Acrylic
From TheBestCaseScenario
| Acrylic | Almost like glass |
| |
| Information | |
| Uses: | Case windows, reservoirs, motherboard covers, PSU covers, case construction |
| Types: | Various colors and thicknesses, cast acrylic and extruded acrylic |
| Price: | 12" x 12" x 1/8" Clear Acrylic Sheet: ~$3.00 |
| Strength: | 17x the strength of glass |
| Weight: | 1/2 the wieght of glass |
| Properties: | As clear as glass, twice as strong, half the weight. Acrylic is very flexible and easily formed and solvent glued. |
| Difficulty: | Easy |
| Related Tools | |
| rtools | |
| Related Tutorials | |
| rtutorials | |
Contents |
[edit] What is Acrylic?
Many people know acrylic under different names. Polymethyl methacrylate (PMMA), or acrylic, has been manufactured by many companies all using different brand names. Many modders just call it plexi, short for the brand name Plexiglas. You may have heard of Plexiglas, Perspex, Acrylite, Acrylplast, Lucite, Rohaglas, or others. They are all the same thing - PMMA. The material was developed in 1928 and brought to the market by the German company Röhm in 1933.
Polymethyl Methacrylate: The Technical Data
Here is a graph from Wikipedia showing the chemical properties of PMMA:
| Chemical name | poly(methyl 2-methylpropenoate) |
| Chemical Formula |
|
| Synonyms | polymethyl methacrylate PMMA poly(methyl methacrylate) methyl methacrylate resin |
| Molecular mass | xx.xx g/mol |
| CAS number | 9011-14-7 |
| Density | 1.19 g/cm3 |
| Melting point | 130-140°C (265-285°F) |
| Boiling point | xx.x °C |
| Refractive index | 1.493 |
| V-number | 55.3 |
| SMILES | C[C](C)C(=O)OC |
To produce one kilogram of PMMA, about two kilograms of petroleum is needed. In the presence of air, PMMA ignites at 460° C and burns completely to form only carbon dioxide and water.
[edit] Why use acrylic over glass?
In comparison to glass, acrylic:
Is stronger than glass
Doesn't shatter
Is impact resistant
Is roughly half the weight of glass
Can be easily formed (requires 100 degrees C)
Transmits more light than glass (92% of visible light)
Doesn't filter UV light - good for modders (unless a special type is purchased)
Is easily solvent-glued
Is easily polished
[edit] Where to purchase acrylic
I have found that when purchasing acrylic and other plastics, it is good to look around locally first. Shipping for a huge sheet of plastic will cost a pretty penny, so it is always good to look around locally before diving into an online purchase. I recommend using Google's map tool to try and find plastics distributors in your area. And, of course, never doubt your phone book. Always check the yellow pages for plastics shops and whatnot.
When looking for acrylic locally, check with:
- Sign makers
- Plastics fabricators
- Plastics distributors/plastic shops
- Hardware stores, home supply stores (Lowe's and Home Depot have a limited selection of acrylic and polycarbonate - usually only in a 1/8" thickness.
However, if your town is anything like I know mine is, you might have a hard time finding any plastic locally. In that case, here are some great web sites stocking acrylic:
McMaster-Carr : Search for "Acrylic"
[edit] Cutting Acrylic with a Table Saw
Cutting Acrylic On a Table Saw
When cutting acrylic, a nice table saw is a huge help. I don't think I have ever worked on an acrylic project without using my table saw. With the right blade, your table saw will quickly become your favorite tool in the shop. But what exactly, is the right blade?
When cutting acrylic, your blade should:
- Have carbide tipped teeth, as to hold the edge on the blade - acrylic wears down metals quickly
- Have a 0 degree rake/offset
- Use the "Triple Chip" format - this is very important
A good table saw blade will run you pretty high, but is very well worth it if you will ever do any serious work with plastics in general, especially acrylic.
Here are some general tips when working with acrylic on a table saw:
- Find the right speed for your blade and type of plastic. Just experiment a bit, you will find what is too slow and melts the plastic, and what is too fast and chips the plastic.
Safety:
- Safety first! When using a table saw, ALWAYS wear eye protection, no matter what.
- Do not wear gloves when working with a table saw as they could get caught in the machinery.
- Never put your hand too close to the blade, four inches is pushing dangerous. If you need to push through a piece of acrylic when close to the blade, use a homemade handle or a scrap piece of wood once you get close to the blade to continue to push it through the saw.
- Never raise the blade much higher than the piece you are cutting.
Here is an example of a piece of acrylic being set up for cutting on the table saw. You can see that the blade is just higher than the piece we are cutting. That way, if you slip and your finger hits the blade, the blade will only cut into you as deep as the blade is raised above the acrylic.
Practice on a few scrap pieces of acrylic first, to get the feel right. When cutting acrylic, it takes a little while to find a speed that is good - too slow or too fast will melt it. But, once you get the hang of it, a table saw is a great tool for cutting acrylic and other plastics. I know that in my workshop, it is one of the most important tools.
[edit] Cutting Acrylic with a Jigsaw/Saber Saw
Plastics are just one of those things that really can't be cut using normal blades and tools used for wood and similar materials. Caution should be taking when deciding to use a jig saw on acrylic. Acrylic cracks pretty easily, and with the wrong blade, your jig saw could get stuck on the acrylic, shake around a bit, and easily crack it. When trying to use a blade meant for wood on acrylic, it cracked as soon as it locked up. The saw was just too powerful for the acrylic and it cracked it.
My cheap Craftsman scroll saw
However, with the right precautions taking, a jig saw or scroll saw can be a great tool to use on acrylic. With the right blades, you can cut practically any shape with these versatile tools.
US Plastic sells jig saw blades specifically for acrylic and other plastics, and I highly recomend the use of these:
They are very inexpensive and last a long time. They make cutting acrylic much easier and safer. If you don't want to buy these, however, a good blade meant for cutting metal will do. A fine toothed blade with 0 offset is really what you need for that clean, easy cut.
Saber saw blades from US Plastic - made for cutting acrylic