Glass

Introduction to Glass Testing Services

Glass is a universal and versatile material used across architecture, aerospace, automotive, electronics, pharmaceutical packaging, and consumer goods. However, thorough testing is necessary to confirm its dependability, safety, and durability. Infinita Lab’s ASTM glass testing services offer standardised techniques for assessing the optical, electrical, chemical, thermal, and physical characteristics of glass – from raw materials and glass containers to architectural flat glass, electrochromic devices, and speciality glasses used in advanced industries.

By adhering to ASTM standards, Infinita Lab ensures consistency, safety, and uniformity across applications such as glass containers, electrochromic units, architectural panels, optical glass, and speciality glasses used in cutting-edge industries. Testing is required across the full lifecycle – from raw material validation and manufacturing quality control to failure analysis and R&D support.

Our Glass Testing Services

Thermal Shock Resistance Testing

Glass containers and industrial glass components are routinely exposed to sudden temperature changes during processing, sterilisation, filling, and service. Thermal shock resistance testing evaluates the ability of glass to withstand abrupt temperature differentials without fracturing – critical for pharmaceutical containers, food and beverage packaging, laboratory glassware, and cookware.

Relevant ASTM Standards:

• ASTM C149 – Thermal shock resistance testing for glass containers, evaluating the durability and resistance of glass to sudden temperature changes by hot-to-cold transfer at defined temperature differentials. The test guides the design of glass containers, quality assurance, and the selection of glass grades for applications requiring thermal shock resistance.

Chemical Resistance Testing

Glass containers used in pharmaceutical, food, beverage, and laboratory applications must resist chemical attack from their contents and cleaning agents. Chemical resistance testing verifies that glass does not react with or leach harmful substances into the product – ensuring safety and regulatory compliance.

Relevant ASTM Standards:

• ASTM C225 – Chemical resistance testing for glass containers, determining the reactivity of glass with chemicals present in food, beverages, and pharmaceutical products. Since many products are sterilised for packing, the test specifies autoclave conditions during testing – the standard for glass container chemical safety in pharmaceutical and food packaging applications.

Hardness Testing

Glass hardness testing provides a measure of surface resistance to scratching and indentation – important for quality control of optical glass, flat glass, and speciality glass products where surface integrity directly influences optical performance and service durability.

Relevant ASTM Standards:

• ASTM C730 – Knoop indentation hardness testing for glass, using a pyramidal diamond indenter to measure the mechanical hardness of glass surfaces – particularly suited for brittle materials and thin glass sheets where conventional hardness testing would cause fracture.

Internal Pressure Strength Testing

Glass containers used in carbonated beverage packaging, pharmaceutical storage, and pressurised product applications must withstand internal pressure without bursting. Pressure strength testing verifies that glass containers meet the minimum burst pressure requirements for their intended application.

Relevant ASTM Standards:

• ASTM C147 – Internal pressure strength testing for glass containers, evaluating the ability of bottles, jars, and other glass containers to withstand internal hydraulic pressure loading – the standard for pressure resistance qualification of carbonated beverage and pressurised pharmaceutical glass containers.

Surface Contamination & Hydrophobicity Testing

Glass surfaces used in optics, semiconductor manufacturing, pharmaceutical container filling, and solar panels must be free of hydrophobic contamination that can impair wettability, coating adhesion, filling efficiency, and optical performance. Contamination testing identifies and quantifies surface contamination through contact angle measurement.

Relevant ASTM Standards:

• ASTM C813 – Hydrophobic contamination testing on glass by contact angle measurement, detecting and quantifying surface contamination that affects wettability – critical for pharmaceutical container filling lines, optical surfaces, and glass substrates where surface cleanliness directly governs product quality and performance.

Optical Stress & Residual Stress Analysis

Residual stresses in glass – arising from forming, annealing, heat treatment, or chemical strengthening – affect mechanical strength, dimensional stability, and optical performance. Optical retardation testing measures internal stress using polarised light to verify annealing quality and process control.

Relevant ASTM Standards:

• ASTM F218 – Optical retardation and residual stress analysis in glass using polarised light, quantifying residual stress magnitude in flat glass, optical glass, and electronic substrate glass – the standard for annealing process verification and quality control of stress-sensitive glass products.
• ASTM C1901 – Optical retardation testing for flat architectural glass, measuring residual stress distribution in large architectural glass panels to verify stress uniformity and quality compliance for building façades, curtain walls, and structural glazing applications.
• ASTM C1279 – Edge and surface stress testing in tempered flat glass using photoelastic measurement, verifying that heat-treated glass has been properly tempered and that compressive surface stress levels meet safety glazing specifications.

Electrical Properties Testing

Glass used in electronic substrates, display panels, semiconductor equipment, and insulating components must meet precise electrical specifications. Volume resistivity testing verifies the electrical insulation performance of glass under DC conditions – essential for electronic and electrical glass applications.

Relevant ASTM Standards:

• ASTM C657 – DC volume resistivity testing for glass, verifying the electrical insulation performance of glass materials used in electronics, displays, semiconductor equipment, and electrical insulating applications.

Chemical Composition Analysis

Glass composition determines its optical, thermal, mechanical, and chemical properties. Chemical analysis of glass and its raw materials is essential for quality control, raw material qualification, and failure investigation – verifying that glass meets the required composition specifications.

Relevant ASTM Standards:

• ASTM C146 – Chemical analysis of glass sand and raw materials used in glass manufacture, determining the chemical composition of silica sand and other glass batch materials to verify suitability and compliance with glass formulation requirements.

Raw Material Particle Size Analysis

The particle size distribution of raw materials – particularly silica sand and mineral batch ingredients – directly governs the uniformity of melting, the quality of the final glass, and the consistency of production. Sieve analysis ensures raw material consistency and batch homogeneity.

Relevant ASTM Standards:

• ASTM C429 – Sieve analysis of raw materials for glass manufacture, establishing the particle-size distribution of silica sand and other batch materials to ensure consistency and uniformity across glass production batches.

Glass Sphere Gradation Testing

Glass spheres used in reflective road markings, shot blasting, and speciality applications must meet precise particle size distribution requirements to perform reliably. Gradation testing provides accurate size distribution data for quality control and specification compliance.

Relevant ASTM Standards:

• ASTM D7681 – Gradation measurement of glass spheres using a stream digital image analyser, providing accurate size distribution data for glass beads and microspheres used in reflective road marking, blasting, and speciality applications.

Accelerated Aging Testing for Electrochromic Glass

Electrochromic glass units – used in smart windows, architectural glazing, and automotive applications – must demonstrate long-term durability under accelerated aging conditions. Accelerated aging testing evaluates the retention of performance of electrochromic devices sealed within glass units after simulated environmental exposure.

Relevant ASTM Standards:

• ASTM E2141 – Accelerated aging testing for electrochromic devices in sealed glass units, evaluating the long-term performance and durability of electrochromic glass under accelerated temperature and humidity cycling – supporting product qualification and service life prediction for smart architectural glazing.

Fluorescence Measurement Testing

Optical glass, speciality glass, and glass used in analytical instrumentation must be characterised for fluorescence properties – including emission linearity and system performance – to support quality control of optical glass components and fluorescence measurement instrument calibration.

Relevant ASTM Standards:

• ASTM E578 – Linearity of fluorescence measuring systems testing for optical glass and fluorescence measurement instruments, verifying that the fluorescence measurement system responds linearly across the intended measurement range – critical for optical glass quality control and analytical instrumentation validation.