Aerosol is a packaging form which encapsulates the contents and propellant in a pressure container and controls the release through a valve. Traditional aerosol cans and emerging bag on valve technology are two mainstream aerosol packaging solutions, each with its own advantages and disadvantages.
This blog will conduct a comprehensive comparative analysis of the two technologies from the aspects of structural principles, performance, application scenarios, etc., to help you gain a deeper understanding of aerosol packaging and provide a reference for product selection
Aerosol Canister
Basic Structure and Features
Aerosol cans are usually composed of an aluminum or tin can body, a valve and a nozzle. The can body is highly pressure-resistant and can withstand high internal pressure. The valve and nozzle control the release of the contents and atomize them into fine particles for easy use. Aerosol cans are usually filled with liquefied gases such as propane and butane as propellants, and the pressure generated by their volatilization is used to push the contents out.
| Structural components | Materials/Features | Functions |
| Can body | Aluminum/Tin | Pressure-bearing, storage |
| Valve | Precision metal parts | Controlled release |
| Nozzle | Engineering plastics | Atomization adjustment |
| Propellant | Liquefied gas | Provide pressure |
Working Principle
The liquefied gas in the can evaporates at room temperature, forming a uniform high-pressure environment in the closed can. When the valve is pressed, the high-pressure gas forces the contents to be discharged through the narrow nozzle and atomized in the air³. The pressure in the can will drop slightly as the contents decrease, but it will always remain within a stable range to ensure the continuity of the spray.
Main Advantages
The biggest advantage of aerosol cans is their stable pressure output and continuous and consistent spray effect. As long as there is content in the can, it can provide relatively constant atomized particles and spray distance. Mature packaging technology also ensures the good leak-proof performance and safety of aerosol cans. In addition, the production process of aerosol cans is relatively simple, and the mass production cost is low, which is conducive to controlling product prices.
Technical limitations
Traditional aerosol cans also have some limitations. Due to the mixing of contents and propellants, and the limitation of pressure balance in the can, it is usually impossible to completely spray the materials in the can, and there will be a small amount of residue. The vertical downward spraying posture also limits the use scenario. In addition, direct contact between the contents and the propellant may introduce impurities and affect the purity of the product.
Bag on Valve
Basic Structure and Features
At the heart of the Bag on Valve system is a flexible plastic bag that encapsulates the contents and prevents them from coming into direct contact with the propellant. The mouth of the bag is connected to a special valve which, together with a nozzle, controls the discharge. Outside the bag, the tank is filled with compressed air or nitrogen, and the contents are discharged by squeezing the bag. The bag on valve structure cleverly realizes the isolation of the contents from the propellant.
| Structural features | Materials/design | Functional advantages |
| Inner bag | Flexible plastic | Isolation protection |
| Special valve | Precision design | Precise control |
| External pressure | Compressed gas | Stable output |
Principle of operation
The bag on valve system utilizes an external gas to squeeze the inner bag, discharging the contents through the valve and nozzle. As the contents diminish, the external gas is continuously replenished, maintaining pressure on the inner bag until the contents are depleted⁷. Since the contents are protected by the flexible bag and isolated from the propellant, an arbitrary spraying attitude can be realized.
Key Advantages
The most outstanding advantage of the bag on valve technology is the complete separation of the contents from the propellant, so that the product is not contaminated by gas impurities and the purity of the product is guaranteed. The squeeze-out method of the flexible bag body also offers the flexibility of 360° spraying without shaking, making it easier to use. In addition, the contents can be fully utilized, reducing waste.
Technical limitations
However, the complexity of bag on valve technology also means higher production costs. The material requirements for the inner plastic bag are high, requiring a delicate encapsulation process and difficult quality control. Although the separation of inside and outside improves the purity of the product, the compressive strength of the plastic bag is not as strong as the metal can body, and the safety is slightly insufficient under extreme conditions. The current market penetration of bag on valve products is still to be improved.
Performance comparison between bag on valve and aerosol canisters
Spray efficiency
The aerosol canister provides a consistent spray effect due to its stable internal pressure. Although the bag on valve system has a more flexible spray angle, the atomized particles are larger and the spray efficiency is slightly lower than that of the aerosol can. The figure below compares the atomized particle distribution of the two technologies:
Product utilization
A major advantage of bag on valve technology is its high product utilization. The contents are squeezed in the flexible bag and can be discharged almost 100%. Aerosol cans are limited by the spray principle and usually have 3-5% residue. This means that for every 100 bottles of product, the bag on valve can produce 3-5 more bottles of actual output.
Service life
The service life of aerosol cans and bag on valves is not much different, mainly depending on the characteristics of the contents and the frequency of use. For some products that are volatile or easily react with packaging materials, the isolation protection of the bag on valve can extend the shelf life. But overall, the two technologies are comparable in service life.
Environmental performance
Propellant usage
Traditional aerosol cans mostly use liquefied petroleum gas as propellant, such as propane, butane, etc. Although these substances are low-cost, they will produce a greenhouse effect and are not environmentally friendly. The bag on valve system usually uses compressed air or nitrogen as a propellant, which is more environmentally friendly.
Recyclability of packaging materials
Aerosol cans are mainly made of aluminum or iron materials, and the recycling process is relatively mature. The plastic bag materials in the bag on valve are of various types, which increases the difficulty of recycling classification and reuse. From the perspective of the recyclability of packaging materials, aerosol cans have an advantage.
Carbon footprint analysis
From the perspective of life cycle carbon footprint, aerosol cans and bag on valves have their own advantages. The production process and logistics transportation of aerosol cans are relatively simple, and the carbon emissions per unit product are low. However, if bag on valve products can be mass-produced, their efficient utilization rate can also reduce carbon footprint. The specific situation needs to be evaluated in combination with product characteristics and production scale.
Cost-effectiveness analysis
Production cost
Aerosol can technology is very mature, and the cost advantage of large-scale production is obvious. In contrast, the valve and bag structure of the bag on valve system is more complex, and the requirements for equipment and process are higher, and the unit production cost is more than 50% higher.
The following is the typical production cost structure of the two packaging:
| Cost items | Aerosol canister | Bag on valve |
| Raw materials | 40% | 35% |
| Production and processing | 25% | 40% |
| Packaging and transportation | 20% | 15% |
| Other expenses | 15% | 10% |
Operating expenses
Due to its excellent product utilization rate, bag on valve products have an advantage in the content cost per unit product. This is particularly prominent in products with higher content value. In addition, bag on valve products can also reduce the additional processing costs caused by residual waste.
Return on Investment
Comparison of the return on investment of aerosol cans and bag on valves requires comprehensive consideration of factors such as product positioning, production scale, and market capacity. Generally speaking, aerosol cans have a greater cost advantage when producing low-value products on a large scale. For high-value products produced in small batches, bag on valves can provide better returns due to their product utilization and flexibility.
Comparison of the Application Areas for Aerosol Canisters and Bag on Valves
Different industries have different needs for aerosol packaging systems, and the Aerosol Canister and Bag on Valve systems are unique. Let's analyze the advantages of each in detail.
Cosmetics & Personal Care
| Product Types | Recommended Systems | Reasons for Selection |
| Perfumes | Aerosol canisters | Consistent atomization and high cost-effectiveness |
| Hair Spray Styling Spray | Aerosol Canisters | Constant and stable spray pressure |
| Foundation Spray | bag on valve | Avoids oxidization and keeps product stability |
| Essence Spray | bag on valve | Can be used at all angles, high product purity |
Product experience and shelf life are critical factors in choosing a packaging system in this sector. Aerosol cans are suitable for products that require constant and stable pressure, while bag on valve systems are better suited for essence products that need to maintain a high level of purity.
Pharmaceutical applications
Pharmaceutical products require packaging systems in the following areas:
Asepticity requirements
Dosing accuracy
Ease of use
Product stability
| Type of drug | Recommended packaging | Key considerations |
| Topical Anti-inflammatory Sprays | Aerosol Canisters | Cost-Effectiveness and Stability |
| Nasal Sprays | bag on valves | Aseptic Requirements & Dosing Accuracy |
| Oral Spray | bag on valves | Product purity and ease of use |
Industrial applications
In the industrial sector, aerosols are used in a wide range of applications such as heavy-duty lubrication, equipment rust prevention and mold cleaning. The selection of industrial applications is based on actual application requirements:
Aerosol cans are suitable for the following scenarios:
bag on valve System Scenarios:
Selection Criteria Key Considerations:
Food applications
Food safety is a primary concern and packaging systems need to comply with regulatory requirements.
| Food Category | Recommended Packaging | Key Considerations |
| Cooking Oil Spray | Aerosol Canisters | Pressure Control & Service Life |
| Fruit & Vegetable Spray | bag on valves | Product Purity & Shelf Life |
| Flavoring Spray | bag on valves | Food Safety & Convenience |
Special Note: Food-grade bag on valve systems utilize specialized food-grade inner bag materials and are subject to relevant food contact material standards.
Application Points Summary
Scenarios for selecting aerosol cans
Scenarios with bag on valve systems
Requires high product purity
High product purity required
High product value
Strict requirements for product stability
Technological Innovations and Cost Optimization in Aerosol Spray Technology
Breakthroughs in materials technology
Bag on Valve technology is undergoing a significant phase of innovation, particularly in materials science:
| Technology Direction | Innovation Focus | Application Value |
| Inner Bag Materials | High Strength Laminates | Improved Product Stability |
| Valve Design | Precision Control System | Improvement of Injection Precision |
| Sealing Technology | New Sealing Materials | Extend Shelf Life |
Improvements in Manufacturing Processes
The application of automation technology promotes the improvement of production efficiency:
Intelligent production line put into operation
Quality control system upgrades
Production process optimization
These advances have led to a gradual reduction in the production cost of bag on valve products and a significant increase in market competitiveness.
The trend of environmental protection leads to product innovation
The green packaging development
Modern packaging technology is developing in the direction of environmental protection:
Use of recyclable materials
Adoption of environmentally friendly propellants
Reducing the use of packaging materials
Upgrading consumer demand
The market demands higher product purity and environmental friendliness:
Non-contact injection system
Use of natural raw materials
Recyclable packaging materials
Optimization of market segment applications
Development in the medical field
Innovations in the field of personal care
Intelligent injection system development
Application of anti-counterfeiting technology
Portable design improvements
Upgraded industrial applications
Enhanced adaptability to special environments
Corrosion resistance enhancement
Spraying efficiency optimization
Suggestions for industry development
Recommendations for manufacturing enterprises
Increase investment in technology research and development
Focus on Environmentally Friendly Applied Materials
Expand the application of market segments
Suggestions for brand owners
Choose suitable packaging system according to product characteristics.
Emphasize product safety and environmental protection
Focus on cost-benefit balance
Conclusion
Aerosol canisters and bag on valve systems each have their own advantages, but bag on valve technology has shown unique advantages in the fields of medicine, high-end cosmetics, etc. with its advantages such as high product purity, 360° spraying, and higher utilization rate.
As a professional filling equipment manufacturer, Weijing provides advanced bag on valve filling machines to help companies improve product quality and achieve production upgrades. Welcome to contact Wejing to learn more about bag on valve filling solutions.
FAQs
Q: What is the main difference between aerosol canisters and bag on valve systems?
A: Aerosol canisters mix contents with propellants, while bag on valve systems separate them using a flexible inner bag. This allows bag on valve systems to maintain higher product purity.
Q: Which packaging system is better for products requiring high purity?
A: Bag on valve systems are better for products requiring high purity, as they prevent direct contact between the contents and propellant. This is especially important for pharmaceutical and high-end cosmetic products.
Q: Do bag on valve systems offer any usage advantages over aerosol canisters?
A: Yes, bag on valve systems allow for 360° spraying angles and nearly 100% product utilization. Aerosol canisters are limited to upright spraying and often leave residual product.
Q: Are aerosol canisters or bag on valve systems more environmentally friendly?
A: Bag on valve systems typically use more environmentally friendly propellants like compressed air or nitrogen. However, aerosol canisters are usually made of more easily recyclable materials like aluminum.
Q: Which packaging system is more cost-effective for mass production?
A: Aerosol canisters are generally more cost-effective for mass production due to their simpler design and manufacturing process. Bag on valve systems have higher production costs due to their more complex components.
