Polyurethane VS. EPS (Expanded polystyrene)
Polyurethane is a relatively new product, roughly around 15 years. EPS has been with us for around 25 years. Polyurethane was produced to replace the shortfalls of expanded polystyrene. Below you will see a detailed difference between polyurethane, and expanded polystyrene.
Polyurethane is highest rated insulation in the world. You will find it in most all of your refrigerators, freezers, and even in your personal carry out coolers. Per inch of insulation it has no equal. The walk in coolers and freezers for use thought the country are made of polyurethane. EPS has a value of R-2 to R-5 per inch. Polyurethane has an R- 7 to R-8 per inch.
Probably the biggest difference between polyurethane and EPS is in the manufacturing of these panels. Both products use OSB for covering both sides of their foam, but here is where the similarity ends. In the bonding of the foam the actual polyurethane is used as bonding agent to the OSB itself. Polyurethane is one of the best glues used in the industry today. Some manufactures of OSB and plywood use polyurethane gives both an excellent R value and the strongest bond in the industry. EPS panels use glue spread on both sides of OSB, and then the OSB is matched together with the EPS, and mechanically held in place and under pressure until the glue is dried.
With all the problems of mold and mildew, moisture resistance is today a very important factor. Polyurethane has one of lowest moisture permeability ratings of any product manufactured for the building industry today. The permeane rating on polyurethane is 1.2. The permeance rating on EPS is 2.0 to 5.0
This difference in a high humidity area would warran another moisture barrier for EPS panels. In calculating R- values, some EPS manufactures use these additional moisture barriers in there calculations.
The polyurethane is a UL class 1 rated foam. This means that polyurethane is not a source for fire. On its'own, polyurethane will not burn. When left on it's own, it will extinguish it self. A Class 1 rating is the highest rating a building product can obtain. Also, polyurethane is a thermal -set plastic. THIS means, that it will not melt. Polyurethane is not affected until temperatures reach 120 degrees and at that time it will only char. EPS on the other hand is not a thermal -set plastic and will begin to soften at termperatures of 70 degree.
Polyurethane has a distinct advantage.
The density of a product will determine the strength of it. EPS has a density of 1lb. The polyurethane has a density of 2.2lb.
Polyurethane is resistant to most counter chemicals. EPS react violently to petroleum based products. PL 400 and liquid nail will literally burn thru EPS.
From our experience, we feel that the investment made equals the quality of product made. We believe that there is no comparison between polyurethane panels and EPS.
|MOQ for roof metal||DX51D/SGCC/SGCH|
|What is the substrate for steel tiles?||hot dipped galvanized or gavalumed pre-painted galvanized|
|What is the thickness ||0.35-0.70mm, depends on customer|
|What colors are available?||RAL Code not only RAL, we can provide the color according to customer' s sample|
|What is the normal color and most economical color?||Ocean blue and off white|
|What lengths can you offer?||ecommand to fit for the container length, within 5.7m|
|What different between PVDF and PE||PVDF is the most advanced painting in construction industry, it is with high corrosion resistance and color retention, and the life time could last to 20-25 years. Currently, PE is the most widely-used painting in the color coated steel coils. It is characterized by good overall performance, and high economic as well.|
|Can you provide the high strength roof sheet? ||Yes, G550, with its yield strength over 550 mpa|
|What containers do you choose usually? 20feet or 40 feet? Why?||20 feet container, it is more economical.|
|How can you load 25MT per 20 feet container?||The metal roof tile is heavy cargos, the 20 feet container get enough room to load 25MT.|
|What is your mini quantity per color?||20 tons/color|
|How many years of the paint would be lasting?||Different zinc, paint coating would lead to different result, and the environment has great impact on the life time of painting|
|What is the leadtime?||Normally for sheets we can delivery it within 25-30 days. Depends on the quantity|
|Where is the delivery port ||ningbo / shanghai / tianjin|
|Quotation validity||7 days|