The Most Frequent Mistakes When Packaging Viscous Products (and How to Fix Them)

If you work in a production plant that packages creams, thick sauces, adhesives, or gels, you have surely faced one of these problems: irregular dosing, containers stained by dripping, or a line that moves slower than it should.

These inconveniences are not coincidental. They usually appear when the packaging equipment is not prepared to work with high-viscosity products. And the consequences go beyond aesthetics: we're talking about material waste, loss of time, and increased machinery wear.

In this article, we review the most common mistakes we find in companies from different sectors, cosmetics, food, industrial chemistry, and explain what technical solutions exist for each one.

Why Packaging Dense Products Requires Specific Equipment

Unlike liquids like water or alcohol, products with high viscosity (above 1,000 cP) exhibit very different behaviors during filling. They don't flow the same, tend to leave residue on the valves, and require more force to move through the pipes.

This means that a filling machine designed for light liquids simply won't work well with a body cream or a barbecue sauce. It might work, but inefficiently.

Sectors Most Affected by These Problems

These types of difficulties appear especially in:

• Cosmetics manufacturers (face creams, masks, balms)

• Food industry (sauces like ketchup, mayonnaise, honey, syrups)

• Industrial chemical products (adhesives, silicones, lubricants, paints)

• Concentrated liquid fertilizers and viscous detergents.

First Mistake: Using Pumps Not Designed for Thick Products

One of the most common mistakes is trying to propel a dense product with a standard centrifugal pump. These types of pumps work perfectly with low-density liquids but rapidly lose efficiency when the viscosity exceeds 500 cP.

The result is predictable: the product does not flow constantly, there are line stoppages, and the pump suffers premature wear.

Which Type of Pump Works Best

For viscous products, it is advisable to use positive displacement pumps. The most commonly used are:

• Piston pumps (ideal for very dense products)

• Lobe pumps (good balance between flow rate and viscosity)

• Reinforced peristaltic pumps (especially useful when the product is sensitive to shearing)

These pumps maintain constant pressure regardless of the product's density, which translates into more regular filling and fewer mechanical problems.

Second Mistake: Valves That Fail to Achieve a Clean Cut

When a valve is not designed for viscous products, the most obvious problem is dripping. The product does not cut cleanly at the end of the fill, ending up staining the container or falling outside of it.

In addition to material waste (which can be between 2% and 5% of the total), this necessitates manually cleaning the containers or constantly adjusting the product's net weight.

The Solution: Anti-Drip Valves with Pneumatic Cut-Off

Valves specific for viscous products incorporate mechanical or pneumatic cut-off systems that guarantee a clean seal. This significantly improves dosing accuracy (with error margins below 0.5%) and reduces cleaning time between cycles.

Third Mistake: Insufficient Pipe Diameter

Although it may seem like a minor detail, the diameter of the pipes plays a fundamental role when working with dense products. If the piping is too narrow, flow resistance increases, and the pump has to exert much more effort to move the product.

This not only slows down the process but also shortens the lifespan of the components.

Fourth Mistake: Not Considering the Product's Temperature

Many viscous products radically change their behavior depending on the temperature. A cream that flows well at 25 °C can become almost impossible to dose if the temperature drops to 15 °C. The same applies to syrups, waxes, or industrial greases.

If this factor is not controlled, dosing will be irregular, and the results will be inconsistent from one batch to another.

Thermal Control Solutions

Depending on the product, it may be necessary to incorporate:

• Hoppers with heating jackets (to keep the product at a stable temperature)

• Heated hoses (especially useful for thermosensitive products)

• Automatic preheating systems before filling

In some cases, simply keeping the product in a climate-controlled room solves the problem. But when viscosity is highly temperature-dependent, it is best to integrate thermal control directly into the packaging line.

Fifth Mistake: Trying to Adapt a Generic Machine

This is probably the most costly mistake in the medium term. Using a standard filling machine for viscous products may seem like an economical solution at first, but it ends up generating more expenses: longer filling cycles, increased maintenance, more product waste, and lower accuracy.

A machine specifically designed for these types of products usually includes:

• Robust and adjustable pumps according to viscosity

• High-performance anti-drip valves

• Hoppers equipped with agitators (to prevent phase separation in products with particles)

• Volumetric or gravimetric dosing systems, according to the product's needs

Furthermore, this type of equipment is sized to withstand the mechanical demands involved in working with dense products, so their lifespan is considerably longer.

At Olmos Maquinaria, we have years of experience designing and manufacturing industrial fillers adapted to high-viscosity products, from cosmetics to industrial chemistry, and we offer personalized technical advice for each case.