NAAC Block Manufacturing Process: From Mixing to Cutting and Curing

A NAAC block manufacturing process normally includes raw material batching, mixing, foaming, pouring, pre-curing, cutting, demolding, and non-autoclaved curing. Unlike AAC, NAAC does not use high-pressure steam autoclaving, so the production line must be designed around stable slurry preparation, controlled pore formation, accurate cutting, and a suitable curing area.

For buyers planning a NAAC block plant, the most important point is not simply how many machines are included. The equipment must match the required daily output, block dimensions, target density, raw materials, factory space, labor conditions, and local building-material requirements. Hengde currently lists NAAC production configurations from approximately 30 m³/day to 300 m³/day, with larger customized configurations also available.

What Is the Complete NAAC Block Manufacturing Process?

The typical process can be understood as eight connected stages:

1. Raw material preparation and batching

2. Mixing

3. Foaming or aeration

4. Pouring into molds

5. Pre-curing and green-body formation

6. Cutting

7. Demolding and handling

8. Non-autoclaved curing and finished-block storage

The critical difference from conventional AAC is the curing stage. ASTM's current C1693-11R25 specification defines AAC as a material cured using high-pressure steam, while a NAAC line does not rely on an autoclave.

This difference affects equipment selection, plant layout, curing space, production scheduling, and the time required before blocks are ready for use.

Which Raw Materials Are Used Before Mixing?

The raw-material system depends on the selected NAAC formulation rather than one universal recipe. Depending on the process, manufacturers may use cementitious materials, sand or fly ash, water, foaming agents, and other additives.

ASTM's description of AAC provides a useful reference for the general aerated-concrete process: cementitious materials, siliceous aggregates, water and an aerating agent are batched and mixed into slurry before casting. However, buyers should not assume that an NAAC formulation must use exactly the same material proportions as AAC.

What Should Buyers Specify for the Batching System?

Before requesting a quotation, specify:

For example, Hengde's published 200 m³/day configuration includes a power metering system, water metering system, screw feeders, and a physical foaming machine. The listed physical foaming machine is 1,100 × 700 × 1,000 mm with 7.5 kW power.

The lesson for buyers is straightforward: do not select a batching and mixing system only by equipment price. The system needs to support the target production capacity and the selected formulation.

How Does Mixing Affect NAAC Block Quality?

After batching, the raw materials are mixed to produce a consistent slurry. This stage determines whether cementitious materials, aggregates, water and aerating components are distributed evenly before the material enters the mold.

Poor mixing can create density variations, inconsistent pore distribution, unstable setting behavior, and cutting problems later in the process.

For this reason, the mixer should be evaluated together with the foaming system rather than as an isolated machine.

Hengde's published 50 m³/day configuration, for example, lists a special mixer measuring 2,000 × 1,200 × 1,200 mm with 22 kW power, together with a physical foaming machine rated at 7.5 kW.

What Should I Ask a Supplier About the Mixer?

Ask for the mixer model, working volume, motor power, mixing cycle, compatible raw materials, and expected batch output.

More importantly, request a formulation trial using your actual raw materials. A mixer that performs well with one sand, cement or fly-ash source may require different process settings when material characteristics change.

How Is the Aerated Structure Formed?

The next stage creates the lightweight cellular structure of the block. Depending on the selected NAAC technology, this may involve a physical foaming system or another controlled aeration method.

The objective is to generate a consistent distribution of air voids throughout the slurry while maintaining enough stability for the material to rise and set.

This is one of the most sensitive parts of the process because excessive or unstable foam can create a large variation in density and mechanical performance.

Why Is Foaming Equipment Important When Buying a NAAC Line?

The foaming system should be evaluated according to:

Foam generation capacity

Foam stability

Integration with the mixer

Target block density

Daily production capacity

Control method

Maintenance requirements

For a 50 m³/day Hengde configuration, the published physical foaming machine is 1,150 × 750 × 1,140 mm and 7.5 kW, while the line also includes a 7.5 kW air compressor.

These parameters demonstrate why the foaming system should be specified as part of the complete production line rather than purchased separately without process matching.

How Is the NAAC Slurry Poured Into Molds?

After mixing and aeration, the slurry is poured into molds.

The mold determines the basic geometry of the green body before cutting. Buyers should therefore decide the required finished block dimensions before finalizing the mold and cutting system.

A useful purchasing specification should include:

Hengde's published 50 m³/day line, for example, lists a mold measuring 1.2 × 1.2 × 0.62 m.

The actual mold size should not be copied directly for another project. It needs to be matched with the buyer's required block dimensions and production process.

When Should NAAC Green Blocks Be Cut?

Cutting normally takes place after the poured material has developed sufficient initial strength to maintain its shape but before final hardening.

This timing is critical.

If the green body is too soft, cutting can cause deformation, edge damage, tearing, or dimensional instability. If it becomes too hard, cutting resistance increases and the cutting process may become less efficient.

ASTM's description of AAC similarly places machine cutting after expansion and setting but before final hardening. NAAC uses a different curing route, but the principle of controlling the green-body condition before cutting remains important.

What Cutting Accuracy Should Buyers Look For?

Cutting accuracy should be stated as a measurable specification rather than described only as “high precision.”

Hengde states that its independently developed cutting system can process 6–8 m³ blanks in a single operation, with dimensional errors controlled within ±1 mm.

A published Hengde 300 m³/day configuration also specifies ±1 mm cutting accuracy and a 2 mm kerf. That line is designed around a three-gantry rotary vertical cutting system.

For a quotation, buyers should ask whether the stated accuracy refers to the machine's cutting tolerance, finished-block dimensional tolerance, or a specific test condition.

What Happens After Cutting?

After cutting, the green blocks are separated, handled, and transferred to the curing area.

Depending on the line configuration, the handling system may include demolding equipment, clamps, conveyors, pallets, stacking equipment, and other transfer systems.

This stage can become a bottleneck in a larger plant if the handling capacity is lower than the cutting output.

For example, Hengde's published 300 m³/day line includes systems for feeding, foaming, mixing, molding, demolding, peeling, cutting, conveying, packaging and control. The stated production workshop area is 2,000–2,500 m², with a listed land area of 6,000 m².

Therefore, a buyer planning a high-output plant should evaluate the entire material-flow route rather than only the main production machine.

How Are NAAC Blocks Cured Without an Autoclave?

This is the defining difference between NAAC and AAC.

NAAC blocks are cured without high-pressure autoclave steam curing. The curing arrangement therefore needs sufficient space and appropriate environmental/process control rather than an autoclave and associated high-pressure steam system.

ASTM C1693-11R25 specifically defines AAC around high-pressure steam curing, so it should not be used as if it were a direct product standard for every NAAC block. Buyers should identify the applicable local or project-specific standard for their intended NAAC application.

Hengde describes its NAAC process as using non-autoclaved curing and provides configurations from 30 m³/day, 50 m³/day, 100 m³/day, 200 m³/day and 300 m³/day.

How Much Curing Space Does a NAAC Plant Need?

There is no single curing-area number that applies to every NAAC plant.

The required area depends on daily output, curing time, block dimensions, stacking height, handling method, climate, and the number of production days represented by the curing inventory.

This is particularly important because eliminating an autoclave does not mean that curing requires no infrastructure. A buyer may save pressure-vessel and steam-system requirements while needing more space for curing and finished-product handling.

What Can Go Wrong in the NAAC Manufacturing Process?

The major production risks occur at the interfaces between process stages.

The important purchasing principle is that a NAAC line should be evaluated as a process chain, not as a collection of individual machines.

Which NAAC Production Capacity Should I Choose?

Hengde currently publishes configurations from approximately 30 m³/day to 300 m³/day, with additional capacity configurations available for larger projects.

These are capacity categories, not universal recommendations. The correct choice should be calculated from realistic market demand, available raw materials, factory space, labor, target products and expansion plans.

For example, Hengde states that its 30 m³/day configuration can occupy approximately 200–500 m², while larger production lines require correspondingly greater space.

How Should Buyers Compare NAAC Production Lines?

Before comparing quotations, prepare the same technical specification for every supplier.

NAAC Line Buyer Checklist

Product requirements

Block length, width and height

Target density

Required strength

Intended application

Local standard or project specification

Production requirements

Required m³/day

Operating hours

Expected working days

Future capacity expansion

Raw materials

Cement type

Sand or fly ash

Water quality

Foaming agent

Additives

Equipment

Batching system

Mixer

Foaming machine

Mold

Cutting system

Demolding equipment

Handling system

Curing arrangement

PLC/control system

Factory

Workshop dimensions

Curing area

Raw-material storage

Finished-product storage

Power supply

Water supply

Material-handling route

A quotation that only lists machine prices is difficult to compare. Ask suppliers to provide the complete process flow, equipment list, technical parameters, plant layout, utilities, installation scope and commissioning requirements.

How Does Hengde Configure a NAAC Production Line?

We configure NAAC production lines according to the required output, raw materials, block dimensions, target density, factory layout, labor conditions and automation requirements rather than treating every project as the same standard line.

Our published configurations include approximately 30, 50, 100, 200 and 300 m³/day, while the broader Hengde production range extends from 30 to 1,000 m³/day for lightweight block and wall-material projects.

For example, our published 200 m³/day configuration includes screw feeders, power and water metering systems, a 7.5 kW physical foaming machine, and conveying equipment.

For larger projects, our published 300 m³/day configuration specifies ±1 mm cutting accuracy, 2 mm cutting kerf, approximately 8–10 production personnel, and a recommended workshop area of 2,000–2,500 m².

The final equipment configuration should still be confirmed through project-specific technical design and raw-material testing.

Frequently Asked Questions About NAAC Block Manufacturing

How long does the NAAC block manufacturing process take?

The total cycle depends on the formulation, green-body setting time, cutting schedule and curing method. Unlike AAC, NAAC does not use the high-pressure steam-curing cycle defined for AAC under ASTM C1693.

Does a NAAC production line need an autoclave?

No. NAAC means non-autoclaved aerated concrete, so its process does not rely on high-pressure autoclave curing. This changes the equipment list and plant layout, but it does not eliminate the need for a properly planned curing area.

What capacity should I choose for a new NAAC plant?

Start with realistic market demand rather than maximum theoretical production. Hengde currently lists approximately 30, 50, 100, 200 and 300 m³/day configurations, so the line can be matched to different production scales.

Can the NAAC block size be customized?

Yes, the mold and cutting configuration can be designed around the required block dimensions. However, buyers should provide the finished block size, target density and local product requirements before the equipment is finalized.

What should I test before buying a NAAC block production line?

Test the actual local raw materials and confirm slurry behavior, foaming stability, setting characteristics, cutting performance and cured-block properties. The supplier should also clarify which product standards and test methods apply to the intended market because ASTM C1693 is specifically an AAC specification.

What information should I send to a NAAC equipment supplier?

Provide the target daily capacity, raw-material sources, block dimensions, target density and strength, available workshop area, local power conditions, intended application, automation preference and local standards. With this information, a supplier can develop a more meaningful equipment configuration and quotation.

Final Takeaway

A NAAC block manufacturing process is not simply mixing → cutting → curing. Stable production depends on the complete sequence from accurate batching and uniform mixing to controlled aeration, green-body formation, precise cutting, careful handling and properly planned non-autoclaved curing.

For buyers, the most important purchasing decisions are production capacity, raw-material compatibility, mixer and foaming configuration, cutting accuracy, curing space, automation level and applicable product standards. Hengde provides NAAC production-line configurations from small 30 m³/day systems to larger-scale solutions, with equipment and layouts configurable according to project requirements.

Request a Custom Quote from Hengde:
Email: hengdegz@gmail.com
Website: www.hengdemachine.com