How the Aerosol Contract Filling Process Works
Ilerspray's aerosol contract filling service follows four sequential stages: loading the active product into the empty container, installing and sealing the valve, injecting the propellant through the valve, and weight control followed by a hot water bath to verify airtightness. The plant, in Torres de Segre (Lleida), has a capacity for more than 12 million units per year.
The Four Stages of the Filling Process
The first stage is container preparation. Empty cans, made of aluminum or tinplate, are inspected for dents, scratches, or manufacturing residues before any product enters. Defective units are rejected at this point, not at the end of the line, to avoid product loss and ensure batch integrity.
The second stage is loading the base product: the active ingredients, without propellant, are dosed into the container using precision volumetric fillers. In formulations containing particles, such as paints or pigmented products, stainless steel mixing balls are incorporated before filling to ensure homogenization during use by the end consumer.
The third stage is the installation and crimping of the valve, which creates the airtight seal capable of maintaining pressure throughout the product's shelf life. The crimping force is calibrated for each valve and can combination, considering the valve type, the cup material, and chemical compatibility with the formulation.
The fourth and final stage is propellant injection through the already sealed valve. It is the most critical phase: the propellant is introduced under controlled pressure and temperature conditions, and the weight is continuously verified to detect any deviation from the client's specification.
How is the Aerosol Checked for Leaks?
Each unit passes through a hot water bath at 50 °C. The heat expands the internal gas and any micro-leak becomes immediately visible; units that do not pass the test are automatically rejected before reaching labeling.
This verification is not optional: the ADR (European Agreement concerning the International Carriage of Dangerous Goods by Road) establishes airtightness as a prerequisite for the transport of pressurized aerosols. Continuous weight control during filling acts as the first line of detection, and the water bath is the definitive batch-by-batch confirmation.
The Propellants Used by Ilerspray
Hydrocarbon propellants, mainly propane, butane, and isobutane, are the most common in the home, automotive, and cosmetic categories covered by Ilerspray's contract filling. They are colorless, odorless, and heavier than air, so they accumulate in low areas of the facility and require specific safety protocols in the plant.
For applications that require it, the formulation can incorporate compressed gases such as nitrogen or compressed air. The choice of propellant directly affects the output pressure, the spray pattern, and compatibility with the active product, so it is decided during the formulation phase, before starting production.
💡 Technical tip: The valve type, propellant pressure, and actuator must be defined together with the formulation, never independently. Changing one of the three elements at the end of development may force the reformulation of the other two and delay the start of the batch.
Which Sectors Can Aerosol Contract Filling Cover?
Ilerspray manufactures under contract for four major sectors: cosmetics (deodorants, hair products, spray creams), home (air fresheners, insecticides, household cleaners), automotive (cleaners, lubricants, protectors), and industrial (degreasers, maintenance lubricants, high-temperature products).
The plant works with both aluminum and tinplate cans, from international container suppliers. The formulation is customized for each client, with technical guidance from the Ilerspray team, and labeling and container design are also part of the service.
Certifications Backing the Process
Ilerspray holds ISO 9001/2015 for the quality management system and ISO 22716/2017 for good manufacturing practices in cosmetics, which enables the production of cosmetic aerosols under European regulatory requirements.
Both certifications imply traceability at every stage of the process, from the receipt of raw materials to the dispatch of the finished batch, and periodic audits by an external body.
Ilerspray's custom aerosol contract filling includes the comprehensive management of all these stages for the client, from formulation and production to quality control and final labeling, with direct logistical access to the Port of Barcelona.
