Laser Cutting Plastic, with Co2 automation, is an important application for the LP8000 series of Co2. There are different options and considerations regarding laser cutting such as:
- Beam spot size affecting the energy used for cutting.
- Fixed beam cutting vs galvo beam delivery cutting.
- Type of and module structure of plastics and how that effect Co2 cutting.
In this article, we will discuss galvo based beams cutting plastic, and in subsequent articles discuss the use of fixed beam for cutting plastic.
Laser Cutting Plastic – Galvo Laser Beam Deliveries
When discussing laser beam delivery system, the methodology that is employed to move the beam from the origin to the product there are options the laser integrator can use to move the beam:
Several terms will be important in this discussion:
- Final Focus Optic- This is the lens that focuses the beam to a point, and is generally the final element in the laser system components. There are also integrations where there are no final focus lenses. These integrations are a separate issue/discussion which will be discussed in future articles.
- Focus distance- Is the space between the final focus optic and the parts being cut.
- Laser beam spot size- This is the physical measurable size of the beam on the product. Think of this as a fine tip pen or felt tip pen. The laser integration automation expert can achieve different spot sizes by changing the type of beam delivery system, as well as the final focus optic. Generally laser beam spot sizes of between 0.003 inch and .0.040 inch.
Keeping these key terms in mind we continue discussing laser cutting plastic Co2 laser automation:
- Fixed beam- This is where the beam is delivered via a tube with a focus optic and end of the tube, generally with a short focus distance. The distance between the laser focus optic and the part being cut is between .25” and 3.0”. The laser beam spot size is the physical measurable size of the laser beam on the product. This distance is usually between 0.003” (inches) and 0.010” (inches).
- Flying mirror- This where the laser beam is delivered via 90 degree mirror turning the laser beam down toward a table (often honey combed with down vacuum draft). These systems are typically built in various table top sizes, from small table top units to large standalone units. OEM’s for these units build them as standalone, with lids that open. Parts are placed inside a cabinet your laser system integrator can provide options for and methods to integrate or automate the systems an example can be viewed here.
- Galvo based beam delivery systems- This is where the laser beam from the generator is run into a box typically approximately sizes at 12 x 12” . The box contains two high speed motors with mirrors. These mirrors are moved back and forth steering or directing the laser beam across the plastic to the cutting point. Different sized laser cutting fields are achieved based on final focus optic chosen. These range between 2.5 inches square to 18.0 inches square and laser spot sizes of 0.008 inches to .08 inches. Specifics on the working area and laser spot size per final focus lens and standard final focus lens options are available here. Laser system automation is capable of providing laser integration with all three major types of beam deliveries. WLSC typically attempts to integrate with galvo based systems. We use fixed beam delivery systems where the application requires, and we provide automation for flying mirror systems where required for customer or end user applications.
Co2 Laser Cutting Plastic with Galvo Based Beam Delivery
Some of the major applications for galvo based laser beam delivery are:
The general purpose and reasons for use of lasers in these plastic /film cutting application:
- Significant reduction of scrap rates.
- Ability to maximize the use on rolls or sheets of plastic eliminating wasted product.
- Ability to change cutting patterns on the fly (in micro-second) when product change over occurs in flexible manufacturing environments.
- Elimination of downtime for cutting pattern changes reducing costs.
- Elimination of replacement of blades and knives providing even more cost reductions.
- Providing the fastest possible cycle times and production speeds providing for faster product delivery to end users.
Laser Cutting Plastic Application From a Real WLSC Customer
Several recent customs have installed a Co2 Laser Cutting Plastic Co2 system with highly successful results. One customer in the food packaging industry needed to create an area on the package for opening, as well as a visual indicator of where the opening area was located. This is so the consumer could easily identify the best area to quickly and effectively open the package to access the food. The packaging material was flowing down a production line at speeds in excess of 300 feet per minute. In a flatten array, prior to being folded, filled with product, and filled, the Co2 laser automation was arranged over the flow of packaging material. This is to score the packages in the correct location, with the correct power, and correct speed to score and line and weaken the packing without punching through the package or creating enough weakness to allow random or unwanted breakage. The Co2 laser automation process allowed the customer to completely eliminate blades and knives with the following advantages:
- Eliminate blades and the need to replace these items.
- Eliminated a heavy scrape rate of the packaging materials from tearing and punching through caused by mechanical cuts.
- Greatly increasing production through put and efficiency of plant production.
- Significant manufacturing cost reductions.
Another end user was running a web of thin plastics that were 16 inches wide. The production lines packaged a product that is 14”wide. This was leaving two inches of plastic on either end of the product. Knifes, blades, and a punch were all tried as methods of trimming the plastic material off the product sides. While these mechanical processes were able to trim the plastic, all of these methods had an usual mechanical issues of:
- Replacing cutting items which become dull.
- Products being damaged.
- Line shut down for cleaning, adjusting, and replacing the mechanical cutting items.
These cost time, money, and plant efficiency. All these manufacturing issues were eliminated when Co2 laser automation was installed to trim both sides of the plastic rolls to the correct width for the products being packaged. The laser integration systems were installed over the moving flow of material, prior the packaging process, and used to trim the plastic roll to exactly the correct size while the line was moving.
Yet another customer was able to replace their mechanical cutting process for clam shells that typically house consumer products. They were able to use Co2 laser integration creating the necessary holes and slots for customers to view and open the product and also for retailers to hang the product on display racks.
The ability to laser cut plastics is one of the ways that Worldwide Laser Service Corporation can work with our end users, to fulfill our mission of reducing manufacturing costs, protecting consumers and products, and providing an eco-friendly green manufacturing environment.
About Worldwide Laser Service Corporation and Laser Cutting Plastic
WLSC began our service using lasers and laser products in July of 1986. For the past 32 years, We have been focused on providing integrated laser solutions for the resolution of production problems, issues, and bottle necks across a wide range of industries and manufacturing process. At WLSC, we maintain a laser applications lab with UV 355nm, Fiber 1064-1067, Co2 10.6µm lasers. We use fixed beam and galvo based beam deliveries for testing of customer product and determination of the best possible laser platform for processing the customers products. WLSC system engineers have over 100 years of combined integration experience and can design, build, install, and maintain the correct laser automation for use in your facility and for your manufacturing process. WLSC maintains corporate office and manufacturing facility in Gilbert AZ 85233. We look forward to hearing from you and working together on your laser marking and laser cutting applications.