Hollow glass microspheres (HGMs) are manufactured through a precision-engineered thermal process that transforms specially formulated glass powders into lightweight, hollow spheres. This process is designed to produce microspheres with uniform size, controlled wall thickness, and high strength-to-weight ratio, suitable for high-performance applications across industries.

At Petra Industries Pvt. Ltd., one of the largest manufacturers and exporters of hollow glass microspheres in India, we follow advanced production techniques to ensure consistent quality and performance under our brand name FILLIT®.

Hollow Glass Microspheres (HGMs) are made from specially engineered glass materials that offer a balance of low density, high strength, thermal stability, and chemical resistance. The most common types of glass used are soda-lime and borosilicate glass. The chemical composition directly influences the microspheres’ thermal expansion, compressive strength, and compatibility with polymers or cementitious systems.

At Petra Industries Pvt. Ltd., we manufacture and supply high-quality FILLIT® Hollow Glass Microspheres with an optimized glass formulation for diverse industrial applications, including paints and coatings, oil well cementing, lightweight concrete, and aerospace composites.

When it comes to the largest and most trusted supplier of hollow glass microspheres in India, one name stands out prominently — Petra Industries Pvt. Ltd. With over two decades of expertise in supplying and distributing high-performance fillers, Petra Industries Pvt. Ltd. has established itself as a leading force in the microsphere and advanced materials market, both domestically and internationally.

Operating under its renowned brand name FILLIT®, the company specializes in producing premium-quality hollow glass microspheres tailored to a wide range of industries, including:

Petra Industries Pvt. Ltd. is one of the largest and most trusted distributors of Hollow Glass Microspheres in India. With over two decades of experience in advanced industrial fillers, Petra has earned a solid reputation for supplying high-performance hollow glass microspheres under its specialized product line.

Microspheres—especially hollow variants like ceramic or glass microspheres—are advanced functional fillers designed to enhance the performance, reduce the weight, and improve the efficiency of materials across various industries. These tiny spherical particles, typically ranging from 10 to 200 microns in diameter, play a crucial role in formulating lightweight, high-strength, and thermally stable products.

At Petra Industries Pvt. Ltd., we specialize in supplying premium hollow glass and ceramic microspheres under our trusted brands, serving industries that demand both performance and precision.

Hollow Glass Microspheres are ultra-lightweight, low-density, and chemically inert spherical particles widely used as functional fillers in high-performance materials. Their unique properties—such as low thermal conductivity, high compressive strength, and excellent dimensional stability—make them ideal for demanding industrial applications across various sectors.

As one of India’s leading distributors of hollow glass microspheres, Petra Industries Pvt. Ltd. supplies top-quality microspheres sourced globally, helping manufacturers achieve weight reduction, enhanced insulation, and improved product performance.

Key Industries & Applications:

Why Choose Petra Industries Pvt. Ltd.?

At Petra, we don’t just supply hollow glass microspheres—we deliver performance-enhancing solutions that drive innovation across industries.

The density of microspheres can vary widely depending on their composition and whether they are solid or hollow. Here’s a breakdown:

P.S.: At Petra Industries Pvt. Ltd., we supply custom density ranges based on the client's application—balancing strength, insulation, and lightweight properties to meet specific performance needs.

Petra Industries Pvt. Ltd. is widely recognized as one of the largest and most reliable wholesalers of hollow glass microspheres in India. With a legacy of over 25 years in supplying advanced industrial fillers, Petra has built a strong reputation for sourcing and distributing premium-quality microspheres to top manufacturers across multiple industries.

Why Petra Industries Pvt. Ltd. Leads the Market:

We offer a wide range of hollow glass microspheres with varying densities, particle sizes, and crush strengths to suit different technical applications—from lightweight fillers in coatings to syntactic foams in aerospace and marine.

Petra partners with leading international manufacturers to import high-purity hollow glass microspheres, enabling us to maintain large inventories and meet bulk demands across India with ease and efficiency.

With a robust supply chain and warehouse capabilities, we serve clients in industries like paints & coatings, construction, oil & gas, automotive, marine, and aerospace—ensuring timely delivery and reliable support.

Our technical team assists customers in selecting the right grade of microspheres based on their formulation, helping optimize performance, reduce material cost, and improve end-product quality.

Known for our flagship filler brand FILLIT, Petra Industries is trusted by OEMs, R&D labs, and industrial formulators for supplying microspheres that deliver both performance and value.

At Petra Industries Pvt. Ltd., we are more than just wholesalers—we are solution providers committed to empowering industries with next-generation materials that are lighter, stronger, and more efficient.

Hollow Glass Microspheres are well-known for their excellent thermal insulation properties, thanks to their low thermal conductivity. These microspheres consist of thin-walled, gas-filled glass shells, which act as highly effective barriers to heat transfer.

Range: 0.03 to 0.06 W/m·K (Watts per meter-Kelvin)

This value is significantly lower than that of most solid fillers, making hollow glass microspheres ideal for thermal insulation in lightweight composite systems.

Why This Matters:

The hollow structure and trapped gas inside each microsphere reduce heat conduction drastically.

As a result, they are widely used in formulations where thermal management, energy efficiency, and temperature resistance are critical.

Applications Where Low Thermal Conductivity Is Key:

Thermal Insulating Paints & Coatings – Helps reduce heat transfer on surfaces

Oil & Gas Cementing – Prevents heat loss during downhole operations

Construction Materials – Used in fire-resistant boards, wall plasters, and insulating panels

Automotive & Aerospace Composites – Improves temperature resistance without adding weight

Electronic Encapsulation & Foams – Maintains structural integrity in thermally sensitive environments

At Petra Industries Pvt. Ltd., we supply high-quality hollow glass microspheres that deliver not just lightweight properties—but also superior thermal insulation performance. Whether you're formulating advanced coatings, lightweight cement slurries, or high-performance composites, our microspheres are engineered to meet the most demanding thermal requirements.

Fillers play a crucial role in composite materials by enhancing their mechanical, thermal, and processing properties while also helping to reduce overall material costs. In modern engineering and manufacturing, fillers are not just additives—they are essential components that help tailor composites to meet specific performance and application needs.

At Petra Industries Pvt. Ltd., we supply advanced functional fillers, including hollow glass microspheres, cenospheres, and other specialty materials, to help manufacturers develop stronger, lighter, and more efficient composites.

At Petra Industries Pvt. Ltd., our fillers are more than materials—they are performance enhancers that help our customers engineer cutting-edge composite solutions. Whether your goal is to lighten, strengthen, insulate, or economize, Petra’s tailored filler solutions are designed to deliver results.

Microspheres—especially hollow types such as hollow glass microspheres and cenospheres—are engineered particles known for their lightweight structure, spherical shape, and multifunctional performance. These properties make them highly valuable across a wide range of industries where materials must be strong yet lightweight, insulating yet durable.

At Petra Industries Pvt. Ltd., we specialize in providing high-performance microspheres that meet diverse technical requirements across oil & gas, construction, automotive, paints & coatings, aerospace, and more.

At Petra Industries Pvt. Ltd., we don’t just supply microspheres—we deliver engineered filler solutions that unlock performance, efficiency, and cost-effectiveness. Whether you need insulation, strength, or weight reduction, our microspheres are designed to meet your specific material goals.

In the oil and gas industry, hollow glass microspheres are critical high-performance additives used primarily to reduce weight, improve insulation, and enhance flow characteristics in demanding downhole and surface-level applications.

At Petra Industries Pvt. Ltd., we supply high-quality hollow glass microspheres tailored for the unique requirements of oilfield operations—delivering consistent performance even under extreme pressure and temperature conditions.

As one of India’s leading distributors, Petra Industries Pvt. Ltd. supplies hollow glass microspheres that meet global oilfield standards—empowering drilling engineers and service companies with lightweight, insulating, and durable filler solutions for optimized oil & gas operations.

Cenospheres — often called hollow ceramic microspheres — are tiny, free-flowing, hollow spherical particles typically composed of alumino-silicate glass/ceramic. They are formed as a by-product of coal combustion (fly ash) in thermal power plants or synthesized to strict specifications for engineering uses. Typical composition is largely silica (SiO₂) and alumina (Al₂O₃) with variable iron-oxide and other minor oxides depending on the feedstock and process. Their shell is rigid and glassy/amorphous, while the interior is hollow and contains air or inert gas, giving cenospheres very low bulk density (commonly ~0.4–0.8 g/cm³, depending on grade) and excellent compressive and thermal stability. These physical characteristics make them uniquely useful as lightweight fillers in polymers, paints, adhesives, syntactic foams, cementitious systems and other engineered materials. Scientific reviews and industrial references describe cenospheres as thermally stable, chemically inert, hydrophobic to slightly hydrophilic depending on surface treatment, and available across a wide particle-size distribution (sub-micron to several hundred microns).

Two principal routes produce usable cenospheres: (A) recovery from coal fly ash, and (B) engineered production / processed hollow ceramic microspheres. In recovery, raw fly ash from coal combustion is processed using density separation, air classification, flotation, and wet or dry screening to isolate low-density hollow spheres from denser fly ash components. Advanced plants add thermal or flame treatments (e.g., vertical thermal flame processes) and multi-stage separation to increase yield and purity. Engineered HCMs (hollow ceramic microspheres) are produced via controlled sol-gel or pyrolysis routes where precursor chemistries create hollow shells with designed wall thicknesses and compositions; this yields tighter control of particle size, wall strength, and chemistry for demanding industrial applications. Processing parameters (temperature, residence time, separation media) and post-treatments (sizing, sieving, surface modification) determine final product grades and performance in downstream formulations. For buyers, it’s important to verify particle-size distribution, bulk density, true density, compressive strength, and chemical composition (SiO₂/Al₂O₃ ratio) — these are the primary parameters that influence application performance.

Cenospheres deliver weight reduction, thermal and acoustic insulation, enhanced rheology control, and cost-effective bulk to formulated systems. Key industry uses include:

Paints & coatings: raise solids content without dramatically increasing viscosity, improve insulation, reduce sag, and can improve abrasion resistance and hiding in specialty coatings.

Polymers & composites: in syntactic foams and lightweight composites they provide buoyancy and maintain compressive strength, widely used in marine buoyancy modules, aerospace interiors, and lightweight structural panels.

Cement, concrete & construction: as partial Portland cement replacements or fillers to reduce weight and thermal conductivity in lightweight concrete and insulating blocks.

Oil & gas: used in cementing slurries, drilling fluids, and subsea syntactic buoyancy materials; small, rigid hollow spheres can reduce slurry density while retaining strength under hydrostatic pressure.

Plastics, adhesives & sealants: improve thermal insulation and dimensional stability. Performance benefits derive from extremely low bulk density (so formulators can boost solids loading), high compressive strength (so the spheres survive processing), and thermal stability up to several hundred °C depending on composition. When surface-treated, they can improve compatibility with organic resins or hydrophobic systems. Market analyses also indicate rising demand driven by lightweighting trends in automotive, construction, and oil & gas.

Comparison depends on target property: density, compressive strength, thermal resistance, chemical inertness, and cost.

Hollow glass microspheres (HGMs) are similar to cenospheres in being hollow and low-density, but HGMs are manufactured from specialty glass and often have tighter dimensional control, lower water uptake, and excellent compressive strength—preferred for high-performance composites and precise formulations.

Engineered hollow ceramic microspheres (lab-made) can be tailored for high temperature stability and specific wall thickness/strength.

Polymeric microbeads (e.g., expandable polystyrene or PMMA) are lighter but have limited thermal stability, lower compressive strength, and can deform under heat or solvent attack—suitable for low-temperature, low-stress fillers.

Expanded perlite and other natural lightweight aggregates offer very low cost but are irregular, abrasive, and less compatible with fine formulations. Choosing between them requires comparing required compressive strength, maximum service temperature, chemical exposure, particle-size needs, and cost constraints. For heavy-duty subsea or high-temperature applications, ceramic cenospheres or engineered ceramic/HGM grades usually outperform polymeric spheres.

A reputable supplier should provide a technical data sheet (TDS) with batch-level or grade-level values for:

In oil & gas, cenospheres and engineered hollow microspheres are used to lower slurry density (lightweight cements), form syntactic buoyancy materials for subsea modules, and as rheology modifiers or lightweight extenders in drilling fluids and completion fluids. In lightweight cementing, adding hollow spheres lowers slurry unit weight while maintaining compressive strength and reducing hydrostatic pressure—valuable for balancing formation pressure and avoiding lost returns. In subsea syntactic foams, spheres provide buoyancy with compressive strength to resist deep-water hydrostatic pressure. In drilling fluids, small hollow spheres can help control density and improve lost-circulation solutions. Tradeoffs include:

Compatibility: spheres must withstand downhole chemical environments (alkaline cements, acids) — shell composition matters.

Crush strength: under high formation or hydrostatic pressure, low-strength spheres may collapse, negating buoyancy or changing slurry rheology.

Cost vs performance: engineered HGMs or ceramic microspheres cost more than generic fly-ash cenospheres but deliver predictable performance in critical downhole applications.

Mixing & handling: uniform dispersion and de-aeration are required to avoid entrained gas and ensure consistent densities. Selecting the correct grade (size, crush strength, coating) and confirming lab tests that simulate field pressures are essential for successful application.