Butter Forming Machine

Overview

The Butter Forming Machine is a continuous extrusion machine that turns bulk butter into wrapped retail prints. Butter is held warm and plastic in a heated hopper, pumped through a heated die that forms it into a rectangular or cylindrical bar, cut into portions of 250 g to 1 kg, wrapped and sealed in film, and carried away on a conveyor to a cooling station. Running at 20 to 60 packs per minute, the machine coordinates pump stroke, blade timing, film advance, and belt speed so that each portion is formed, separated, and wrapped in step. All product-contact parts are stainless steel for food hygiene.

Hopper

Incoming butter is buffered in the Hopper, a heated accumulation vessel that keeps the product at a stable 35 to 45 °C so it extrudes consistently. The polished stainless Hopper Tank has a sloped bottom that gravity-feeds the pump, a slow Agitator Blade turns gently to prevent the butter separating or developing cold spots, and a Hopper Heater of 3 to 5 kW maintains plasticity. A Thermistor Cartridge reports hopper temperature back to the control system. Holding the butter in a narrow temperature band is what makes the downstream forming repeatable: too cold and it will not flow, too warm and the print will slump.

Extrusion head

Forming happens in the Extrusion Head. A reciprocating Pump Piston draws a measured charge from the hopper and forces it into the Die Block, a brass or aluminum cavity that shapes the butter into the finished print cross-section. The die is kept at 35 to 40 °C by an embedded Heating Cartridge so the extruded surface stays smooth and does not tear, and a Thermal Control PID loop regulates the cartridge duty cycle from a thermostat feedback signal. Portion mass is set by the pump's displacement per stroke.

Cutoff

As the formed bar emerges it is divided by the Cutoff Mechanism. A Solenoid Valve running on 24 VDC directs compressed air to a double-acting Pneumatic Cylinder, which drives a Cutoff Blade through the butter once per portion. The blade is electrically heated, typically 500 to 1000 W, so it slices cleanly without butter sticking to the edge and dragging. A Pressure Sensor monitors the pneumatic supply so a loss of air pressure can be detected before it causes a missed or partial cut.

Wrapping unit

Each portion is then enclosed by the Wrapping Unit. Wrapper stock is drawn from the Film Roll, a spool of 200 to 400 mm wide foil or parchment on a pneumatic arbor. A stepper or servo Film Drive advances the film in time with the cutoff so each print lands on a fresh length of wrapper. The Seal Bar, a heated element held at 120 to 150 °C, bonds the film overlap, and a Film Cutter then severs the wrapped pack free of the continuing film web.

Discharge conveyor

Finished packs leave on the Discharge Conveyor. A food-grade Conveyor Belt of stainless or modular plastic, 400 to 800 mm wide, carries the product, driven by a Conveyor Motor of 1 to 2 kW running at up to 60 m/min on a variable-speed drive. The belt rides on a stainless Conveyor Frame with cleanout access for washdown. An optional Cooling Section passes the packs through chilled brine or a CO₂ spray to harden the butter before palletising.

Control

The machine is run from the Control Panel. A compact Control PLC sequences the pump stroke, solenoid timing, conveyor speed, and heater duty cycles, while the operator sets portion size, rate, and temperatures and reads alarms and counts on the HMI Screen touchscreen. A regulated Power Supply feeds the 24 VDC control circuits, and a Solenoid Manifold block centralises the pneumatic valves and pressure regulation that drive the cutoff and film handling.

Operation

In production the operator sets portion mass and line rate at the HMI, and the PLC holds the hopper, die, and seal-bar temperatures while phasing the pump, blade, film drive, and conveyor against one another. Hygiene practice requires regular washdown of all product-contact stainless parts, and routine maintenance covers blade and seal-bar heaters, film-drive synchronisation, pneumatic seals, and the temperature sensors that keep the butter in its working range.