Custom Search

Sunday, July 15, 2012


RoHS is often referred to as the lead-free directive, but it restricts the use of the following six substances:
  1. Lead (Pb)
  2. Mercury (Hg)
  3. Cadmium (Cd)
  4. Hexavalent chromium (Cr6+)
  5. Polybrominated biphenyls (PBB)
  6. Polybrominated diphenyl ether (PBDE)
PBB and PBDE are flame retardants used in several plastics.
The maximum permitted concentrations are 0.1% or 1000 ppm (except for cadmium, which is limited to 0.01% or 100 ppm) by weight of homogeneous material. This means that the limits do not apply to the weight of the finished product, or even to a component, but to any single substance that could (theoretically) be separated mechanically—for example, the sheath on a cable or the tinning on a component lead.

ROHS test

Restriction of Hazardous Substances

The Directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment 2002/95/EC (commonly referred to as the Restriction of Hazardous Substances Directive or RoHS) was adopted in February 2003 by the European Union. The RoHS directive took effect on 1 July 2006, and is required to be enforced and become law in each member state. This directive restricts the use of six hazardous materials in the manufacture of various types of electronic and electrical equipment. It is closely linked with the Waste Electrical and Electronic Equipment Directive (WEEE) 2002/96/EC which sets collection, recycling and recovery targets for electrical goods and is part of a legislative initiative to solve the problem of huge amounts of toxic e-waste. In speech, RoHS is often spelled out, or pronounced /ˈrɒs/, /ˈrɒʃ/, /ˈrz/, /ˈrhɒz/.

Saturday, July 14, 2012


Polyethylene is classified into several different categories based mostly on its density and branching. The mechanical properties of PE depend significantly on variables such as the extent and type of branching, the crystal structure and the molecular weight. With regard to sold volumes, the most important polyethylene grades are HDPE, LLDPE and LDPE.
  1. Ultra high molecular weight polyethylene (UHMWPE)
  2. Ultra low molecular weight polyethylene (ULMWPE or PE-WAX)
  3. High molecular weight polyethylene (HMWPE)
  4. High density polyethylene (HDPE)
  5. High density cross-linked polyethylene (HDXLPE)
  6. Cross-linked polyethylene (PEX or XLPE)
  7. Medium density polyethylene (MDPE)
  8. Linear low density polyethylene (LLDPE)
  9. Low density polyethylene (LDPE)
  10. Very low density polyethylene (VLDPE)
UHMWPE is polyethylene with a molecular weight numbering in the millions, usually between 3.1 and 5.67 million. 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/cm3). UHMWPE can be made through any catalyst technology, although Ziegler catalysts are most common. Because of its outstanding toughness and its cut, wear and excellent chemical resistance, UHMWPE is used in a diverse range of applications. These include can and bottle handling machine parts, moving parts on weaving machines, bearings, gears, artificial joints, edge protection on ice rinks and butchers' chopping boards. It competes with Aramid in bulletproof vests, under the tradenames Spectra and Dyneema, and is commonly used for the construction of articular portions of implants used for hip and knee replacements.
HDPE is defined by a density of greater or equal to 0.941 g/cm3. HDPE has a low degree of branching and thus stronger intermolecular forces and tensile strength. HDPE can be produced by chromium/silica catalysts, Ziegler-Natta catalysts or metallocene catalysts. The lack of branching is ensured by an appropriate choice of catalyst (for example, chromium catalysts or Ziegler-Natta catalysts) and reaction conditions. HDPE is used in products and packaging such as milk jugs, detergent bottles, margarine tubs, garbage containers and water pipes. One third of all toys are manufactured from HDPE. In 2007 the global HDPE consumption reached a volume of more than 30 million tons. PEX is a medium- to high-density polyethylene containing cross-link bonds introduced into the polymer structure, changing the thermoplast into an elastomer. The high-temperature properties of the polymer are improved, its flow is reduced and its chemical resistance is enhanced. PEX is used in some potable-water plumbing systems because tubes made of the material can be expanded to fit over a metal nipple and it will slowly return to its original shape, forming a permanent, water-tight, connection.
MDPE is defined by a density range of 0.926–0.940 g/cm3. MDPE can be produced by chromium/silica catalysts, Ziegler-Natta catalysts or metallocene catalysts. MDPE has good shock and drop resistance properties. It also is less notch sensitive than HDPE, stress cracking resistance is better than HDPE. MDPE is typically used in gas pipes and fittings, sacks, shrink film, packaging film, carrier bags and screw closures.
LLDPE is defined by a density range of 0.915–0.925 g/cm3. LLDPE is a substantially linear polymer with significant numbers of short branches, commonly made by copolymerization of ethylene with short-chain alpha-olefins (for example, 1-butene, 1-hexene and 1-octene). LLDPE has higher tensile strength than LDPE, it exhibits higher impact and puncture resistance than LDPE. Lower thickness (gauge) films can be blown, compared with LDPE, with better environmental stress cracking resistance but is not as easy to process. LLDPE is used in packaging, particularly film for bags and sheets. Lower thickness may be used compared to LDPE. Cable covering, toys, lids, buckets, containers and pipe. While other applications are available, LLDPE is used predominantly in film applications due to its toughness, flexibility and relative transparency. Product examples range from agricultural films, saran wrap, and bubble wrap, to multilayer and composite films. In 2009 the world LLDPE market reached a volume of almost 24 billion US-dollars (17 billion Euro). LDPE is defined by a density range of 0.910–0.940 g/cm3. LDPE has a high degree of short and long chain branching, which means that the chains do not pack into the crystal structure as well. It has, therefore, less strong intermolecular forces as the instantaneous-dipole induced-dipole attraction is less. This results in a lower tensile strength and increased ductility. LDPE is created by free radical polymerization. The high degree of branching with long chains gives molten LDPE unique and desirable flow properties. LDPE is used for both rigid containers and plastic film applications such as plastic bags and film wrap. In 2009 the global LDPE market had a volume of circa 22.2 billion US-dollars (15.9 billion Euro). VLDPE is defined by a density range of 0.880–0.915 g/cm3. VLDPE is a substantially linear polymer with high levels of short-chain branches, commonly made by copolymerization of ethylene with short-chain alpha-olefins (for example, 1-butene, 1-hexene and 1-octene). VLDPE is most commonly produced using metallocene catalysts due to the greater co-monomer incorporation exhibited by these catalysts. VLDPEs are used for hose and tubing, ice and frozen food bags, food packaging and stretch wrap as well as impact modifiers when blended with other polymers.
Recently much research activity has focused on the nature and distribution of long chain branches in polyethylene. In HDPE a relatively small number of these branches, perhaps 1 in 100 or 1,000 branches per backbone carbon, can significantly affect the rheological properties of the polymer.

Pearl-fibre Fabric

Pearl-fibre Fabric
 Naturally anti-Ultraviolet
 Skin-affinity & Nutrient.
 Breathable and Comfortable

Modal Fabric

Modal Fabric is boasted with its luxurious softness, the ultimate sensual feeling next to the skin.
MicroModal fabric is more developed fabric, with 1dtex fibre fineness.
MicroModal®Air fabric is more and more innovated fabric, with 0.8dtex fibre fineness.
ProModal® fabric is the perfect combination of Modal® fabric and Tencel® fabric, to unite outstanding softness with optimum function.

Thermocool fabric

ThermoCool is a Multi-functional and ecological evolution born from ADVANSA technological experience of modified cross-section fibres.
  The fibre is hollow with channel, keep the body at a comfortable temperature whatever the outside temperature or the physical inensity of your exercise. Without any kind of chemical Treatments, provide enhanced comfort coupled with moiture management during physical exertion.

Coolmax fabric


Coolmax is a trademark and a brand name for a series of moisture-wicking technical fabrics developed in 1986 by DuPont Textiles and Interiors (now Invista). The fabrics employ specially-engineered polyester fibres to improve "breathability" compared to natural fibres like cotton.
Structure: Coolmax fibres are not round, but are slightly oblong in cross-section with grooves running lengthwise along the threads. They are manufactured in either a tetrachannel or hexachannel style. The series of closely spaced channels creates capillary action that wicks moisture through the core and out to a wider area on the surface of the fabric which increases evaporation.
Uses: CoolMax fabric was originally developed for clothing intended for use during extreme physical exertion — sweat can evaporate quickly so the wearer is kept dry. Other useful properties include resistance to fading, shrinking and wrinkling. The fibres are now often woven with other materials like cotton, wool, Spandex and Tencel. As a result, CoolMax is found in a wide variety of garments from mountain climbing gear, to casual sportswear and underwear.
CoolMax fabric mattress covers and bed sheets have also been designed for those who have hot flashes or night sweating due to illness, medication or menopause.
Competitors: Most competing fabrics are made from polyester or nylon. Other brand names are Capilene® polyester, Supplex® nylon, Pertex® fabrics and polynosic rayons like Tencel®.
'Wick away' or 'wickaway' is a general term used for fabrics that are engineered to draw moisture away from the skin through capillary action and increased evaporation over a wider surface area.