• Malik Engineers

Extruder for Producing Oriented Sheet from Nylon

Malik Engineers has developed an Extrusion Line for producing oriented sheet from nylon. This is mainly used in manufacture of power transmission belting, as inner, load bearing tensile member between outer rubber layers. The application demands very high tensile strength for the nylon sheet (tensile member). To produce such highly oriented sheet, nylon material in granule or pellet form is first melted inside a single screw extruder which is electrically heated and conveys the melted material, continuously forward through a T-die which extrudes a flat, thick sheet. The thick sheet is continuously drawn away by the chilling rollers set (3 rolls) in S-fashion, led by roller conveyor and wound on suitable winder. The sheet thus produced is not oriented in extrusion stage. In the second stage, the sheet produced in stage-1 is reheated between set of feeding and pulling rollers. The reheating of sheet is done in orientation oven, which is placed between feeding rollers, and stretching rollers stand. The stretching rollers considerably draw down the thick sheet to lesser thickness, which causes orientation of molecules in the pulling direction and hence considerable increase in tensile strength of the sheet. To relieve stresses developed during orientation process, the oriented sheet is passed through a long length stabilization oven and wound for storage. Full line is provided with automatic digital controllers and frequency controllers for the motors for infinite speed variation. It gives reliable operation, minimum maintenance and high product accuracy and strength, while minimising wastage. The unit is offered in standard size of 65 mm screw size (extruder) with output capacity of 40 kg/hour and oriented sheet width up to 320 mm.