Screws & barrels | machinery feature
New concepts in screws and barrels help to extend
component lifetime and boost throughput
Turning a profit: screws and barrels
Screws and barrels are at the coalface of plastics processing, and are often the components that wear down first. So, enhancing wear resistance can be the first consideration for extending machine lifetime. Nordson Xaloy Europe has developed a bimetallic
barrel alloy with enhanced resistance to corrosive and abrasive wear, which extends the working life of extrusion barrels in general-purpose applications. The key to the corrosion resistance of the X220 alloy is its higher chromium content relative to other barrel inlays for general-purpose use – twice that of Nordson Xaloy’s own X200 inlay and greater than the standard alloy in Europe, says the company. The new inlay also has greater hardness: 64 to 69 on the Rockwell HRC scale, versus 58 to 65 for the X200. In acid immersion tests of sample weight loss, X220
alloy exhibited a 55% improvement over other European alloys in sulphuric acid and a 44% improvement in hydrochloric acid. “The new X220 inlay improves productivity and
product quality through better screw-to-barrel fit, reduces downtime, and prolongs the working life of the barrel,” according to David Hotchkiss, global product manager. A bimetallic inlay is a high-hardness alloy that lines the inner wall of the barrel. As general-purpose inlays, the iron-based X200 and the iron-chromium-based X220 can be used with a wide range of polyolefin, styrenic, and other resins at filler loadings up to 15%. For vinyls,
www.pipeandprofile.com
certain fluoropolymers, and other potentially corrosive resins, Nordson Xaloy supplies the X306 nickel-cobalt alloy. The tungsten carbide/nickel-based alloy X800 provides high wear and corrosion resistance for highly filled resins and high-temperature engineering polymers.
Expanded output US-based Reiloy Westland – part of Germany’s Reifenhäuser since 2012 – is in the process of building a new facility to help it increase output of screws and bar- rels. The new plant, in Maize, Kansas, is eight miles from the company’s existing facility in Wichita and – at 55,000 sq ft – more than twice its size. The company has already ordered a Weingärtner MPMC 600-6000 – a 5-axis, multi-purpose machining centre that will be used to make both screws and barrels.
It will be delivered in July this year, by which time
the new plant is expected to be ready. “It increases the dimensional capacity of the
products we can manufacture,” the company said. The company intends to be very active at this
year’s NPE, with a number of new products and concepts on show. For starters, it will introduce its new patent-pending mixing screw. Based on the Eagle mixing screw, which the company first introduced in 1991, it has undergone multiple redesigns over its history.
March 2015 | PIPE & PROFILE EXTRUSION 19
A new mixer screw from
Reiloy West- land is based on its earlier Eagle screw
Reiloy
Westland’s NPE app will help visitors negotiate the show
s
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48