PureFinish® is a post-processing technique. This technique allows stainless steel to be finished to a smoother surface with a low and reproducible SRI value below 0.010. In practice, this produces a surface with a very low degree of adhesion characteristics. The PureFinish® treatment has been extensively tested by TNO. TNO, a Dutch organisation is the leading institute for Applied Scientific Research. The SRI value (Soil Retention Index) was investigated because this parameter most accurately describes the relationship between surface structure, contamination and cleanliness.
Within the food and pharmaceutical industries hygiene is a top priority, not only for safety but also to prevent contamination and to ensure the quality of the product in terms of taste, aroma and appearance. The occurrence of contamination through bacteria, proteins or other elements must therefore be prevented. Process plants require a defined, homogeneous and reproducible surface for all parts that come in contact with food, beverage and pharmaceutical products.
These machines are capable of cleaning and descaling complex welded fabricated components and constructions. They are designed specifically to clean wide head and base plates, ribs, re-enforcements along with the welded seams after construction.
All round blasting is achieved after 3D simulation and actual placement of the blast wheels in the optimum locations of the blast chamber. The chamber can be designed with 2 blast zones, each zone designed to blast clean the surface of the infeed side and the second, the outfeed side and end. As the fabrication passes through the chamber, all gussets, re-enforcements, ribs, angles are descaled and cleaned to Sa Swedish standards and with the desired profile to optimise the adhesion of the coating to be applied.
The equipment requires to easily meet the most stringent customer specifications regarding surface cleanliness and cost, for steel traders, steel fabricators, equipment manufacturers, shipyards and manufacturers of wind power stations. In wind power applications roller conveyor systems are utilised for shot blasting of the steel sheets or plate required for the fabrication of the towers for off-shore and land based windmills.
Typical applications fall into these fabricating industries:
Steel traders/ distributors
Gas and oil
Power generation – including wind turbine columns
Transport – rail, bus, lorry, earthmoving, agricultural
Steel portal frame, tower block, stadium and steel construction
Bridge , crane, access, scaffolding and lifting gear
Partners for Steel
There are distinct benefits to be offered by the cooperation between the manufacturers of both shotblast equipment and multispindle drill/saw lines. The objective of cooperation (as partners for steel) is to support customers in resolving the interface problems between the various technologies, integrating shotblasting, measuring, marking, drilling and sawing or punching and shearing or coping and profiling thereby offering customers added value and profit from the processing of steel.
Steel trading companies and fabricators shot blast their steel plate, sections and pipes to achieve a degree of surface cleanliness that is required before protective coatings are applied or other surface preparation needs.
Automated roller conveyor shot blast systems offer solutions which guarantee a highly-efficient descaling, rust /oxidisation removal and general surface cleaning of all kinds of steel.
Shot blasting is a process for the surface treatment of plate, pipes, beams, tubes and bars.
Due to the design, roller conveyor shot blast systems are ideally suited for this application as it allows fast and highly-effective cleaning and surface preparation and at the same time, provides the surface with a profile to which a coating will adhere well, accommodating a wide- range of commercial to marine offshore standards.
The equipment descales the surface of the steel ready to accept a first-class coating, or further engineering processes.
Equipment design and efficiency are paramount and should include the following as basic design and inclusions;
Infeed and outfeed vestibules should be long enough to stop abrasive escapement
The blast chamber itself should be constructed from wear-resistant manganese steel
The blast chamber requires to be further periphery lined with replaceable tiles again manufactured manganese steel, for durability
The blast requires to be delivered by a number of highly-efficient blast wheels set at an ideal angle to optimise the blasting coverage of the profile or plate
The blast wheels require to be driven by highly energy efficient electric motors, that are energy saving to the latest design standards of power efficiency
The system requires to recycle the abrasive and to include an airwash separation screen that is also highly-efficient in its function of separating out dust, scale and fines out to waste bins
Only good cleaned abrasive should be recycled back for re use
Abrasive level control is a vital inclusion, as without information, the efficiency of cleaning, repeatability and uniformity of the steel surface is all but impossible
A rotational brush and blow off unit, after blasting will complete the process and provides a very clean component that can be either removed from the outfeed conveyor or be handled automatically for further processing
Dust and contaminated air requires to be always drawn through the shotblast system under negative atmosphere, and passed through a very efficient cartridge-type dust collector/filter unit with a discharge back into the hall as low as 1mg/cu mtr down to 0.5 micron particulates and has an efficiency of upto 99.09%
By placing the cleaned spent air back into the building, residual and any ambient heat can be retained in the winter months which can contribute to the reduction of heating costs of the internal working environment
Generally, standard equipment concepts allow the processing of components from 1000mm wide, upto 5200mm wide and 600mm high. Other configurations may be offered as bespoke equipment and to accommodate more complexly designed fabrications.
Fine-blanking can achieve flatness and cut edge characteristics that are unobtainable by conventional stamping and punching methods and surface finishing adds additional value.
Fine blanking is capable of combining several steps normally required by traditional stamping making this procedure a very time-efficient process. In a single step, fine blanking can produce a part which would normally require multiple operations in terms of man hours and equipment set-ups. Fine blanking is known and is a recognised method for creating component parts with fully sheared crisp clean edges, close tolerances and profile, eliminating in many cases, secondary requirements.
The production of fine blanks can be formed from various metal types of steel, non-ferrous including zinc, aluminum, aluminum alloys, copper and brass for the automotive industry and other industrial sectors.
Many companies keep the important operation of surface finishing in-house and utilise various systems such as rotary vibrators, centrifugal disk machines and waste water treatment systems. The size and shape of the parts as well as the surface finish requirements, determine which type of mass finishing system is required.
To be cost-effective, mass finishing operations for many and various fine blanked parts require the utilisation of different mass finishing technologies.
Shorter cycle times with centrifugal disk finishing
Centrifugal disk finishing systems are ideal for such applications. When it comes to intensive grinding and polishing, centrifugal disk machines are usually 10 – 30 timesmore productive. Their separation system guarantees batch integrity. However, these finishing systems are somewhat limited by the batch size. For example, a batch of relatively high quantity of parts weighing 400 kg require to be divided into several smaller batches.
Typically, for these larger production capacities, a fully automatic centrifugal disk finishing machine which processes the parts without any operator involvement all the way to depositing the finished parts into dedicated parts bins, is an ideal option. The effluent from this centrifugal disk machine can be cleaned with an effluent treatment process centrifuge after which the cleaned water and compound can be recirculated many times, to achieve considerable cost savings.
Alternatively, consideration could be given to a fully automated rotary system and possibly with several small centrifugal disk finishing machines. The effluent from all these finishing machines can be handled by a waste water centrifuge before being recycled. This allows running several surface finishing processes with optimum results and excellent cost control.
Do you know the difference between standard rotary vibro bowls and high speed processing?
For the processing of larger quantities of component parts a range of high-speed rotary vibrators is an available option, with superior grinding performance and with process economics in mind.
In high speed rotary vibrators, (already in use at numerous manufacturers of fine blanks, stampings, folded or bent, sawn, cold and hot forged component parts), batches of 400 kg can be processed irrespective of whether a batch consists of 10 or 45,000 parts. The performance of high speed rotary vibrators is up to 60% higher than that of standard rotary vibrators which contributes to a quick payback or amortisation.
Click image to watch an automated
centrifugal disk system in operation
Post written by Sandra Banks
Personal Assistant / Digital Marketing
One of the most technically challenging aspects of mass finishing is the ability to effectively treat the internal channels of precision components. This is especially true in industries which face very stringent requirements, such as; automotive, aerospace, tooling and medical. It is essential for these manufacturers to achieve precise finishing results.
Fully automatic operation produces precise and consistent results
A new specialised line of rotary vibrators that do not have an inner dome, which allows for automatic, precise surface grinding, smoothing and high gloss polishing of such specialised components. New DL vibrators allow for fully automatic and reliable treatment of such inner contours, resulting in excellent finishing results, achieved in either wet or dry operational mode. Even with extremely delicate and complex contours the dimensional integrity of the work pieces is fully maintained. Depending on the components, their original surface readings and the selected finishing process, Rz values of as low as 0.1 µm can be achieved.
In this type of machine, one or multiple work pieces may be attached to specially designed fixtures. The complete unit with the attached work piece(s) is then firmly mounted into the DL vibratory finishing system. For certain applications the loading and unloading operation can take place with a pneumatic lifting device, this eliminates the need for entirely removing the media from the work bowl when unloading the fixture with mounted part(s).
The vibratory energy is provided by two high-performance vibratory motors, placed on the outer wall of the work bowl, which is transferred to the work pieces that are mounted to the bottom of the work bowl. The intense vibration causes the processing media to flow through and around contours, internal passages or undercuts in the work pieces, without getting stuck.
Compared to standard vibratory systems, this sophisticated machine design combined with powerful vibratory motors (3,000 RPM) produces a 30% increase in processing intensity, resulting in comparably short cycle times. Adjustment of the imbalance weights and control of the motor speed, with frequency inverters, provides the ability to adapt the processing intensity to match the work pieces and the desired finishing task.
Equipment suitable for a multitude of finishing tasks
DL rotary vibrators are the perfect solution for finishing complex work pieces, such as; housings, pump or fan wheels, blisks, dies and moulds, tools, automotive wheels and a variety of other work pieces. Ensure you have sample processing trials carried out on your components so that you receive a tailor-made finishing solution, with the highest finishing quality, short cycle times and high cost efficiency.
All DL vibratory finishing systems are equipped with an easy to use control panel, which includes process timers. For wet finishing operations, compound and water are fed into the machine with a precise dosing system.
The quality of consumables used in mass finishing is a key factor in surface processing. Using consumables with a consistent high quality is crucial to attain set surface specifications, process times, costs and to manage considerations to any environmental impact.
There are in excess of 1700 types of vibratory media consisting of various shapes, sizes and incorporating a percentage of abrasive. These are divided typically between ceramic and plastic families.
Ceramic Media Production
A ceramic media has a higher density than that of plastic media. Ceramic chips of various shapes and sizes are formed, fired and held at certain temperatures and durations; providing an infinite range of variation and capability.
A consistent, supreme quality media is extremely important for the user to obtain a uniquely stable and reproducible surface finishing result.
Ceramic media is manufactured to exacting standards, controlled in a fully-automated way.
Plastic Media Production
The manufacture of the plastic media is also totally automated.
The plastic media is of a lower density than that of the ceramic media, therefore it is suitable for a more gentle treatment of critical component parts and softer metals.
The process involves mixing, forming and curing of the media and the whole process is computer controlled and continuously monitored. This quality standard ensures a consistent wear and cutting performance, and repetitive results during the finishing process.
Surface Finishing Compounds
Compounds can be added to the vibratory process, optimising the surface specification for: degreasing, brightening, polishing, corrosion protection and producing surfaces free of stains.
Another important function is keeping the process clean. The compound continuously flushes tiny metal particulates from the chip media and other contaminants out of the mass finishing system, keeping the media active and the parts free from contamination.
Depending on the specific process, compounds will provide various options of acidity and alkalinity as a pH factor.
Despite compounds being used for many years in mass finishing applications research and development constantly progress new formulations for special applications.
The range of different compounds is broadly diversified:
The Long-life Rutten has the longest ultimate life expectancy of any, lasting upto 20 times longer than a standard blast wheel or turbine.
This is a highly-engineered blast wheel with exceptionally tight tolerances and built-in specialist superior steel alloys. Due to the higher value materials and the high specification machining costs of these materials, the initial investment and cost of component wear parts are more highly valued.
However, if maintenance and/or production problems are presently a big issue, the economics of this blast wheel can be demonstrated in ultimately high production speeds and demanding applications.
Least Maintenance And Highest Specifications
Less costs for maintenance up to 16 times higher wear resistance and service life of up to 40,000 operating hours (over 18 years on a single shift).
The proven Rutten Long-Life turbines, equipped with components made from carbide steel are characterised by their extremely long service life of up to 40,000 operating hours resulting in significantly higher equipment uptimes and drastically reduced time requirements for maintenance.
They offer substantial savings in energy consumption and spare part costs/hour. The blades have a precise design with a high recognition value and in addition allows the “Y” blade to be turned and used twice. Long-Life turbines are installed in a wide range of new shot blast equipment and can be easily retrofitted into existing shot blast machines.