Shampoo filling machine technical guide (2025): formulations, shampoo types & troubleshooting

Why understanding shampoo formulation matters in filling

Many startup beauty brands, OEM factories, and personal care product manufacturers focus solely on filling output, speed, and equipment cost when selecting shampoo filling machines, overlooking the most critical factors—the shampoo’s formulation structure and viscosity.

In fact, the following aspects of shampoo formulation are also critical:

• Surfactant ratio
• Thickening system
• Whether it contains silicone oil (silicone shampoo)
• Whether it contains pearlescent agents or suspended particles
• Whether it is an organic herbal shampoo

All these factors directly impact filling precision, speed, nozzle selection, pressure settings, and even determine whether a gravity-fed, piston-driven, or servo-controlled filling machine should be used.

Therefore, this guide addresses shampoo filling challenges by starting with shampoo formulations, then extending to filling equipment selection and troubleshooting the most common issues encountered in actual production.

Shampoo formulation structure

Understanding the formulation structure of shampoo is the first step in selecting the right shampoo filler.

Modern shampoo formulations typically consist of 10 key functional components. Different ratios affect product viscosity, flowability, foaming properties, stability, and the choice of filling equipment.

Understanding these ingredients aids in selecting the appropriate piston-type filling machine, servo-driven filling machine, or gravity-fed filling machine.

Surfactants 40–70%

The most critical component affecting fluidity, serving as the primary cleansing and foaming agent in shampoo.

Type	Example	Characteristics	Impact on Filling Machines
Anionic surfactants	SLES, SLS, ALS	Strong foaming, high fluidity	Suitable for gravity-fed filling machines
Amphoteric surfactants	CAPB	Mild, increases viscosity	Recommended servo-piston fillers
Nonionic surfactants	APG	Natural ingredient trend	Viscosity instability, requires servo-driven machines

Thickeners （1–5%）

The core ingredient determining shampoo viscosity and filling difficulty (significantly influencing filling machine selection).

• Salt Thickeners: NaCl (most common, influenced by surfactant ratio)
• Polymer Thickeners: Carbomer, Xanthan Gum
• Low-Molecular-Weight polymers: PEG series

High-viscosity shampoos → requires servo piston shampoo filler

Conditioners（1–5%）

Make hair smooth and tangle-free.

• Silicone oils (Dimethicone, Amodimethicone) — commonly used for smoothness
• Cationic polymers (Polyquaternium)
• Plant oils (Argan Oil, Coconut Oil)

Silicone-containing shampoos are thicker, requiring higher pressure and torque during filling.

Humectants (1–3%)

Prevents scalp dryness: glycerin, propylene glycol.

Proteins (0.2–1%)

Keratin, Hydrolyzed Proteins → Key selling point for styling shampoos.

pH Adjusters (0.1–1%)

Citric acid, lactic acid → Shampoo pH typically ranges from 4.5–6.5

Preservatives (0.1–0.8%)

Prevents mold and spoilage: Phenoxyethanol, IPBC

Fragrance (0.1–1%)

One of the key differentiators in commercial shampoos

Colorants trace amounts

Used for brand recognition (blue, green, clear, etc.)

Water (Aqueous Base) 10–30%

Base solvent

Common issues in shampoo filling technical troubleshooting & guide

If your shampoo packaging machine malfunctions, the following troubleshooting steps may also apply.

The shampoo lathers excessively

There are five reasons for shampoo filling foaming:

• Shampoo contains surfactants (SLS/SLES) → Greater shear force produces more foam.
• Filling speed is too fast.
• Nozzle positioned too high above liquid surface → Generates turbulence.
• Low temperature → High viscosity → Bubbles resist collapse.
• Fluctuating pump pressure.

Technical solutions for shampoo foaming:

• Use submerged filling (Nozzle dives into the bottle.)
• Start slow → Medium speed → End slow (S-curve filling).
• Use anti-foaming suction nozzles.
• Increase material temperature to 30–40°C.
• Use variable frequency motors to maintain stable flow rate.

Shampoo filling inaccuracy (overfill/underfill)

Primarily caused by the following six factors:

• High shampoo viscosity causing unstable flow rate.
• Material temperature fluctuations.
• Pneumatic valve actuation delay.
• Worn piston seal rings.
• Inconsistent pump flow rate.
• Excessive backflow system resistance.

Shampoo packaging inaccuracy solutions:

• Replace pneumatic with servo drive (300% accuracy improvement).
• Add temperature control system.
• Install encoder on piston travel.
• Implement online weight feedback system.
• Periodically calibrate fill volume.
• Eliminate air resistance in return lines.

Low productivity in shampoo bottle packaging

Causes:

• Slow material reflux.
• Insufficient pump pressure.
• Weak vacuum suction system.
• Product is too viscous, requiring heating.

Solutions for shampoo bottle packaging speed：

• Increase pipe diameter to ≥ 32mm.
• Install a secondary booster pump.
• Add agitation and heating to the material tank.
• Replace with a screw pump (suitable for high viscosity).

Shampoo bottle filling issues: dirty bottle necks and liquid residue

Four Primary Causes:

• Incorrect nozzle selection.

• Excessively high filling speed.

• Narrow bottle neck.

• Liquid stringing.

Solutions for dirty shampoo bottle openings and residual liquid on bottle surfaces:

• Nozzle should reach the bottom during filling
•  Increase descent speed
• Use double-layer anti-drip nozzles
• Increase back-suction volume

Difficulties in winter shampoo filling

Caused by these three factors:

• Low temperature → Increased viscosity → Poor flowability
• Increased pump load
• Surging filling inaccuracies

Solutions for difficult shampoo filling：

• Heat material tanks to 35°C
• Pipe heating (hot water circulation or electric heating strips)
• Switch from piston pumps to screw pumps
• Reduce filling speed while improving stability