In antilock braking and stability-control encoder rings, the PA12-bonded ferrite compound is processed as supplied rather than blended with unfilled PA12, because dilution of the magnetizable fraction below the manufacturer’s specified volume loading shifts remanence and coercivity outside the sensor ASIC detection window. Compliance records for this application are aligned to IATF 16949:2016 supplier quality clauses, RoHS Directive 2011/65/EU Annex II, and REACH Regulation (EC) No 1907/2006; material marking follows ISO 11469:2016. The formulation addition ratio is fixed at 100% virgin compound for safety-relevant wheel-speed encoder rings, with regrind from cold-runner and sprue limited to 10 wt% in non-safety validation lots only after secondary drying at 80°C for 6 h to a moisture content below 0.1%. The downstream production route is multi-cavity injection molding in hardened, wear-protected tooling; a reciprocating screw with L/D ratio of 20:1 and non-return valve is used because the ferrite filler accelerates screw and barrel wear. Melt temperature is held at 250–270°C, mold temperature at 60–80°C, and injection speed is kept in the lower half of the machine capability to reduce shear heating at the gate. Hold pressure is set between 600 bar and 900 bar on the hydraulic pressure transducer, and gate freeze is confirmed by shot-weight stabilization across 20 consecutive cycles. After ejection, multipole magnetization is performed on a capacitor-discharge fixture, and pole-pitch verification uses a Hall probe referenced to IEC 60404-8-1:2015. The terminal component is a multipole encoder ring, typically 24 to 96 alternating poles, mounted on a bearing seal or tone wheel for active wheel-speed sensors.

Why Do Thin-Wall Electric Power Steering Sensor Targets Demand a Compound with Low Water Uptake?

Thin-wall rotor position sensor targets for column-assist and rack-assist electric power steering systems are subjected to cabin humidity swings and thermal cycling, which generate differential swelling between the overmolded PA12 compound and the steel hub. Water absorption measured per ISO 62:2008 at 23°C saturation for PA12 is approximately 1.5 wt%, while at 50% relative humidity equilibrium moisture uptake is 0.7–0.8 wt%; this is lower than PA66, which absorbs 2.5–3.0 wt% under the same condition. The applicable compliance stack includes IATF 16949:2016, environmental testing per ISO 16750-4:2010, RoHS Directive 2011/65/EU, and REACH Regulation (EC) No 1907/2006. The formulation addition ratio is 100% as-supplied compound; runner regrind is excluded from EPS safety-class targets because viscosity shifts from a second heat history alter thin-wall filling and magnetic filler orientation. External mold release may be applied as a dry, silicone-free agent, but no internal lubricant or impact modifier is added because both reduce tensile strength measured per ISO 527-2:2012 below the value required by the part drawing. The downstream process is thin-wall injection molding on an all-electric machine with clamp force from 800 kN to 1200 kN, a 30 mm screw, and a cold-runner valve-gated tool; wall thickness is below 2.0 mm. Melt temperature is controlled within 255–265°C, mold temperature within 70–85°C, and injection velocity is profiled to maintain a flow-front velocity above 150 mm/s in the thin section. Post-mold magnetization uses a multi-pole fixture matched to the sensor pole count, and magnetic field amplitude is verified against IEC 60404-8-1:2015. The terminal part is an EPS rotor position sensor magnet ring overmolded onto a sintered or machined steel hub.

Across sealless magnetic couplings for chemical dosing pumps, the PA12-bonded ferrite compound is selected because it avoids eddy-current losses associated with metallic magnetic assemblies and provides sufficient torque transmission in low-speed, positive-displacement pump heads. The applicable compliance framework includes ISO 5199:2002 for chemical process pump construction, Directive 2014/34/EU when the pump is installed in an ATEX-classified zone, RoHS Directive 2011/65/EU, and REACH Regulation (EC) No 1907/2006. The addition ratio is 100% compound without let-down; insert overmolding uses the same feedstock without adhesion-promoting primers, provided the stainless steel hub surface is prepared to Ra 0.8–1.2 µm according to ISO 21920-2:2021 and preheated to 100–120°C immediately before placement in the cavity. Downstream production is insert injection molding with a vertical or horizontal machine, a cold-runner tunnel gate, melt temperature 250–270°C, mold temperature 60–80°C, and injection speed reduced to 20–40 mm/s because high-speed filling of thick coupling rings can trap air at the insert interface and create magnetic voids detected by flux mapping. After molding, the rings are annealed at 80°C for 2 h in a nitrogen-purged oven to relieve molded-in stress before magnetization; multi-pole magnetization is performed on a dedicated fixture with pole count matched to the pump’s drive and driven rotors. The terminal products are inner and outer rotor magnet rings for sealless centrifugal or gear pumps, magnetized as multi-pole rings and assembled into containment shells.

When Multipole Rings Replace Sintered Ferrite Segments in Electric Oil Pump Rotors

Plastic-bonded ferrite multipole rings replace sintered ferrite segments in electric oil pump rotors where complex pole geometry and insertion into a rotor stack are combined with a need for corrosion resistance in hot transmission fluid. Compliance is governed by IATF 16949:2016 for automotive service, and environmental testing follows ISO 16750-4:2010 temperature and humidity profiles; material restrictions follow RoHS Directive 2011/65/EU and REACH Regulation (EC) No 1907/2006. The formulation addition ratio is 100% as-supplied compound; regrind reuse is permitted only up to 15 wt% when blended with virgin material, and only after the mixed feed passes melt volume-flow rate retest per ISO 1133-1:2022 Procedure A at 275°C and 5 kg, with a deviation of no more than 10% from virgin. The downstream process is injection molding of ring-shaped rotor magnets in a cold-runner, multi-cavity tool with wear-resistant gate inserts; melt temperature is 250–270°C, mold temperature 60–80°C, and hold pressure is profiled to maintain part weight within ±0.5% of the validated process. Because the compound is an isotropic ferrite-filled PA12 type, anisotropic alignment is not performed; after ejection, the ring is magnetized in a capacitor-discharge fixture to the required pole count, typically 8 or 10 poles for electric oil pump rotors, and flux uniformity is checked by Hall probe mapping against IEC 60404-8-1:2015. The terminal product is a multipole rotor ring bonded or press-fitted into the rotor assembly of a 12V or 24V electric oil pump or coolant pump.

Linear Position Encoder Targets in High-Humidity Industrial Environments

Linear position encoder targets for machine tools, packaging lines, and synchronized linear axes require pole-pitch stability under humidity cycling, oil mist, and periodic thermal excursions. The material is processed as single-component feedstock without dilution; no colorant or pigment addition is recommended because non-magnetizable pigments displace the magnetizable fraction and reduce magnetic remanence measured per IEC 60404-8-1:2015. The relevant normative set includes ISO 294-4:2018 for processing shrinkage measurement, ISO 62:2008 for moisture uptake, RoHS Directive 2011/65/EU, REACH Regulation (EC) No 1907/2006, and ISO 11469:2016 for polymer marking. The downstream production route is two-position injection molding of encoder segments onto a pre-machined aluminum carrier; the carrier is preheated to 90–110°C and surface roughened to Ra 1.0–1.6 µm per ISO 21920-2:2021 to create mechanical interlock. Melt temperature is set at 250–265°C, mold temperature at 60–80°C, and injection speed is limited to 40–60 mm/s to minimize filler orientation gradients along the part length. After molding and cooling, the encoder target is magnetized with alternating poles at the pole pitch specified by the encoder sensor, typically 1.0–5.0 mm; flux density is mapped along the full travel length using a Hall array, with acceptance tolerance tied to the sensor datasheet. The terminal component is a linear magnetic encoder scale or target strip used in industrial automation axes.

Because PA12-bonded ferrite rotor rings maintain dimensional stability better than PA66 equivalents under 80% relative humidity, they are used in appliance and power-tool brushless motor sensor rings where the part must survive condensation after cold storage. Compliance for household appliances is aligned to IEC 60335-1:2020, with material restrictions under RoHS Directive 2011/65/EU and REACH Regulation (EC) No 1907/2006. The compound is used at 100% virgin feedstock for first-production runs; regrind from runners is allowed up to 20 wt% in non-safety commercial parts after validation of melt volume-flow rate per ISO 1133-1:2022 and after drying to below 0.1% moisture. Downstream processing is high-cavitation cold-runner injection molding with melt temperature 250–270°C, mold temperature 60–80°C, and in-line multi-pole magnetization after part ejection. The terminal part is a sensor magnet ring for brushless motor commutation or rotor position feedback in washing machines, dishwashers, power tools, and small appliance drives.

In automated laboratory pipetting and micro-dosing platforms, published data for this specific KEBABLEND M 48/67 PA12 configuration is limited; however, the material’s PA12 carrier is used for non-fluid-contact magnet carriers where high dimensional reproducibility and low moisture uptake are required. The applicable compliance framework is IEC 61010-1:2010 safety for laboratory equipment, RoHS Directive 2011/65/EU, and REACH Regulation (EC) No 1907/2006; USP Class VI or ISO 10993-1 evaluation is not typically performed for this application because the magnet is isolated from fluid paths. The addition ratio is 100% as-supplied compound; no let-down with lubricated PA12 is approved because internal lubricant reduces mechanical interlock with overmolded polycarbonate or PBT carriers. Production is insert molding or two-shot molding with a cold-runner system, melt temperature 250–265°C, mold temperature 60–80°C, and capacitor-discharge magnetization after ejection. Terminal components are miniature multi-pole magnet rings used in pipettor Z-axis drives, microplate transfer arms, and syringe pump stepper motor feedback assemblies.