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Density system unit unit-code symbol or abbrev. notes sample default conversion combination output units Metric: kilogram per cubic metre: kg/m3 kg/m 3: 1.0 kg/m 3 (1.7 lb/cu yd)
Typical densities are 29 to 120 kg/m 3 (49 to 202 lb/cu yd) with the lower figure being common. [1] Densities as low as 14 kg/m 3 (24 lb/cu yd) can be produced. [2] Base polymer for EPE foams range from Low-density polyethylene (LDPE) to High-density polyethylene (HDPE). [2]
— "Values ranging from 21.3 to 21.5 gm/cm 3 at 20 °C have been reported for the density of annealed platinum; the best value being about 21.45 gm/cm 3 at 20 °C." 21.46 g/cm 3 — Rose, T. Kirke. The Precious Metals, Comprising Gold, Silver and Platinum .
HDPE is known for its high strength-to-density ratio. [4] The density of HDPE ranges from 930 to 970 kg/m 3. [5] Although the density of HDPE is only marginally higher than that of low-density polyethylene, HDPE has little branching, giving it stronger intermolecular forces and tensile strength (38 MPa versus 21 MPa) than LDPE. [6]
The high molecular weight makes it a very tough material, but results in less efficient packing of the chains into the crystal structure as evidenced by densities of less than high-density polyethylene (for example, 0.930–0.935 g/cm 3). UHMWPE can be made through any catalyst technology, although Ziegler catalysts are most common.
Conversions between units in the metric system are defined by their prefixes (for example, 1 kilogram = 1000 grams, 1 milligram = 0.001 grams) and are thus not listed in this article. Exceptions are made if the unit is commonly known by another name (for example, 1 micron = 10 −6 metre).
The specific weight, also known as the unit weight (symbol γ, the Greek letter gamma), is a volume-specific quantity defined as the weight W divided by the volume V of a material: = / Equivalently, it may also be formulated as the product of density, ρ, and gravity acceleration, g: = Its unit of measurement in the International System of Units (SI) is newton per cubic metre (N/m 3), with ...
LDPE is defined by a density range of 917–930 kg/m 3. [6] At room temperature it is not reactive, except to strong oxidizers; some solvents cause it to swell. It can withstand temperatures of 65 °C (149 °F) continuously [6] and 90 °C (194 °F) for a short time. Made in translucent and opaque variations, it is quite flexible and tough.