Composites suitable for rotational molding technology based on poly(ε-caprolactone) (PCL) and filled with hollow glass microspheres or functionalized hollow glass microspheres were prepared via melt-compounding. The functionalization of hollow glass microspheres was carried out by a silanization treatment in order to improve the compatibility between the inorganic particles and the polymer matrix and achieve a good dispersion of hollow glass microspheres in the matrix and an enhanced filler–polymer adhesion.

The crystallization behavior of materials was studied by DSC under isothermal and non-isothermal conditions and the nucleating effect of the hollow glass microspheres was proven. In particular, the presence of silanized hollow glass microspheres promoted faster crystallization rates and higher nucleation activity, which are enhanced by 75% and 50%, respectively, comparing neat PCL and the composite filled with 20 wt% hollow glass microsphere.

The crystalline and supermolecular structure of PCL and composites crystallized from the melt was evaluated by WAXD and SAXS, highlighting differences in terms of crystallinity index and structural parameters as a function of the adopted crystallization conditions.

We are spoiled for choice when it comes to choosing a thermometer, from the trusty old mercury thermometer to modern-day digital sensors. Centuries ago, though, measuring the ambient temperature was performed by devices such as the Galileo thermometer.

A Galileo thermometer is a meteorological instrument consisting of a sealed glass tube filled with a clear liquid containing small glass bulbs of varying densities. Ambient temperature changes also alter the liquid’s density, causing different bulbs to rise or fall, which indicates the temperature.

Although this specific thermometer as we know it today wasn’t designed by Galileo himself, all the principles that the thermometer is based upon were discovered and implemented by Galileo Galilei and his thermoscope.

What Is A Galileo Thermometer?
A Galileo thermometer is a meteorological instrument consisting of a sealed glass tube filled with a clear liquid containing small glass bulbs of varying densities. Ambient temperature changes also alter the liquid’s density, causing different bulbs to rise or fall, which indicates the temperature.

Each bubble is partially filled with a different colored liquid. Small metal tags of different weights are also hanged below each bulb to adjust their “density,” while each tag also contains a number.

Any changes in air temperature change the density of the liquid as well. This causes the bubbles inside the liquid to rise and fall in response to changes in the fluid’s density.

By observing the different heights at which the glass bubbles are floating, the temperature can be determined. This is done by identifying the number of the tag below the bubble floating at the “right height.”

If this sounds confusing to you, you are not alone. If I only described to you what a Galileo thermometer looks like and how it responds to temperature changes, it would be difficult to understand what is really happening and why.

One needs to understand the principles and forces at work that make all the parts in this thermometer behave the way they do and how they all work together to help determine the atmospheric temperature.

ARTICLE SOURCE: ownyourweather

Hollow glass microsphere that also known as vitrified small ball is a kind of micron-sized hollow sphere with smooth surface, its main chemical composition is soda lime borosilicate glass, and the natural accumulation state of them is white light inorganic powder. Composition and hollow structure endow the microspheres with unique properties different from other inorganic non-metallic or hollow materials.

In addition to low density, high compressive strength, high temperature or corrosion resistance, low thermal conductivity, nice fluidity and chemical stability, advantages such as non-toxic, odorless, electric insulation, sound-proofing, anti-radiation, self-lubrication and easy surface modification are also showed by hollow glass microspheres.

These characteristics make hollow glass microspheres widely used as additives in many fields, such as water-based lightweight building insulation paint, low-density drilling fluids and cementing slurry, lightweight components in aerospace and vehicles, ship floating block and coatings, electronic components, high molecular composite materials, putty powder, artificial marble, and natural / synthetic products, etc.

Nowadays, hollow glass micropheres composites are also an object of study in additive manufacturing, such as 3D printing, to improve flow melting and thermal insulation. Özbay and Serhatlı studied processing and properties of different combinations of hollow glass microphere filled with polyamide 12 (PA12) matrix, by Selective Laser Sintering (SLS) manufacturing method. As a result, they obtained a 20% of density reduction and a significant rise in the E-modulus with the composition PA12/hollow glass microphere (80/20).

In the automotive industry, the polyamide (PA6) and polyamide 6.6 (PA66) are often used because of their typical hydrogen bonds, due to their polar chemical structure, with a short GF reinforcement, commonly 30 wt%. Composites of PA6 or PA66 reinforced with glass fibers ensure great mechanical and thermal properties and can be found in air intake manifolds, rocker covers, radiator end tanks, fuel rails, electrical connectors, engine encapsulation and others. In this sense, GF and hollow glass microphere combination may constitute an excellent solution to combine lower density, dimensional stability, and good mechanical properties. Berman et al. have studied the effects of replacing calcium carbonate (high density filler) with hollow glass microphere (low density filler) in an unsaturated polyester resin matrix sheet molding compound (SMC) reinforced with short GF (10~15 wt%). The composite was fabricated in SMC manufacturing, lay-up and hot pressing. As a result, they obtained a 12% of density reduction but compromised the mechanical properties. Nevertheless, all values of tensile, flexural and impact properties were higher than the corresponding properties of low and ultra-low-density composites reported in the literature.

Thus, the goal of this study was to fabricate a composite based in PA6 reinforced with GF and hollow glass microphere and to investigate the effects of hollow glass microphere content on the density, mechanical properties of the composites comparing its properties with the traditional PA6/GF (70/30) wt% composite, widely used today in automotive industries. It’s expected to find a formulation with at least 10% density reduction and maintenance of mechanical properties. In this paper, fundamental results for understanding the relationship between structure and property of both the matrix and the fillers will be discussed in terms of microscopic observations, mechanical properties, and thermal stability.

Hollow glass microspheres, also called bubbles, microbubbles, or micro balloons, provide the benefits of low density, high heat and chemical resistance.

These microscopic spheres of soda-lime/borosilicate glass are low-density particles that are used in a wide range of industries. The hollow microspheres are used to reduce warpage and shrinkage, to adjust the rheological properties, to reduce part weight, and to lower cost.

Hollow glass microspheres have been used as low-density fillers for various kinds of polymeric compounds. Hollow Glass Microspheres for the applications of paint & coating, construction & insulation coating. Due to its excellent advantages of lightweight, bulk density, lower thermal conductivity, higher compressive strength, improved dispersion and liquidity.

Our hollow glass microspheres are genuine and cost-effective alternative having similar specification which have a relative density in the range of 0.15 to 0.20g/cc.

Hollow glass microspheres are a ultra-lightweight, inorganic, non-metallic, hollow alternative to conventional fillers and additives. They find applications in many demanding industries such as paints, coatings, adhesives, sealants, cast polyester, compounding and many more. The low-density material is used to reduce weight, lower costs and enhance product properties.

The unique spherical shape of the hollow glass microspheres offer a number of important benefits, including higher filler loading, lower viscosity and reduced shrinkage. It further makes it more adaptable to a variety of production processes including spraying, casting and molding.

The chemically stable soda-lime-borosilicate glass composition provides excellent water resistance to create more stable emulsions. They are non-combustible and non-porous, so they do not absorb resin. The hollow glass microspheres also create stable voids, which result in low thermal conductivity and low dielectric constant.

Hollow glass microspheres are available in a variety of sizes and grades to help you meet your product and processing requirements.

How to Reduce Density of Rubber Vacuum Glass Bead Foaming Agent Special for Rubber Weight Reduction

Why rubber has high density;

The density of the rubber without filler is 0.9g/cm, but the rubber needs to add inorganic filler because of its strength, temperature resistance, shrinkage resistance, cost reduction and other characteristics. The filler density is generally 2.5-3.6, which will greatly increase the weight, leading to the rubber density exceeding the standard.

Inorganic filler powder

Methods for reducing the density of rubber;

The vacuum glass beads are added to the rubber. The density of the vacuum glass beads is 0.23-0.28g/cm, 3-5 times lighter than the rubber. The compressive strength is 35-42MPA. It has high strength and does not crush. It can be filled into rubber and other materials to effectively reduce the weight to meet the density standard.

Vacuum glass beads are often used to replace foaming agents in rubber soles. Because of their high strength, strong weather resistance, high hardness, and strong aging resistance, vacuum glass beads will not collapse for a long time after they are made into soles, delaying their service life.

Real shot of vacuum glass bead

Why vacuum glass beads can reduce weight;

Vacuum glass bead is a kind of bubble type ultra-fine inorganic powder. The microscopic view is closed spherical hollow particles. The glass bead is filled into the resin, plastic and rubber to achieve foaming effect and effectively reduce the product density.

Vacuum glass bead morphology;

Vacuum glass bead is a kind of low density inorganic white solid powder, which is made by chemical method. It presents spherical vacuum powder under a microscope. The density of conventional products is generally 0.15-0.8g/cm, and it is often used for thermal insulation coatings, plastic foaming, rubber weight reduction, etc.

Plastic anti warping glass beads;

The vacuum glass bead can prevent warping, reduce shrinkage, resist high temperature, fire and other characteristics after being added into the plastic. The recommended usage is 7-20%, which is adjusted according to the product characteristics.

Vacuum glass beads are widely used;

It can be used for reflective coatings, silica gel pads, silica gel products, resins, thermal insulation coatings, thermal insulation coatings, thermal insulation layers, thermal insulation paints, thermal insulation intermediate coatings, rubber soles, rubber pads, yoga mats, reflective coatings, thermal insulation coatings, printing coatings, plastic products, plastic plates, wood plastics, man-made boards and other products with wide applications and strong chemical stability.


Q: The role of plastic filled hollow glass beads;

Answer: Hollow glass beads have the effects of low density, insulation, light weight and heat insulation. Adding them to plastics can reduce the weight. Increase liquidity.

Q: The effect of insulating glass beads used in thermal insulation coatings;

Answer: After insulating glass beads are added to the thermal insulation coating, the thermal insulation effect of the coating can be greatly enhanced.

Q: What is added to rubber to reduce density;

Answer: The use of vacuum glass beads can effectively reduce the density, increase the volume and enhance the overall performance of rubber.

Q: What is the thermal conductivity of the vacuum glass bead;

Answer: The special thermal conductivity of nano water-based thermal insulation coating is 0.03, which effectively reduces the performance of 15-25 ℃.

The Global Hollow Glass Microspheres market is anticipated to rise at a considerable rate during the forecast period, between 2022 and 2028. In 2021, the market is growing at a steady rate and with the rising adoption of strategies by key players, the market is expected to rise over the projected horizon.

Hollow glass microspheres are a new type of material developed widely in recent years with excellent performance. The main components of the product are borosilicates, hollow spheres with a particle size of 10-250 μm and a wall thickness of 1-2 μm. This product has the advantages of light weight, low thermal conductivity, high strength and good chemical stability. After special treatment, it has the properties of lipophilic and hydrophobic, and it is very easy to disperse in organic materials such as resins. Hollow glass microspheres are widely used in glass fiber reinforced plastics, artificial marble, artificial agate, and other composite materials, and have obvious weight-reducing effect and sound insulation effect, so that the products have good crack resistance and reworkability. Widely used in aviation, aerospace, new high-speed trains, luxury yachts, thermal insulation coatings, bowling, and other areas, and played a unique good role.

First of all, the increasing demand for hollow glass microspheres drives the market size structural properties such as recyclability, reusability increase demand for efficiency, and modernization of infrastructure. Second, North America dominates the global hollow glass microspheres market, and is experiencing high growth owing to the increased demand for efficiency in many end-user industries. Product innovation in terms of quality and application development is another driving factor for the growth of hollow glass microspheres market in North America. The U.S. and Canada are expected to lead the hollow glass microspheres market in the North American region, the U.S. Asia Pacific is growing at a significant rate as these materials have started gaining prominence in this region. The growth in this region can be attributed to increased consumption of hollow glass microspheres in China.

The Global Hollow Glass Microspheres Market Size was estimated at USD 209.43 million in 2021 and is projected to reach USD 349.72 million by 2028, exhibiting a CAGR of 7.60% during the forecast period.

Sinosteel Maanshan Mining Research Institute Co., Ltd. updated the review status of listing application on December 19, and the company’s IPO application has been accepted.

Tongbi Finance and Economics learned that the company’s predecessor, “Research Institute of Ferrous Metallurgical Mines of the Ministry of Metallurgical Industry”, was founded in 1963 and was a key scientific research institute directly under the former Ministry of Metallurgical Industry. The company has long been engaged in professional services for comprehensive utilization of mineral resources, providing customers with technical services and technical engineering services in mining, mineral processing, rock and soil, mine safety and environmental protection, etc; At the same time, the company pays attention to the technical research and development of new materials such as hollow glass beads, new mining curing materials, carbon aerogel, spherical weighting materials, and realizes the industrial mass production of hollow glass beads.

The State Council and various ministries and commissions have successively issued a series of policies, including the “cornerstone plan”, committed to ensuring the supply security of national strategic mineral resources. With the support of the above national strategies and industrial policies, the industry of comprehensive utilization of mineral resources has broad development space. With the progress of product technology and application technology, hollow glass beads are more widely used in more downstream industries, and the application field will be further expanded in the future. For example, in the field of new energy vehicles, hollow glass beads are used as filling materials to reduce the density and weight of adhesives and interior and exterior trims, achieve lightweight vehicles, improve the physical and chemical properties of adhesives and interior and exterior trims, and improve production efficiency. With the increasing demand of new energy vehicles for lightweight and improving production efficiency, hollow glass bead products are expected to be more widely used in the future. In addition, with the continuous emergence of emerging industries and the continuous development of traditional industries, hollow glass bead products will expand more application fields.

In recent years, the development and utilization intensity of China’s mineral resources has rapidly improved, mining and dressing technology and equipment have made continuous progress, and the comprehensive utilization level has greatly improved. In addition, at present, entrepreneurs all over the country are very optimistic about the development prospects of the sand and gravel industry and the business opportunities for the development and utilization of mineral resources, and have invested in the construction of large and medium-sized sand and gravel production bases. At the same time, major state-owned enterprises and domestic large cement enterprise groups have begun to set foot in and layout the sand and gravel aggregate industry according to the industry development trend. Their involvement has injected new development impetus into the development of the sand and gravel industry and become a new force to promote the high-quality and high-level development of the sand and gravel industry.

Polymer is a very broad term that encompassed a large amount of materials. The world “polymer” refers to materials that are composed of repeating identical molecules.

The type of molecule, the length of the chain, the amount of cross-linking, the presence of various chemical groups – all affect the behavior as well as chemical and physical properties of the material.

Many different polymers can be used as raw materials for hollow glass microspheres. The most common polymer microspheres are made from polyethylene, polystyrene, and poly(methyl methacrylate).