IMG-20150424-WA0001

The Emergence Of Polyurea

Back in the 80s of the last century the technical literature mentions the polyurea for the first time. Just then, as a result of a reaction injection molding techniques (RIM), used in the automotive industry in the manufacture of bumpers by Texaco Chemical (which became later in the Huntsman Corporation), instead of the traditional high molecular weight polyurethane polyols used polyetheramines – a substance similar to them, but containing the ends of macromolecules hydroxyl and amine groups. This discovery has led to a reduction in molding time parts and to a few seconds pushing the productivity to incredible level.

The same firm adopted the idea of ​​using this new technology in the field of chemical sprayed coatings. Its implementation took more than ten years though. A series of extensive researches on the synthesis of amine crosslinkers (chain extenders) and isocyanate oligomers were carried out, which contributed to a fundamentally new type of equipment and technologies that helped to overcome such problems as substrate wetting, low adhesion between the substrate and the coating and mediocre quality of the finished coating. The new technology is now oftentimes called ‘sprayed polyurea elastomeric coatings’. In the late 90s of the twentieth century the United States and Canadian enterprises began to develop the market quite rapidly. In 2000, the Polyurea Development Association (PDA) was founded, which includes raw material suppliers, equipment manufacturers and contractors who install coatings on objects.

The geography

The most significant demand of sprayed coatings technology applied to the body pickups, popular in America, making them more durable, as well as a protective layer over the polyurethane foam insulation on roofs. At present, the volume of polyurea in North America is estimated at tens of thousands of tons per year, the market develops sprayed coatings and in Asia. In Europe, the market has started gaining momentum significantly during the recent years. The UK market is fueled by a number of innovators, such as Britannia, concentrating its efforts on producing totally efficient roof coatings and roof waterproofing products, such as Polyshield line-up.

Polyurea is the most promising to date material for coatings having a truly amazing properties. Formulation of raw materials is tailored to the requirements of the final product. All variety of properties polyurea coating is achieved by variation of the original components, so we get the material with predetermined properties.

The benefits

Protective coatings of polyurea stand out from the other types of coatings with strength, elasticity, abrasion resistance, durability, resistance to aggressive chemicals, the lack of effect on the coating of moisture and temperature and high adhesion. Polyurea technology is characterised by rapid response times. Curing occurs within a few minutes, which makes it possible to walk on the coated surface almost immediately after its application. Polyurea elastomers do not contain volatile organic solvents that make them nonflammable and nontoxic.

As a result, improvement of formulations and equipment expanded and the possibility of applying polyurea, especially where the possibility of other materials is exhausted. The technology now offers:

– waterproofing and decorative coating of swimming pools, facing tanks made of concrete and metal, septic tanks, dams, canals, wells

– waterproofing of foundations, floors and walls in rooms with high humidity and corrosive to concrete aggressive liquids

– flooring for shopping centers, multi-storey car parks, industrial premises and many more.

 

 

Read More

mw_3136

The industrial application of ultrasound technologies

Ultrasonic systems are applied in numerous industries – their cost-efficiency, effectiveness and eco-friendliness are the vital aspects giving the technology a massive popularity boost. Mentioned below are the most common spheres of ultrasonic use according to Hilsonic, one of the leading ultrasonic cleaner manufacturers in the UK and the company deeply involved in ultrasound technologies development.

Degassing

The impact of sonication on melt significantly increases the intensity of the formation of bubbles of dissolved gas, and as a result, its content can be reduced by two times or even more, even if sonication is not prolonged. The occurrence of gas bubbles in the melt is followed by flotation of scattered hard nonmetallic inclusions, which increases the density of the casting and melt flowability, enabling to penetrate into the smallest recesses of the mold. Further degassing, there is a significant decrease in the grain, which results in further improvement of physico-mechanical properties of the casting. Melt treatment is usually performed immediately before casting and may be carried out both in a stationary volume of the furnace or mixing bucket using a submersible radiator with a working tool of refractory materials, and by ‘scoring’ the metal in the channel by means of a special tray or using a multi-layer filter screen of glass that provide, besides ultrasonic degassing, filtering the melt. The technology is applicable to a low-density low-melting metals and their alloys.

Intensification of galvanic and chemical processes

(more…)

Read More