Optical grade PMMA lens

LED lens is an optical component with a spherical part of the surface made of transparent substances (such as glass, crystal, plastic, etc.) according to the law of refraction of light. As an optical grade product, it has strict requirements for light transmission, thermal stability, density, refractive index uniformity, turbidity, maximum long-term operating temperature, etc. One of the most common materials used for TIR lenses is "PMMA", which is often asked by fans. The most common material used in TIR lenses is PMMA, which is often asked by fans.

What is PMMA?

PMMA is polymethyl methacrylate material, commonly known as organic glass, acrylic, etc. It is a polymer with good transparency, optical properties, impact resistance and aesthetic properties, is a common glass replacement material, is known as the "queen of plastic" organic synthetic transparent materials.

The relative molecular mass of PMMA is about 2 million, and the chain of molecules is soft, so the strength of PMMA is relatively high, and the resistance to stretching and impact is 7 to 18 times higher than that of ordinary glass. When it is used as plexiglass, even if it breaks, it will not produce bursting fragments like ordinary glass.

Main characteristics of PMMA

Colorless and transparent:

Light transmittance of 90% - 92%, toughness, more than 10 times greater than silica glass;

Good performance:

Good dielectric and insulating properties, high arc resistance, excellent weathering/aging resistance;

High heat resistance:

Have tough, hard, rigid characteristics, heat deflection temperature 80 ℃, bending strength 110Mpa.

PMMA acrylic Extrusion Linear Lens Series

Process processing

At present, PMMA production technology mainly has suspension polymerization, solution polymerization and propriety polymerization 3 kinds of process. PMMA is generally produced by suspension polymerization process for small-scale intermittent production and solution polymerization and propriety polymerization process for large-scale continuous production, and it is generally processed by casting, injection molding, machining, thermoforming and other processes, and has good post-processing properties.

Wide range of applications

With excellent optical properties, PMMA materials are widely used, among which the main application areas of common PMMA are advertising light boxes, signs, lamps, bathtubs, meters, etc., while high-end PMMA is used in liquid crystal displays, optical lenses, automobile lampshades, bulletproof glass, aircraft cockpit glass, medical polymer materials, military optical equipment, high-speed railway windows, police shields, high-end diving goggles, etc., which are used in China The 12th Five-Year Development Plan of Petrochemical and Chemical Industry is listed in the list of high-end petrochemical and chemical products in the 12th Five-Year Plan.

Used in optical lenses

PMMA has strong light transmission, heat resistance, and good scratch resistance, and is one of the key materials for lighting equipment.

The advantages of PMMA compared to glass are: easy to shape design, processing and molding, especially some special optical design; more lightweight, PMMA density is nearly half of glass; glass is not recyclable, PMMA can be recycled.

And optical grade PMMA and ordinary grade acrylic also has a difference: optical grade PMMA light transmission is higher, good transparency. Ordinary acrylic transmittance is 92%, optical grade PMMA is 93%, can be used for LED lenses, lights, lens products, light guide, etc.