Lipstick Molding Machine Product

Overview

A lipstick molding machine automates the production of molded lip color sticks from molten base formulations (typically wax, oil, and pigment blends). The machine excels at small-to-medium batch production for cosmetic brands seeking consistent tube fill, smooth demolding, and rapid cooling without manual labor.

Core operation cycles through a rotating carousel: molten mass is injected into tube-shaped mold cavities, the filled molds circulate through an insulated cooling tunnel, and solidified lipsticks are ejected mechanically at the demolding station.

How It Works

Raw lipstick mass (a blend of wax, oils, and pigments) is loaded into the Mass Tank, a 120-liter jacketed vessel heated to 75–85 °C by dual 2.5 kW Heating Elements. A Stirrer Motor-driven Stirrer Shaft with paddle blades maintains homogeneous temperature and pigment suspension, preventing settling and color streaking.

The Pump and Fill system draws molten mass from the tank via a positive displacement Fill Pump (2 cc/rev) controlled by a stepper motor. This pump delivers precise volumetric shots (typically 3–4 grams per lipstick) at intervals synchronized with carousel indexing.

The Mold Carousel is a 600 mm aluminum rotary platen holding 24 interchangeable Mold Cavity Inserts arranged radially. Each insert is a tube-shaped aluminum cavity with a 12 mm bore—the standard lipstick tube diameter. The carousel rotates via a stepper motor with electromagnetic indexing brake, advancing one position (15° increment) every 12–20 seconds.

As the carousel indexes, a fresh empty cavity arrives at the fill station directly beneath the Nozzle Ring. The fill head contains 24 solenoid-gated nozzles (one per cavity); the appropriate nozzle opens for 0.5–1.0 seconds, injecting molten lipstick mass into the cavity. Solenoid timing is controlled by the Control System PLC, which tracks carousel position via an absolute Position Encoder.

Immediately after fill, the carousel rotates, and the filled cavity enters the Cooling Tunnel. This insulated chamber, cooled to 5–15 °C by an 8 kW chiller, solidifies the lipstick stick rapidly—typically 3–4 minutes of residence time for full hardness. The cooling rate is critical: too fast and the lipstick surface cracks or shrinks excessively; too slow and production rate suffers. Glycol-water circulates through the tunnel jacket at controlled flow, modulated by the Circulation Pump.

After cooling, the carousel continues rotating, and the solidified lipstick cavity reaches the Demolding Head. A pneumatic Pneumatic Ejector cylinder (50 mm bore, 150 mm stroke) drives upward 24 hardened Ejector Pins mounted in a Stripper Plate, pushing the finished lipstick stick cleanly out of the cavity.

Optionally, a Flaming Burner (a propane torch head with 10 kW output) heats the top surface of the ejected lipstick for 0.5–1 second, melting the surface slightly to create a smooth, glossy finish and seal the stick. This flaming step is operator-selectable and is controlled by a Flaming Solenoid proportional gas valve.

The finished lipstick falls into a collection chute and is conveyed to packaging. The ejected cavity re-enters the carousel rotation and awaits the next fill station.

At full speed (24 molds × 5 rotations/minute = 120 cavity fills/minute), the machine produces 60–100 complete lipsticks per minute depending on cavity count and cooling time.

Temperature Control and Quality

The Mass Tank is maintained at constant temperature via proportional heating and stirrer action. Any deviation (e.g., ambient temperature drop in winter) is detected by an RTD RTD or Thermocouple Probe, and the PLC adjusts heater power automatically. This prevents viscosity swings that would affect fill accuracy.

The Cooling Tunnel cooling rate is equally critical. The PLC monitors both inlet and outlet Pressure Sensor readings on the coolant loop; if the chiller fails or tubing clogs, pressure differential spikes, and the system alerts the operator before lipstick quality degradation occurs.

Fill Accuracy and Solenoid Sequencing

The Pump and Fill system achieves fill accuracy within ±0.2 grams. The pump displacement is fixed (2 cc/rev), but pump speed varies with carousel position. The fill pump runs continuously, but each of the 24 Solenoid Valves gates flow to individual cavities. When the PLC detects a cavity at the fill station, it energizes that specific solenoid for a metered pulse, delivering the programmed volume.

Solenoid valve timing is stored as a recipe in the HMI Touchscreen 10-inch touchscreen. Operators can create multiple recipes for different lipstick formulations (different viscosity = different dwell time) and switch between them instantly without hardware changes.

Demolding and Surface Finish

The Demolding Head ejector pins are hardened steel, 6 mm diameter × 80 mm length. Their height must match cavity depth precisely; if pins are too short, lipsticks stick in the cavity; if too long, they can puncture the soft lipstick surface just after ejection. Pin wear is monitored and pins are replaced after 50,000–100,000 cycles.

The optional flaming step provides a luxury finish: the top surface melts slightly, hiding the parting line (seam) and creating a glossy, seamless appearance. This is particularly valued for high-end cosmetic brands.

Modular Mold Design

Cavity inserts are interchangeable. A brand producing multiple lipstick shades can prepare 24 inserts before the shift, snap them into the carousel, run one color, swap inserts, and run the next color. Change-over time is 5–10 minutes.

Related Subsystems

• Mass Tank melts and homogenizes lipstick formulation.
• Mold Carousel indexes and positions mold cavities.
• Pump and Fill delivers precise fill volume.
• Cooling Tunnel solidifies filled lipsticks.
• Demolding Head ejects and optionally finishes lipsticks.
• Control System automates entire cycle with recipe storage.

Maintenance and Consumables

Ejector pins and cavity inserts are wear items replaced quarterly. Stirrer paddles degrade over time (typically 6–12 months) and are stocked as spares. Solenoid coils have a design life of 1–2 million cycles; a spare kit is recommended. Glycol-water coolant should be tested semiannually for water absorption (glycol draws moisture from humid air) and replaced annually.