment as well. Your choice of architect and the experience that they bring to the design of your home will have a direct influence on the value of your investment.
The Mega Green Structures building system is a modular system. As with all modular systems, designing within the parameters of the system will give you the most economical design with no wastage. It is therefore prudent to choose an architect who has a good understanding of the particular building system that you wish to build with and knowledge of modular building in general. With any modular system there are always a number of peculiar design considerations that must be adhered to and straying from those parameters will always increase costs as you will be paying for wastage. Protect your investment and choose your architect with care. For more information on the building industry visit www.allaboutbuilding.co.za or e-mail firstname.lastname@example.org