초록 ▼

The disclosed method is particularly applicable for jacketing pipes of a diameter of between 50 mm and 500 mm and is provided for high jacketing speeds and high throughputs. The pipe is heated initially to a temperature at least sufficient to cause a subsequently applied epoxy resin-curing agent pow

The disclosed method is particularly applicable for jacketing pipes of a diameter of between 50 mm and 500 mm and is provided for high jacketing speeds and high throughputs. The pipe is heated initially to a temperature at least sufficient to cause a subsequently applied epoxy resin-curing agent powder blend to melt; a coherent and uniform epoxy coating is desired which may require subsequent heating of the epoxy coating. The epoxy coating will cure at a temperature from 145 degrees Centigrade to 155 degrees Centigrade within 50 to 70 minutes and the layer thickness should be between 30 and 50 micrometers. Prior to applying the jacket, the thermally produced reaction products must escape; this is ensured by an infrared radiation step which raises the temperature to about 200 degrees Centigrade. In the case of a thermo-sensitive interior of the steel pipe, this heating step provides not only for the evaporation of reaction products, but it is the same step which makes sure that the preheated and slightly melted powder obtains sufficient fluidity.

대표청구항 ▼

Method of jacketing an elongated cylindrical metallic object, comprising the steps of: heating the object to a temperature of at least 80° Centigrade; applying a powdery precondensated blend of an epoxy resin and a curing agent to said object, said blend having properties of curing within 50 to 70 m

Method of jacketing an elongated cylindrical metallic object, comprising the steps of: heating the object to a temperature of at least 80° Centigrade; applying a powdery precondensated blend of an epoxy resin and a curing agent to said object, said blend having properties of curing within 50 to 70 minutes at a temperature of 145°to 155°Centigrade, the amount of blend so applied being sufficient to obtain a base layer thickness of 30 to 50 micrometers; raising the temperature of the epoxy base layer from the outside to about 200°Centigrade by passing the object through a source of thermoenergy to evaporate reaction products from a melted and coherent epoxy coating; extruding a double hose upon the hot base layer at an extrusion temperature between 165°Centigrade and 190°Centigrade, the double hose having two layers accordingly wherein the inner one of the two layers includes an adhesive of ethylene copolymer, the outer layer of the two-ply hose being a thermoplastic synthetic material, having a thickness so that the ratio of the relative volume of applied hose material to the relative volume of the base is at least 36 to 1; subsequently curing the base layer by applying the thermoplastically coated object to a cooling medium for about an hour under conditions which limit the temperature of the thermoplastic layer to a temperature of 50°Centigrade to 60°Centigrade; and subsequently permitting the object with jacket to cool to room temperature.