CNC machines employ advanced technology to produce precise, exact acrylic parts, but the process is time-consuming. It takes extreme accuracy to create acrylic without shattering it, needing just the right amount of pressure. We understand how to shape and carve acrylic utilizing the newest CNC cutting technologies at Industrial-man.
Today, we'll examine the acrylic polymer production procedure, often known as optical prototyping. It's among the most widely used polymers on the planet, and it competes with glass and polycarbonate. Because acrylic pieces are used in so many different industries, it seems like a great option to investigate their manufacturing techniques, particularly CNC acrylic machining, which is employed in practically every type of acrylic manufacture.
This article will show you how to select the correct blank, trim, and engrave it with CNC cutters and what to do once the machining is complete.
Because of its remarkable characteristics, acrylic has become a widely used polymer. First and foremost, it is five times tougher than glass. And by tougher, we imply shatter-resistant and shock-resistant. It's also really transparent. Acrylic features transparency of 93 percent, which means that just 7% of the entering light is lost as it passes through it. To put it in perspective, window glass is typically 84 to 90 percent transparent, whereas polycarbonate remains 91% clear.
Admittedly, the difference is negligible, but it exists. Apart from its clarity, acrylic does not decay when exposed to UV radiation over lengthy periods of time, unlike other polymers. For instance, polycarbonate becomes yellow, while other polymers become brittle. The same holds true for oxidation and moisture resistance.
What do such characteristics imply? The acrylic pieces are extremely long-lasting, robust, and clear. As a result, they're ideal for a variety of uses. Light tubes, car headlights, store and marketing banners and logos, and other items All of the aforementioned applications need extreme accuracy and a high level of surface polish. Acrylic CNC cutting is a fantastic solution, especially
because acrylic is fairly sturdy and stiff.
Acrylic blanks have been typically made in one of two ways: extrusion or molding. The first approach is used to make sheets, while the second method is employed to make plates and other structures. Acrylic thickness ranges from 1, 5, and 25 millimeters when both processes are used. Acrylic is a wonderful choice for carving out flattened logos and signage since it comes in a wide range of thicknesses. Let's have a look at which blanks are suitable for CNC acrylic machining.
Extrusion is the process of melting huge amounts of acrylic granules in a particular container and then extruding the resultant liquid via a specially created hole called an extrusion nozzle. Acrylic is molded in the same way as any other substance. Melted granules are put into a molding form, which is then cooled and removed. When using a cutting tool, extruded as well as cast blanks respond differently.
Extruded acrylic contains greater residual stresses, making it more prone to fractures and fragile in general. It's for this reason that cutting it is a catastrophe. Choose just cast blanks if you wish to employ acrylic CNC cutting in your production process. Extruding them is not worth the
and effort
Let's talk about acrylic fixing after we have settled on the sort of blank we'll utilize. We are not going to get into the intricacies of CNC machining acrylic since any plastic or metal CNC machining will suffice. However, we do not advocate using a woodcutter because they are less stiff. So, let's return to the fixtures. There are several techniques to clip acrylic. However, the blank thickness is the most important factor to consider.
Despite its rigidity, acrylic is nevertheless plastic, and you'll have to make sure that lengthy pieces or huge sheets are fastened tightly over the whole surface. Simple clamps and vises may be used to fasten smaller items. Lengthier sections are frequently bonded or taped to the worktable, and a suction table is a necessity if you intend on cutting acrylic sheets frequently. It will correctly fasten and unclamp the sheets.
Cutting Tool
Cutting tools that are specific to the job are required. Special acrylic slicing bits are required since they contain grooves that guarantee excellent chip removal and, as a result, accuracy. Furthermore, while piercing acrylic, the drilling tip inclination must be significantly less than when piercing metal. It ought to be 60° rather than 120.
This has also been tweaked to improve chip removal. If you've not attained a perfectly crystal clean surface after cutting, don't panic; it's impossible. You'll need to put in more work with finishing procedures to acquire a perfectly translucent portion.
Feed Rate
After you've secured the acrylic in position, it's time to get down to business. Acrylic blanks are machined in the vast majority of cases. Acrylic milling on a CNC cutter is comparable to cutting polycarbonate in many respects. To begin, utilize a comparable RPM range: 15,000 to 18,000 RPM. Then utilize a consistent and forceful feeding pace.
This is necessary to prevent the instrument from becoming too stationary and creating heat as a result of the cutting friction. When the feeding rate is too slow, the chips may begin fusing back onto the item, destroying the surface polish and accuracy that you paid so much for.
Coolant
The temperature of the CNC cuter must be kept to a minimum throughout any CNC acrylic slicing operation. This is why many acrylic sheets are chilled before being machined. Chip removal is improved, and the starting temperature is reduced. Besides that, ordinary coolants can be used; nevertheless, if they contain lubricants, make sure these oils don't react with PMMA.
CNC Acrylic Engraving
Engraving is a type of machining that is done on acrylic. Acrylic engraving is conducted in the same manner as milling is performed but using a distinct cutting tool. Because many acrylic elements are used for advertising or aesthetic reasons, this is a highly common procedure.
Advanced CNC techniques have made it possible to engrave the most intricate designs on plastic sheets. The resultant groove can subsequently be covered with paint to let the pattern stand out more.
Postprocessing Machined Acrylic
After achieving the proper accuracy and shape for the acrylic pieces, they must always be ground and polished. This is commonly accomplished by using lower grit polishing instruments in succession, followed by a linen cloth dampened with a polishing solution.
Aside from that, certain chemical polishing processes entail the use of a specific gas to dissolve the acrylic's exterior coating. Last but not least, there are unique diamond cutter single tip machining methods, in which a highly pointed and resilient single-tip mill cuts a little bit of plastic off the surface.
Industrial-man takes pleasure in producing transparent acrylic optical parts in the plastic milling business using 3-axis, 4-axis, and even 5-axis CNC machinery as a competent prototype maker. We've embraced the newest diamond cutting technology to help us progress the advancement of ultra-precision production.
This process, known as SPDM or SPDT, can equal the capabilities of 5-axis micro-milling to manufacture a variety of high-quality lenses and lighting guides in an assortment or freeform arrangement. In order to retain the finest quality manufactured clear plastic bits in the market, we will strive to develop our CNC prototyping operations and improve manufacturing machinery, including cutting tools, in the foreseeable future.
There are several companies to choose from regarding the services of CNC acrylic machining. Finding the correct one is critical to achieving the desired results. At ARES CNC Machining, we offer high-quality CNC acrylic machining services that meet all the needs of our customers. You can find more information about our CNC acrylic machining services on ARES.