Hot runners for polycarbonate

The new Diamond Lux range of hot runner systems developed by Inglass-HRSFlow is particularly suitable for the moulding of polycarbonate components that need high aesthetic quality, such as, for example, the various components of car headlamps. Remaining in the automotive industry, these systems are also ideal for application in the production of quarter windows and panorama roofs by means of multishot technology, which allows the integration of positioning and mounting features.
These systems have been developed focusing mainly on thermal optimisation of the hot runners, a factor crucial in the aesthetics of moulded parts. To achieve this, the platens have been insulated using spacers that feature low thermal conductivity and reduce power loss at thermal bridges. Similarly, contacts towards the mould are now made using low thermal conducting material and have been geometrically improved in order to reduce thermal power dissipation.
Resistance heaters are positioned symmetrically at the top and bottom of the manifolds, to reduce cold areas and dwelling times. The use of screw-in nozzles avoids all contact with the mould, with the exception of the tip of the nozzle, and optimal thermal control of the nozzles is guaranteed by special brass sleeve heaters. Each heater allows accurate and consistent thermal control of the injection point area and the high thermal conductivity of the brass helps to standardize the temperature profile, ensuring tolerances of around 10°C throughout the system. The nozzle is fully protected by a stainless steel tube that ensures uniform temperature distribution, reducing thermal dissipation and at the same time protecting the thermocouple wires. The nozzle is designed to optimise the space available in the injection area.
All the internal ducts are designed to avoid dead spots that could cause defects that would be unacceptable in transparent parts. Particular care has been taken over the quality of the injection point, so that no marks are left on the part even when using high injection pressure.