Glass bubble,Hollow glass microspheres , Glass sphere beads, Manufacturer & suppliers

RTP Company announces the availability of specialty compounds containing hollow glass microspheres which reduce part weight, enhance properties and lower part costs in demanding applications.

High loadings of these microspheres, which are manufactured by 3M and known as ScotchliteTM Glass Bubbles, can be added to thermoplastics to reduce overall part weight, and thus per part material costs. Additionally, they can modify polymer characteristics, achieving lower viscosity, improved flow, and reduced shrinkage and warpage.

For example, some compounds containing ScotchliteTM Glass Bubbles can have their specific gravity reduced by as much as 30 percent. The use of glass bubbles also provides more uniform control and reproducibility than other methods typically used for weight reduction, such as foaming agents.

ScotchliteTM Glass Bubbles reduce thermal conductivity and lower dielectric constants of most thermoplastics. Non-combustible and non-porous, the glass bubbles do not absorb moisture. Compounds containing ScotchliteTM Glass Bubbles are available in most engineering resins and easily adapt to common processing methods, including injection molding and extrusion. Applications that can benefit from this weight saving technology exist in the aerospace, automotive, marine, electronic, and medical industries.

FROM:RTP Company

In this work, hollow glass microsphere reinforced triglycidyl-p-aminophenol (TGPAP) epoxy composites was prepared and the influence of hollow glass microsphere on mechanical and thermal properties of the composites was investigated.

Mechanical behaviors of the composites with various weight fractions of hollow glass microsphere from 0 to 9% were investigated in terms of impact property at both room temperature (RT) and liquid nitrogen temperature (77 K). The fracture surfaces of undoped epoxy and the composites were examined by scanning electron microscopy (SEM).

The results show that both the impact strength at room temperature and 77 K are all enhanced by the addition of hollow glass microsphere with appropriate contents.

Furthermore, the thermal conductivity and coefficients of thermal expansion of undoped epoxy and hollow glass microsphere/epoxy composites were also investigated from 77 K to room temperature.

It is found that the composites show lower thermal conductivity and coefficient of thermal expansion than undoped epoxy. The results indicate that hollow glass microsphere/epoxy composites are promising cryogenic materials.

Observing glass beads under a microscope

40 mesh solid glass beads with a rounding rate greater than 85%

40-mesh glass beads with a rounding rate greater than 80%

200 mesh solid glass beads

hollow glass beads

325 mesh glass beads with a rounding rate greater than 90%

FROM:HS glass beads

The objective of this work is to improve the structural characteristics of hollow glass microsphere filled epoxy syntactic foam composites with little voids content and improved hollow glass microspheres dispersion in the composite.

A modified degassing technique has been introduced during resin casting process of the hollow glass microspheres filled syntactic foam composites. The effect of hollow glass microspheres content volume fractions (5–25%) on the degassing techniques was examined. The syntactic foam composites were characterized by analysing structural morphology using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy(TEM), and density measurements (theoretical and experimental).

Less than 5% void content has been achieved in this study. This resulted in improved tensile and dynamic mechanical properties (DMA).

New glass bubbles for 5G, the newest member of its high-strength hollow glass bubbles product line, provides a unique, low-loss high speed high frequency (HSHF) resin additive for composite materials that designers use to build 5G devices and assemblies. The Glass Bubbles help designers enable products that can meet the rigorous transmission requirements and increased power demands that come with 5G implementation, while lowering the per volume cost of raw materials.

The Glass Bubbles for 5G help enable designers of HSHF copper clad laminate (CCL) to produce smooth, lightweight 5G substrates for building printed circuit boards (PCBs) – the building blocks for 5G wireless radio systems. They can also be used in plastic composites that a 5G signal transfers through, such as base station assemblies, radome shells, or even mobile phone cases. For further information see the IDTechEx report on 5G Small Cells 2021-2031: Technologies, Markets, Forecast.

Signal loss and interference have always been a factor in PCB manufacturing and will become more challenging as 5G networks operate at higher signal frequencies. Using The Glass Bubbles as a resin additive in the CCL helps control dielectric properties, allowing design engineers to reduce signal transmission loss at higher frequencies and improves signal reliability. The Glass Bubbles have one of the lowest dielectric constants of any known materials additive, making it attractive for the electronics industry.

“The Glass Bubbles have been used for more than 50 years and recent innovation has enabled the design of a bubble targeting the unique needs of 5G electronics. The new Glass Bubbles were designed specifically for 5G to help improve data transfer speeds in higher frequency applications,” said Brian Meyer, President of Advanced Materials Division. “They are committed to the 5G space, and we’re excited to apply our science where it matters most, collaborating on the low-loss materials needed to help designers with their higher speed wireless communications challenges now and in the future.”

Blending in Glass Bubbles for 5G HSHF CCL can also help designers lower their substrate materials costs by displacing typically higher cost resins. Further, lightweight Glass Bubbles occupy up to 20 times more space compared to the typical solid mineral fillers. Considering the cost per unit volume (instead of price per lb. or kg), The Glass Bubbles are a cost-effective choice in many applications.

FROM:

Technology created by researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) is literally shedding light on some of the smallest particles to detect their presence – and it’s made from tiny glass bubbles.

The technology has its roots in a peculiar physical phenomenon known as the “whispering gallery,” described by physicist Lord Rayleigh (John William Strutt) in 1878 and named after an acoustic effect inside the dome of St Paul’s Cathedral in London. Whispers made at one side of the circular gallery could be heard clearly at the opposite side. It happens because sound waves travel along the walls of the dome to the other side, and this effect can be replicated by light in a tiny glass sphere just a hair’s breadth wide called a Whispering Gallery Resonator (WGR).

A magnified photograph of a glass Whispering Gallery Resonator. The bubble is extremely small, less than the width of a human hair.

When light is shined into the sphere, it bounces around and around the inner surface, creating an optical carousel. Photons bouncing along the interior of the tiny sphere can end up travelling for long distances, sometimes as far as 100 meters. But each time a photon bounces off the sphere’s surface, a small amount of light escapes. This leaking light creates a sort of aura around the sphere, known as an evanescent light field. When nanoparticles come within range of this field, they distort its wavelength, effectively changing its color. Monitoring these color changes allows scientists to use the WGRs as a sensor; previous research groups have used them to detect individual virus particles in solution, for example. But at OIST’s Light-Matter Interactions Unit, scientists saw they could improve on previous work and create even more sensitive designs. The study is published in Optica.

Today, Dr. Jonathan Ward is using WGRs to detect minute particles more efficiently than ever before. The WGRs they have made are hollow glass bubbles rather than balls, explains Dr. Ward. “We heated a small glass tube with a laser and had air blown down it – it’s a lot like traditional glass blowing”. Blowing the air down the heated glass tube creates a spherical chamber that can support the sensitive light field. The most noticeable difference between a blown glass ornament and these precision instruments is the scale: the glass bubbles can be as small as 100 microns– a fraction of a millimeter in width. Their size makes them fragile to handle, but also malleable.

Working from theoretical models, Dr. Ward showed that they could increase the size of the light field by using a thin spherical shell (a bubble, in other words) instead of a solid sphere. A bigger field would increase the range in which particles can be detected, increasing the efficacy of the sensor. “We knew we had the techniques and the materials to fabricate the resonator”, said Dr. Ward. “Next we had to demonstrate that it could outperform the current types used for particle detection”.

A diagram showing the new WGR experiments. Test particles (shown here in green) are passed through a light field, which distorts the light wavelength, which can be used to detect the particles.

To prove their concept, the team came up with a relatively simple test. The new bubble design was filled with a liquid solution containing tiny particles of polystyrene, and light was shined along a glass filament to generate a light field in its liquid interior. As particles passed within range of the light field, they produced noticeable shifts in the wavelength that were much more pronounced than those seen with a standard spherical WGR.

With a more effective tool now at their disposal, the next challenge for the team is to find applications for it. Learning what changes different materials make to the light field would allow Dr Ward to identify and target them, and even control their activity.

Despite their fragility, these new versions of WGRs are easy to manufacture and can be safely transported in custom made cases. That means these sensors could be used in a wide verity of fields, such as testing for toxic molecules in water to detect pollution, or detecting blood borne viruses in extremely rural areas where healthcare may be limited.

For Dr. Ward however, there’s always room from improvement: “We’re always pushing to get even more sensitivity and find the smallest particle this sensor can detect. We want to push our detection to the physical limits.”
By Andrew Scott

The objective of this work is to improve the structural characteristics of hollow glass microsphere filled epoxy syntactic foam composites with little voids content and improved hollow glass microsphere dispersion in the composite.

A modified degassing technique has been introduced during resin casting process of the hollow glass microsphere filled syntactic foam composites. The effect of hollow glass microsphere content volume fractions (5–25%) on the degassing techniques was examined. The syntactic foam composites were characterized by analysing structural morphology using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy(TEM), and density measurements (theoretical and experimental).

Less than 5% void content has been achieved in this study. This resulted in improved tensile and dynamic mechanical properties (DMA).

Hollow glass microspheres are increasingly being used in the construction of energy-efficient building structures by several constructors, designers, and building owners. The product is extensively accepted to be utilized in coatings in order to achieve high overall solar reflectance within building coatings. These coatings have the capability to reflect solar energy back into the atmosphere, which is achieved by utilizing conventional fillers like calcium carbonate, and titanium oxide among others.

Increasing adoptionof titanium oxide coated hollow glass microspheres.

Increasing application scope in paints and coatings.

Growing product consumption across Asia-Pacific.

In order to give full play to the effect of hollow glass microspheres, it is necessary to ensure that the hollow structure remains intact during the addition process. The strong shear in the twin-screw extruder can easily break the glass beads. Once the hollow glass beads are broken, they will become glass fragments with a density of 2.5g/cm3, which cannot achieve weight reduction. This is also the main reason why many application products did not achieve the desired effect in the initial stage of the experiment.
Therefore, how to reduce the breakage rate of microbeads in the twin-screw extruder granulation process is the key to the excellent performance of hollow glass microbeads.
Specifically, it can be considered from the extruder thread combination, feeding and pelletizing method, main engine speed, and compressive strength of microbeads.

01 . Adjustment of twin screw thread combination

In a twin-screw extruder, the shear force of the screw on the material makes the filler evenly dispersed. The spherical shape of the microbeads is easier to disperse, and excessive shear force can easily cause them to break. Therefore, the angle of the thread block of the meshing section should be adjusted, and the shear force should be reduced according to the low shear design. The specific adjustment method is as follows (real shot by St. Wright Laboratory):

After improving the thread combination
Comparison of crushing rates caused by different feeding methods and granulation methods

02. Adjustment of feeding method
To better reduce the bead breakage rate, you should:
1) Select side feeding to reduce the chance of microbeads being sheared in the screw.
2) Select long particles for granulation to reduce the damage of strong mechanical force during granulation.
After improving the thread combination
Comparison of crushing rates caused by different feeding methods and granulation methods

Remark:
1. Sanlight HS46, compressive strength: 16000psi, D90 (typical value) 30μm, specific gravity 0.46g/cm3.
2. Sanlight HL60S, compressive strength: 18000psi, D90 (typical value) 55μm, specific gravity 0.60g/cm3.

03. The influence of the rotational speed of the twin-screw machine
When the rotation speed is high, the shear force on the material is greater, which makes the microbeads more easily broken. Therefore, under the premise of ensuring the production process, reduce the speed and reduce the shear force of the screw.
After improving the thread combination, long particle granulation and side feeding conditions
Comparing the crushing rate caused by different screw speeds

When the content of microbeads is about 10wt%, the crushing rate of microbeads increases with the increase of screw speed, and the crushing rate rises to 7.23% at 400r/min.

04. Common problems and solutions

1) What is the normal breakage rate of microbeads during extrusion?
Due to the problem of the processing method, the microbeads will have a certain breakage rate during the extrusion process.

Optimization:
Adjust the screw combination, add microbeads to the side feed, granulate long particles, and the crushing rate can be controlled at 2-3%.

2) Does the addition of microbeads affect the resin processing performance?
Microbeads are an inorganic powder filler, similar to other inorganic fillers, which can improve the heat resistance of the resin after adding. Therefore, the processing temperature is increased.

solution:
1. The extruder is at the original processing temperature;
2. Add a small amount of lubricant to the formula to solve.

3) After the microbeads are fed from the side, how to ensure the uniformity of feeding?
solution:
1. Side feeding chooses twin-screw forced feeding;
2. A stirring rod should be added to the side feeding to prevent microbeads from “bridging” and ensure uniform feeding.
4) Will the mechanical properties of the resin drop significantly after adding microbeads?
Part of the impact performance will be sacrificed after adding microbeads, but part of the flexural modulus can be improved.

ways to improve:
1. Add a small amount of toughening agent;
2. Modify the surface of the microbeads with a coupling agent to improve the binding properties of the microbeads and the resin.
In addition, the compatibility of hollow glass microspheres with resin is not good, and the interfacial adhesion between resin and glass microsphere material will become poor, which will greatly reduce the performance of hollow glass microspheres, so improve the interfacial adhesion between them. Compatibility is very important.

Commonly used methods to improve compatibility include:
(1) Add compatibilizer: use coupling agent or maleic anhydride graft resin to improve the interface adhesion between the two;
(2) Surface etching: using acid and alkali to produce a large number of defects on the surface of the microbeads, at this time, the resin will be filled into the defect gap to achieve a stable effect;
(3) Surface modification: Through the reaction of strong oxidants and or acid-base and SiO, compatible functional groups such as silicon carboxyl groups and hydroxyl groups are generated; these functional groups can also be modified, and these modified functional groups can be grafted, polymerization and other reactions. Thereby improving the interfacial adhesion.

FROM: Eighth Element Plastic Edition

Hollow glass microspheres are industrially useful lightweight materials that exhibit high mechanical performance and are flexible. These are used as reinforcing materials in a polymer matrix to produce lightweight composites. According to Researcher, the global hollow glass microspheres market is expected to witness a moderate growth rate during the forecast period. Product innovations and technological advancements in the hollow glass microspheres industry are going to drive the global market. Moreover, growth in multiple other applications such as plastics, paints, and life sciences further pushes the market growth.

Of the many fillers now available to composites manufacturers, hollow glass microspheres, also called micro-balloons, are the most versatile.Microspheres pack a lot of functionality into a tiny package. Hollow glass microspheres can be produced by processing perlite that is a common volcanic glass.

The most obvious benefit of the hollow microsphere is its potential to reduce part weight, which is a function of density. Compared to traditional mineral-based additives, such as calcium carbonate, gypsum, mica, silica, and talc, hollow glass microspheres have much lower densities. Densities and crush ratings, however, vary dramatically across product lines. The market is expected to continue to be driven by the ongoing product developments in the hollow glass microsphere industry.