TIPS FOR WELDING THERMOPLASTICS

From the archives IAPD
Welding is the process of uniting sur­faces by softening them with heat. When welding thermoplastics, one of the key components is the material itself. For as long as plastic welding has been around many people still do not understand the basics which is critical to a proper weld.

The No. 1 rule of welding thermoplas­tics is you must weld like-plastic to like-plastic. In order to get a strong, consis­tent weld, it is necessary to make sure your substrate and your welding rod are identical; for instance, polypropylene to polypropylene, polyurethane to polyurethane, or polyethylene to polyethylene.

Here are some tips for welding differ­ent types of plastics and steps to ensure a proper weld.

Welding Polypropylene

Polypropylene (PP) is one of the easiest thermoplastics to weld and is used for many different applications. PP has excellent chemical resistance, low spe­cific gravity, high tensile strength and is the most dimensionally stable poly­olefin. Proven applications using PP are plating equipment, tanks, ductwork, etch­ers, fume hoods, scrubbers and orthope­dics.

In order to weld PP, the welder needs to be set at approximately 572°F/300°C; determining your temperature will depend on which type of welder you pur­chase and the recommendations from the manufacturer. When using a thermo­plastic welder with a 500 watt 120 volt heating element, the air regulator should be set at approximately 5 p.s.i. and the rheostat at 5. By doing these steps, you should be in the vicinity of 572°F/300°C.

Welding Polyethylene

Another fairly easy thermoplastic to weld is polyethylene (PE). Polyethylene is impact resistance, has exceptional abra­sion resistance, high tensile strength, is machinable and has low water absorp­tion. Proven applications for PE are bins and liners, tanks, laboratory vessels, cut­ting boards and slides.

The most important rule about weld­ing polyethylene is that you can weld low to high but not high to low. Meaning, you can weld low density polyethyl­ene (LDPE) welding rod to high density polyethylene (HDPE) sheet but not vice versa. The reason being is quite simple. The higher the density the more difficult it is to break down the components to weld. If the components cannot be bro­ken down at the same rate then they can­not join together properly. Other than making sure your densities are compat­ible, polyethylene is a pretty easy plastic to weld. To weld LDPE you need to have the temperature at approximately 518°F/ 270°C, the regulator set at approximately 5-1/4 to 5-1/2 and the rheostat at 5. Like PP, HDPE is weldable at 572°F/300°C.

Tips for Proper Welds

Prior to welding thermoplastics, there are a few simple steps that need to be taken to ensure a proper weld. Clean all surfaces, including the welding rod, with MEK or a similar solvent. Groove the substrate large enough to accept the welding rod and then cut the end of the welding rod to a 45° angle. Once the welder has adjusted to the proper tem­perature, you need to prep the substrate and the welding rod. By using an auto­matic speed tip a lot of the prep work is done for you.

Holding the welder about an inch above the substrate, insert the welding rod in the tip and move it in an up and down motion three to four times. Doing this will heat the welding rod while heating the substrate. An indication the substrate is ready to be welded is when it starts getting a fogging effect — similar to blowing on a piece of glass.

Using firm and consistent pressure, push down on the boot of the tip. The boot will push the welding rod into the substrate. If you choose to, once the welding rod adheres to the substrate, you can let go of the rod and it will automati­cally pull itself through.

Most thermoplastics are sandable and the strength of the weld will not be affected when sanded. Using 60-grit sandpaper, sand off the top part of the welding bead, then work your way up to 360-grit wet sandpaper to get a clean fin­ish. When working with polypropylene or polyethylene, it is possible to regain their glossy surface by lightly heating the surface with a yellow open flame propane torch. (Keep in mind that nor­mal fire safety procedures should be fol­lowed.) Once these steps are completed you should have a weld that looks simi­lar to the photo at bottom left.

Conclusion

Keeping the above tips in mind, welding thermoplastics can be a fairly easy process to learn. A few hours of practicing welding will give the “feel” for maintain­ing the right even pressure on the rod straight down into the weld area. And experimenting on different types of plas­tics will help master the procedure. For other procedures and standards, contact your local plastics distributor.

For more complete tips on plastic welding go to: http://en.wikipedia.org/wiki/Hot_gas_welding#Hot_gas_welding


ROUTER BITS FOR THE SIGN INDUSTRY

By Van Niser
Signs and the information they convey have become an integral part of daily life. Companies of various sizes serve this vast market, but they all have common problems when it comes to routing of the materials common to the industry. Wood, aluminum, foam and plastic all have different cutting characteristics and no individual tool can solve all routing problems. This is particularly evident in the routing of plastics in the sign industry. As a starting point, plastics can be placed into two general categories: flexible and rigid. The tools of choice for flexible plastic usually involve the use of single or double edge “O” flute tools, which are available in straight or spiral flute configurations. In terms of rigid plastics double edge straight “V” flute tools, spiral “O” flutes with hard plastic geometry, and two and three flute finishers are recommended. The tool materials for most of these router bits are readily available in high-speed steel for hand operations and solid carbide for CNC routing. . Solid carbide is a very durable material when utilized in a controlled environment of CNC, but not reliable in hand routing, which tends to be less rigid with more opportunity for tool breakage. The aforementioned recommendations are general in nature and are just a beginning for tool selection. In order to target an application, the sign maker has a new resource on the Internet at www.plasticrouting. com. This site provides a specific tool recommendation for a variety of plastic materials. The major emphasis of this web site is to recommend router tools that provide the best finish at a productive feed rate. Sign makers, who historically use smaller diameter tools to achieve the necessary radii associated with lettering, will be pleasantly surprised. The tool diameter is the controlling factor in feed rate, but larger diameters were not necessarily superior in terms of finish. The use of micro grain carbide with the necessary geometry to achieve chip evacuation has made smaller diameter tools more effective for the sign industry. The site can also be accessed via a link on IAPD’s web site at www.iapd.org. Recently, there have been several new styles of specialty tools developed to improve finishes with faster cycle times without tool changes and or advanced programming techniques. Both should prove to be advantageous to the sign industry. The first of these tools was developed to provide a smooth bottom surface in lettering or pocketing applications. Most router tools are designed to plunge and rout with the emphasis on the side geometry rather than the point. Consequently, the point end would always leave swirl marks, which required a secondary operation to remove the swirls.

thumbs_solid-carbide-bottom-surfacing

The new tool (Figure 1) utilizes a near flat point with radiused corners to create a smooth bottom with an aesthetically pleasing result.

thumbs_solid-carbide-rout-and-chamfer

The second innovation (Figure 2) is the development of a rout and chamfer bit designed for plastic sheets. By combining both a straight flute optimized for cutting plastics with a cutting edge sized for specific sheet sizes and a 45 degree chamfer edge, these tools can rout out plastic parts and apply a variable depth edge chamfer in a single pass.

By combining these features into a single tool, tool changes within the machining cycle are eliminated and CNC routers without tool changing spindles have new capabilities for parts production. The advances in router tooling have generally followed the rapid growth and usage of CNC routers or router tables as they are commonly called in the sign industry. These machines have revolutionized the speed and accuracy of sign making and the ability to produce intricate shapes and designs with specialized software. Router tooling has enhanced the CNC user by providing stronger tools with improved cutting geometry specific to the material being machined. However, merely choosing the correct tool without effective machining practices is an exercise in futility. Consequently, a review of proper machining practices would be in order. • Maintain CNC machines per manufacturer’s recommendation with proper lubrication of machine slides and drive systems • Check for play in the table or spindle mounting systems • Establish a collet, collet nut, and tool holder maintenance program and replace collets after 600-700 hours of usage • Insure part rigidity by following proper spoilboard techniques • Establish colleting procedures to maximize tool rigidity • Maximize chipload to minimize tool wear • Select tools with the shortest possible cutting edge length to achieve depth of cut • Use straight through tools where the cutting edge length and shank are the same size to reduce breakage • Maximize dust collection to completely evacuate gummy chips produced by some plastics The right tool for the job and sound CNC machining practices will improve throughput, product quality and profitability in the sign industry.

ELITE OUTDOOR KITCHENS

Elite Outdoor Kitchens and Design is a company that creates, designs and installs outdoor cabinets and products using the best alternative to wood, King StarBoard® ST.   It is a marine-grade polymer that has been used in the manufacturing of cabinets on yachts and cruise ships for over 50 years.  King StarBoard ST is produced locally in North Port, FL.  King StarBoard ST allows Elite Outdoor Kitchens the flexibility to do almost anything that can be done with wood.  The application possibilities of KingStarBoard ST ranges from cabinetry, to furniture, planters and storage units.

King StarBoard ST makes it possible for companies such as Elite Outdoor Kitchens and Designs, to build the most environmentally friendly and durable line of outdoor products.

BOAT OUTFITTERS

The Marine Industry’s Plastic Transformation

By Boat Outfitters
As most of you are probably aware, our parent company is ironically named Teak Isle Mfg. With the introduction of marine grade plastics in the early 90’s, specifically King Starboard®, the marine industry underwent a dramatic shift away from wood component parts towards plastic component parts.

In 1990, 90%+ of Teak Isle’s fabricated parts were composed of Wood. By 1995, 90%+ were plastic. The first and obvious answer is durability. King Starboard® will last the lifetime of your boat with essentially zero maintenance. Teak requires regular oiling to keep the wood from discoloring and breaking down.

King Starboard® is a UV stabilized homogeneous sheet that will never discolor or require any oiling or refinishing. King Starboard® is easily fabricated using standard woodworking materials and for the most part works just like wood.

The advantage when working with Starboard is that the sheets are perfectly consistent. You do not have to accommodate for grain direction, color inconsistencies, and knots in the wood. You also are not limited by board width and therefore you avoid gluing up boards to create wider products.We stock over 10 different colors of King Starboard®. Largely these are different shades of white to match gel coat colors and give boats a clean flush look.

beforeafter

When King Starboard® was first introduced it was very comparable in cost to teak wood. Now, because of environmental restrictions as well as new political restrictions in Burma (which accounts for nearly 1/3 of the world’s total teak production), Teak prices have skyrocketed.

CUSTOM HOME BUILDER RECOMMENDS KING STARBOARD® ST

Being a custom home builder of waterfront homes for over twenty years, we are constantly trying to come up with products that will withstand the elements better for our outdoor kitchens.  I have tried all types of wood and plywood and have since determined that King Starboard ST will withstand the elements and is far superior to any other material I have tried.  You can use this material for all your outdoor cabinetry needs with the utmost of confidence.  Your callbacks will be over.

Gary Graber, President
GNG Construction, Inc.

NEW ARTISTIC ASPECTS OF KING STARBOARD®

Michael Servet, a sculptor in the Washington D.C. area, is producing sculptural art forms using King StarBoard®, hardwoods and various other materials.  Servet is capturing still and moving images in interesting and complimentary settings.

Here is one of his many creations using King StarBoard®

art

KING PLASTIC CORPORATION OPENS NEW WEST COAST DISTRIBUTION CENTER

MEDFORD, Ore., April 19, 2011 — King Plastic Corporation, worldwide supplier of polymer sheet, slab and massive shape products in a broad range of materials, has opened a new warehouse facility in Medford, OR, to better service its commercial customers in the western United States.

“The new warehouse lets us take advantage of our ability to deliver products quicker to customers in western states. Now we can reduce both freight costs and shipping times, while providing our commercial customers more immediate access to our products,” said Jeff King, president of King Plastic Corp.

“Storing products and palletizing inventory in Medford, Oregon will allows us to provide next-day service – if not same day service – which will be a great benefit to our west coast customers,” added manager, Steven King.

All orders will still be placed through our corporate office in North Port, FL  34288.

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About King Plastic Corporation
Founded in 1968, King Plastic Corporation is a leading manufacturer of quality polymer sheets, slabs and massive shapes—including several products pioneered by the company. Its polymers are sold worldwide through a network of top plastics distributors to customers who fabricate products for the marine industry (King StarBoard® brand), signage, food service, neutron shielding, construction, industrial and other applications. The company headquarters is a state-of-the-art, 150,000 square-foot manufacturing facility in North Port, Florida. Visit www.kingplastic.com for more information.

KING PLASTIC POLYMER SHEETS WORK LIKE WOOD

This enlightening video will demonstrate the ease of working with King Plastic polymer sheets. From cutting to routing, welding, bending, fasteners and cleaning, this video tells the whole story to working with the polymer sheets that work as easily as working with wood.

GOING GREEN WITH KING PLASTIC POLYMER SHEETS

green in every color logoWhen producing our products, King Plastic uses processes that are non-polluting and conserve energy and natural resources, making it economically sound and safe for employees, communities and consumers. The polymers are completely recyclable and left over materials are recycled back into our products. When cutting or fabricating, there is no harmful dust, but instead small shavings that are recyclable. It contains no known harmful substances, including carcinogens or toxins. Off-gassing does not occur when the sheets are cut and fabricated. It is not necessary to use acids or harsh chemicals for finishing, cleaning, or maintenance. The outstanding durability of products made using our sheets maximizes product life cycles thus reducing the overall impact on our environment.

King Colorfast Environmentally Friendly Polymer Sheets

King’s polymer sheets stand up to thousands of uses and keep your bright ideas looking bright for years.  King ColorCore® and King ColorBoard® polymer sheets are the versatile, durable and colorfast to provide that competitive edge in your business you’re looking for. Both polymer brands are UV stabilized and waterproof for a lifetime of worry-free use in harsh outdoor environments. King ColorCore® and King ColorBoard® are also available in several gauges and a variety of matched colors. King ColorCore® unique PolyFusion™ process is a state-of-the-art technology that fuses contrasting layers of colors into a single homogeneous sheet. It is ideal for engraving to make indoor and outdoor signs, as a building sheet for playgrounds, and other recreational and industrial applications.

Using King products may qualify you for LEED Green building rate points.

For additional information, details and technical information please call King Plastic Corporation at 941-493-5502 or send us an email.

SUPPORT TECHNIQUES FOR KING STARBOARD®

Does King StarBoard® require support when bearing a load?

The King StarBoard® Family of Marine Grade Polymers are strong, but they are not a structural material. When using these products, they must be supported by a load bearing framework.

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ELITE OUTDOOR KITCHENS USES KING STARBOARD® ST

By Jennifer Briggs

The Ultimate Experience in Outdoor Living!

Being outdoors is part of our lifestyle, and what better way to spend a relaxing weekend than having hors d’oeuvres or barbeque made in a beautiful kitchen on your outside patio! “Elite Outdoor Kitchens and Design can create this outdoor experience and lifestyle for you,” says Rita Pogany, co-owner of the company for the last four years. (more…)