Micron-Level Asphalt Foaming System AF-BOX 3C6N (20-Times High-Expansion Patented Foamed Bitumen Unit)

The micron-level asphalt foaming system AF-BOX 3C6N is a highly-integrated modular foaming device independently developed for HIRAP high-intensity asphalt recycling and hot-mix asphalt production. It achieves up to 20-times expansion rate and 11-second half-life, solving key pain-points for high-RAP content recycled pavement construction.

Key Features & Working Principle

This system applies patented three-chamber six-nozzle technical architecture. Through high-pressure precision metering, the system generates micron-diameter foam bubbles. High-temperature asphalt mixes with atomized water for instant volume expansion.

After foaming, bitumen forms ultra-thin 5-10μm film. It penetrates the interface between aged asphalt and recycled aggregate, realizing complete wrapping effect. It softens aged bitumen properly, improves blending of old-new binder and enhances low-temperature crack resistance of mixture.

Its intelligent unit keeps real-time tracking for foam expansivity of the system and half-life. With the micron-level asphalt foaming system, every ton of hot-mix material can obtain stable and controllable foaming quality. Qualified foam from this system shall show creamy dense texture without large naked-eye bubbles or undiffused liquid bitumen streaks.

Performance & Material Matching

Under standard test condition with 70# base bitumen at 155℃: water-usage ratio keeps 2%, measured expansivity reaches 20 times, foam half-life reaches 11 seconds, both indexes surpass general industry thresholds.

With this system, 70# and 90# base bitumen get optimal foaming performance. When this system processes SBS modified bitumen, users should add dedicated foaming agent or raise working temperature by 10℃. Only clean fresh water can be adopted for foaming. Hard-water application requires regular nozzle maintenance for scale removal.

System Composition of the Micron-Level Asphalt Foaming System

3C6N Foaming Main Unit

Patented three-chamber six-nozzle core component, guarantees stable and consistent micron-size bubble generation.

Intelligent Control Unit

Real-time data monitoring for foaming expansion rate and half-life. Digital control ensures stable quality for every batch of asphalt mixture.

Modular Cabinet

Compact integrated cabinet layout. It supports quick installation and retrofitting for different brands of existing asphalt mixing plants.

Engineering Value & Cost-Saving

For projects using this system with RAP content higher than 30%, traditional technology often suffers poor aggregate coating, aged asphalt brittleness and grading segregation. This equipment solves those typical bottlenecks on-site.

Benefiting from the micron-level thin-film coating effect of this system, asphalt dosage can be reduced by 5-10% without sacrificing road performance. Even under fixed asphalt dosage, foamed bitumen improves residual stability and high-temperature anti-rutting performance. Marshall test verification is recommended for final asphalt proportion confirmation.

Export & On-site Installation

This modular foaming equipment can be delivered under FOB Qingdao. Complete operation manuals are supplied together with machine. Our technical team provides remote guidance for plant retrofitting and commissioning work.

AF-BOX System Composition of the micron-level asphalt foaming system and Specifications

AF-BOX (3C6N) Micron-Level Asphalt Foaming System – Foamed Asphalt Parameters

Why Micron-Level Bubbles Matter

Foamed bitumen works by expanding the binder so that a small mass covers a large aggregate surface. The size of the bubbles produced during that expansion determines how well the coating performs. Large bubbles burst quickly and leave patches of aggregate without a binder film; small, evenly distributed bubbles produce a thin but continuous film that reaches the aged surface of reclaimed material and holds it in the mix.

The AF-BOX 3C6N achieves this with a patented three-chamber six-nozzle architecture rather than a single injection point. Water is introduced in stages, which narrows the bubble size distribution and produces what the industry describes as micron-level foaming. The practical consequence is a film thin enough to cover more aggregate per unit of binder, which is the mechanism behind the stated 5–10% reduction in asphalt dosage.

Reading the Expansion and Half-Life Figures

Two measurements describe foaming performance on the AF-BOX 3C6N: expansion ratio and half-life. Under the standard condition of 70# base bitumen at a measured working temperature of 155 °C with a water dosage ratio of 2%, the system measures 20 times expansion and an 11-second half-life. Both figures exceed the common industry reference points of 8 times expansion and 8 seconds half-life.

• 20 times expansion means the bitumen volume grows twenty-fold, which is what allows a reduced binder mass to coat the full aggregate surface.
• 11 seconds half-life means the foam stays workable long enough to be mixed and distributed inside the drum before it collapses.
• 2% water ratio, inside the recommended 1–3% band, leaves no excess moisture in the finished mixture.

The control package monitors expansion rate and half-life in real time. That matters for two reasons: the figures are the acceptance criteria that the plant will be judged on, and a drift in either one is the earliest indication that a nozzle is scaling up or that the water supply has changed.

Bitumen Types and Water Quality

70# and 90# base bitumen deliver the best foaming performance, and the recommended working temperature range is 150–160 °C. SBS modified bitumen can also be foamed, but it is advisable to use a special foaming agent and to raise the working temperature by about 10 °C to obtain a satisfactory result. Regarding water, clean fresh water free of impurities is required; where hard water cannot be avoided, nozzles must be cleaned on a regular schedule to prevent scale accumulation and blockage.

Retrofitting an Existing Mixing Plant

The system is supplied as a modular unit comprising the 3C6N foaming main unit, an intelligent control unit and a modular cabinet. That arrangement is what allows it to be fitted to most mainstream brands of asphalt mixing plant without rebuilding the host plant: the existing drum, screens, hot bins and mixer continue to operate unchanged, and the foaming skid is tied into the bitumen line and the control system.

Because the retrofit is modular, the survey carried out before fabrication decides how smooth the installation will be. Recording the bitumen tapping point, the available space beside the plant, the water supply quality and the host control protocol in advance avoids the assumption-driven delays that account for most overruns on retrofit projects. For a worked example of the process, the Hengshui retrofit described in our project notes covers the full sequence from survey to acceptance.

The Commercial Case for High-RAP Production

A foaming system changes what a plant can sell. With micron-level foaming, mixtures containing more than 30% reclaimed asphalt pavement can be produced with stable coating and reduced segregation risk, which raises the proportion of reclaimed material that can be used in each tonne of mix. Since reclaimed material is already owned and stockpiled, replacing virgin aggregate and binder with it is a direct reduction in the cost of the finished tonne.

The environmental argument is a by-product of the same change. Higher reclaimed content means less new material quarried, less binder consumed and lower fuel use per tonne when the mixture is produced as warm mix. For projects tendered with a sustainability criterion, being able to document those figures is often worth as much as the saving itself.

Installation, Utilities and Support

The unit is built at the LIJIU works in Dezhou, tested before shipment and quoted FOB Qingdao, with ISO 9001 certification held for the manufacturing operation. Site requirements centre on the electrical supply for the control cabinet, a water supply of consistent quality and clean access to the bitumen line. Daily care is limited mainly to the nozzles and the water circuit, which is why a small stock of spare nozzles and filter elements is the most useful consumable to hold on site.

Further Reading

For general industry background, see the Asphalt Institute and the Federal Highway Administration asphalt pavement recycling programme. These are independent, non-commercial references and are not connected with LIJIU.

Related equipment and guides

• AF-BOX Foaming System
• LIJIU Emulsified Asphalt Equipment LRA-LRB-LRC Series (6-15t/h Modified Bitumen Emulsification Plant)
• Bagged Bitumen Melting Equipment KRD-30 KRJ-40 (2-6t/h High-Performance Patented Melting Unit)

Standards and references

Specifications on this page follow ISO 9001:2015 Quality management systems. Ask us for the full test report when you request a quote.