Integrated solutions for plastics extrusion
Seven typical lines, and which systems each of them needs.
Meltblown runs through gravimetric blending and feeding, melting in the extruder, melt filtration, metering-pump dosing, melt distribution and spinning at the die. With Sealion gravimetric dosing control the filaments come out more even and the extrusion more stable.
Natural gas is flammable and explosive, and a fractured pipe leaking gas does not bear thinking about — which is why wall thickness on gas pipe is held to a stricter standard than most. Sealion gravimetric control together with ultrasonic in-line gauging addresses uneven wall thickness on the line.
PE water pipe is extruded in one pass from dedicated polyethylene and used in municipal water networks, irrigation schemes and agricultural sprinkler systems — particularly where the pipe has to stand up to acid, alkali and corrosion. Gravimetric control, ultrasonic gauging, a marking printer and a diameter gauge control the line as it runs, so every metre is accounted for.
Catheters are small, intricate and geometrically demanding, with hygiene requirements to match, and they need wall thickness held steady above all. Gravimetric control keeps the melt output stable while ultrasonic gauging measures and records wall thickness, inner and outer diameter continuously against the process spec.
Wire and cable are drawn, stranded and then sheathed; the more complex the specification, the more the process repeats and the tighter the base thickness of the sheathing has to be held. Gravimetric control, ultrasonic gauging, marking and diameter measurement together give the line one integrated control scheme.
Film is a multi-layer composite built from a complicated set of raw materials and blends, so the dosing has to be exact. Sealion's multi-component blending system takes the labour out of it and doses accurately; paired with gravimetric control, the output at the die is precise as well.
PVC-O is made by stretching formed PVC-U pipe both axially and radially, and because of that biaxial orientation the measurement and control of wall thickness becomes critical. The gauging system on such a line is held to a stricter standard, and ordinary ultrasonic in-line gauging cannot measure PVC-O reliably.
Everything upstream of the stretching is settled: gravimetric and dosing control hold the material used per metre, with diameter gauging and marking running in line. The wall-gauging step has to be confirmed on site against diameter, orientation ratio and melt temperature, with a sample trial first where needed — this is one thing we do not promise in general.