Hot Runner Technology |
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Hot runner technology enables injection molded parts with the highest surface quality , as required in particular by the automotive industry . In many applications , systems from Oerlikon HRSflow support cost-efficient , material-saving production with highly precise process control . Examples include a “ smart ” car rear panel in 2K technology as well as injection-molded light guide elements for which the new , patent-pending CTC gate insert is used . Beyond , the advantages of the company ’ s FLEXflow technology with servo-controlled needle positioning are demonstrated by the cascade injection molding of headlight covers and the back molding of films in a lightweight construction application . The supporting element of a “ smart ” car rear panel using 2K technology is a frame made of PC / ABS . In the first step , this is injection molded using a hydraulic 2-drop hot runner system from Oerlikon HRSflow . In the second step , the part is overmolded with PMMA or alternatively PC using a single nozzle from the Ga series . Finally , the part is decorated directly in the mold with a capacitive yet aesthetically pleasing film . In addition to Oerlikon HRSflow , Kurz , ENGEL and Schöfer also contributed to the success of this innovative project , which required , among other things , extensive rheological calculations due to the complex |
requirements . For the injection molding of an automotive light guide element , Oerlikon HRSflow ’ s new patent-pending CTC gate insert provides optimum properties . It is made of steel with superior mechanical properties and wear resistance . In addition , flash formation is completely avoided thanks to optimum thermal control in the gate area in conjunction with a cylindrical shut-off . Both factors help optimize productivity in the manufacture of the light guide element . Forgiving dimensional requirements simplify machining of the nozzle seat , and a smart solution that allows the gate opening to be renewed with minimal effort facilitates maintenance work . In general , injection molded parts that require a wide process window due to difficult conditions such as low shot volumes , long packing times and high holding pressure values are among the typical applications for the new CTC . LED headlight bars made of crystal-clear polycarbonate ( PC ) are a proven application of Oerlikon HRSflow ’ s FLEXflow technology . The systems ’ servo motors enable synchronized needle movements for precisely controlled flow front progression during sequential injection molding . Sudden pressure drops that occur when additional gates are opened are perfectly damped , so that the cavities |
are filled evenly and residual stresses in the molded part are minimized . There is also a high degree of flexibility during the holding pressure phase because the needle closing profile ( speed and stroke ) can be adapted to meet product dimensional requirements . The possibilities of hot runner technology in the design of future cockpits are illustrated by a joint project between the Koller Group , Dietfurt , and Oerlikon HRSflow using the example of a laptop housing demonstrator part . |
A prefabricated and preformed film is back-injection molded with PC using the FIM ( Film Insert Molding ) process . Mold development was carried out jointly with Koller Formenbau , while the back molding process was developed with the automotive lightweight specialist Koller Kunststofftechnik . While the film was initially displaced below the injection point , this washout effect could be reliably avoided by using and optimizing Oerlikon HRSflow ’ s electrically controllable FLEXflow hot runner system . |