CAST v EXTRUDED Acrylic Full Version

I must have erred when I uploaded. Only the second half appeared. My apologies. Here is the full version.
A "fact" that has existed for ever says cast acryilc is much better and whiter than extruded acrylic. This video shows that fact to be a myth, based on lack of curiosity., ignoring logic and misunderstanding the basic physics of "whiteness".
A myth is defined as "A widely held but false belief or idea".
Another "fact" about engraving acrylic is that it cannot be done without fume debris and surface contamination. There are many solutions to remove the fume damage after engraving but nobody has ever taken the time to decode the root cause of the fume debris and fix it . In this video myth number 2 bites the dust also.

[@Dunne08]

Great video, I learned a lot! Everything was explained as clear as acrylic.

[@krash20]

Sir, this video contains more information than 10 additional other videos I have watched. Coagulations on the scientific approach you have used to make the demonstrations. Is there any way to clean condensed evaporated acrylic? I am struggling with extruded acrylic on my K40 laser. Will have to make some tests.

[@izaberipoklon]

Hi, I need an opinion or answer, I need to do a lot of rowmark plastic engraving, doing medals, is it safe all the time engraving without air , with air its hard to clean plastic after, client want deep engraving, so 'marking' isn't possible , thank you !

[@SarbarMultimedia]

Hi The problem you are concerned about (I presume) is damaging the lens with fumes if you don't use air assist to protect it. There may be several solutions to your dliema but it depends on the power of your tube , the lens and nozzle system you are using and the type and pressure of your air assist. To give advice tailored to your system I will need to know more than we can transmit via youtube comments. You can disguise your email address in a cryptic form that will befuddle the KZbin algorthm that prevents email addresses in comments. For example include your details in a normal sentence such as ...... I will be visiting john761 at the famous G company next week. I will reply and you can then send me pictures and details.

[@ianjohnson8419]

Does engraving solid gray as dithered B&W give you a smoother engraved surface, or does it give you the same noticeable scan lines as solid black?

[@SarbarMultimedia]

Because these are random and mainly single dots the scan lines do not show. Instaed, you are attempting to create a randon "frosted" finish. If you can feel depth to the finished product, you are either using too much power or not running fast enough. The idea is to mark the SURFACE and not to engrave to any depth. . By creating very few "fumes" the surrounding damage (hazyness) will be zero and will just wipe away with a dry cloth..

[@Rick.123]

I heard once that the main difference is that cast is virgin material and extruded is a mix with recycled ones

[@SarbarMultimedia]

Hi Rick See this video to see how the pelletes are made and become the base material for extruded acrylic sheet kzbin.info/www/bejne/jZ2baKGYpad6naM The claim is that they grind 100% pure PMMA as the feedstock. However the difference between cast and extruded is not the chemisrty but just the polymerisation efficiency . How this percentage is affected when you mix cast and extruded scrap is something I cannot find anything about. .However, I suspect it is the rapid mechanical extrusion process that is responsible for the lower polymerization and only the cell cast and continuous cast has the higher polymerization because of the virgin liquid componenets used and the lengthy, stress-free manufcaturing process. I will be looking into the differences again in the next video which will be about the cutting characteristics of the two (or 3 ) types of acrylic.

[@SarbarMultimedia]

see kzbin.info/www/bejne/oKWWXmBjnLF8q5o

[@patrykstaniszewski4312]

Hello can you give a Polish translate ? 🎉 Plesr

[@SarbarMultimedia]

Hi Patryk Press CC at bottom of screen to select English subtitles. Now press Settings icon and choose subtitles. This displays another window where it says Autotranslate. Select this and you can choose a language for subtitles Naciśnij CC na dole ekranu, aby wybrać angielskie napisy. Teraz naciśnij ikonę Ustawienia i wybierz napisy. Spowoduje to wyświetlenie kolejnego okna z napisem Automatyczne tłumaczenie. Wybierz to i możesz wybrać język napisów

[@patrykstaniszewski4312]

Bat hi don,t have a Polish

[@patrykstaniszewski4312]

?