Various applications of PBT plastic

PBT, or polybutylene terephthalate, is a semi-crystalline engineering thermoplastic with properties and composition similar to those of polyethylene terephthalate (PET). It belongs to the polyester resin family and shares the same characteristics as other thermoplastic polyesters. PBT is a high-performance material with a relatively high molecular weight; it is generally regarded as a plastic that boasts high strength, great rigidity, and ease of processing. The color of PBT ranges from white to bright shades.

Use

PBT is widely used in everyday life and is commonly found in electrical, electronic, and automotive components. PBT resin and PBT composites are two types of materials employed in a variety of applications. Among these, PBT composites contain multiple components, which may include PBT resin, glass fiber fillers, and additives; whereas PBT resin consists solely of the base resin. This material is typically used in mineral- or glass-filled grades.

For outdoor use and applications where fire hazards are a concern, we add additives to enhance their UV resistance and flame retardancy. After these improvements, PBT products can be widely used in a variety of industrial fields.

PBT resin is widely used in the manufacture of PBT fibers as well as electronic components, electrical parts, and automotive components. For example, TV accessories, motor housings, and motor brushes all utilize PBT composites. After reinforcement, PBT can also be employed in products such as switches, sockets, spools, and handles. Meanwhile, unfilled PBT material is commonly found in certain brake cable linings and brake levers.

When a material is needed that combines high strength, excellent dimensional stability, resistance to a wide range of chemicals, and superior insulating properties, PBT is the material of choice. Moreover, when bearing performance and wear resistance are critical factors, PBT is again the ideal selection. For this reason, components such as valves, parts for food-processing machinery, wheels, and gears are all manufactured using PBT. In particular, in the food-processing industry, PBT’s applications are largely driven by its low hygroscopicity, strong resistance to staining, and inability to absorb food flavors.

Advantage

The primary advantages of PBT lie in its solvent resistance and low shrinkage during molding. In addition, it exhibits excellent chemical resistance and is easy to mold thanks to its rapid crystallization. PBT can withstand high temperatures up to 150 degrees Celsius, with a melting point reaching 225 degrees Celsius. After the addition of fibers, its mechanical and thermal properties are further enhanced, enabling it to endure even higher temperatures. Other notable advantages include:

Excellent anti-fouling performance

Excellent machinability

High intensity

Resilience

Excellent stiffness-to-weight ratio

Resistance to environmental changes

Excellent machinability

It has better impact resistance than PET.

Excellent dimensional stability

Block ultraviolet radiation

High electrical insulation performance

Multiple grade levels available.

Disadvantages

The drawbacks of PBT limit its application in certain industries, including:

Lower strength and stiffness than PET

The glass transition temperature is lower than that of PET.

Glass tends to deform easily when used as a filler.

Poor resistance to acids, bases, and hydrocarbons.

The future of PBT

With population growth and innovations in the automotive, electrical, and electronics industries, the use of PBT will steadily increase. This trend is particularly evident in the automotive industry, where demand for lighter, more durable, low-maintenance, and cost-competitive materials is on the rise.

Due to the issue of metal corrosion and the high cost of addressing it, the use of engineering-grade plastics such as PBT is on the rise. Many designers seeking alternatives to metal materials are turning increasingly to plastics, viewing them as a viable solution. Currently, a new type of PBT material has been successfully developed, offering superior performance in laser welding and providing a brand-new solution for welded components.