Extrusion International 5-2023

55 Extrusion International 5/2023 storage techniques. These are highly precise parts, but can also be heavy and bulky to remove by hand. Use of a dedicated work cart ex- clusively reserved and equipped for extruder head maintenance is recommended. This cart along with a supply of spare components and hardware is easily jus- tified, especially when examining the poten - tial cost savings that result from well-main- tained tools. The following should be considered: 1.) Maintain a clean, organized work area with soft and clean renewable work surfaces 2.) Use a vise with soft jaws, such as copper 3.) Use special equipment, such as tip removal tools, etc. 4.) Standard tools include wrenches, soft-faced hammers, etc. 5.) Maintain a supply of soft, clean rags 6.) Use cleaning solutions in spray bottle 7.) Use spare parts as suggested by your tooling supplier, properly organized and stored 8.) Keep handy your equipment’s repair/maintenance manual 9.) Have a small surface plate to provide a true flat surface 10.) Use a set of appropriate gauge and tip pins for initial tool location adjustment 11.) Make sure you have all the proper lifting aids avail- able, including overhead hoists, hydraulic lifts, etc. In most situations, the head and tooling will still be at el - evated temperatures, therefore lined gloves are needed when handling. Today, tubingmanufacturers competewith companies all over the world. To be a successful and profitable com - pany, quality and efficiency 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 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 prod - uct 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 machined to a deter- mined specification, ensuring perfect concentricity and alignment. The material is then distributed in the proper location 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 calculated 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 sav - ings of about 12% of total cost can result. Savings will vary de- pending on the de- signs, of course. Get help for heavy parts and awkward situ- ations. Surfaces and edges are hard and therefore somewhat brittle, so dropping a part or striking parts together can result in damage. Store your tools properly in a dry, clean area – a dedi - cated spot for each tool is best. These areas should have soft surfaces and each instrument should be covered after cleaning. Also, tools should be segregated so that they do not come into contact with each other. And tools and all instruments should be cleaned thoroughly before storage. For disassembly of tools, it is imperative to use purpose-built tooling to facilitate disassembly. These should be available from your supplier. If they are not, consult with a reputable tooling house for replacements. The cost of these tools is easily offset by potential dam- ages, frequently caused by improper equipment such as hammers and drifts. Follow the guidelines outlined in your operator’s manual. Individual tools may have specif- ic recommendations, so contact your supplier if anything is unclear. Your supplier understands that optimum per- formance relies on proper care and maintenance. Here are some useful tips: 1.) Clean your equipment while it is still hot as the resi- due 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 compound crosshead, (plastic and rubber) clean the plastic tooling first; the rubber sec - ond. 3.) Never use steel tools such as scrapers or screwdrivers because these can scratch and mar the tooling. 4.) Don’t use open flames because this generates ex - cessive heat especially in thin sections, which can affect hardness, concentricity and tolerances of components. Recommended cleaning tools and materials include: a.) Brass pliers to grip material and aid in pulling b.) Brass scrapers available in different widths for cleaning flat exposed surfaces c.) Brass bristle tube brushes that are available in di- ameters 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 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 com - EXTRUSION TOOLING