Polycarbonate had earned the tag as the most suitable material for use in the automotive industry. However, in recent times, Polymethyl Methacrylate, the PMMA polymer or commonly known acrylic plastic, has efficiently risen to the growing demands of the automotive industry in replacing polycarbonate for the most important use in the industry, namely, automotive glazing.
Long established for use in a variety of vehicle applications such as decorative trim, ambient lighting and door entry strips, automotive glazing is one of those fields that offer the highest growth potential for PMMA.
Related key features of acrylic plastic that make it ideal for the process of automotive glazing are discussed below.
To make a comparison on a very basic level, PMMA is half the weight and more transparent than glass, thereby providing crystal clear visibility even in the case of fluctuating and unstable temperatures. Owing to its molecular structure, thermoformed acrylic sheets are now used almost exclusively for car window glazing where all the necessary requirements for light-weight materials that are safe, easy to process and perform in all weathers are met.
High on Scratch Resistance
Another important requirement for glazing is scratch resistance. Standard PMMA already has the highest surface hardness of all thermoplastics even when uncoated. However, for automotive glazing, there are stringent conditions to be fulfilled to meet the ideal state of scratch resistance. The application of a coating is therefore mandatory. Considering that PMMA is intrinsically UV as well as weathering-resistant, a single-step coating works well. In contrast, thermoplastics that have low resistance to weathering require a two-step coating system. This results in relatively high costs for coating.
New design possibilities
PMMA glazing is 40 to 50 percent lighter than conventional glass, which piques the interest of automobile manufacturers. With the advantages being immediately obvious, PMMA is now seen as the right fit for automotive glazing. Weight savings apart, the transparency of acrylic plastic as well as its very high weathering resistance, pleasant acoustic properties, and exceptional form ability allow freedom enabling entirely new design possibilities.
Less stress birefringence
PMMA exhibits very little stress birefringence and this serves as a major benefit over other thermoplastics such as polycarbonate, which was primarily employed for glazing in the past. Compared with traditional materials such as polycarbonate, moulded PMMA, offers a distinct possibility of functional integration – reducing recess depth and assembly costs.
The new goal in the automotive industry is to develop clean low fuel consumption vehicles. Given the awareness and the need for eco-friendly initiatives in the current scheme of things, PMMA serves as a perfect alternative to glass in the automotive glazing segment. As vehicle manufacturers push the boundaries of design, so too is automotive glazing evolving.
SUMIPEX® PMMA polymer offers characteristics that meet the latest challenges in the transportation sector. It’s a monumental challenge for car makers that want to adjust to recent environmental requirements and are thinking about alternatives that reduce greenhouse gas and save fuel. It is the perfect partner in this movement because it helps make cars lighter.
As a leading manufacturer of SUMIPEX® PMMA polymer, Sumitomo Chemical is happy to assist you in understanding its properties and how it best suited to automotive glazing. To know more, reach out to us here.