Isostatic Press - Rubber Mold Forming Plant
RM 7

Pressing of large blocks by means of isostatic press techniques is an alternative to near net shape pressing on uniaxial presses.

This technique
• offers economic advantages with the manufacturing of very small magnets
• and yields magnet with highest energy content due to excellent magnetic alignment grades.

NKE designs and supplies complete and tailor-made plants, which are designed for semi automatic manufacturing of large anisotropic NdFeB permanent magnets which, after sintering, are sliced and diced to final shape.

Processing of the powder to magnetically aligned and isostatically pressed blocks is done under inert gas conditions.

The main items of the plant are:
• powder supply system with gravimetrically controlled powder flow into the mould
• inert gas glove box, comprising - two sluices, vibrating table and O₂ sensor
• pulse magnetizing equipment comprising coil and capacitor
• vacuum sealing machine
• isostatic press
• depacking box with inert gas conditions.

Specifications
Standard specifications of our plants are
• weight of magnets between 0.5 and 6 kg
• maximum length of sintered blocks: 220 mm
• tap density: 2.5 g/cm³
• dimensions of aligning coil
• inner diameter: 120 mm
• homogeneous length: 300 mm
• total length: 450 mm
• capacitor
• maximum energy: 80 kJ
• maximum voltage: 3000 Volt
• pulse rate: 3 min^-1
• maximum aligning field at about 80 kJ: > 2500 kA/m
• isostatic press
• diameter of pressure vessel: 240 mm
• length of vessel: 500 mm
• maximum pressure: 200 Mpa
• cycle time: about 6 min

Rubber moulds and respective supplementary means for powder filling, magnetic aligning and pressing are designed and supplied according to customers needs.