What Is Polycarbonate – Explore Properties, Grades & Industrial Applications

Do you know there is plastic material that is over 200 times stronger than glass? Well, that is polycarbonate.

Many businesses use polycarbonate as protective panels, machine parts, glazing panels and protective barriers, among other applications. However, before you choose polycarbonate for any application, it is important to understand its properties, features, fabrication techniques, and grades, among other vital properties.

Chemical Structure and Composition

Polycarbonate is a polymer that is composed of long chains of repeating chemical units. These chains have carbonate groups, which are represented by -O-(C=O)-O-, attached to the molecules of bisphenol.

This type of structure makes a robust and solid material. The chemical formula of the repeating unit is (C15H16O2)n, with n being the number of repeating units linked together.

Composition

· Bisphenol A (BPA)

Bisphenol A is the polycarbonate backbone. It consists of two rigid aromatic rings, which are linked with a short bridge. These rings add rigidity to the polymer chain, enhancing strength and impact resistance without compromising on light transmission.

· Carbonate Groups

The bisphenol units of the polymer chain are joined by carbonate groups. These connections keep the structure intact, while ensuring slight movement between the units. This balance makes the material flexible making polycarbonate absorb impact rather than cracking.

· Oxygen, Carbon, and Hydrogen Atoms

Oxygen atoms are present in the carbonate bond, and they determine the response to heat and light. The rings and chain structure consist of carbon and hydrogen atoms. Collectively, these elements determine stability of the material, transparency and general chemical behavior.

Properties of Polycarbonate

a) Mechanical Strength

Polycarbonate is more robust than most standard plastics. It has a tensile strength of about 60-75 Mpa, making it bend instead of breaking when struck.

Owing to this exceptional strength, you can use this material to make polycarbonate shields, machines parts and panels. These parts can withstand constant pressure without breaking or collapsing.

b) Optical Clarity

Polycarbonate is a glass-like, transparent material that can transmit up to 90 percent of the visible light. It does not lose its clarity when exposed to extreme pressure or heat.

It is for this reason that you will find polycarbonate lenses, polycarbonate windows, and polycarbonate display covers, among many other accessories.

The best part, polycarbonate guarantees better visibility without compromising strength.

c) Heat Resistance

Polycarbonate is heat resistant and capable of maintaining shape up to 130–140 °C. It is also continuously usable at 115–125 °C without softening. This capability to withstand extreme heat conditions makes it suitable in electronics, lighting, appliances, and other mechanical components that generate or are subjected to high temperatures.

d) Electrical Insulation

Polycarbonate is non-conductive making it an excellent insulator. It has high dielectric strength and volume resistivity that assist in protecting delicate electronic components. It is applicable in housings, switches, connectors, and other items where reliability and electrical safety is a big concern.

e) Dimensional Stability

Polycarbonate will retain its shape under changing pressure or temperatures. Its thermal expansion is moderate at approximately 65–70 × 10⁻⁶ /°C, and thus components will not readily warp or shrink. This stability is required in precise assemblies, mechanical components, and parts that must fit together accurately.

f) Fire Resistance

Polycarbonate is resistant to fire compared to most plastics. Flame-retardant grades will self-extinguish once a flame is removed. This property enhances safety in electrical housings, building panels and transport interior helping to limit the spread of fire.

Common Grades and Variants

When it comes to choosing polycarbonate material for any project, you will find many grades. Most of these polycarbonate grades may be optimized by adding more treatments for superior performance.

a) General-Purpose (GP)

General-purpose polycarbonate is transparent, robust, and simple to shape. It is tough and transparent, used in machine housings, panels, protective covers, and in common consumer products where durability and transparency are needed without special resistance to heat, fire or chemicals.

b) UV-Resistant

UV-resistant polycarbonate has additives that prevent sunlight damage. It remains clear and strong even when it is exposed outdoors. This grade is used in roofing sheets, skylights, outdoor signs, and greenhouse panels to make them durable and prevent yellowing when exposed to sunlight.

c) Abrasion-Resistant (AR)

AR Polycarbonate has a hard surface that is resistant to scratching. Transparent surfaces remain clear despite repeated contact. This grade is used in displays, protective shields, windows and panels in high-traffic areas to ensure that they retain clarity and appearance over time.

d) Flame-Retardant

Flame-retardant polycarbonate slows ignition and prevents the spread of fire. It complies with standards like UL94 V-0. This grade is used in electrical housings, transport interiors and building panels to minimize the risks of fire. Flame-retardant PC is also widely used for EV charger enclosures.

e) Optical Grade

Optical-grade polycarbonate is highly transparent. It enables good transmission of light for optical covers, lenses and light guides.

f) Bullet-Resistant

Bullet-resistant polycarbonate is composed of several layers that absorb extreme force. It distributes force to avoid cracking or shattering. This grade is used in security glazing, protective barriers, and safety windows as a reliable protection against high-impact threats.

g) Anti-Static (ESD)

Anti-static polycarbonate prevents the buildup of static electricity. It protects delicate electronics parts from discharge damages. This grade is used clean rooms, data centers, and electronic assembly spaces where safety, product integrity, and consistent performance are required in an environment with sensitive electronics.

h) Food-Approved / Medical Grade

Medical-grade and food-approved polycarbonate adheres to high health and safety standards. It is resistant to contamination, chemical leaching and constant cleaning. This grade is used in medical equipment, laboratory equipment, and food containers to ensure hygiene, safety and compliance with regulations.

i) Reinforced

Reinforced polycarbonate is filled with glass fibers or other fillers to increase strength. This grade is used in automotive parts, structural components, and industrial applications to support heavy loads.

Physical Forms

a) Solid Sheets

Solid polycarbonate sheets are flat uniform panels composed of pure polycarbonate. They are strong, impact-resistant and transparent. They are also easy to cut, drill or shape, which makes them an excellent choice for protective barriers, windows, machine guards and any other place demanding durable, clear and flat material.

b) Multiwall / Twin-Wall Sheets

Multiwall polycarbonates sheets consist of two or more layers with air gaps between these layers. The inner chambers help in reducing weight and enhance thermal insulation without losing strength. These sheets are best used in greenhouses, roofing panels, skylights and places that require light penetration and structural reinforcement.

c) Corrugated Sheets

Corrugated polycarbonate sheets are wavy in design, and this makes these sheets stiffer. This design offers additional strength. They are used in industrial roofing, wall cladding and in outdoor covers that need durable and weather-resistant solution.

d) Blends

Polycarbonate blends are a mixture of polycarbonate with other plastics or additives to improve on certain properties. For example, blends may improve chemical resistance and flexibility. They are used in appliance housings, consumer goods and mechanical component for custom use without compromising the strength of polycarbonate.

How Polycarbonate Is Manufactured

The production of polycarbonate involves conversion of raw chemical materials into long polymer chains, which are then molded into sheets, parts, or granules.

Ideally, you will follow this process:

A. Polymerization (Phosgene) Process

Step 1: Preparation of the Raw Material

This starts with preparation of the main chemicals. Bisphenol A is dissolved in water mixed with sodium hydroxide. This reaction forms a reactive salt which can easily react with other molecules. Phosgene is also dissolved in organic solvent, typically dichloromethane to obtain a second liquid phase.

Step 2: Interfacial Polymerization

In a controlled reactor, the two ready liquids are combined to create two layers. A chemical reaction takes place at the contact point between the layers. Here, carbonate links are formed as the bisphenol salt reacts with phosgene. Initially, short polymer chains are created and then made long using a catalyst.

Step 3: Chain Growth and Stabilization

As the reaction continues, longer and more stable polymer chains are formed. Close observation of temperature and mixing results in equal chain length. This is also the step that determines the ultimate strength, clarity and heat resistance of polycarbonate.

Step 4: Polymer Separation

After completion of reaction, the organic layer will contain polycarbonate while salt byproducts found in the water layer. The two layers separate naturally. Each is drained one at a time and then the polymer solution is recovered cleanly.

Step 5: Removal of Solvent and Granulation

The organic solvent gets evaporated or precipitated using alcohol. Then the solid polycarbonate obtained is dried and then cut into small granules. These granules now become the new raw material in the molding, extrusion, and other forming process.

B. Forming (shaping) Process

Polycarbonate shaping is a process that is used to shape solid resin to useful components using controlled pressure, heat or cutting to obtain the desired shapes.

· Injection Molding

Polycarbonate is produced through injection molding where the granules are melted and then pushed into a closed mold under pressure. The final shape is determined by the mold.

Once cooled, the part is ejected. The process produces repeatable units of housing, connector and technical components of similar size.

· Extrusion

Polycarbonate is produced through extrusion where molten material is forced through a shaped die. The plastic is then constantly squeezed out and hardened into sheets, rods or tubes. The extruded polycarbonate is used in building panels, glazing sheets and structural profiles.

· Thermoforming

Thermoforming is the process of shaping the hot sheets of polycarbonate. The sheet is softened and then stretched on a mold either by pressure or vacuum.

The sheet is allowed to cool and take up shape of the mold. The process is used on oversized parts like equipment covers, equipment trays and protective enclosures that have smooth and round surfaces.

· Blow Molding

Blow molding is used to manufacture hollow polycarbonate. Air pressure is used to increase the size of the molten material in the mold. The material then spreads on the walls and acquires the shape of the mold. The process is applied to containers and duct-fluid handling components that must have uniform wall thickness and hollow structure.

· 3D Printing

3D printing is a technology whereby polycarbonate parts are created using heated filament in layers. These layers are then well bonded to one another. This process is employed in the production of complex shapes and internal features of parts.

· CNC Machining

CNC machining is a cutting process whereby the solid blocks of polycarbonate are cut with the use of computer-controlled cutting tools. This process removes material from the blocks with accuracy producing tight tolerances, smooth edges and finer details. CNC machining is applied in the production of custom parts, prototypes and precision parts where flexibility and precision are critical.

Benefits of Polycarbonate

• Polycarbonate is hard and it does not break easily when hit. It is used in machine guards, protective panels and safety shields to protect people and equipment.
• It is transparent and effective in allowing light to pass through.
• The material neither deforms nor degrades in the presence of heat. It finds its use in electronics, appliances and other materials that are subjected to high temperatures.
• Polycarbonate is versatile in any form of forming such as molding, extrusion, or thermoforming. Complex and custom designs can be designed without affecting durability.

Disadvantages of Polycarbonate

• Polycarbonate is easily scratched when they are not coated with any protective coating.
• This material tends to crack or degrade when it encounters strong solvents or some chemicals. It should be handled carefully in the presence of cleaners or factory liquids.
• Polycarbonate is more expensive than regular plastics.
• Untreated polycarbonate turns yellow or brittle when exposed to sunlight. Therefore, UV-stabilized grades are required in outdoor applications.

Comparison of Polycarbonates and Their Applications

FAQs

Can polycarbonate be recycled?

Yes. Polycarbonate is recycled into new products by many facilities.

Is polycarbonate safe for food and medical use?

Yes. Certified grades comply with food and medical safety when made and utilized properly.

Can polycarbonate be used outdoors long-term?

Yes. UV-stabilized grades can withstand the effect of sunlight.

Weprofab is your No.1 Polycarbonate Material Supplier in China

Are you looking for polycarbonate sheets, rods, tube or other finished products? Weprofab is your trusted supplier in China with over 15 years of experience fabricating polycarbonate parts.

At Weprofab, we ensure you get fabricated polycarbonate parts that meet the necessary safety standards and regulations. Our engineers will work closely with your team for custom polycarbonate part designs for your unique project requirements – Get a quote now.</a >