Optical clarity is a vital characteristic of devices relying on transparency for visual inspection and analysis. Where glass was once preferred due to its ability to transmit light, acrylic polymer – first developed over eight decades ago – now holds a large share of the market.
Like glass, polymethyl methacrylate – commonly called “acrylic” – offers superior optical qualities as well as chemical resistance and biocompatibility, but additional benefits like impact strength, lower costs, and disposability now afford acrylic its forerunner status in parts and component manufacturing in many industries.
In order to obtain the glass-like finish that is not only recommended and aesthetically desirable, but also absolutely necessary in a wide variety of applications, plastics specialists often utilize a finishing technique known as flame polishing.
Flame Polishing in a Nutshell
Flame polishing acrylic is accomplished by directing a high temperature flame onto the acrylic surface. Some of the pivotal elements of the process include:
* Beginning with a part that has been expertly machined
* Using a specialized flame polisher, typically an oxygen-hydrogen welding torch
* Ensuring an appropriate flame – ideally a bluish, almost invisible, approximately 3″ long, and narrow flame
* Applying the heat at a correct distance from the surface
* Moving the heat source quickly and without disruption
* Requiring a skilled and experienced operator, which is often the most important factor in achieving a quality finish
* Employing an annealing cycle to relieve stresses imposed by the finishing process, thereby preventing stress cracking or crazing upon use
Advantages of Flame Polishing
Flame polishing acrylic is a process that, like other plastics finishing methods, is best suited for specific applications; however, it does boast a few distinctive advantages:
* Universality – flame polishing can add a glass-like finish to almost any acrylic element
* Rapid results – flame polishing yields an optically clear finish in a relatively short amount of time
* Compatibility with components engineered with complex geometry and hard-to-access edges – flame polishing can reach where other methods cannot
The results of flame polishing acrylic, when performed by a qualified expert, are functionally and aesthetically superior to most other acrylic finishing techniques. For applications where optical clarity is required, as well as for those where a glass “look alike” is desired, flame polishing acrylic is a clear and affordable choice.
To enlist a plastics expert for your next project – whether prototype or large production run – visit Pepctplastics.com. The specialists at PEP Connecticut Plastics will help you select the finishing process that will be the best fit for your application.
