Yingfeng Machinery－More Than 30 Years Experience In Clay Brick Making Machine ,Tunnel Kiln, Rotary Tunnel Kiln.
How to Prevent Clay Bricks from Collapsing in Tunnel Kilns？
2026-04-30
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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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Heating Rate: Maintain a steady rise of 6–8°C/h. Sudden temperature spikes, especially in winter, can cause thermal shock and structural failure.
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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.
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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.
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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."
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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.
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Track Leveling: Regularly inspect kiln car tracks. Uneven rails cause vibration and jolting, which can topple a stack that is already weakened by heat.
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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.
Related questions
1
How to Crusher Output in Sintered Brick Plants Efficiently？
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.
2
Why Poor Drying & Dehumidification Causes Cracked Clay Bricks?
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.
3
Which Ceramic Clay Split Face Brick Making Machine Adapts to Various Overseas Regions and Raw Materials?
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.
4
How Can Brick Factories Double Profits in 3 Months?
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!
5
What Soil Brick Machine Can Use Local Raw Materials Without Spending Extra on Transportation?
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.
6
Why Do Overseas Brick Factories Prefer VP Hard Plastic Extruder?
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.
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