NORRES Schlauchtechnik GmbH und Co. KG, Gelsenkirchen, Germany, recently became the first manufacturer to develop an extra-rugged high-temperature hose made of polyurethane that is more resistant to heat and ageing than any material employed in the past. This hose is consequently ideal for even the toughest applications, for example for conveying glass fibre-reinforced granulates or ones with sharp edges. Last year was already remarkable for the hose supplier's market launch of its innovative HT-PUR in the AIRDUC® HT-PUR 351 and 355 for transporting hot gases or powders. The new AIRDUC® HT-PUR 356 will allow NORRES, a leading manufacturer of industrial hoses and hose systems, to extend its product family with an unprecedentedly rugged and heat-resistant hose type.
The new high-temperature hose
The new high-temperature special hose impresses with a very high flow rate for hot, ultra-abrasive substances in combination with a significantly longer service life. At temperatures of 125 °C, 150 °C short term possible, the AIRDUC® HT-PUR 356 transports sharp-edged granulates just as efficiently as ceramic powder.
Featuring a spring steel wire firmly embedded in the wall, the hose is capable of electrostatic discharge according to BGR, so that static charge and resulting process disruptions are avoided. It is smooth with high axial strength but nevertheless flexible, with a wall thickness of 2 – 2.5 mm. The profile is flow-optimised, guaranteeing a high delivery rate. The high smoothness of the interior hose surface leads to less deposition of the delivered material and allows gentler material transport. The outcome: dramatically enhanced durability, minimal abrasion and improved pressure resistance at higher temperatures.
Before HT-PUR
When hot solids like granulates are transported, the temperature can often reach 90 °C to 150 °C. These warm or hot granulates are increasingly conveyed direct from the dryers to the extruders or injection moulding machines. Until now, hose systems made of thermoplastic elastomers (TPE) or hand-made synthetic fabric with a neoprene surface coating designed specifically for high temperatures have mainly been used in such cases. These hoses, however, have a tendency to age excessively or become soft when subjected to extreme heat, leading to severe abrasion. Moreover, the labour costs for manufacturing them manually are disproportionately high. Metal hoses are liable to leak within a short time and are also too inflexible and expensive.
The solution: HT-PUR
Last year, NORRES embarked on an innovative project to develop a solution that would make the polyurethane material more resistant to heat and less susceptible to ageing. This new material, which represents an advanced form of the company's existing premium polyurethane, is cross linked in a simple and efficient way. It withstands a continuous operating temperature of 125 °C and can be used at up to 150 °C for short periods. It is clearly superior to the materials traditionally employed, such as ordinary polyurethane, neoprene or thermoplastic elastomers, when it comes to resisting ageing under heat. The fact that it shows a 40 percent improvement in mechanical stability during heat exposure is an immense advantage. The pressure resistance of HT-PUR is also substantially better at higher temperatures compared to hoses made of premium polyurethane.
Advantages for users
AIRDUC® HT-PUR 356 hoses are with diameters from 32 to 200 mm. They generate important savings potential for users everywhere thanks to their small offcut, lower warehousing costs and increased durability.
Innovation, know-how and long-term testing combined with the highest quality standards regarding materials and techniques – the proven NORRES recipe for excellent products that bring tangible benefits to users.