1. Hopper cylinder \u2013 It is made of cast steel and is jacketed for water-cooling. The insides are made wear resistant by chrome plating or nitrited alloy steel. The insides also have spiral undercuts for high feeding efficiency.<\/p>\n
2. Rollfeeder \u2013 The feed roll is operated by the screw by the means of a gear and pinion. The feed roll surface is hardened and an inside chamber for tempering fluid is provided.<\/p>\n
3. Forward cylinder \u2013 The cylinder is made of nitrited alloy steel (for high wear resistance) and peripheral drilling for circulating tempering fluid is provided. Sometimes, bi \u2013 metallic linings are given. The pins are made of high grade alloy steel hardened fro greater wear resistance.<\/p>\n
4. Screws \u2013 The twin screws are made of cast steel and are chrome plated. They are usually bored for cooling. The diameter of normal screws is 60 \u2013 200 mm with a length of 5 \u2013 20 times the diameter. The functions of the screw are manifold \u2013 mixing, blending, homogenizing, dispersing, compounding, degassing. Twin screw extruders are the most commonly used extruders. They can either be intermeshing or nonintermeshing. Nonintermeshing extruders behave like two single screw extruders with only minor interactions between the two screws. Another classification is the direction of rotation of screws. Co \u2013 rotating screws have both screws rotating in the same direction and the material exchanges from screw to screw. On the other hand, the counter \u2013 rotating screws have material transported through the extruder in a figure eight channel.<\/p>\n
5. Feeding screws \u2013 They are made of high alloy steel and polished, nitrited or satellite on their tips. They are also drilled for tempering fluid circulation.<\/p>\n
6. Dies \u2013 Many special arrangements of extruder dies are used for composite layered sheets. Two types of rubber enter the die from two extruder barrels and exit as one sheet. The top and bottom layers are of different materials.<\/p>\n
7. The mixing chamber \u2013 The chamber which contains the screws and where the actual mixing takes place. This region is the region of maximum power consumption as well as maximum temperature rise. The throughput of an extruder is typically ~ 400 kg\/hr.<\/p>\n
8. Vacuum zone \u2013 A vacuum zone inside the cylinder is created by the use of screws with high thread height. This is done to vent the rubber from inclusions of gases to eliminate porosity.<\/p>\n
9. Extruder tempering system \u2013 Usually it is a closed circuit type with electrical heating. Both single \u2013 and twin \u2013 screw extruders may use hot oil circulation systems for temperature regulation. The sump temperature is set to 204 degrees, and the extruder barrel is heated or cooled depending upon internal heat generation. Circulation may be constant (no temperature controllers) or may be adjusted to control individual zone temperatures.<\/p>\n
10. Gear reducer \u2013 The screw speed varies normally from 30 \u2013 60 rpm. The gear reducer reduces the motor speed to this speed. They are usually provided with forced feed lubrication system.<\/p>\n
11. Thrust bearings \u2013 They form an integral part of the extruder system. Optimized design for long life at the maximum extrusion pressure and screw speed.<\/p>","protected":false},"excerpt":{"rendered":"
1. Hopper cylinder \u2013 It is made of cast steel and is jacketed for water-cooling. The insides are made wear resistant by chrome plating or …<\/p>","protected":false},"author":1,"featured_media":74862,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[103],"tags":[159],"class_list":["post-75555","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-extruder-machine","tag-extruder-parts"],"yoast_head":"\n