What is acrylic (PMMA)?

Let's look at some of the common names:

Acrylic glass (organic glass) is an acrylic resin. It is a clear plastic that can be coloured and tinted.

Other names: Plexiglas, Acrylite, Acrima, polymethyl methacrylate, acrylic glass. Most of these names come from popular brands.

Polymethyl methacrylate is the full and most correct name for acrylic glass

There are two production methods:

Casting or extrusion; the resulting sheets are called "cast" and "extruded" acrylic. They look identical and have similar basic properties and technical characteristics, but they do differ from each other. It is important to know which of these methods was used to make the material in order to understand how it will behave during processing and under specific conditions of use.

1. Extrusion: the molten material is pushed out through a die (high molecular weight).

2. Casting (cell casting): the resin is poured between flat glass plates and left to harden (low molecular weight).

Extruded acrylic is stronger than cast acrylic, easier to process and polish, has better chemical and impact resistance, withstands higher thermal loads and is easier to form, with better results.

Compared with cast acrylic, extruded acrylic comes in fewer sheet thicknesses (determined by the capabilities of the extruder), but longer sheets are possible. The thickness tolerance is much tighter (only 5 % instead of 30 % for cast acrylic).

By type of sheet, acrylic can be:

clear;
tinted clear;
frosted;
solid-coloured;
textured;
fluorescent.

Clear acrylic

Coloured acrylic

Fluorescent acrylic

Technical characteristics of acrylic at 20°C


Property	Value
Density	1100–1200 kg/m³
Service temperature	-60 to 100°C
Thermal conductivity	0.19–0.3 W/(m·K)
Coefficient of linear expansion	7·10^-5…9·10^-5
Softening point	90–133°C
Frost resistance	-50°C
Linear shrinkage	3.5–5%
Impact strength	7.8–13 kJ/m²
Breaking strength	61.7–70 MPa
Tensile strength	40 MPa
Compressive strength	70 MPa
Flexural strength	140 MPa
Light transmission	over 88%

Advantages of acrylic:

Lightweight – 2.5 times lighter than ordinary glass (1.19 g/cm³).
Strength – 5 times stronger than glass.
Light transmission – transmits up to 93% of visible light.
Environmentally friendly – easily recycled and releases no toxic substances.
Moisture resistance.
Safety – minimal risk of injury from fragments.
Practicality – easy and convenient to work with.
Durability – retains its properties for more than 15 years.
Temperature resistance – can be used at temperatures down to -50°C.

Disadvantages of acrylic:

highly flammable;
reacts to alcohol (ethanol, methanol);
prone to chipping;
scratches easily;
may crack at bends.

Where acrylic is used:

Construction: façade elements, interior partitions, glazing, interior décor, greenhouses, barriers.
Advertising agencies: signs, information boards, sign plates, name badges, cloakroom number tags, light boxes
Retail: price tag holders, product stands, protective screens for checkouts, air conditioner deflectors, product containers, protective covers
Many other fields: spectacle lenses, aquariums, souvenirs, etc.