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Machinery
World
Rubber & Tyre Knowledge On-The-Go Special Supplement
http://rubbermachineryworld.com / http://tyremachiner...
Rubber extruders have a varied field of application.
So, when you come across a rubber profile, strip,
hose, cable, wire, ...
4
| EXTRUDERS |
Rubber & Tyre Machinery World | FEB 2016
Image of A Strainer Extruder - Pelmar Engineering Ltd.
5
Your Extruders And Its Extrusion
Process
Prasanth Warrier
With Inputs of Dr. S.N. Chakravarty
Rubber extruders have a va...
(a) a device system
(b) a barrel
(c) a ram or screw for forcing the rubber
through the barrel and
(d) a head holding the d...
A Screw Extruder consists of five
components viz.
(a) Drive system
(b) A feed hopper
(c) A screw rotating within
(d) A bar...
9
Extruder Screw
The screw rotated within the Barrel, the
usual clearance is approximately 0.40 mm.
Normally, the barrel i...
Core Diameter
The key screw design elements are Pitch,
Flights and Core Diameter.
Flights: The built up part in between
wh...
Extruders are usually designated by the
diameter of the extruder barrel. The ratio
of relative output of extruders varies ...
Each HFE has an hopper and feed roller
section with spiral undercut liner that
allows your compound to enter the
extruder ...
15
sensitivity of the metal detector is
found to be calibrated to a low value
that it virtually renders the detector
usele...
The different Cold Feed Extruders (CFE)
and their uses are:
Plain Barrel Type Cold Feed Extruder:
These CFE’s as the name ...
This flexibility in Pin Type Cold Feed
Extruders endears to all making it a
‘Universal extruder’ for many rubber
compound ...
Roller-Head-Extruder
Roller Head Technology involves a
combination of extruder with preform head
and two-roll calender. Th...
Extruder Head and Die Design
The key to the extrusion is the extruder
head that transforms the shape of the
rubber while l...
This depends on Polymer, Carbon type and
PHR, Viscosity, Lead angle (Bevel) of die etc.
Some of the die heads include:
1) ...
Your main goal of extrusion is to get the highest output
at good quality of product within the safe temperature
limits of ...
Gear Box
A gearbox is the single-most-expensive-
component on an extruder. Hence, you
should be more cautious while select...
defines the capacity and durability of your
extruder gearbox is the power (HP/kW)
rating along with its service factor (SF...
KELACHANDRA MACHINES
(MFRS. OF RUBBER INDUSTRIAL MACHINERY)
Chingavanam - 686 531, Kottayam, Kerala. India.
Phone Off: +91...
Here are 6 other key criteria of a gearbox
evaluation, which you should know
1. Gear Design, Hardness and its
Construction...
changed and consists of carburized and
ground gears. These gears are capable of
delivering much more power in its smaller
...
AMCL MACHINERY LIMITED
SERVICE TO THE NATION FOR FOUR DECADES
For all your enquiries please contact:
AMCL MACHINERY LIMITE...
KELACHANDRA MACHINES
(MFRS. OF RUBBER INDUSTRIAL MACHINERY)
Chingavanam - 686 531, Kottayam, Kerala. India.
Phone Off: +91...
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
Extruders - Special Supplement From Rubber & Tyre Machinery World
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Extruders - Special Supplement From Rubber & Tyre Machinery World

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Rubber extruders have a varied field of application. So, when you come across a rubber profile, strip, hose, cable, wire, cord coating, tire tread, v-belt, tube, or blank remember that they are only a few handful of products manufactured using extrusion process. In this Knowledge On-The-Go Special Supplement, we bring to you a ‘collector’s edition’ on Extruders and Extrusion incorporating the fundamentals.

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Extruders - Special Supplement From Rubber & Tyre Machinery World

  1. 1. Machinery World Rubber & Tyre Knowledge On-The-Go Special Supplement http://rubbermachineryworld.com / http://tyremachineryworld.com EXTRUDERS
  2. 2. Rubber extruders have a varied field of application. So, when you come across a rubber profile, strip, hose, cable, wire, cord coating, tire tread, v-belt, tube, or blank remember that they are only a few handful of products manufactured using extrusion process. Rubber industry only had Hot Feed Extruders until 1950’s. Then came the Cold Feed Extruders and other variations as we see them today. Life today is mostly spent trying to catch up with latest developments. However, in the process the basics and fundamentals are sometimes overlooked. In this issue, we bring to you a ‘collector’s edition’ on Extruders and Extrusion incorporating the fundamentals, that I hope will find space in your digital library. My sincere thanks to Dr. S. N. Chakravarty, President of Elastomer Technology Development Society, for his inputs with the material for this edition. As always, I welcome your feedback on rubbermachineryworld@gmail.com. Best Regards Prasanth Warrier | Editor’s Note | Extruders And Extrusion Extruders and the process of Extrusion has different applications in the rubber and tyre industry. 3 rubbermachineri rubbermachineryworld +Rubbermachineryworld1 grp/home?gid=8252803 rubbermachineri (Disclaimer: All the pictures and statements in this special supplement are sourced from web or shared by respective companies. All copyrights belong to actual owner. Rubber Machinery World does not independently verify them nor will vouch for their genuineness, hence will not be liable for any misrepresented data. The images are used here for representation purpose only.) Rubber & Tyre Machinery World | FEB 2016
  3. 3. 4 | EXTRUDERS | Rubber & Tyre Machinery World | FEB 2016 Image of A Strainer Extruder - Pelmar Engineering Ltd.
  4. 4. 5 Your Extruders And Its Extrusion Process Prasanth Warrier With Inputs of Dr. S.N. Chakravarty Rubber extruders have a varied field of application. So, when you come across a rubber profile, strip, hose, cable, wire, cord coating, tire tread, v-belt, tube, or blank remember that they are only a few handful of products manufactured using extrusion process. Introduction Extruders are machines, which shape rubber to a profiled strip by forcing it through a die. In the simplest form an extruder consists of four basic components viz. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS |
  5. 5. (a) a device system (b) a barrel (c) a ram or screw for forcing the rubber through the barrel and (d) a head holding the die which ultimately gives the desired shape. The fundamental distinction between two types of extruders is in their mode of operation: 1. Continuous: Delivers rubber in a continuous manner and has a rotating member or screw; here the pressure is produced by a screw. 2. Discontinuous: Delivers rubber in an intermittent fashion and has a reciprocating ram or screw. These type of extruders are ideally suited for batch type processes such as injection moulding. Screw Type And Ram Type Extruders In Ram Extruders, a quantity of warm compound is placed into the cylinder, the die is attached to cylinder and ram pushes the compound through the die to form a profiled section. Advantages: • Extrusion can be carried out at lower temperatures. • Difficult compounds can be extruded. • Easy to clean. • Useful to short runs. • Useful for compounds which need to be strained through gauge for quality products requiring completely contamination-free material. Ram extruders are not frequently used and are good for very specialized extrusions. Ram extruders are not frequently used and are good for very specialized extrusions. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image of A Ram Extrusion Line - Barwell 6
  6. 6. A Screw Extruder consists of five components viz. (a) Drive system (b) A feed hopper (c) A screw rotating within (d) A barrel (e) A head and die. The basic principle is that the screw carries material from the feed hopper by acting as a conveyor or a hump providing pressure to extrude or force the material along the machine barrel through the head and the die. The extruder drive system comprises of an AC or DC motor along with a reduction gear unit for power transmission. The extruder drive has to turn the screw at the desired speed. It should be able to maintain a constant screw speed because variations in screw speed will result in throughput fluctuation, which in turn will vary the dimensions of the extrudate. The purpose of the feed hopper is to receive material and pass it down to the flights of the screw. It is mostly supplied in the form of strip. The basic principle is that the screw carries material from the feed hopper by acting as a conveyor. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image of A Screw Type Cold Feed Extruder - Pelmar Engineering Ltd. 8
  7. 7. 9 Extruder Screw The screw rotated within the Barrel, the usual clearance is approximately 0.40 mm. Normally, the barrel is fitted with a detachable liner in the form of a sleeve which is highly wear and corrosion resistant, made of hardened steel. The barrel is made double walled for steam or water circulation so that a constant temperature is maintained in the extruder head. A conventional extruder screw has three geometrically different sections. 1. Feed section (closest to the feed opening) generally has deep flights and consists of approximately 1/5th of the length of the screw. The material in this section will mostly be in solid state. 2. Metering section (closest to the die) usually has shallow flights and consists of approximately 2/5th of the length of the screw . The material in this section will mostly be in molten state. 3. This section connects the feed section and the metering section, is called as compression section. In going from feed section towards the metering section, a compression of the material in the screw channel takes place, which is essential for the proper functioning of extruders. The compression streamlines flow, helps to eliminate air and also ensures a constant pressure in the head. Screws are made of steel alloy forging, heat treated to a machinable hardness and hard chrome plated. The flight lands are surface hardened to approximately 600 Brinnel. The screw is internally bored to facilitate water-cooling. The extrusion process has to be effective. What does this mean to you? Your extruded profile temperature must be within required limits to prevent scorching. A conventional extruder screw has three geometrically different sections - Feed, Metering and Compression. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS |
  8. 8. Core Diameter The key screw design elements are Pitch, Flights and Core Diameter. Flights: The built up part in between which the rubber compound traverses. Pitch: Distance between two consecutive flights Core Diameter: Diameter of the Core Shaft Each manufacture has their own design of screw. However, the basic function remain same. An adjustment can be made for volume occupied by the flight lands. Screw design has a direct bearing on out put and quality of Extrudate. Output rate depends upon the screw design and geometry of extrudate. In general, you could increase output by either or a combination of the following - Decrease the Flights - Increase the Pitch - Increase the Core Diameter Reputed manufacturers offer different screw designs to process your specific rubber compound requirements. One of the basic characteristics of all the extrusion process is the clearance between Barrel and screw. This is generally permitted to a limit in order to control •  porosity • extrusion temperature Reputed manufacturers offer different screw designs. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Schematic of a screw inside barrel and the different terms. Image from Web.10
  9. 9. Extruders are usually designated by the diameter of the extruder barrel. The ratio of relative output of extruders varies as the square of the screw diameter . Thus the output of a 60 mm extruder will be 2.2 times that of a 40 mm extruder. The extruder is operated in such a manner so that temperature is gradually more from feed to discharge, the die being the hottest part. When you choose a rubber extruder, you should deliberate and discuss extensively upon the design, material technology and manufacturing accuracy of screw, barrel and die-head. Very few manufacturers world-wide can guarantee you a well-designed and precisely manufactured rubber extruder. An additional designation often used is the length to diameter (L/D) ratio . This is an important factor in the selection of extruders to match process requirements. The length of a rubber extruder depends on whether it is a hot feed or cold feed type. Hot feed extruders are usually very short about 3D to 5D while cold feed ones range from 12D to 24D. Hot Feed Extruder (HFE) Rubber industry only had Hot Feed Extruders until 1950’s. HFE’s extrude your rubber compounds at reduced temperatures. The screw depth of a HFE is relatively larger and you get a consistent output due to its short screw design. L/D ratio is mostly in the range of 4:1 to 6:1 which keeps your rubber compound dwell time and its temperature increase to a minimum. In many cases the screw has increasing pitch. When you choose a extruder, you should discuss the design, material technology and manufacturing accuracy. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image:VMI 12
  10. 10. Each HFE has an hopper and feed roller section with spiral undercut liner that allows your compound to enter the extruder easily. The feed roller on a hot feed extruder allows your compound to pass the scraper knife, directed around the roll and then fed back into the hopper. The feed roll bearings are placed in positions to prevent contamination. You can vary the output by changing the screw speed using variable speed drives. Despite these advantages, the HFE’s are getting outdated in many applications. Because the rubber that is fed into a Hot Feed Extruder needs to be pre-heated or warmed using two-roll mills to achieve the required degree of viscosity and temperature that facilitates smooth flow of rubber, its compaction and extrusion through the die. And that made experts consider Cold Feed Extruders. Cold Feed Extruder (CFE) Cold Feed Extruders are designed and manufactured with specially designed screws best suited for cold feeding of rubber. While manufacturers offer L/D ratio up to 24:1, the most preferred by end-users is generally in the range 12:1 to 18:1. In most cases, the screw has decreasing pitch. The screw has increasing root diameter with more flight depth at feed end which increase from feed to discharge. And of course, there are various other designs available. You can discuss with your manufacturer and avail various options of screws for a wide range of compound and extrusion applications. The output of an extruder is dependent on size of extruder i.e. the ratio of L/D. First estimate of out put is expressed as : Output = A (L/2) x R x d   A=Cross sectional area of extruder L=Lead Length R=Revolution per minute d=density of rubber Generally these exists a liner relationship between RPM & output For feeding the cold rubber, it is recommended that you use a feeding conveyor with metal detector to remove metal particles. This avoids damage to the screw or barrel. In some plants, the Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image of Hot Feed & Cold Feed Extruder Screws 14
  11. 11. 15 sensitivity of the metal detector is found to be calibrated to a low value that it virtually renders the detector useless. Every CFE comes with a Temperature Controller Unit (TCU) that controls the barrel temperature so that the shape and size of the extruded products are uniform. For feeding the cold rubber, it is recommended that you use a feeding conveyor with metal detector to remove metal particles. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image from Web: Feeding conveyor with Metal Detector Image from Web: A Set of Compact TCU’s below Cold Feed Extruder.
  12. 12. The different Cold Feed Extruders (CFE) and their uses are: Plain Barrel Type Cold Feed Extruder: These CFE’s as the name suggests have a plain barrel and used in manufacturing of hoses, blanks, fluorocarbon rubber, butyl rubber, etc. Pin Barrel Type Cold Feed Extruder: These are equipped with metallic pins fixed along the circumference in full length of screw. These pins enhance the mixing and dispersion of your rubber as it is kneaded between the barrel and screw. And the result is processed rubber with outstanding homogeneity and extrudate quality. The number of pins may be optimised by process and if required pins from last zone i.e. towards head may be blocked. These pins are generally 8 to 10 in circumference. For example, in 10 rows you will have 8x10 =80 pins protruding out of the barrel towards the screw center. The flexibility in Pin Type Cold Feed Extruders endears to all making it a ‘Universal Extruder’ for many rubber formulations. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image from Web: Pin Barrel Type Cold Feed Extruder 16
  13. 13. This flexibility in Pin Type Cold Feed Extruders endears to all making it a ‘Universal extruder’ for many rubber compound formulations involving varied applications. Hard rubber compounds also can be processed because of high extruder torque. Vent Type Cold Feed Extruder Vent type or vacuum type extruders were developed for production of non-porous profiles and hoses. These CFE’s have a custom-built screw, and a degassing barrel with a vacuum pump attached to vent bubbles out of extruded compounds. Co-extrusion Customer-specific customization and usage complexity demands led to the introduction of co-extrusion for manufacturing of various profiles. And so you today have Simplex, Multiplex (Duplex, Triplex, Quadruplex, and Quintuplex) and Roller Head technology. Multiplex lines of piggy- back type of 2,3,4, and 5 layers have a compact construction. Multiplex lines of piggy-back type have compact construction. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image Of Quadruplex. Source: Canmade 18
  14. 14. Roller-Head-Extruder Roller Head Technology involves a combination of extruder with preform head and two-roll calender. They offer twin advantages of – high uniformity of the material thickness over the entire sheet width with absence of air traps even at higher thicknesses (~20mm thick as against conventional calender lines that give max 3mm thick sheets with or without air traps) and excellent homogeneity of the material produced. Both these characteristics are important for high-quality rubber products such as tire components, V-belts, conveyor belts, tank linings, cover sheets, blank sheets and roofing sheets. For even thickness across the entire sheet width of the roller head, there are three options that can be used alone or in combination with one another – roll crowning, roll crossing or roll bending, that will compensate for the elastic deflection of rolls. In today’s world you will see that usages of these technologies are overlapped. For example, in tire industry, you can notice that - Tread & Sidewall are extruded using Simplex, Duplex, Triplex, Quadruplex Lines - Apex are extruded using through Simple and Duplex. - Inner Liner are extruded using Simple, Duplex & Roller Head Technology. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image: KraussMafei Berstoff 20
  15. 15. Extruder Head and Die Design The key to the extrusion is the extruder head that transforms the shape of the rubber while leaving the barrel to produce a dimensionally accurate and stable profile. The purpose of extruder Head is to equalise the pressure from the screw and barrel andto transport the compound smoothly at equal pressures and speed to the die. The purpose of Die is to give the compound the desired shape. The extrudates shrink along their length and increase in thickness and width, the behavior being termed ‘die swell’ which depends upon (i) rheological characteristics compound (ii) shape of head and extrudate (iii) pressure in the head (iv) the head and compound temperatures. Generally die making and die design depends on experience, however a good control on compound properties gives better extrusion. It is necessary to get a swelling factor at each point of profile for a particular compound. This varies from centre of die to extreme ends. Die swell is defined as ratio of extrudate section & cross section of die. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image: Bharaj Make Cold Feed Extrusders equipped with Co-Extrusion Head 21
  16. 16. This depends on Polymer, Carbon type and PHR, Viscosity, Lead angle (Bevel) of die etc. Some of the die heads include: 1) Straight Head / Tube Head for hoses (circular or square) and technical profiles. 2) Cross Heads for hoses and technical profiles from one, two or three different compounds. 3) Single Tread Heads for rubber profiles. 4) Multiple Tread Heads (Piggy-back) for rubber profiles. 5) Slit Tube Heads for producing sheets inexpensively. 6) Preform Heads for sheets and rubber profiles. 7) Strainer Heads to strain raw rubber, rubber compounds and reclaim rubber. 8) Pelletizer Heads to process rubber materials ground into granules. 9) Pork chop Heads to produce granulated raw rubber. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Die swell depends on Polymer, Carbon type and PHR, Lead angle of die, etc. Source: CGEC 24
  17. 17. Your main goal of extrusion is to get the highest output at good quality of product within the safe temperature limits of the products. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image: Triplex Extruder. Source: Troester 25
  18. 18. Gear Box A gearbox is the single-most-expensive- component on an extruder. Hence, you should be more cautious while selecting. First things first – Why do your single screw extruders need gearboxes? Extruder manufacturers prefer 1800/1500 RPM or 1200/1000 RPM motors (depending on your country of use) because they are economical, readily available and compact in size to mount on your extruder base. However, most rubber extruder screws during production run in the speed range of 4 rpm to 40 rpm. Hence, the role of a gearbox or gear reducer here is to reduce the drive motor’s speed and, in turn, multiply the available torque from the motor in order to produce sufficient power to mix and push out your rubber compound. As an individual and independent component, the key specification that A gearbox is the single-most- expensive component of an extruder. Hence, you should be more cautious while selecting. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image:Wikov 26
  19. 19. defines the capacity and durability of your extruder gearbox is the power (HP/kW) rating along with its service factor (SF). Single screw extruder gearboxes are normally rated for power (HP/kW) or torque at a specific rpm based on common calculations and standards. This uniform standard allows you to compare gearboxes from different manufacturers. Your extruder manufacturers follow these guidelines and select a model for different service factors and applications. A key question you should ask is whether, the SF considered by your manufacturer is optimal for your extrusion application or not. Knowledge of AGMA (American Gear Manufacturers Association) recommendation will certainly help you to discuss better with extruder manufacturers, but experienced gearbox manufacturers can guide you even better. I have witnessed buyers in Asia been taken for a ride for their ignorance and offered lower specification gearboxes on their extruders to compete on cost. When you compare gearboxes, always evaluate on calculated power. The formula for calculated power of a gearbox is: Calculated Power = Quoted Power X Service Factor Typically, single screw rubber extruder gearbox has service factors of 1.5 or 1.75 for optimal operating capacity. For example, a 6 inch pin type cold feed extruder gearbox with a calculated rating of 367.5 kW would have a quoted rating of 210 kW with a 1.75 service factor. The overall rating of a gearbox is based on the ratings of all its individual components. This includes the gear teeth design, gear hardness, shaft dimensions, bearing selection and sizes, housing design (thickness & rigidity), and thermal considerations. All these considerations are to ensure that your gearbox has sufficient support and capacity to effectively transmit the motor torque to the screw without significant distortion or failure. Within the gearbox, the most important component (and most expensive) is it’s thrust bearing. You evaluate a thrust bearing based on its type and life (B-10 or L-10 rating). The B-10 Life (sometimes called L-10 Life) of the thrust bearing is based on an engineering calculation that estimates the number of hours of operation at which 10 per cent of the bearings are likely to fail. Additional rating adjustment factors are to be applied to the basic B-10 life based on application factors including how the bearing is mounted. For example, a thrust bearing that is mounted between two radial bearings is more likely to have precise thrust bearing alignment, and will therefore have a higher rating adjustment factor. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | 30
  20. 20. KELACHANDRA MACHINES (MFRS. OF RUBBER INDUSTRIAL MACHINERY) Chingavanam - 686 531, Kottayam, Kerala. India. Phone Off: +91- 481-2430325. Fax: +91- 481-2430596 e-mail: km1912@gmail.com
  21. 21. Here are 6 other key criteria of a gearbox evaluation, which you should know 1. Gear Design, Hardness and its Construction Each of the individual gears that go into your gearbox assembly are rated for power or torque based on their strength and durability ratings. The calculations would be according to industry standard AGMA rating systems. Factors include the gear tooth pitch, center distance, material and hardness. 2. Gear Shafts The shafts must be designed to transmit the full power and torque capacity of the gears. The length and diameter of these shafts is decisive and must match the ability to transmit this torque without excessive deflection, fatigue and failure. The diameter of the input shaft must be adequate to properly support sheaves (in the case of belt driven models) or a coupling. The output shafts must be properly designed to handle the correct range of screw shanks that will be inserted. Adequate access to the drive keys is beneficial when they become worn or damaged and need to be replaced. 3. Radial Bearings and Seals The radial bearings support the rotational forces of the gear shafts and must be designed to handle the load forces and speeds effectively. The dynamic load capacity of these radial bearings must also be considered when evaluating the design and durability of the gearbox. Radial bearings must also be properly lubricated and sealed. 4. Gearbox Housing Design - Construction Cast Iron is the cost-effective material of choice for most manufacturers. Traditionally, CI gearboxes are made in two pieces, split either horizontally or vertically. Newer designs have the gearbox housing cast as one piece to reduce any potential leakages. 5. Thrust Bearing Thrust bearing isolates the backward forces from the screw. The larger the screw and/or the higher the back pressure, the greater the backward thrust forces. There are three basic types of thrust bearings – cylindrical, spherical and tapered. 6. Serviceability When you select a gearbox, you should give prime importance to the availability to affordable parts and service. It is best to select rubber extruder suppliers who purchase their gearboxes from proven and reputable manufacturers that specialize only in gearboxes for better serviceability. An old gearbox manufactured around through-hardened process and shaved gears technology has shafts, bearings and housings designed accordingly. Replacing new hardened gears with a higher HP capacity, does not automatically guarantee the gearbox rating to increase, if you do not replace the assembly with stronger shafts, bearings and housing. Gear manufacturing technology today has Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | 33
  22. 22. changed and consists of carburized and ground gears. These gears are capable of delivering much more power in its smaller size. When old gear designs are constructed using the new materials and process, the power calculations yield much higher gear tooth ratings. But if the rest of the design is unchanged, and the same bearings, shafts, and housings are used, the total gearbox rating cannot simply be based on the new higher gear rating alone. The higher torque could never be applied to the original sized input shaft without causing bending or twisting. The bearings and/or shafts would be overloaded with the higher forces, and the housing would probably not have sufficient strength to resist significant distortion. Reputed gearbox rebuilders will guide you well. Automation The different levels of automation of down- stream line for extruders makes the extrusion operations highly user-friendly and efficient. In the case of extruder heads, there are different options depending on user requirement - a simple, single-compound single-component mechanically opening extruder head to a sophisticated cost- effective PLC controlled hydraulically opening multi-compound multi-cavity head. So, rubber extrusion is in itself a vast and interesting subject. Rubber & Tyre Machinery World | FEB 2016 | EXTRUDERS | Image of Extrusion Line. Source: CGEC RMW 35
  23. 23. AMCL MACHINERY LIMITED SERVICE TO THE NATION FOR FOUR DECADES For all your enquiries please contact: AMCL MACHINERY LIMITED Works: Plot No.A1/1, MIDC, Butirobi-441122, Nagpur Mumbai office: 202, Ackruti Centre Point, MIDC Central Road, Andheri (East), Mumbai-400 093. Contact person: Mr. S.H. Mehta Mobile No. +91-9004697430. Email: Website: www.amcl.inshmehta@amcl.in • Rubber Mixer – 76" liter and 270 liter. • Mixing Mills – 16", 22", 26" and special sizes • Hot feed extruders – 6" and 8" • Rubber Calenders – 2/3 rolls. • Bias Tyre Building machine – RB1/RB3 • Automatic LCV Tyre Building Machine – RB1619 • Automatic Truck Tyre Building Machine-RB2022 • Mechanical Tyre Curing Presses – Scooter to Truck size • Bladder Curing Presses • Tube Splicers Product Range
  24. 24. KELACHANDRA MACHINES (MFRS. OF RUBBER INDUSTRIAL MACHINERY) Chingavanam - 686 531, Kottayam, Kerala. India. Phone Off: +91- 481-2430325. Fax: +91- 481-2430596 e-mail: km1912@gmail.com

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