► News Contents    |
| It’s true, at least for PE-TRA Band saw machines. PET-RA band saws which are 24 x 7 machines, and hence generating heaps of chips, have a basic layout with an improved and efficient catchment area for chips and coolant. All currently produced PE-TRA Band saw machines are integrated with newly designed, more efficient Chip removal system, which effectively produce dry chips and also removes other foreign materials. |
| PE-TRA Band saw’s
basic layout is such that, it effectively collects almost all
the chips and coolant , splashed during cutting operation and guides
it to the chip conveyor. Coolant through blade guide is a feature in
PE-TRA Band saw, which forces most of the chips directly into the chip
conveyor. A chip removing motorized wire brush, rotating at rated speed,
which is installed at a pre-designated angle, also cleans the chips
efficiently and forces it directly to the chip conveyor. All care has
been taken to avoid coolant splash outside the machine working area. |
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Improved design of Chip conveyor now makes it possible to easily clean conveyor housing, by removing the Coil or Screw* itself, just through simple maneuvering, during periodic cleaning or maintenance (*Warning- Please Switch OFF the machine before carrying out any such cleaning operation. Please consult machine manual). Then finally a very effective and efficient chip removal system, which removes dry chips and other foreign items, returning the coolant back to the coolant tank, thus avoiding any breakdown and damage to the electrical and mechanical parts. |
| This Screw type chip
removal system, in which Screw is supported at both ends, installed
in a housing which is located at the bottom and lowest portion
of the machine and effectively collecting the chips from the cutting
area and as well as from other portions of the band saw machine. Chip
conveyors Screw’s ‘end coil’ has unique profile which is clearing
chips as well as foreign items effectively, without overloading the
system. Chips are then fed to an outlet or chute, which has a ‘relieve
area’ and then expanded profile over the length and is inclined too
for relevant results. Hence when chips and other foreign articles exits
from chip conveyor outlet, they first comes across a ‘relieve area’,
where foreign materials (like nuts, bolts or metal pieces etc) gets
the space thus avoids any overloading on the Chip conveyor system. As
the chip conveyor screw moves continuously, churning out the chips out
to ‘relieve area’ , which in turn makes the chips and other items
to move, up in extended and expanded area. During this process, coolant
gets back into the tank, making the chips completely dry. |
| Kindly note, PETRA machines tried their best to remove chips and keep the machine working space clean, but as a manufacturer, we always recommend to clean the machine periodically (highly recommended-after every working shift. Please follow Instruction Manual before cleaning) which also helps in keeping the downtime to minimum and enables machine to perform consistently. It is also in the higher interest of the user too. |
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| PETRA Machines once again proved its Bandsaw machine’s capability by successfully cutting a very challenging material in a very efficient manner. |
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This material is a high temperature alloy used to manufacture turbocharger nozzle ring. A nozzle ring is located in exhaust-gas turbine of a turbocharger and is subjected to severe stresses due to continuously varying operating conditions. This is a corrosion resistance material (Chromium and Cobalt is 34.5% by weight), as the exhaust gases are highly corrosive. |
| Due to its contents (Cr, Co, Si), it is one of the most difficult material to cut economically. Hence, at PETRA, we undertook this challenging project to establish its optimum cutting parameters. |
| For these trials, we used the material (which is invariably used by nozzle ring manufacturers) in the form of tubes as well as rounds. We cut it by using a Carbide teeth bandsaw blade. After establishing the various parameters, we arrived at conclusive data, which shows, how efficiently, the PETRA bandsaw cut this challenging material. We achieved a consistence performance of cutting this material and arrived at an average tool life of 63000 sq.cm with optimum cutting parameters. |
| There is one more tough material, a stainless steel with composition of Cr-24 to 26%, Ni-19 to 20% and Si is 1.5%, which PETRA Bandsaw cuts very efficiently and with consistency. A batch of solid round of 76mm diameter, we cut it with Carbide blade and achieved an average tool life of 68000 sq cm. |
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PETRA band saw’s unique force and feed feature helps in a successful cutting of this material, as with this arrangement , blade never gets over loaded and automatically adjust the feed according to resistance to the blade teeth and the set load. |
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► An ultimate performance by PETRA Bandsaw Machine Model DC300A in Machine Tools Exhibition 08 at Goteborg, Sweden
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| PETRA Machine’s Model DC300A, once again proved its all round capabilities, at the Machine Tool Exhibition in Goteborg, Sweden. Machine was on display at our associate, TEAM RIX AB’s stand. |
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We cut Material St52-U3 of diameter 250mm, with a blade of make RIX Sagen (Blade model ‘TOP’) and of size 4150 x 34 x 1,1 mm and had 2/3 TPI. We cut almost 4,10 sq meters with cutting time of 8 min per cut, with an average cutting rate of 61,32 sq cm /min at 55 meters/min blade speed. The cuts were perfect.
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| On the last day of the exhibition, after cutting an area of 4,10 sq meters, we loaded the machine for its ultimate test with the same blade and the material at an average cutting rate of 106,80 sq cm/min with a blade speed of 65,34 meters/min. |
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| These result shows, how perfect the machine is. It is very efficient in cutting, also saving on energy, with only 3,6 ampere current drawn at the peak. Its chip conveyor is also much efficient, churning out heaps of dry chips continuously into the bin. |
| ►Contact us for more information |
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Real time Feed Rate and Cutting Rate data
Monitoring System
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| With our efforts towards of continuous innovations to make PE-TRA Bandsaw machines more operators friendly, we have come out with a concept of Real Time Feed Rate and cutting rate data on display. It’s an utmost important feedback to the operator, owing to control / regulates the blade speed and feed, as the blade teeth gets dull in a production metal cutting operation. |
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Why Feed data is important?
As
we are aware, feed is downward movement of the blade in mm/min, which
operator applies thru a hydraulic feed regulating valve. It depends on
material, its area of cutting, blade TPI, blade condition, and machine
condition and certainly the productivity requirements. Also a
fractional variation in feed may vary the blade performance and
geometry of the cut. So one can see how critical this data is.
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| Also, when the blade gets dull, actual feed rate may vary from the 'applied' at Feed valve. It happens due to dull teeth and consequently blade teeth take more loads during that point of cutting. |
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Our
experience shows, an Operator can optimally use a blade in a continuous
cutting operation by maintaining optimum cutting rates and subsequently
the productivity.
An
operator with actual feed rate data on the display, he could manage the
machine more efficiently, may achieve a better production with a better
blade life.
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Also
operator knows the exact cutting rate in sq.cm/min on the display
corresponding to the area of cut. It gives him an extra arm to control
/ regulate the cutting operation to optimum performance. This is a very
important feature, as an ideal cutting operation means cutting with
constant cutting rate.
The devise uses an encoder which in turn sends the signals to the PLC to display the data in mm/min format.
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| PETRA Machines goes one step ahead in automation of its Bandsaw machines. Now the cutting arm limits itself to the desired height with pre-programmed safety height limit. This feature serves as an idle time killer in a cutting operation. |
| ►Contact us for more information |
| PETRA Machines has designed and developed a Clamping System for Small Diameter bars in Bundle, which effectively hold the bars in position, allow machine to cut at optimum speeds and feeds,avoid burrs and increases the durability of the blade. |
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Back |
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This Clamping system for Small
diameter bars in bundle has been successfully integrated with PETRA
Machine's standard Dual Column Bandsaw Machine Model DC300A.
Anyone cutting the small diameter bars in bundle knows,how difficult to cut. Practically speaking,it is not from the point of view of 'Cutting difficulty' of these diameter bars, but from the point of view of the its end result and henceforth its cutting and operational cost. |
| The main problem occur in a normal standard machine(even after using a correct TPI blade, speed and feed) are: 01.Burrs on the face of the cut piece. 02.Some times one of the bars in the bundle rotates and damages the blade. 03. Reduction in the blade durability. |
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Normal working pressure in a standard bandsaw may be 40bar, which may exert a force of 1 ton and this force is very high as far as 12 mm dia bars clamped in bundle is concerned.This high pressure tend to make the bundle gets disturbed and bars may jump of or even rotate. |
| At PETRA Machines, we analyzed these problems and concluded to have a reduced clamping pressure in the Feeding vise and a top guide at the shuttle vise, which would not exert any pressure on the bars, but shall touch the bars and restrict their upward movement and most importantly an extra vertical clamp just near to the blade at the exit. This clamp is a mechanical clamp with adjustments for various sizes and keeps the optimum pressure on the 'Cut lengths', to avoid any movement after the cut is over. |
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The unique feature of this clamp is , to reduce the feed at the 'near end of the cut' to avoid any damage to the bar edges. The machine is already having its standard vertical clamp at the front vise, behind the blade line.This comprehensive clamping system for such applications, has given the best results in terms of , nearly eliminating the burrs at the edges and improvement in tool life, with optimum speeds and feeds. Hence reducing the cutting time. A 12mm diameter bundle (12mm dia x 14 no bars in a single row bundle) takes only 12 seconds to cut, mainitaining the excellent surface finish and durability of the blade.The results are excellent and encouraging too for other small size below 35mm diameter. |
| ►Contact us for more information |
| PETRA band saws attracted a considerable interest between metal cutting
professionals. The most important portal for metall cutting in Germany
published an article about our products. Klick www.sägebörse.de to access the portal. |
| ► See PE-TRA aslo at: Manufacturing talk Newmac |
| ►Contact us for more information |
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PETRA Machines Ltd. marked it presence felt at EMO-2007 at Hannover with its improved machine model CutMaster DC300A and ToolMaster DC300. Using Patented technology of precise, parallel movement of the frame including Ball Rail System on both columns, PE-TRA machines displayed the optimal cutting performance. |
| It was a live and ultimate performance of PE-TRA bandsaw machine’s capability when CutMaster DC300A was continuously loaded with solid round of 270 mm of 42CrMo4 (G+T) and consistently resulting in 6 min 15 sec cycle time, means a cutting rate of 91 sq cm/min. Blade used is M42 Bimetal and till the end of exhibition, it had already cut over 9 sq meters and still with the teeth intact even after aggressive test at cutting feed toping 120 sq cm/min. |
| This performance has been achieved due to unique design of its Cutting Arm technology which is absolutely smooth, and practically creates no vibrations in the arm as well as in the blade. Its sensitive Down Feed/Force pure mechanical/hydraulic control system works very efficiently and hence eliminates any erratic loading of the tool. Chip cleaning mechanism with direct motor mounted brush at a pre-designed angle also envisage into efficient cleaning of blade gullet, which is exactly needed for such high performance cutting. Its chip conveyor is also much efficient, churning out heaps of dry chips continuously into the bin. |
| Over & above, its Hydraulic system runs so cool after continuous cutting that oil temperature is still at environmental level. Hence results shown by the CutMaster DC300A is a collective performance of all these machine features. |
| Such price/performance attracted interest from many metal cutting professionals present at EMO 2007. |
| ►Contact us for more information |
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| PETRA Machines co. is fulfilling its commitment to provide the best value to its customers. Based on intensive collaboration with blade producers we decided to increase the size of the wheels on DC300 ToolMaster and DC300A CutMaster models in 2006. |
| The modification was introduced to increase the durability of the blades. Very often the customers experienced blade breakage before the blade had dulled. The fact that the size of the wheels is very important for the life of the blade had been neglected in many current designs. |
| The main reason for this is that the blade wheels of the band saw were too small according to the recommendations of blade producers who recommend that the diameter of the wheels should be approximately 500 times the thickness of the blade. |
| The design of the machine allowed for increase of diameter from 400mm to 500mm without increase of the external dimensions of the machine. |
| The mass of the wheels increased consequently by more then 50% meeting another recommendation from blade producers - the heavier the better. |
| ►Contact us for more information |
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