Negri Bossi are one of the market leaders in supplying injection moulding machinery for processing PVC. On screw diameters from 80mm and over, internal cooling is now available for PVC applications.
Negri Bossi’s PVC technology has been developed to provide consistent and cost-effective production of visually and dimensionally perfect parts. Rather than offering a slightly modified standard machine, Negri Bossi have developed a more bespoke solution that provides the low shear, high torque, greater temperature regulation and resistance to chemical attack needed.
Negri Bossi’s high level of modularity allows perfect matching of injection unit to clamp size. This is most important for PVC, where residence times are particularly critical, but items such as drainage products require large tools with multiple moving cores.
Their ST servo-hydraulic technology is particularly suited to the typical “duty cycle” associated with PVC components with the long static phases involved. This provides high performance whilst maintaining low energy consumption. These benefits are also available on the larger Vector models when specifying the smart energy solution.
PVC ready models offer high torque hydraulic screw drive or optional electric screw drive on the ST range. Vector machines already have electric screw drive and can also be fitted with reduction gearboxes. These specifications provide the torque and screw speed stability required for optimum material processing.
Negri Bossi has developed specific injection unit solutions for rigid PVC, with low compression ratio screw profiles, the option of monolithic screw design to reduce ‘hang-ups’ and barrel cooling fans/mica bands to aid the removal of excess shear heat.
The recent addition of internal barrel screw cooling ensures better control of material temperature reducing degradation and improving the quality of the melt.