POLISHING: When polishing Acrylic there are various techniques involved depending on the end result required and what has to be cut and polished. All these methods can be used in polishing of Acrylic Display Mounting panels and Acrylic blocks although the latter tends to be done with MarK Free 97% techniques or over .
"97% Mark free": Laser cutting provides a very smooth polish with high clarity. There can be the occasional sub surface marks due to the heat of the laser causing stess marks. Laser cutting gives a very sharp lip to the edge but we will polish the sharpness away free of charge.
"98% Mark free" There are 2 methods of achieving this high quality finish. The first is flame polishing and the second is diamond polishing. Each technique requires a higher amount of labour and is therefore more expensive than laser cutting. Flame polishing costs more than Diamond polishing because of the addtional preparation work involved.
Flame polishing starts with cutting the Acrylic and then scraping or sanding off most of the surface marks caused by cutting. Then we use a flame torch (see image below) to melt the surface at a specific temperature which gives it the polished finish. This finish is said to " glow" which is specific to flame polishing. Some lines can remain and will get melted in as marks but it is a at very low percentage due to our preparation work. Occasionally if the flame polishing is interrupted some burning can result but again this will be very low percentage or the panel will be rejected by Quality Control. Flame polishing is not appropriate above 15mm.
Diamond polishing We start by cutting the panel oversize by a few miilimetres and then cutting it back using a revolving diamond cutting tool. This leaves a high quality polish but edges can still be sharp so we dull these off for safety. Sometimes swirl marks can be seen from the rotating diamond blades. This method is suitable up to 40mm thickness.
"99% Mark free" This is our ultimate finish and is achieved by preparing the surface carefully by laser or router. It is then diamond polished and after that a lot of labour is put into buffing away all except a very low percentage of marks. All sharp lip edges are smoothed off. This is the highest quality method and is also the most costly. It can be done on all thicknesses up to 40mm.
Laser cutting in general: Laser cutting is not just used to provide a polished edge. Cutting by this method costs more than other methods but complex shapes can be laser cut and etched which cannot be cut by any other method. With thicknesses over 20mm Acrylic laser cutting can cause concaving on the edges. Laser cutting can be used to cut and polish tight curves and large numbers of Acrylic shapes more cheaply.
Remember that diamond polshing can only be done to flat straight edges not to curves. So if there is a curved corner it will have to be flame polished and a thick corner or curve may be better laser cut as a flame torch perhaps cannot access the edge.
Cost: There is an additional cost for polishing which can add from a few pence to a few pounds per metre so please advise us at the enquiry stage which level of "Mark free" you want so that we can include the cost in our quotation.
