Vacuum Glass: The Ultimate in Silence and Energy Efficiency

 

Vacuum glass represents a revolutionary advancement in glass processing, functioning like a highly engineered, flattened thermos bottle.

Core Technology:
It consists of two glass panes separated by a mere 0.1-0.2 mm vacuum gap, maintained by microscopic support pillars. This structure eliminates air conduction and convection, making its thermal insulation exceptionally effective.

Key Advantages:

• Superior Insulation: With a thermal conductivity (K-value) often below 0.4 W/(m²·K), it far outperforms conventional double glazing, significantly reducing energy costs.

• Excellent Soundproofing: Its vacuum core is highly effective at blocking low-frequency noise (e.g., traffic rumble), achieving a weighted sound reduction index (Rw) of 36-40 dB or higher.

• Slim Profile: It provides top-tier performance in a much thinner unit, ideal for space-sensitive applications like building retrofits.

Applications:
This technology is key for passive houses, luxury buildings requiring quiet comfort, and energy renovation projects where its slimness is a major advantage.

In short, vacuum glass is a pinnacle of glass processing, offering an unmatched combination of energy savings and acoustic comfort for modern construction.

The Versatile World of Glass: More Than Meets the Eye

 Glass is one of humanity’s oldest and most widely used materials. Unlike crystalline solids, glass is an amorphous material—its atomic structure is disordered, which gives it both transparency and brittleness. Most common glass is made from silica, soda ash, and limestone, melted at high temperatures and rapidly cooled.

The history of glass dates back to around 3500 BCE in Mesopotamia. The Romans advanced glassmaking with blowing techniques, and during the Industrial Revolution, mass production began. A major breakthrough came in the 20th century with the invention of float glass, which made large-scale uniform panes possible.

Today, there are many types of glass designed for different uses:

• Tempered Glass: Heat-treated for extra strength; shatters into small, safe pieces.

• Laminated Glass: Has a plastic interlayer that holds the glass together when broken.

• Low-E Glass: Features a coating that reflects heat while letting light in.

• Self-Cleaning Glass: Uses sunlight and rain to break down and wash away dirt.

• Smart Glass: Can change its transparency with electricity or light.

Glass offers unique advantages: excellent light transmission, chemical resistance, and full recyclability. It’s also energy-efficient when designed for insulation.

Looking forward, glass is becoming smarter and more functional. Examples include energy-generating photovoltaic glass and switchable smart windows. It continues to enable innovations in technology, architecture, and sustainability.

In summary, glass is both ancient and cutting-edge. It’s a material that continues to evolve, playing a key role in modern design and innovation.

Smart glass coating could cool glass buildings

 Researchers at the Fraunhofer Institute have developed a smart coating for building glass that can automatically darken in sunlight. This technology combines electrochromic and thermochromic materials, responding to both electrical stimuli and temperature changes. In modern buildings with extensive glass curtain walls, the coating effectively reduces indoor overheating caused by solar radiation, thereby decreasing reliance on energy-intensive air conditioning systems.

The construction industry is one of the major sources of global greenhouse gas emissions. In Germany, for example, according to statistics from the Federal Environment Agency, the building sector accounts for approximately 30% of the country's carbon dioxide emissions and 35% of its energy consumption. Buildings with large glass facades and roofs, especially office structures, experience sharp rises in indoor temperatures during strong summer solar radiation. Traditional shading devices such as blinds and curtains often compromise visual aesthetics and obstruct views. As a result, such buildings commonly rely on air conditioning for cooling, leading to high electricity consumption and an increased carbon footprint.

To address this issue, the Fraunhofer Institute for Silicate Research (ISC) and the Fraunhofer Institute for Organic Electronics, Electron Beam, and Plasma Technology (FEP) jointly led the EU-funded "Switch2Save" project. They collaborated with universities and industry partners across several European countries to advance the development and application of smart window coating technology.

In this smart coating system, the electrochromic component is based on a transparent conductive film. Applying voltage to the film triggers the migration of ions and electrons, enabling the glass to reversibly transition from transparent to dark. The thermochromic coating, on the other hand, automatically reflects solar heat when the ambient temperature reaches a specific threshold, operating without external power as a passive response mechanism.

The electrochromic elements can be integrated with sensors and a control system to monitor light intensity and temperature in real time. When values exceed set parameters, the system sends an electrical signal to the conductive film, gradually darkening the glass. This effectively blocks heat input and provides anti-glare functionality. On cloudy days or at night, the glass returns to full transparency, maximizing the introduction of natural light.

The technology has already been implemented in practical building applications. For instance, this smart glass system has been installed in the pediatric clinic of a large hospital in Athens, Greece, and an office building in Uppsala, Sweden. Researchers will conduct a year-long energy consumption monitoring study to compare electricity usage of air conditioning systems before and after retrofitting, verifying energy-saving performance under real climatic conditions.

In terms of manufacturing, the team employs wet chemical processes and vacuum coating technology. The electrochromic coating is integrated onto a flexible polymer film, while the thermochromic layer is prepared on an ultra-thin glass substrate. Roll-to-roll production methods enable economical and scalable manufacturing. The final product is only a few hundred micrometers thick and weighs less than 500 grams per square meter, making it easy to install in existing building windows without structural modifications.

Currently, the project team is focused on further enhancing the technology’s applicability. Efforts include combining electrochromic and thermochromic units to improve regulatory flexibility, developing coating processes suitable for curved glass, and expanding color options beyond gray and blue to meet diverse architectural aesthetic needs.

As global warming and the EU Green Deal advance, the demand for energy-efficient building technologies is growing rapidly. All buildings in the EU are expected to achieve carbon neutrality by 2050. Smart window technologies like Switch2Save are poised to play a key role in promoting the low-carbon transformation of the construction industry.

U-Shaped Glass: Technical Specifications and Applications

 

1. Definition & Production Process

U-shaped glass, also known as channel glass, is a building glass material manufactured from recycled glass and quartz sand. Key production stages include:

• Melting at 1470°C

• Forming via continuous rolling process

• Annealing treatment
  Optional enhancements:

• Embedded wire mesh for reinforcement

• Textured surfaces using patterned rollers

2. Classification Systems

Category	Types/Parameters
Surface Finish	Standard fine pattern, Wave pattern, Fine stripe, Thick stipple, Transparent
Mechanical Strength	Standard (≥70MPa flexural strength), Tempered (≥150MPa), Film-reinforced
Color Treatment	Clear, Color-glazed, Filmed, Sandblasted/Frosted

3. Key Technical Properties

Property	Performance Data
Optical	85% light transmission (single layer); <50% transmission (double U-section with air gap); Reduces light pollution via diffuse reflection
Thermal	U-value down to 1.84 W/(m²·K); 30% improved insulation when filled with thermal materials
Mechanical	Withstands structural deformation stresses; Vertical span up to 6 meters

4. Architectural Applications

• Facades:

  • Double-skin curtain wall at Shenzhen Bay Super Headquarters Base

  • Curved facade at Shanghai Expo Chile Pavilion

• Interiors:

  • Light-transmitting partitions at Wanho Haomei Art Hotel

  • Landscape screens at Ningbo Jiuzhuli Project

• Special Structures:

  • Airport terminal skylights (designed to DIN-1249)

  • Illuminated art walls at Shanghai Glass Museum

5. Installation Requirements

• Joint Design:

  • Elastic gaskets + flexible sealants

  • ±15mm joint width for thermal expansion

• Geometric Limits:

  • Max. height: 6m

  • Min. curvature radius: 500mm

  • Vertical tolerance: ≤5mm (≤5m height), ≤7mm (5-7m height)

• Structural Compliance:

  • Transfers loads to main structure via aluminum frames

  • Non-load-bearing use only

  • 10-20mm air layer mandatory in double-layer installations

The Truth Behind the 0.1% Tempered Glass Self-explosion Rate: 5 Major Project Selection Pitfalls and a Scientific Guide

 In 2025, a 1,200 square meter curtain wall at Dubai Marina Tower required emergency replacement due to spontaneous glass explosions, resulting in a direct loss of $2.3 million. Globally, there are 37 construction accidents caused by spontaneous glass explosions each year. As a project manager, do you have a true risk control plan?

1. Overturning Perceptions: The Scientific Truth Behind the Self-Explosion Rate
1.1 Visualization Experiment on the Root Cause of Self-Explosion
▷ Ordinary Soda-Lime Glass: Nickel Sulfide (NiS) Content ≥ 0.04g/㎡ → Differences in Thermal Expansion Coefficients Cause Localized Stress Concentration
▷ Ultra-Clear Glass Raw Materials: Iron Content ≤ 0.015% → 83% Reduced NiS Formation Rate (Source: Glass Journal 2025)

1.2 Comparison of Authoritative Data
Glass Type Average Self-Explosion Rate After Homogenization Treatment (HST) Hot-Dip Process Cost
Ordinary Tempered Glass 0.3%-0.4% 0.08% +$1.2/㎡
Ultra-Clear Tempered Glass 0.07% <0.01% +$0.8/㎡
💎 Key Conclusion: Ultra-clear glass combined with a two-stage HST treatment can reduce lifetime maintenance costs by 52% (calculated based on a 20-year construction cycle).
II. Five Deadly Traps in Project Procurement
Trap 1: Superstitious Devotion to "International Brands" and Ignoring Raw Material Traps
▷ Tragic Case: A landmark Southeast Asian project sourced European-branded glass. Excessive iron content in the raw materials resulted in a 0.5% spontaneous explosion rate.
▷ Scientific Circumvention: Require suppliers to provide a source report for the raw glass sand (e.g., we use Cristal Mining ultra-clear sand from Australia).

Trap 2: Failing to Clearly Define Cutting Accuracy Tolerances
[Comparison Chart: Curtain Wall Installation Results of ±0.3mm CNC Waterjet Cutting vs. ±1.2mm Conventional Cutting]
▷ Cost: A tolerance >±0.8mm results in an average installation delay of 2.3 weeks.
▷ Our Solution:
→ Italian BAVELONI CNC Cutting Line with ±0.3mm Error
→ Free CAD Drawing Optimization Services

Trap 3: Lack of Field Wind Pressure Measurement Data
▷ Mandatory Inspection Items for Hurricane Zones:
- Basic Requirement: ≥4000Pa (National Standard GB/T 15227)
- Requirement for High Wind Zones: ≥9000Pa (e.g., coastal/super-high-rise buildings)

Trap 4: Ignoring Edge Stress Concentration
[Insert Micrograph: Edge Roughness Comparison]
▷ Poor Edge Grinding → Stress Concentration Factor Increases by 300%
▷ Our Process:
→ German Bystronic Fine Grinding Line + Argon Ion Polishing
→ Edge Stress ≤12MPa (EN 12150 upper limit is 24MPa)

Trap 5: No Self-Destruction Warranty During Acceptance
▷ Unwritten Industry Rule: Most Suppliers' Warranties Only Cover "Manufacturing Defects" and Exclude the Risk of Self-Destruction
▷ Our Commitment:
→ Written Commitment: 0.1% Self-Destruction Rate Guarantee
→ 72-Hour Response for Self-Destruction Replacement
III. Joy Shing A Revolution in Glass Quality Control
China Construction Group Zhuhai Project Demonstrates
"Using our 12mm ultra-clear tempered glass:

Consumption: 86,000 m2
Lifecycle: 3 years
Self-explosion record: 0 (verified by regular thermal imaging testing)"

Float Glass: The Unsung Hero of Our Transparent World

 The windows, car windshields, phone screens, and even glass furniture you interact with daily mostly originate from one revolutionary process – float glass. It silently underpins our modern lives.

The Core Mystery: How Float Glass is Made

Before float glass, flat glass production was laborious and time-consuming. In 1959, UK's Pilkington Company successfully developed the float process, revolutionizing the industry.

Its secret lies in a bath of molten tin:

1. Melting Raw Materials: Sand, soda ash, and other materials melt into glass in a high-temperature furnace (around 1600°C).

2. Floating on Tin: The molten glass is poured onto the surface of the molten tin. Due to density differences, it naturally spreads out, forming an even thickness.

3. Perfect Formation: Under gravity and surface tension, the glass forms an incredibly smooth, mirror-like surface – no polishing needed! Thickness is controlled by temperature and drawing speed.

4. Annealing & Strengthening: The glass ribbon moves into a long annealing lehr for precisely controlled cooling. This removes internal stresses and significantly increases strength and stability.

5. Cutting to Size: The cooled, hardened glass ribbon is automatically cut into sheets of the required size.

The Outstanding Qualities of Float Glass

This unique process gives float glass unmatched advantages:

• Exceptional Flatness & Optical Quality: The tin-formed surface is ultra-smooth with virtually zero optical distortion, providing clear vision.

• Flexible Thickness Control: Ranges from ultra-thin (0.5mm) to ultra-thick (25mm), meeting diverse needs.

• High Purity & Uniformity: Strict material and process control minimizes bubbles/stones, ensuring high, consistent light transmission.

• Superior Cost-Effectiveness: Continuous, large-scale, automated production lowers costs, making quality glass widely accessible.

• Excellent Processability: Easily undergoes deep processing like tempering, laminating, coating, or insulating to create safety glass, energy-efficient glass, decorative glass, and more.

Ubiquitous Transparency

Float glass is everywhere in modern life:

• Architecture: Curtain walls, windows, doors, skylights – providing views and light.

• Transportation: Car windshields/windows, train/aircraft windows – ensuring safety.

• Technology: The foundation for displays in phones, tablets, TVs, etc.

• Home & Industry: Glass furniture, mirrors, solar panel covers, instrument windows.

The Future: Transparency & Sustainability

The float process continues to evolve:

• Greener: Optimizing fuels (e.g., natural gas, hydrogen), improving furnace efficiency, reducing emissions.

• Smarter: Applying automation, big data, and AI to boost efficiency and quality.

• Stronger: Developing ultra-thin, ultra-thick, ultra-clear, high-strength specialty glass.

• Recycling: Increasing the use of recycled cullet (waste glass) to save resources and energy.

Thermal cracking mechanism and engineering response of single-piece fireproof glass

Introduction

As a key material for building exterior protection, the thermal cracking behavior of glass in fire directly affects the escape of personnel and the spread of fire. This article focuses on the thermal cracking mechanism of **single-piece fireproof glass (DFB)** and analyzes its fire-resistant nature.

1. The core driving force of thermal cracking: temperature difference stress

Research has confirmed (Xie, Keski-Rahkonen, etc.) that the fundamental cause of glass cracking is the critical thermal stress caused by **uneven heating:

Ordinary soda-lime glass: critical temperature difference is only **80~90℃

6mm tempered fireproof glass**: critical temperature difference **330~380℃

10mm tempered fireproof glass**: critical temperature difference **470~590℃

When the temperature difference between the exposed area (fired) and the shielded area (frame) of the glass exceeds the threshold in a fire, the tensile stress generated exceeds the tensile strength of the glass (usually 30~50MPa), which triggers the crack.

2. Key factors affecting cracking

| Edge processing quality | Mechanical polishing edge strength (78MPa) > rough grinding edge (56MPa), micro crack expansion strength attenuation 15%+ |

| Installation method | Point support stress concentration > frame installation; aluminum frame fire resistance > wooden frame |

| External intervention | Spray cooling will accelerate cracking when the glass temperature is > 250℃ |

| Glass type | Borosilicate glass (expansion coefficient 4×10⁻⁶/K) Thermal shock resistance Rolled soda-lime glass (9×10⁻⁶/K)

📌 Engineering warning: Fireproof glass design must reserve a safety factor K≥2.5 (refer to curtain wall specifications)

3. Technical breakthrough direction

1. Material upgrade

Borosilicate glass: low expansion + high softening point (800℃), the mainstream fire protection solution in Europe, and has broken through the bottleneck of mass production in China

Microcrystalline glass: zero expansion characteristics, temporarily limited to high-end special applications

2. Process control

Stress strengthening: surface compressive stress > 90MPa (national standard bottom line) can improve bending strength (formula: σ≈0.83σ tempering + 38)

Edge finishing: HF acid etching/mechanical polishing to reduce microcracks

3. Intelligent simulation application

Thermal-mechanical coupling simulation based on tools such as ANSYS can predict:

Stress distribution of different installation methods (see Figure 1)

Critical rupture time (error <10%)

Simulation confirms: The maximum tensile stress of framed glass is concentrated at the junction of the frame and shielding (31~32MPa)

IV. Engineering application suggestions

1. Carefully select glass type

Borosilicate monolithic fireproof glass (EN 12600/ANSI Z97.1 certification) is the first choice for high-end projects

Strictly control the discrete risk of soda-lime-silicon fireproof glass

2. Optimize installation design

Preferentially use a four-point support structure to reduce stress concentration

The shielding width needs to be verified by thermal simulation

3. Scenario protection

Avoid enabling the sprinkler system at high temperature (>250℃)

Conclusion

To understand the mechanism of thermal cracking, it is necessary to make breakthroughs in three dimensions: material nature (boron silicon > sodium calcium), process precision (edge ​​stress control), and installation science (thermal stress dispersion). With the large-scale mass production of domestic borosilicate glass and the popularization of digital simulation technology, the safety of fireproof glass will achieve a qualitative leap.