Prestar S.R.O

Tube straightening machines

Using straightening machines tubes of a round section can be straightened.

From the transverse conveyance the tube is fed to the entry plastic VARIO-trough. The trough opening adapts to the tube diameter. Rotary catch drivers get over the tube the initial rotation and ensure feeding the tube between rollers of the straightening machine.

10-roller straightening machine is equipped with an automatic adjustment of rollers according to the set values:

• Tube diameter
• Tube wall thickness
• Material ultimate strength

After the automatic roller settings, heights of rollers and their inclination angles may be trimmed manually. The set data can be stored to be used for repeated settings.
The roller setting – height, inclination angle – is ensured by servomotors. The tube straightening machine enables both wet and dry straightening. During wet straightening the machine is equipped with suction and filtration through a filtration station.

After straightening the tube is braked and tipped out from the discharge trough on the stacking magazine. The tube straightening machine can be equipped with an automatic separator of tube package piece-by-piece and feeding tubes to the entry VARIO-trough.

Family:  WR-10-50,WR-10-70,WR-30-90,WR-50-120,WR-60-200

Depending on diameter, wall thickness and ultimate strength the following parameters can be achieved on the tube straightening machine:

• Straightening speed – up to 140m/min
• Straightness – up to 0.3mm/m

Tube packaging machines

Tubes are fed by longitudinal or transverse conveyors to a tube packaging machine.
Operators of the machine select a tube bundle size, or an exact number of tubes in a bundle.

Pursuant to the settings an impulse sensor tracks the number of incoming tubes and reads the number of placed tubes being bundled layer by layer. The number of tubes in each layer is specified by a control program.
After reaching the required bundle size the fastened pack moves on a mobile cart to a strapping position. The tube bundle can be strapped either manually (by strapping tools) or by automatic packaging into a foil followed by strapping.
While strapping the bundle, the packaging machine is forming a next tube bundle.   Tube bundles can be packed into a hexagon or square form.

After forming, the bundle is placed on a transverse chain conveyor for storing up to 5 pieces of bundles. In this position it is possible to weigh the bundle automatically and print required data.
In the same manner hexagon or square bars are bundled.

Tube ends quality non-destructive testing system

• Outer diameter of tubes – 31,8…..114,3 mm
• Maximum length of tubes – 25 m
• Cycle time for inspecting two tubes – 50s
• Detection of defects – magnetic powder method

Tube finishing lines 

In order to interconnect individual operations (e.g. cutting of tubes to a precise length, non-destructive testing, placing to bags) we design feeding and conveyance of tubes using roller and belt conveyors, transversal handlers, chutes etc.

The effect is an automated conveyance and processing of tubes in a required cycle. Setting parameters is performed by operators on the control panel.

Tube grinding machine  

A tube is transferred from a transverse table to the entry line formed by oblique rubber rollers. The tube is conveyed by a specified speed towards the grinding machine.
The grinding machine is formed by several frames equipped with abrasive belts. The belts are pressed to the tube depending on the required material reduction of the tube surface.
Abrasive belt grinding is a wet process. At the discharge end the tube is dried by air flow.
After the grinder passes through the entire length of the tube, the tube stops at the exit conveyor.
The tube is transversally discharged on the oblique table or towards further processing.

Tube parameters:

Tube diameter:           up to 90mm

Grinding speed:             up to 25m/min

Surface quality after grinding:      up to Ra 0.4 µ

Chamfering of tubes and pipes

After chamfering edges at both ends of the tube or bar, the tube is placed by feed handlers to the chamfering position no.1 on the roller conveyor.
Rollers convey the tube face the positive stop. Then it is conveyed by the feed handler to the chamfering position no.2.

The tube is clamped by hydraulic jaws and towards the face a headed spindle set up with tools for chamfering edges is thrown out. The spindle is height-adjustable depending on the tube diameter.After chamfering the spindle moves to the initial position, the tube is relieved from the jaws and the feed handler moves the tube to the next roller conveyor – chamfering position no.3. By analogy the opposite end of the tube is chamfered.

In conclusion the tube is discharged on the oblique table to further machining.

Collecting and storage cradles

Automatic buffers or collection systems are essential for the maximum possible continuity in the production and processing of rod and tube materials. Buffer and collecting-troughs, sorting deposit troughs, belt collecting troughs with plastic struts or centre infeed, upright troughs to hold scrap, mobile belt troughs, low-noise collecting-deposit troughs and sliding buffer troughs by Prestar assure ultimate productivity.

Tube sawing and tube cutting machines

We perform cutting of tubes, having a diameter of up to 120 mm, to exact lengths by disc saws.

The tubes are put transversally between clamping jaws by handlers. The jaws are furnished with a plastic coating to avoid damage of the tube surface.By means of hydraulics tubes are clamped in jaws and the cutting of the tube starts from below with a disc saw blade of a diameter of 450mm.

Shift of the disc saw blade against the tube is program-optimized so that the shift speed is not constant. The disc saw blade is emulsion-lubricated.

After cutting the tube is relieved and transversally transferred to the storage table or to further conveying.
After setting the exact length of the tube after cutting one saw is fixed and two or more saws are travelling, placed on the linear guidance system. After setting the required length of the tube the travelling saw moves to a cutting position.
This way the tube can be cut to the exact length with trim of ends and at the same time into two or more parts.

Tube polishing machine

Polishing machine using felt wheels and grinding paste.

Length of polished tubes or profiles:

• from 1000 up to 6000 mm

Polished tubes and profiles:

• Squared profile: up to 100 x 100 mm
• Tube: up to ø130 x 2 mm

​Speed of polishing wheels:

• from 1000 up to 3000 m/min