28um Expandable Polymer Microspheres 20–35um SY829 97%

SY829 28 μm Thermally Expandable Polymer Microspheres

SY829 is a thermally expandable polymer microsphere developed as a physical blowing agent for lightweight polymer processing.

The unexpanded microspheres have an average particle size of approximately 28 μm and a particle size range of 20–35 μm. SY829 starts expanding at 150–160°C and reaches maximum expansion at 195–205°C.

It is suitable for controlled foaming, density reduction and fine closed-cell formation in compatible polymer systems.

SY829 Technical Specifications

How SY829 Expandable Microspheres Work

SY829 consists of a thermoplastic polymer shell containing an expandable core.

When heated:

1. The polymer shell begins to soften.

2. Internal pressure increases.

3. The microspheres expand into hollow microballoons.

4. Fine closed cells form inside the material.

This physical expansion increases material volume without significantly increasing weight.

Key Advantages of SY829

• Approximately 28 μm average particle size

• Controlled 20–35 μm particle size range

• High solid content above 97%

• Defined thermal expansion window

• Fine and uniform closed-cell structure

• Effective density and weight reduction

• Improved product thickness and volume

• Reduced risk of large foam cells

• Improved surface smoothness

• Good dispersion in compatible formulations

• Suitable for medium- and high-temperature processing

Lightweight and Density Reduction

SY829 creates hollow microstructures inside the polymer matrix.

Depending on the formulation and process, it can help achieve:

• Lower finished-product weight

• Reduced material density

• Increased product volume

• Lower raw-material consumption

• Improved cushioning

• Better thermal insulation

• Improved sound and vibration damping

Fine Closed-Cell Foaming

Each SY829 microsphere forms an individual hollow cell during heating.

This controlled microcellular structure can help reduce:

• Large bubbles

• Uneven cell distribution

• Surface pinholes

• Rough surfaces

• Irregular product thickness

• Local density differences

SY829 is suitable for applications requiring both lightweighting and controlled surface quality.

Suitable Materials

SY829 can be evaluated in compatible materials such as:

• PVC

• EVA

• PE

• PP

• TPE

• TPR

• TPU

• EPDM

• Rubber compounds

• Adhesives

• Sealants

• Printing inks

• Coating systems

Compatibility should be confirmed according to the material viscosity, processing temperature and required performance.

Main Applications

Thermoplastic Extrusion

SY829 can be evaluated in extrusion applications including:

• Plastic profiles

• Foam sheets

• Tubes and hoses

• Cable materials

• Sealing strips

• Synthetic wood

• Lightweight panels

It can help reduce density while maintaining a fine and uniform surface.

Injection-Molded Products

SY829 may be used in compatible injection-molding formulations for lightweight components.

Typical applications include:

• Automotive interior parts

• Plastic housings

• Sealing components

• Gaskets

• Lightweight molded parts

• Functional plastic components

Footwear and Shoe Soles

SY829 can be evaluated in EVA, TPR, TPU and compatible rubber formulations.

Potential benefits include:

• Reduced shoe weight

• Improved cushioning

• Increased softness

• Controlled sole thickness

• Fine foam cells

• Improved surface appearance

Synthetic Leather

SY829 can create a lightweight foamed layer in synthetic leather and coated fabrics.

Potential advantages include:

• Increased thickness

• Reduced coating weight

• Improved softness

• Better flexibility

• Enhanced cushioning

• Smooth surface appearance

Foam Printing Inks

SY829 can be used in heat-activated printing formulations to create raised effects.

Typical applications include:

• Textile foam printing

• Wallpaper printing

• Decorative graphics

• Raised printing

• Braille printing

• Three-dimensional patterns

Coatings

SY829 can be evaluated as a lightweighting and texture-modifying additive in compatible coatings.

Potential applications include:

• Textile coatings

• Leather coatings

• Automotive coatings

• Paper coatings

• Industrial coatings

• Decorative coatings

Adhesives and Sealants

SY829 may help reduce density and improve compressibility in compatible adhesives and sealants.

Potential applications include:

• Automotive sealants

• Construction sealants

• Gap-filling adhesives

• Foam tapes

• Lightweight bonding layers

• Compressible sealing materials

Automotive Components

SY829 can be evaluated in automotive polymer and elastomer products such as:

• Weather strips

• Glass run channels

• Interior trim

• Sealing profiles

• Gaskets

• Sound-damping components

Lightweight Composite Materials

Other potential applications include:

• Lightweight putty

• Artificial stone

• Polymer clay

• Composite panels

• Construction materials

• Porous ceramics

• Decorative molded products

Recommended Processing Methods

SY829 can be evaluated in:

• Extrusion

• Injection molding

• Compression molding

• Calendering

• Coating

• Printing

• Casting

• Polymer compounding

Uniform dispersion before thermal expansion is important for consistent foaming performance.

Processing Temperature Guidance

SY829 starts expanding at approximately 150–160°C and reaches maximum expansion at approximately 195–205°C.

For stable processing:

• Keep premixing temperatures below the expansion range.

• Match the actual material temperature to the required expansion level.

• Avoid premature expansion during mixing.

• Control residence time at elevated temperatures.

• Avoid excessive shear after expansion begins.

• Prevent prolonged heating above the maximum expansion range.

• Conduct laboratory trials before commercial production.

Excessive temperature or prolonged heating may damage the expanded shell and reduce the final expansion effect.

Factors Affecting Expansion

The final foaming result depends on:

• Base polymer

• SY829 dosage

• Actual material temperature

• Heating time

• Processing pressure

• Melt viscosity

• Mixing efficiency

• Product thickness

• Cooling conditions

Machine temperature settings may differ from the actual temperature experienced by the microspheres.

Recommended Addition Level

The optimum dosage should be selected according to:

• Target density

• Required expansion ratio

• Base material

• Product thickness

• Processing method

• Mechanical requirements

• Surface-quality requirements

Small-scale formulation testing is recommended before production scale-up.

SY829 vs. Chemical Blowing Agents

SY829 may be evaluated alone or combined with a compatible chemical blowing agent.

Why Choose SHBC SY829?

• Defined 20–35 μm particle size range

• Approximately 28 μm average particle size

• High solid-content white powder

• Controlled Tstart and Tmax ranges

• Suitable for industrial formulation development

• Stable batch supply

• Sample evaluation support

• Custom packaging options

• Bulk production capability

• Technical support for grade selection

Storage and Handling

Store SY829 in its original sealed packaging in a cool, dry and well-ventilated area.

Keep the product away from:

• Direct sunlight

• Heat sources

• Open flames

• High humidity

• Excessive pressure

• Premature expansion temperatures

Avoid unnecessary friction and strong compression. Review the Safety Data Sheet before industrial use.

Frequently Asked Questions

What is SY829?

SY829 is a thermally expandable polymer microsphere used as a physical blowing agent and lightweight polymer additive.

What is the particle size of SY829?

The average particle size is approximately 28 μm, with a particle size range of 20–35 μm.

What is the solid content?

The solid content is greater than 97%.

What is the appearance of SY829?

SY829 is supplied as a white powder.

At what temperature does SY829 start expanding?

The expansion start temperature is approximately 150–160°C.

What is the maximum expansion temperature?

The maximum expansion temperature is approximately 195–205°C.

How does SY829 reduce product weight?

The microspheres expand into hollow microballoons, increasing material volume and reducing the density of compatible products.

What materials can be used with SY829?

SY829 can be evaluated in PVC, EVA, PE, PP, TPE, TPR, TPU, EPDM, rubber, coatings, adhesives and other compatible systems.

Can SY829 be used in extrusion?

Yes. It can be evaluated in profiles, sheets, hoses, cables, sealing strips and other extrusion applications.

Can SY829 be used for injection molding?

Yes. Temperature, pressure, dosage, residence time and mold conditions should be optimized through testing.

Can SY829 be combined with chemical blowing agents?

Yes. It may be used alone or combined with compatible blowing agents to adjust density and cell structure.

Is application testing necessary?

Yes. Laboratory and pilot-scale testing are recommended because expansion performance depends on the formulation, equipment and processing conditions.

Request SY829 Samples

Contact Shanghai SanYu Biotechnology Co., Ltd. for SY829 samples, technical specifications, SDS information and bulk supply.

Please provide:

• Base material

• Final application

• Processing method

• Processing temperature

• Target density

• Required expansion level

• Current blowing agent

• Estimated purchase quantity