Question 1

How to Prevent Clay Bricks from Collapsing in Tunnel Kilns？

Accepted Answer

1. Pre-firing Material Constraints (The "Foundation" Stage)

Collapse often begins before the bricks even enter the kiln if the green body lacks physical integrity.

Moisture Threshold: The residual moisture content must be kept below 6%. High moisture levels drastically reduce the compressive strength of the bricks, causing the bottom layers to buckle under the weight of the stack.
Material Aging: Clay requires at least 3 days of aging to ensure uniform plasticity and water distribution. Insufficient aging leads to internal stresses and a fragile structure.
Mechanical Density: Ensure an extrusion pressure of ≥40kg/cm² to increase the density of the green body, making it more resistant to deformation at high temperatures.

2. Strategic Stacking Techniques (Mechanical Stability)

Stacking is not just about volume; it is about managing gravity and thermodynamics.

The "Four-Point" Standard: Stacks must be level, stable, vertical, and straight. Any minor deviation in the center of gravity will be amplified as the bricks soften in the heat.
Airflow Optimization: Follow the principle of "Dense Edges, Sparse Centers" and "Dense Tops, Sparse Bottoms." This balances the temperature across the kiln cross-section, preventing the edges from over-firing while the center remains under-fired.
Load Management: Due to the high sensitivity of clay, limit the stacking height to 12 layers or fewer. This minimizes the static pressure on the base bricks.

3. Dehumidification in the Preheating Zone (The "Critical" Stage)

This is the most common zone for collapses. If moisture is not evacuated efficiently, the bricks effectively "steam" and lose their rigidity.

Inlet Temperature Control: Keep the initial drying air below 116°C. Temperatures above this threshold cause the surface to harden too quickly, trapping steam inside and creating internal pressure.
Heating Rate: Maintain a steady rise of 6–8°C/h. Sudden temperature spikes, especially in winter, can cause thermal shock and structural failure.
Ventilation and Pressure: Ensure the exhaust fan provides sufficient negative pressure. Poor ventilation causes moisture to linger and re-condense on the bricks, leading to "soggy" bricks that collapse instantly.

4. Firing Zone Temperature Management (Thermodynamic Control)

Once the bricks reach high temperatures, preventing them from entering a pyroplastic state (melting) is vital.

Anti-Overfiring Measures: Strictly monitor the sintering peak. Exceeding the clay's softening point leads to viscous flow, where the bricks begin to behave like liquid and slump.
Internal Fuel Ratio: Control the amount of internal additives (coal powder or gangue). Excessive internal fuel generates uncontrollable heat within the stack, causing the bricks to "melt from the inside out."
Visual Monitoring: Use inspection holes to watch for "white-out" conditions or "shimmering/swaying" stacks, which are immediate warning signs of imminent collapse.

5. Infrastructure and Mechanical Integrity (Environmental Factors)

The physical environment of the kiln must remain consistent to prevent mechanical triggers.

Track Leveling: Regularly inspect kiln car tracks. Uneven rails cause vibration and jolting, which can topple a stack that is already weakened by heat.
Kiln Structure Maintenance: Check for sagging roof bricks or protruding exhaust ports. Mechanical obstructions are a frequent cause of "domino-effect" collapses during car movement.

Question 2

How to Crusher Output in Sintered Brick Plants Efficiently？

Accepted Answer

In sintered brick production lines, the output and quality are often restricted by four key pieces of equipment: crushing equipment, belt conveyor equipment, vacuum extruders, and kiln thermal equipment. Among them, jaw crushers and hammer crushers, as common primary and secondary crushing equipment, directly determine the overall production efficiency of the entire line. Many brick plant operators are eager to maximize crusher output while ensuring the particle size of crushed materials—here are practical and actionable tips to achieve this goal.

First, ensure proper feeding. To make the jaw plates wear evenly and reduce operating costs, gangue or hard shale should be evenly distributed along the feeder inlet and fill the crushing chamber completely. Uneven feeding will not only accelerate jaw plate wear but also reduce crushing efficiency, leading to unnecessary energy waste.

Second, adjust the feeder amplitude reasonably. During normal use of the feeder, you can adjust the amplitude through the knob on the control box within the rated amplitude range according to the required productivity, so as to achieve stepless adjustment of the feeder. Sufficient amplitude ensures that materials enter the crushing chamber continuously and stably, avoiding gaps that affect output.

Third, pay attention to feeding precautions. It is crucial to prevent iron blocks from entering the crushing chamber, as iron blocks can damage jaw plates and other key components. The height of the materials to be crushed should not exceed the fixed jaw plate, and the maximum feed particle size should be smaller than the feed inlet—large blocks are likely to block the crushing chamber and reduce crushing efficiency.

Fourth, set a reasonable discharge port size. The discharge port is the distance between the two jaw plates at the lower end of the crushing chamber. Too small a discharge port will cause blockages and excessive energy consumption, leading to serious damage to the crusher; too large a discharge port will increase the load of the second crushing. Finding the optimal size according to the production needs is the key to improving output.

In addition, regular inspection and replacement of jaw plates, proper lubrication of bearings, and scientific adjustment of the discharge port opening are also essential links to ensure stable and high output of the crusher. By following these tips, sintered brick plants can effectively improve crusher production capacity while ensuring product quality.

Question 3

Why Poor Drying & Dehumidification Causes Cracked Clay Bricks?

Accepted Answer

Clay sintered bricks are widely used in construction projects around the world, favored for their durability, thermal insulation, and environmental friendliness. However, many construction teams and brick manufacturers often encounter a frustrating problem: clay bricks crack, crumble, or have uneven texture after sintering. What most people don’t realize is that the root cause of these quality issues is often inadequate drying and dehumidification technology—a key step that is easily overlooked in the brick-making process.

As a professional engaged in the brick-making industry for years, we often receive questions like: “Why do my clay bricks crack after sintering?” “How to make clay bricks stronger and more durable?” Today, we will popularize the critical role of drying and dehumidification technology in clay sintered brick production, and tell you how to avoid common quality problems completely.

First, let’s understand the basic principle: clay raw materials contain a lot of moisture, and if this moisture is not fully removed before sintering, it will expand rapidly when heated in the kiln, generating huge internal pressure. This pressure will directly cause the bricks to crack, burst, or even break into pieces—just like the “tofu bricks” that have been exposed in some quality incidents, which are mostly related to insufficient drying and dehumidification before sintering. In addition, uneven drying will lead to inconsistent moisture content in different parts of the brick blank. During sintering, the shrinkage degree of each part is different, resulting in uneven surface, low compressive strength, and poor weather resistance of the finished bricks.

Many small and medium-sized brick factories still use traditional natural drying or simple hot air drying methods. These methods have obvious defects: natural drying is greatly affected by the weather, and it is easy to cause the brick blanks to get damp again or dry unevenly; simple hot air drying often leads to too fast surface drying and too slow internal moisture diffusion, forming a “dry shell” on the surface, which traps the internal moisture and eventually causes cracks during sintering. These problems not only reduce the qualified rate of bricks but also increase production costs and affect project progress.

The good news is that these quality problems can be completely solved with advanced drying and dehumidification technology. Our company’s clay sintered brick making machine is equipped with a high-efficiency intelligent drying and dehumidification system, which perfectly solves the pain points of traditional drying methods. The system can accurately control the temperature, humidity, and air flow during the drying process, realizing uniform drying of the brick blanks from the inside out. It can quickly and thoroughly remove the moisture in the clay, ensuring that the moisture content of the brick blanks before sintering is controlled at the optimal range of 2% or less—which is the key to ensuring the quality of sintered bricks.

With our machine, you don’t have to worry about cracked, crumbly, or uneven clay bricks anymore. The sintered bricks produced by our equipment have uniform texture, high compressive strength, strong weather resistance, and no cracks or defects. They fully meet the international construction quality standards and are widely used in residential buildings, industrial workshops, and municipal engineering. Whether you are a brick manufacturer or a construction enterprise, our machine can help you improve production efficiency, reduce waste, and create higher economic benefits.

Question 4

Which Ceramic Clay Split Face Brick Making Machine Adapts to Various Overseas Regions and Raw Materials?

Accepted Answer

Overseas brick factories are distributed in different regions, with great differences in raw material types, voltage standards and transportation conditions. Many buyers buy brick making machines that are not suitable for local conditions—either they cannot adapt to local ceramic clay and other raw materials, or they cannot be used normally due to voltage mismatch, or they are difficult to transport due to large volume. So, which ceramic clay split face brick making machine can adapt to various overseas regions and raw materials?

Our Ceramic Clay Split Face Brick Red Brick Making Machine is designed with "global adaptability" as the core, perfectly solving the problem of regional mismatch. In terms of raw material adaptation, it has strong compatibility, and can process not only pure ceramic clay, ordinary clay, but also mixed raw materials such as clay mixed with sand, tailings and coal gangue. It can automatically adjust the mixing ratio according to the characteristics of local raw materials, ensuring stable product quality without additional raw material processing equipment.

In terms of voltage adaptation, we can customize the motor voltage according to the local voltage standards of different countries and regions—whether it is 220V (North America, Southeast Asia), 380V (Europe, Africa), or other special voltages, we can meet the requirements, avoiding equipment failure caused by voltage mismatch and ensuring normal production.

In terms of transportation, the machine adopts a detachable design, which can be disassembled into small parts for transportation, greatly reducing the volume and transportation cost. For regions with inconvenient transportation (such as remote areas in Africa and Southeast Asia), it can be easily transported to the factory and assembled quickly—only 1-2 days are needed to complete the installation and commissioning, and it can be put into production immediately.

In addition, the machine is designed with a dust-proof and moisture-proof structure, which can adapt to different climate conditions—whether it is the high temperature and dryness in Africa, the humid and rainy in Southeast Asia, or the low temperature in Europe, it can operate stably without being affected by the climate. Up to now, our machine has been used in more than 60 countries and regions around the world, adapting to various complex working conditions and winning unanimous recognition from local customers.

Question 5

How Can Brick Factories Double Profits in 3 Months?

Accepted Answer

Choose JKY High-Efficiency Red Brick Making Machine!Choose JKY High-Efficiency Red Brick Making Machine!

In the global construction market, especially in Southeast Asia, Africa and the Middle East, the demand for red bricks is growing rapidly. For brick factory owners, the core of making money is high output, low cost and stable operation. If you are still troubled by low production efficiency, high labor costs and frequent equipment failures, JKY high-efficiency red brick making machine is your best profit partner.

As a professional red brick making machine manufacturer with 10+ years of experience, we have designed the JKY series red brick making machine according to the actual needs of global brick factories. Different from the backward equipment on the market, JKY red brick making machine adopts advanced double-stage vacuum extrusion technology, which makes the produced red bricks dense, high in hardness and no cracks, and the qualification rate is as high as 99.8%, which is easier to be recognized by the market and sold at a good price.

In terms of production efficiency, JKY red brick making machine has a variety of models to meet the needs of different scales of brick factories. The hourly output of small models can reach 12,000 standard bricks, and the hourly output of large models can reach 25,000 standard bricks. A single machine can produce 0.3-1.3 billion standard bricks a year, which is 30% higher than ordinary brick making machines. At the same time, the machine is equipped with an automatic control system, which can realize automatic feeding, mixing, extrusion and cutting, saving 5-8 laborers compared with traditional equipment, and greatly reducing labor costs.

What’s more, JKY red brick making machine is easy to operate and maintain. Even workers without professional experience can get started quickly after 1-2 days of simple training. The key parts are made of high-quality alloy steel, which has been processed by special heat treatment, with a service life of more than 15 years, reducing the frequency of maintenance and spare parts replacement, and saving a lot of maintenance costs for brick factories.

We provide global one-stop service, including on-site installation, commissioning, technical training and 24-hour after-sales consultation. No matter which country you are in, our professional team can respond quickly to solve your production problems. Now contact us to get a free quote and on-site inspection service, and let JKY red brick making machine help you realize profit growth quickly!

Question 6

What Soil Brick Machine Can Use Local Raw Materials Without Spending Extra on Transportation?

Accepted Answer

What Soil Brick Machine Can Use Local Raw Materials Without Spending Extra on Transportation? This is the most common question asked by brick manufacturers in emerging markets like South Africa, Uzbekistan, and South America—after all, raw material transportation costs often account for 30-40% of the total production cost, which greatly reduces profit margins.

The answer is the JZK Soil Brick Machine. Unlike traditional brick machines that only work with high-quality, expensive special clay, the JZK Soil Brick Machine is designed with super strong raw material adaptability, which is its core advantage. It can efficiently process various local raw materials, including ordinary soil, coal gangue, shale, fly ash, construction waste, and industrial tailings—resources that are easy to obtain locally and even considered “waste” by many factories.

You don’t need to spend a lot of money purchasing and transporting special clay from other regions; you just need to collect local raw materials, process them simply, and put them into the JZK Soil Brick Machine to produce high-quality bricks. Whether it’s the red soil in Gqeberha, South Africa, the shale in Andijan, Uzbekistan, or the construction waste in Peru, this machine can handle it easily, truly realizing “using local materials to make local bricks” and saving a huge amount of transportation costs for your factory.

In addition, the JZK Soil Brick Machine is equipped with a double-stage vacuum extrusion structure, which ensures that the bricks produced from local raw materials have high density, strong compressive strength, and low cracking rate—the finished product rate is as high as 98% or more. It also adopts an eco-friendly design, with no waste water, waste gas, or noise pollution during production, fully complying with international environmental standards, so you don’t have to worry about environmental compliance issues.

For brick manufacturers who want to reduce transportation costs and make full use of local resources, the JZK Soil Brick Machine is the most cost-effective and reliable choice.

Question 7

Why Do Overseas Brick Factories Prefer VP Hard Plastic Extruder?

Accepted Answer

In the global brick making industry, more and more overseas brick factories are choosing the VP Hard Plastic Extruder as their core forming equipment. From Africa to South America, from Southeast Asia to the Middle East, the VP series has won wide recognition for its stability, efficiency, and cost-effectiveness. What are the core advantages that make it stand out among numerous brick making equipment?

1. High Stability, Low Failure Rate — Reduce Maintenance Costs

The VP Hard Plastic Extruder adopts a robust structural design, with key components such as the auger and vacuum chamber made of high-wear-resistant alloy materials, which have a service life of up to 8000-10000 hours. The equipment has passed strict quality testing before leaving the factory, and the failure rate is less than 2% per year. Compared with traditional extruders that often break down, the VP series can save you a lot of maintenance time and costs, ensuring continuous production and avoiding losses caused by shutdowns.

2. Energy-Saving and Environmental Protection — Conform to Global Environmental Standards

Against the background of global environmental protection, energy-saving equipment has become the first choice for brick factories. The VP Hard Plastic Extruder adopts an optimized power system, which can save 15%-20% of electricity compared with traditional extruders under the same output. At the same time, the equipment has a good dust removal and noise reduction design, which meets the environmental protection standards of most countries and regions, helping you avoid environmental fines and establish a green production image.

3. Strong Adaptability to Raw Materials — Reduce Raw Material Costs

Different regions have different raw material conditions, which is a major problem for many brick factories. The VP Hard Plastic Extruder has strong adaptability, and can process various raw materials such as clay, shale, coal gangue, fly ash, and river sludge. Even for low-quality and low-plasticity raw materials, it can be fully mixed and extruded through the twin-stage mixing and extrusion process, reducing the dependence on high-quality raw materials and saving raw material procurement costs.

4. Fast Mold Replacement — Realize Multi-Variety Production

In the face of the changing market demand for bricks, the ability to quickly switch product types is crucial. The VP Hard Plastic Extruder is designed with a quick mold change structure, which can complete the mold replacement within 30 minutes, realizing the flexible production of standard bricks, porous bricks, hollow bricks, and other products. This allows you to quickly respond to market changes, expand product categories, and increase market competitiveness.

5. Global After-Sales Service — No Worries About Use

We provide global after-sales service for the VP Hard Plastic Extruder, with professional technical teams in major overseas regions. Whether it is equipment installation, commissioning, maintenance, or technical training, we can provide timely and professional support. We also provide a one-year free warranty and lifelong maintenance service, ensuring that you can use the equipment with peace of mind and focus on your production.

If you want to choose a stable, efficient, and cost-effective hard plastic extruder for your brick factory, the VP series is definitely your best choice.

Question 8

Semi-Automatic VS Fully Automatic Brick Packing Machine: Which Fits Your Factory?

Accepted Answer

Choosing the right brick packing machine is a critical decision that directly impacts your production efficiency, investment return, and long-term scalability. With two main options dominating the market—semi-automatic and fully automatic brick packing machines—many brick factory owners struggle to determine which one aligns with their output, budget, and operational needs. Let’s break down the key differences to help you make the perfect choice.

Semi-automatic brick packing machines are the ideal choice for small-to-medium brick plants with a daily output under 5,000 bricks per hour. They require minimal operator intervention—just a few workers to load and position bricks—while the machine automatically handles strapping and wrapping. With a lower initial investment and quick ROI (12–18 months), these machines are cost-effective, easy to maintain, and flexible enough to adapt to different brick sizes with simple manual adjustments. They’re perfect for factories transitioning from manual packing to automation without a large upfront cost.

Fully automatic brick packing machines are designed for large-scale brick plants and tunnel kiln production lines with high output demands (over 7,000 bricks per hour). These systems feature robotic palletizing, automatic brick separation, and integrated conveying, requiring zero manual labor for the entire packaging process. Equipped with CE/ISO certification, customizable stacking patterns, and remote monitoring and fault diagnosis, they ensure consistent, export-grade packaging and minimize downtime. While the initial investment is higher, the long-term benefits—24/7 operation, reduced labor costs, and improved scalability—make them a strategic investment for factories targeting global markets.

Assess your daily output, budget, and expansion plans: if you’re a small factory looking to cut costs and boost efficiency, a semi-automatic brick packing machine is your best bet. If you’re a large-scale manufacturer aiming for global competitiveness, a fully automatic system will deliver the productivity and reliability you need.

Question 9

Roller Kiln vs Shuttle Kiln: Which Is Better for Your Brick Factory?

Accepted Answer

For brick and ceramic manufacturers, the choice between a roller kiln and a shuttle kiln directly affects production capacity, product consistency, and long-term profitability. As two of the most popular industrial kilns in the global market, roller kilns and shuttle kilns have distinct advantages and applicable scenarios. This article focuses on production efficiency, energy consumption, and cost, helping you make an informed decision for your brick factory.

What Is a Roller Kiln? Key Advantages for Mass Production

A roller kiln is a continuous conveying kiln that uses high-temperature-resistant rollers to transport blanks through the kiln chamber. It is designed for large-scale, continuous production, which is why it is widely used in modern brick and ceramic factories around the world. The entire production process – from preheating to cooling – is fully automated, reducing the need for manual intervention and minimizing human error.

One of the biggest advantages of a roller kiln is its high production efficiency. With a short firing cycle, it can process hundreds or even thousands of pieces of bricks or ceramic tiles per hour. Additionally, the uniform temperature distribution in the kiln ensures that every product has the same quality, avoiding defects caused by uneven heating. In terms of energy consumption, roller kilns are more energy-efficient than shuttle kilns because they can recover waste heat from the cooling zone and reuse it for preheating, reducing fuel consumption and environmental impact.

However, roller kilns require a higher initial investment, as they need supporting automated conveying systems and precise temperature control equipment. They are most suitable for large brick factories with stable production lines and high output requirements, such as those producing standard clay bricks, ceramic tiles, and terracotta panels.

What Is a Shuttle Kiln? Flexibility for Small-Batch Production

A shuttle kiln is an intermittent kiln that uses a movable kiln car to load and unload blanks. Unlike roller kilns, it does not require a continuous conveying system – each batch of blanks is loaded onto the kiln car, pushed into the kiln for firing, and then pulled out after cooling. This design makes shuttle kilns highly flexible, as they can easily switch between different product types and firing processes without stopping production for a long time.

Shuttle kilns are ideal for small-batch, multi-variety production. For example, if your factory produces antique bricks, special-shaped ceramic parts, or refractory bricks with different specifications, a shuttle kiln can meet your needs by adjusting the firing temperature, time, and atmosphere for each batch. Another advantage of shuttle kilns is their lower initial investment – they are simpler in structure and do not require complex conveying systems, making them suitable for small and medium-sized brick factories or startups.

The main disadvantage of shuttle kilns is their lower production efficiency and higher energy consumption. Since they need to heat up and cool down for each batch, a lot of heat is wasted, leading to higher fuel costs. They also require more manual labor for loading and unloading, which may increase labor costs in the long run.

Efficiency & Cost Comparison: Roller Kiln vs Shuttle Kiln

Comparison Items	Roller Kiln	Shuttle Kiln
Production Mode	Continuous, 24/7 operation	Intermittent, batch production
Daily Output	High (suitable for mass production)	Low to medium (suitable for small-batch production)
Energy Consumption	Low (waste heat recovery, high thermal efficiency)	High (heat loss during heating/cooling cycles)
Initial Investment	High (automated systems, precise control)	Low (simple structure, no complex conveying)
Labor Cost	Low (fully automated, less manual operation)	High (manual loading/unloading required)
Applicable Products	Standardized, flat products (clay bricks, ceramic tiles, terracotta panels)	Custom, multi-variety products (antique bricks, refractory bricks, special-shaped parts)

Final Suggestion: If your factory focuses on large-scale, standardized production and pursues high efficiency and low energy consumption, a roller kiln is the better choice; if you need flexible production for small-batch, custom products and have a limited initial budget, a shuttle kiln is more suitable. Yingfeng Machinery offers customized roller kiln and shuttle kiln solutions, helping you balance efficiency and cost to maximize profits.

Question 10

What is the complete production process for terracotta dry‑cladding panels?

Accepted Answer

The manufacturing process consists of 12 carefully controlled stages, from raw material preparation to final packaging. Each stage is described below.

1. Raw material selection & pre‑treatment

Composition: high‑plasticity clay (50–70%), shale, grog (pre‑fired crushed clay, 20–30%), feldspar, quartz, and other fluxes.
Crushing: jaw crusher for coarse crushing, followed by a hammer crusher to reduce particle size to ≤2 mm.
Screening: vibratory screens remove iron impurities and oversize particles to ensure uniform fineness.

2. Batching & mixing

Automated weighing of each component with an accuracy of ±0.5%.
Twin‑shaft mixer adds water (moisture content 18–22%) and intensively blends the materials into a homogeneous mass.

3. Aging (tempering)

The mixed clay is placed in a sealed aging silo for 24–48 hours (up to 72 hours for premium products).
Purpose: allow water to penetrate from particle surfaces to the interior, promote clay hydration and organic decomposition, and improve plasticity.

4. Vacuum extrusion

Two‑stage vacuum extruder: the upper stage mixes, the lower stage houses the vacuum chamber and extrusion screw.
Vacuum level: –0.092 to –0.096 MPa to completely remove entrapped air and prevent bubbles or lamination.
Die design: custom‑built for each panel size (e.g., 300×600 mm, 400×1200 mm) with multiple parallel cavities – creating a hollow, ribbed structure that reduces weight by 30–50% and accommodates dry‑cladding anchors.
Extrusion speed: 0.5–2 m/min, ensuring the green body has sufficient strength to support its own weight without deformation.

5. Cutting to length

A synchronized flying saw cuts the continuous extruded strip to required lengths (typically 300–1200 mm) with a tolerance of ±1.5 mm.
Chamfering or beveling can be performed simultaneously.

6. Secondary machining (back grooves / holes)

Automatic drilling or grooving machines create dovetail slots, trapezoidal grooves, or cylindrical holes on the back side.
Position tolerance: ±2 mm, ensuring secure engagement with the dry‑cladding anchors.

7. Drying (removal of free water)

Green panels go through a multi‑layer roller drying kiln with a controlled temperature profile:
- Inlet zone: 40–60 °C (prevents rapid shrinkage and cracking)
- Middle zone: 100–120 °C (rapid water removal)
- Outlet zone: 60–80 °C (slow cooling to relieve stresses)
Drying cycle: 6–12 hours; residual moisture after drying <0.5% (strictly <0.3% for some products).
100% visual inspection for cracks, warping, edge defects, etc.

8. Surface treatment (optional)

Engobe application: a fine clay slurry is sprayed to cover coarse particles and produce a smoother surface.
Glazing: metallic glaze, matte glaze, or stone‑effect glaze is applied by spraying or roller coating, thickness about 0.1–0.3 mm.
Texture printing: wood grain, fabric texture, or cement‑look patterns can be added via rollers or silk screens.

9. High‑temperature firing

A wide‑body roller kiln (150–300 m long) with three zones: preheating, firing, and cooling.
Firing temperature: 1120–1180 °C (typically 1120–1150 °C for terracotta‑body panels).
Heating rate: 10–15 °C/min in the preheating zone, 5–8 °C/min in the firing zone.
Soaking time: 30–60 minutes at peak temperature – ensures complete sintering, full mineral transformation, and stable colour development.
Cooling: forced air or natural cooling to below 70 °C before exiting the kiln to avoid thermal shock cracking.

10. Calibrating & edge grinding

A double‑end edge grinder precisely grinds the length and width dimensions to achieve tolerances of ±1.0 mm (length/width) and ±0.5 mm (thickness).
Edges are chamfered or rounded for neat joint alignment during installation.

11. Quality inspection

Physical properties:
- Modulus of rupture ≥13 MPa (some export grades require ≥18 MPa).
- Water absorption ≤6% (terracotta standard; low‑absorption grades reach 3–5%).
- Freeze‑thaw resistance: no cracks after 25 cycles.
Appearance:
- Colour difference: ΔE ≤1.5 measured by colorimeter.
- Dimensional accuracy: 5% batch sampling using callipers and straightedges; flatness deviation ≤0.5%.
Non‑destructive testing: tap‑sound test to detect internal cracks.

12. Packing & warehousing

Each panel is separated by soft padding (PE foam or cardboard) and packed in reinforced cartons or wooden pallets.
Labels clearly show batch number, size, colour code, and production date.
Store in a well‑ventilated, dry warehouse; stacking height ≤1.5 m to prevent moisture damage or pressure cracking.

Question 11

How to Make Fired Bricks？

Accepted Answer

The production of fired bricks is a tightly integrated process combining raw material proportioning, forming, drying, and high-temperature firing. Its core principle is to trigger physical and chemical reactions at high temperatures to sinter the brick body, thereby endowing it with high strength and durability. The full standard production process for fired bricks is as follows:

1. Raw Material Preparation and Proportioning

Main raw materials (clay, shale, coal gangue) are crushed and ground by crushers and pulverizers,then blended with water in a mixer, with impurities sieved out.

2. Green Brick Forming

The mixed clay material is piled up for ageing. It is then fed into a vacuum extruder to extrude clay strips, which are cut into standard green bricks by an automatic brick cutter. The wet green bricks are neatly stacked on kiln cars manually or by automatic stacking machines before being sent to the drying kiln.

3. Green Body Drying

Freshly formed green bricks have a high moisture content (approximately 15%–25%). Direct firing would cause rapid water evaporation and crack the bricks. Low-temperature drying is therefore essential. Stacked wet green bricks are conveyed into a tunnel drying kiln and dried at a low temperature using waste heat from the firing process to control moisture and prevent cracking.

4. High-Temperature Firing

Dried green bricks are transported on kiln cars into a tunnel kiln or annular kiln for gradient heating and sintering at 900–1100°C. The high temperature fuses and shapes the raw materials, hardening and strengthening the bricks.

5. Cooling and Finished Product Treatment

Bricks are slowly cooled in the dedicated cooling zone inside the kiln. After exiting the kiln, qualified products are sorted manually or mechanically, then stacked for delivery from the factory.

Question 12

How To Open A Clay Brick Factory?

Accepted Answer

Step 1: Investigate the market and confirm the demand

To determine new plant production scale should refer to the local market conditions.First of all, we shall thoroughly investigate local brick and tile market conditions and grasp following situation:current market demand,actual production volume of existing companies, how big the market gap is,current selling price of brick and tile products and the demand and price trend.Besides,is there the same new brick factory to be built?What is the production scale?After mastering above conditions, the new plant can be determined.

Step 2: Confirm brick type

Formulate product production plan according to the condition of raw materials.When you build a new factory, you must have a clear understanding of the local production materials.After determining the dosing plan and selecting raw materials, we must determine the production plan and scale according to local market conditions. It is suitable for hollow brick or hole brick?Whether annual production scale should be 50 million or 80 million?

Step 3: Confirm the production process and equipment

Selected production process and equipment according to raw materials.Clarify your raw material properties before starting new plant.Please have experienced technical staff to plan the production route and conduct selection or design production equipment.Not all equipment can adapt to your raw materials.

Step 4: Infrastructure construction

After determining production scale, it is possible to determine area, process direction, equipment layout of production plant and the location of living area according to the size of production volume.Plan plant elevation based on local geological, hydrological and meteorological conditions.]Arrange various production workshops according to the wind direction.To determine the mode of production, shall it be labor-intensive companies or technology-intensive enterprises,requires whole careful plan and design by technicians based on the results of technical and economic analysis.

1. Civil work: including Chenhuachi, workshops, doors, windows, and roofs of aging workshop.Meet installation requirements of reversible spreaders, multi-bucket excavators and conveyor belts.At the same time, water supply and drainage and heating are completed.

2. Aging workshop:The crushing workshop completes all civil construction tasks inside and outside the crushing room and feeding room.Complete the plant closure work.Meet installation requirements of feeder boxes, belts, crushers, vibrating screens, back-feed belts, and aging conveyor belts etc.

3. Molding workshop:including the feeding box, mixer, clay machine, extruder, cutting and transportation construction, as well as the kiln base after pouring belt,top car machine, tractor, kiln channel pavement, cushion and other construction.

4. The civil construction scope for air compressor stations, plumbing, substations, fire pump rooms, etc. includes drying kiln, roasting kiln, ferry car,hydraulic pusher,return tractor,traction machine, winch, tidal fan, blower, kiln cooling fan,pipeline , heat exchanger,kiln car production, track and so on.

Step 5:Preparation before production

1. organization construction

2. Make plans and regulations

3. Maintain and add equipment

4. Clean up the existing dry site and drying supplies

5. Maintain kiln

6. Maintain electrical equipment

7. Prepare sufficient fuel

8. Preparation of auxiliary items for production

9. Construct road and drainage

10. Prepare raw materials in advance

11. Ensure safety precautions

12. Run a test

13. Prepare spare parts

1. Pre-firing Material Constraints (The "Foundation" Stage)

2. Strategic Stacking Techniques (Mechanical Stability)

3. Dehumidification in the Preheating Zone (The "Critical" Stage)

4. Firing Zone Temperature Management (Thermodynamic Control)

5. Infrastructure and Mechanical Integrity (Environmental Factors)

What Is a Roller Kiln? Key Advantages for Mass Production

What Is a Shuttle Kiln? Flexibility for Small-Batch Production

Efficiency & Cost Comparison: Roller Kiln vs Shuttle Kiln

1. Raw material selection & pre‑treatment

Composition: high‑plasticity clay (50–70%), shale, grog (pre‑fired crushed clay, 20–30%), feldspar, quartz, and other fluxes.

Crushing: jaw crusher for coarse crushing, followed by a hammer crusher to reduce particle size to ≤2 mm.

Screening: vibratory screens remove iron impurities and oversize particles to ensure uniform fineness.

2. Batching & mixing

Automated weighing of each component with an accuracy of ±0.5%.

Twin‑shaft mixer adds water (moisture content 18–22%) and intensively blends the materials into a homogeneous mass.

3. Aging (tempering)

The mixed clay is placed in a sealed aging silo for 24–48 hours (up to 72 hours for premium products).

Purpose: allow water to penetrate from particle surfaces to the interior, promote clay hydration and organic decomposition, and improve plasticity.

4. Vacuum extrusion

Two‑stage vacuum extruder: the upper stage mixes, the lower stage houses the vacuum chamber and extrusion screw.

Vacuum level: –0.092 to –0.096 MPa to completely remove entrapped air and prevent bubbles or lamination.

Die design: custom‑built for each panel size (e.g., 300×600 mm, 400×1200 mm) with multiple parallel cavities – creating a hollow, ribbed structure that reduces weight by 30–50% and accommodates dry‑cladding anchors.

Extrusion speed: 0.5–2 m/min, ensuring the green body has sufficient strength to support its own weight without deformation.

5. Cutting to length

A synchronized flying saw cuts the continuous extruded strip to required lengths (typically 300–1200 mm) with a tolerance of ±1.5 mm.

Chamfering or beveling can be performed simultaneously.

6. Secondary machining (back grooves / holes)

Automatic drilling or grooving machines create dovetail slots, trapezoidal grooves, or cylindrical holes on the back side.

Position tolerance: ±2 mm, ensuring secure engagement with the dry‑cladding anchors.

7. Drying (removal of free water)

Green panels go through a multi‑layer roller drying kiln with a controlled temperature profile:

Inlet zone: 40–60 °C (prevents rapid shrinkage and cracking)

Middle zone: 100–120 °C (rapid water removal)

Outlet zone: 60–80 °C (slow cooling to relieve stresses)

Drying cycle: 6–12 hours; residual moisture after drying <0.5% (strictly <0.3% for some products).

100% visual inspection for cracks, warping, edge defects, etc.

8. Surface treatment (optional)

Engobe application: a fine clay slurry is sprayed to cover coarse particles and produce a smoother surface.

Glazing: metallic glaze, matte glaze, or stone‑effect glaze is applied by spraying or roller coating, thickness about 0.1–0.3 mm.

Texture printing: wood grain, fabric texture, or cement‑look patterns can be added via rollers or silk screens.

9. High‑temperature firing

A wide‑body roller kiln (150–300 m long) with three zones: preheating, firing, and cooling.

Firing temperature: 1120–1180 °C (typically 1120–1150 °C for terracotta‑body panels).

Heating rate: 10–15 °C/min in the preheating zone, 5–8 °C/min in the firing zone.

Soaking time: 30–60 minutes at peak temperature – ensures complete sintering, full mineral transformation, and stable colour development.

Cooling: forced air or natural cooling to below 70 °C before exiting the kiln to avoid thermal shock cracking.

10. Calibrating & edge grinding

A double‑end edge grinder precisely grinds the length and width dimensions to achieve tolerances of ±1.0 mm (length/width) and ±0.5 mm (thickness).

Edges are chamfered or rounded for neat joint alignment during installation.

11. Quality inspection

Physical properties:

Modulus of rupture ≥13 MPa (some export grades require ≥18 MPa).

Water absorption ≤6% (terracotta standard; low‑absorption grades reach 3–5%).

Freeze‑thaw resistance: no cracks after 25 cycles.

Appearance:

Colour difference: ΔE ≤1.5 measured by colorimeter.

Dimensional accuracy: 5% batch sampling using callipers and straightedges; flatness deviation ≤0.5%.

Non‑destructive testing: tap‑sound test to detect internal cracks.

12. Packing & warehousing

Each panel is separated by soft padding (PE foam or cardboard) and packed in reinforced cartons or wooden pallets.

Labels clearly show batch number, size, colour code, and production date.

Store in a well‑ventilated, dry warehouse; stacking height ≤1.5 m to prevent moisture damage or pressure cracking.

Crushing: jaw crusher for coarse crushing, followed by a hammer crusher to reduce particle size to ≤2 mm.

Vacuum level: –0.092 to –0.096 MPa to completely remove entrapped air and prevent bubbles or lamination.

Die design: custom‑built for each panel size (e.g., 300×600 mm, 400×1200 mm) with multiple parallel cavities – creating a hollow, ribbed structure that reduces weight by 30–50% and accommodates dry‑cladding anchors.

Extrusion speed: 0.5–2 m/min, ensuring the green body has sufficient strength to support its own weight without deformation.

A synchronized flying saw cuts the continuous extruded strip to required lengths (typically 300–1200 mm) with a tolerance of ±1.5 mm.

Position tolerance: ±2 mm, ensuring secure engagement with the dry‑cladding anchors.

Inlet zone: 40–60 °C (prevents rapid shrinkage and cracking)

Middle zone: 100–120 °C (rapid water removal)

Outlet zone: 60–80 °C (slow cooling to relieve stresses)

Glazing: metallic glaze, matte glaze, or stone‑effect glaze is applied by spraying or roller coating, thickness about 0.1–0.3 mm.

A wide‑body roller kiln (150–300 m long) with three zones: preheating, firing, and cooling.

Firing temperature: 1120–1180 °C (typically 1120–1150 °C for terracotta‑body panels).

Heating rate: 10–15 °C/min in the preheating zone, 5–8 °C/min in the firing zone.

Cooling: forced air or natural cooling to below 70 °C before exiting the kiln to avoid thermal shock cracking.

A double‑end edge grinder precisely grinds the length and width dimensions to achieve tolerances of ±1.0 mm (length/width) and ±0.5 mm (thickness).

Modulus of rupture ≥13 MPa (some export grades require ≥18 MPa).

Store in a well‑ventilated, dry warehouse; stacking height ≤1.5 m to prevent moisture damage or pressure cracking.