Extrusion International 1-2023

33 Extrusion International 1/2023 10.) Use a set of appropriate gauge and tip pins for initial tool lo- cation adjustment; 11.) Make sure you have all the proper lifting aids available, includ- ing overhead hoists, hydraulic lifts, etc. In most situations, the head and tooling will still be at elevat- ed temperatures, therefore lined gloves are needed when handling. Today, tubing manufacturers com- pete with companies all over the world. To be a successful and prof - itable company, quality and effi - ciency are essential. This is especial - ly true in extrusion, where material costs are usually much higher than labor costs. Like a racing car stuck in the pit, many extruders sit idle because of poor or damaged tool- ing, plus excess maintenance time. Overhead costs add up and losing money is the result. Some start up quickly and make scrap, whereas others start up and run a product oversized to hold minimum toler- ance. They waste 10% to 20% of the material, which can run from 50% to 90% of the product cost. The tooling supplier goes to great lengths so that tips and dies are machined to a determined specifi - cation, ensuring perfect concentric- ity and alignment. The material is then distributed in the proper loca- tion as part of the finished product. Understanding Maintenance Procedures: Get Organized Before You Start Example 1 : In this example, with an improperly centered tool, a calcu- lated out-of-tolerance area of 0.059 in 2 (38 mm 2 ) was derived. When the two surface areas were compared, the calculated material waste was 11.8% of the finished product. The formula is % wall = min. wall thick - ness, max. wall thickness X 100. Example 2: Alternatively, if the % wall can be increased from 80% to 95%, a savings of about 12% of total cost can result. Savings will vary depending on the designs, of course. Get help for heavy parts and awk- ward situations. Surfaces and edges are hard and therefore somewhat brittle, so dropping a part or strik- ing parts together can result in dam- age. Store your tools properly in a dry, clean area – a dedicated spot for each tool is best. These areas should have soft surfaces and each instrument should be cov- ered after cleaning. Also, tools should be segregated so that they do not come into contact with each other. And tools and all instru- ments should be cleaned thorough- ly before storage. For disassem- bly of tools, it is imperative to use purpose-built tooling to facilitate disassem- bly. These should be available from your supplier. If they are not, con - sult with a reputable tooling house for replacements. The cost of these tools is easily offset by potential damages, frequently caused by im- proper equipment such as hammers and drifts. Follow the guidelines outlined in your operator’s manual. Individual tools may have specific recommendations, so contact your supplier if anything is unclear. Your supplier understands that optimum performance relies on proper care and maintenance. Here are some useful tips: 1.) Clean your equipment while it is still hot as the residue is easier to remove. It helps to remove and clean one piece of tooling at a time in order to maintain elevated tem- peratures. 2.) When cleaning a dual com - pound crosshead, (plastic and rub- ber) clean the plastic tooling first; the rubber second. 3.) Never use steel tools such as scrapers or screwdrivers because these can scratch and mar the tool- ing. 4.) Do not use open flames be - cause this generates excessive heat especially in thin sections, which can affect hardness, concentricity and tolerances of components. Recom - mended cleaning tools and materi- als include: a.) Brass pliers to grip material and aid in pulling; b.) Brass scrapers available in dif - ferent widths for cleaning flat ex - posed surfaces; c.) Brass bristle tube brushes that are available in diameters from 1/16" to 1" in 1 /16" increments (ide- al for cleaning holes and recesses); d.) Brass rods – different diameter rods are good for pushing material out of flow holes; e.) Copper gauze for cleaning and polishing exposed round or conical surfaces; f.) Copper knives for removing residue from recesses and other hard-to-reach areas. Also, polishing compound restores polished sur- faces; g.) Compressed air, which is more effective for releasing plastic, but also aids in rubber removal. Be care - ful not to force debris into recesses with compressed air; h.) Cleaning solutions may be use - ful, so remember to use fresh, clean rags (used rags often have metal chips embedded in them, which may scratch polished surfaces); i.) Cleaning oven – for plastic only. Follow manufacturer's recom - mendations. If no temperatures are specified do not exceed 850 degrees F (454 degrees C). Don’t quench tooling to cool, as this could affect tooling hardness, concentricity and tolerances. j.) Purging compounds – several are offered to purge the extruder screw/barrel of residual polymer and rubber compounds. Material for Optimum Machining Efficiency Clean parts are critical to ex- trusion tooling performance and quality manufacturing. This is es - Guill 900 W-Stripe