Injection Moulding Machine & Dryer

Selection criteria

Shot accuracy, mould temperature control, resin drying.

Supply chain

Injection-moulding machines come from Austrian and German brands (ENGEL, ARBURG) and very large Chinese makers (Haitian, Yizumi), with Ningbo and Foshan as major centres. For insulation bobbins, small-shot accuracy, mould temperature control and resin drying matter most.

Buyer FAQ

What clamp force and shot size do I need for coil bobbins?

Estimate clamp force as projected area times about 0.4–0.6 t/cm² for glass-filled PA66; most bobbins run on 50–150 t machines with multi-cavity moulds. Choose a screw so the shot uses about 20–80 % of barrel capacity, because very small shots on a large barrel hurt shot accuracy and degrade the resin.

How dry must PA66+GF be before moulding?

Dry to 0.2 % moisture or less, typically 2–4 h at 80 °C in a desiccant dryer with a dew point around −40 °C. Wet resin causes splay, voids and brittle parts, while over-drying causes yellowing. Run the mould at about 80–100 °C so the glass fibres are well covered and the part crystallises fully.

What acceptance checks should I require for moulded bobbins?

Check critical dimensions such as terminal-pin positions (often ±0.05 mm), short shots and weld lines at thin flanges, and pin retention force. Require material certificates showing UL 94 V-0 and a suitable temperature index for the motor's insulation class. A hi-pot test across the bobbin wall confirms there are no thin spots or voids.

Where it is used