Extrusion International 1-2025

29 Extrusion International 1/2025 aids available, including overhead hoists, hydraulic lifts, etc. In most situations, the head and tooling will still be at elevated temperatures, therefore lined gloves are needed when handling. Today, tubing man- ufacturers compete with companies all over the world. To be a success- ful and pro table company, quality and ef ciency are essential. This is especially 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 tooling, 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 tolerance. 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 ma- chined to a determined speci ca - tion, ensuring perfect concentricity and alignment. The material is then distributed in the proper location as part of the nished 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 in2 (38mm2) was derived. When the two surface areas were compared, the calculated material waste was 11.8% of the nished product. The formula is % wall = min. wall thick- ness, max. wall thickness X 100. Ex- ample 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 depend- ing 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 covered af- ter cleaning. Also, tools should be segregated so that they do not come into contact with each other. And tools and all in- struments should be cleaned thoroughly before storage. For disassembly of tools, it is imperative to use purpose- built tooling to facil- itate disassembly. These should be available from your supplier. If they are not, consult with a reputable tooling house for replace- ments. The cost of these tools is easily offset by po- tential damages, frequently caused by improper equipment such as hammers and drifts. Follow the guidelines outlined in your opera- tor’s manual. Individual tools may have speci c 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 temperatures. 2.) When cleaning a dual com- pound crosshead, (plastic and rub- ber) clean the plastic tooling rst; the rubber second. 3.) Never use steel tools such as scrapers or screw- drivers because these can scratch and mar the tooling. 4.) Do not use open ames because this generates excessive heat especially in thin sec- tions, which can affect hardness, concentricity and tolerances of components. Recommended clean- ing tools and materials include: a.) Brass pliers to grip material and aid in pulling; b.) Brass scrapers avail- able in different widths for cleaning at exposed surfaces; c.) Brass bris - tle tube brushes that are available in diameters from 1/16" to 1" in 1 /16" increments (ideal for cleaning holes and recesses); d.) Brass rods – different diameter rods are good for pushing material out of ow holes; e.) Copper gauze for clean- ing 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 pol- ished surfaces; g.) Compressed air, which is more effective for releasing plastic, but also aids in rubber re- moval. Be careful 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. Fol- low manufacturer's recommenda- tions. If no temperatures are speci- ed 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 ex- truder screw/barrel of residual poly- mer and rubber compounds. Removing Excess Material for OptimumMachining Ef ciency Clean parts are critical to extru- sion tooling performance and qual- ity manufacturing. This is especially true for the sealing and locating surfaces – that control uniformity of the production process. For gen- eral maintenance of the tools, be- fore storage or tooling changeover, a thorough cleaning and removal of the excess material assures the precision machining alignments required to produce end products to the precise tolerances. Equip- Guill Kelpac