Introduction to PMMA and PC
The chemical name of PMMA is polymethyl methacrylate. Important optical plastic, good comprehensive and optical properties, transparency comparable to optical glass, almost unabsorbable visible light full-band light, light transmittance > 91%, good gloss, light, and robust and suitable formability, good chemical and weather resistance
PC polycarbonate, impact toughness (first of thermoplastics), high heat resistance, good cold resistance, bending resistance, tensile strength comparable to nylon, high elongation and modulus of elasticity, good dimensional stability, wear resistance similar to nylon, corrosion resistance, high transparency, but prone to cracking. Commonly used to make gears, bearings, colourless transparent PC can be used to make airplanes car windshields.
What is the structure of the PC PMMA composite panel, and what is its role
There are two main structures of composite panels: PC/PMMA and PMMA/PC/PMMA, with layer ratios of 9:1 and 1:8:1, respectively. PMMA provides high hardness and weather resistance, good PC impact resistance, and formability. The combination of the two can be well used for various high-pressure and hot-press IMD/FIM moulding processes, such as automotive controls, interior parts, different instrument panels, mobile phones, monitors, bags, helmets, etc. After the surface hardening treatment, the composite board is 3D high-pressure moulding and texturing and can be used for mobile phone covers.
The PC PMMA solid board extrusion line from the PC PMMA solid board extrusion line mainly consists of an extrusion system, rolling system, laminating system, cutting and stacking system.
The single screw extruder screw adopts PMMA/PC exhaust design, which is more suitable for the melting exhaust extrusion of PMMA/PC materials and has the characteristics of good plasticization, high output, no material popping, etc. high-precision melt pump can realize stable extrusion pressure and accurate quantitative production.
The mould adopts a unique runner design, dedicated to sheet forming of PMMA/PC transparent material, to ensure sheet thickness uniformity, super mirror flow channel to ensure sheet surface quality; GWELL PC PMMA solid board extrusion line and components all adopt products, the system is stable and reliable, the whole line is controlled by touch screen, easy to operate, display rich information; The above configurations can ensure that the entire extrusion system is stable and reliable, and provides the most effective guarantee for the back press moulding.
Differences between PMMA, PC, and PVC
Both PMMA and PC are thermoplastic engineering-grade plastics. According to various performance characteristics, acrylic is mainly used in advertising displays and craft gifts, while PC is primarily used in industrial manufacturing and outdoor decoration.
- Hardness: PMMA is less complicated than PC. The surface of PMMA is easy to scratch, so the sheet surface protective film cannot be torn during PMMA processing and production, and the surface should be prevented from being scratched and left unsightly marks during packaging. PC hardness is relatively high, ordinary nails and wood will not scratch, and excellent wear resistance.
- Light transmittance: PMMA has better light transmission performance than PC. PMMA has a light transmittance of 92%. It is as highly transparent as glass, so it is called plexiglass, especially optical grade and light diffusion grade PMMA, which has exceptionally high light transmittance and is suitable for manufacturing optical lenses and industrial lenses. The light transmittance of PC is only about 87%, which can only be applied to outdoor roof lighting covers and outdoor advertising lightboxes.
- Processing performance: PMMA is more accessible to process than PC. PMMA has low hardness and is easy to form. It can be used for cutting, engraving, gong, milling, drilling, turning, chamfering, trimming, polishing, bending, and other processing with woodworking machinery. PC processing is complex, and the processed surface effect is not good, the brightness is not enough, and it is easy to crack and collapse.
- Temperature resistance: PC is more resistant to high temperatures than PMMA. PC is resistant to high temperatures of 135 degrees, while PMMA begins to soften when it reaches 85 degrees.
- Other properties: PC is better than PMMA in stamping resistance, tensile strength, low-temperature resistance, acid, and alkali corrosion resistance, dimensional stability, and temporal stability.
- Hardened PMMA considers the high transparency of PMMA and the hardness of PC. It is usually used in aircraft windshields, automobile doors and windows, electrical panels, equipment covers and other fields.
Advantages of PC PMMA composite panel
- The 3D glass effect can be achieved through texture design and 3D high-pressure moulding, low cost, and the drop resistance of plastic. It is also the most potent competitor for the 3D glass back cover.
- PMMA/PC composite board meets wireless charging needs without shielding. PMMA provides high hardness and weather resistance, good impact resistance and formability of PC. The co-extrusion of the two materials greatly expands the new application of battery covers.
In fact, in summary, it is low cost, high appearance value, and easy processing. After all, plastic materials using IMD/IML process are bound to mature, and PC is also the primary application material in electronic products.
Main application areas of PC PMMA composite panel products
1. Touch screen, the lens sheet
Product application: Touch panels, lenses and other window lenses, mobile phones, tablets, monitor lenses, mobile phone buttons, membrane switches, etc.
2. Smart holster thick plate
PC PMMA solid board can be used as a protective case substrate for smartphone designs. Through excellent machinability and hot fit performance, to achieve various visual effects that customers want.
3. IMD in-mould decoration and in-mould FIM
PC+PMMA composite sheet is suitable for general purpose base films for various high-pressure and hot-press IMD/FIM forming processes. Automobile control parts, interior parts, instrument panels, mobile phones, monitors, bags, helmets, etc.
4. Mobile phone cover
After the surface hardening treatment, the composite board is 3D high-pressure moulding and texturing and can be used for mobile phone covers.
Advantages of PC PMMA composite panel products
1) Light transmittance
The light transmittance of the solar panel can reach up to 89%, which is compatible with glass. The UV coated board will not produce yellowing, atomization, poor light transmission when exposed to the sun. After ten years, the diluted transmission loss is only 10%, the PVC loss rate is as high as 15%-20%, and the glass fiber is 12%-20%.
2) Impact resistance
The impact strength is 250-300 times that of ordinary glass, 30 times that of an acrylic sheet of the same thickness, and 2-20 times that of tempered glass. It falls two meters below 3 kg hammer without cracks and has the nickname “unbroken glass”.
3 )UV protection
PC PMMA solid board is co-extruded with anti-ultraviolet (UV) coating and anti-condensation treatment on the other side, which integrates anti-UV, heat insulation and anti-fog functions. It can block the penetration of ultraviolet rays and is suitable for protecting valuable works of art and exhibits from UV damage.
The specific weight is only half that of glass, saving the cost of transportation, handling, installation, and supporting the frame.
According to the design drawings, cold-formed methods can be used on the construction site and installed into arches, semicircular roofs and windows. The minimum bending radius is 175 times the thickness of the plate and can also be hot bent.