What is the function of glass beads in aerosol cans?

In daily life, when we use aerosol paint or festival snow spray cans, we can always hear a crisp “clinking” sound from inside the can. — this is actually the glass beads inside the canister at work. These seemingly simple little beads are the key to ensuring uniform and stable spray effects. Today, we will reveal the three secrets of these glass beads: why are they indispensable? How are their size and quantity selected based on different products? And how do factories precisely dispense these glass beads?

1. The role of glass beads

(1) Promote uniform mixing of contents

Long-term static placement causes pigments, drugs, or solvents to separate and settle. Glass beads roll and collide to vigorously stir the contents, quickly restoring a uniform mixture and ensuring that the concentration of the sprayed material remains stable and consistent. For example, in automotive painting, fine paint mist can create a natural color transition on the car body and a high-quality appearance.

(2) Preventing Sedimentation from Blocking Valves

Sedimentation near valves can clog nozzles or channels, causing the spray mechanism to malfunction. Glass beads physically disperse sedimentation, reducing the risk of blockages and ensuring smooth and reliable spray flow.

(3) Improving Spray Quality and Effectiveness

Uniform mixing ensures consistent physical and chemical properties of the contents (e.g., viscosity, dispersion), achieving the desired spray effect (e.g., coverage or drug release). Take the common “snow spray can” used during festivals as an example: when shaking the can, the rolling and colliding of glass beads vigorously mixes the internal foaming agents and other components, producing white foam that is more fluffy and uniform, thereby simulating a realistic snowflake falling effect and enhancing the visual experience of festival celebrations or stage performances.

2. How to choose the size and quantity of glass beads?  

(1) Size selection  

‌Spray paint type‌: We recommend large diameter beads of 16-20 mm, which can thoroughly disperse pigment particles through vigorous rolling to ensure an even and smooth paint film (such as automotive spray paint cans).

‌Snow spray applications:‌ Use medium-sized beads with a diameter of 6-10mm to balance mixing force and foam fineness (e.g., holiday decoration snow spray cans).

(2) Quantity Configuration

‌Single Bead Solution‌: Suitable for small containers under 200mL or low-viscosity liquids, saving space while meeting basic mixing requirements.

‌Multi-ball Solution‌ (2-3 balls): Designed for large containers over 500mL or high-viscosity products (e.g., spray paint containing metal powder), enhancing mixing efficiency through multi-directional collisions.

‌Operating Principle‌: The balls form a three-dimensional stirring network when shaken, effectively preventing component layering or sedimentation, ensuring consistent spray quality.

In general, glass beads play an important role in mechanical agitation in aerosol cans, preventing the contents from separating and settling through rolling and collision, avoiding valve blockages, and ensuring spray quality. Their size and quantity must be carefully selected based on product type and can specifications, while automatic glass bead dispensers enable precise and efficient production, ensuring that glass beads function stably.

3. Automatic Glass Bead Placing Machine

The automatic glass bead machine consists of two parts: a funnel and a rotating disc for selecting glass beads.  

(1) The funnel feeds the beads through the selection disc, placing them in the tank in a regular pattern according to the specified number of beads.  

(2) The machine can automatically detect insufficient or misaligned beads.  

(3) It improves productivity and reduces labor.

(4) Compressed air is used as the power source, ensuring stable and reliable operation.  

(5) Widely used in industries such as automatic spray painting, confetti production, cosmetics, and other applications requiring glass bead dispensing.

In general, glass beads play an important role in mechanical agitation in aerosol cans, preventing the contents from separating and settling through rolling and collision, avoiding valve blockages, and ensuring spray quality. Their size and quantity must be carefully selected based on product type and can specifications, while automatic glass bead dispensers enable precise and efficient production, ensuring that glass beads function stably.