- A concrete case of PARTNERSHIP
- "PINK" SURFACE TREATMENT FOR STAINLESS STEEL EXECUTION
- CHAIN with self-lubricating Iglidur® bushes
- NYPLOY PROCESS®
- LATEST TEST ON CHAINS WITH HARD CHROMIUM PLATED PINS
1) A concrete case of PARTNERSHIP
An important customer who works in the “tunnel” manufacturing sector for ice-cream production had serious problems with the chain produced with carbon steel determined by the type of application and in particular by “rust” formation and chain lubrication.
However, the problem was due to the fact that they couldn’t utilize solely material of Series 300 and more precisely, Stainless Steel 304 and since it’s a “tender” material and not heat treatable, it would have certainly solved the problem of oxidation but it would have consequently caused problems of wear between the chain parts, in particular, between the pin and the bush.
We suggested highly qualified types of stainless steel that when subject to particular heat treatments, resistance and superficial hardness considerably increase and moreover, without compromising the oxidation resistance.
Once the correct equilibrium among the types of steel was found, we studied the “lubrication” problem with a “standard” production chain and therefore, lubricated, which dispersed a highly pollutive black powder during the application in a way that the hygiene of the product (ice-cream) was compromised.
Experience obtained in collaboration with one of our suppliers of plastic parts brought us to suggest the insertion, between the two chain parts more frequently subject to wear and that is the pin and the bush, of a third part in self-lubricating plastic material with minimum thickness but highly tough. The same, after being inserted between the 2 parts, acts as an anti-friction bearing (bushing) between them.
In this way, the chain gives prominence to 2 notable advantages:
- it can work without any type of lubricant and that’s where the name “lubricant free” comes from
- it permits longer life of the chain since it avoids, as we previously mentioned, friction and consequently wear created between two steel parts rotating in dynamic contact .
Our customer is totally satisfied and they promised to develop and suggest this solution in various sectors where chain lubrication represents a weighty pollutive factor such as in the food industry or applications where chain servicing or a plant for constant lubrication is quite expensive and in this way can be avoided.
There are various solutions: self-lubricating bushings can be used to limit wear, to resist abrasion , temperatures and crushing as well as the fact that they can be used completely immersed in water.
It’s a matter of evolution of the basic product “chain” , an innovation which allows Rosa Catene to propose mutual collaboration aiming at research and resolutions of problems in this and in other innumerable sectors.
2) "PINK" SURFACE TREATMENT FOR STAINLESS STEEL EXECUTION
Progress and market demand always searching for advanced products with regard to quality/services and improvements in the life performance of the base product called "chain" brought us to develop and study, with regard to stainless steel, resolutions of problems concerning premature wear and tear caused by "mild" material of the cylindrical contact elements such as pins and bushes.
For this purpose, today we suggest a new surface treatment called "PINK" with a nonconsiderable cost in comparison to the results obtained and which offers the following characteristics:
- The treatment is carried out on the cylindrical parts exposed to wear and tear and that is, bush/pin and eventually, roller
- Treated components appears black colour
- The surface hardness reaches 1100/1200 Vickers (contrary to 750 of the normal cementation of the carbon alloyed steel) with a thickness of 40/50 Micron which implies a major resistance to wear with the consequent life extension of the chain
- Self-lubricating and anti-seizing up thanks to the presence of anti-adhesion compounds on the hard surface which prevent the forming of micro-cracks caused by friction stresses with reduction of the friction coefficent between the chain components
- Resistance to saline fog between 300/400 hours
- It result effective at temperatures between –40°C/+500°C
This treatment is obtained by spreading, same as hardening, and not by coating as for the "hard croming", "chemical nickel plating" etc…..therefore it avoids the risk of exfoliation of the covering treatment which causes scaling which could be dangerousin specific applications such as the food industry.
Another interesting feature always for the food industry is that it doesn’t eliminate the dust which generate among the components of the chain due to the wear, but thanks to above characteristics of hardness/wear resistance its appearance is delayed.
This treatment doesn’t have a specific homologation for the food industry and it’s inadvisable where the chain acts as a fulcrum for the food-product, i.e., where the chain is in direct contact with the product; while, it is suggested in any application in which the chain is not in contact with the product, therefore normally, even in the food industry.
3) CHAIN with self-lubricating Iglidur® bushes
This solution is particularly suited when the use of any type of lubricant is not allowed because toxic or anyhow because product or environment pollutant. At present it is used widely in the food industry and mostly for bakery and deep-freeze plants.
It's a matter of fitting between the steel bushes of the chain and its pin a thin bush in plastic material with following characteristics:
- elimination of need of lubrication
- high abrasion-resistance
- low frictional coefficients when working by dry method and good compressive strength
- excellent life
- cushion properties and resistance to temperatures between -40°C and +90°C
- good resistance to organic and inorganic acids
There is a wide selction of self-lubricating bushes among which it is possible to choose the most suitable material according to application, in order to grant, beyond the above mentioned standard characteristics, even features for every special application. Our technical staff is at your disposal to recommend the execution, which is most suited to your needs.
NYPLOY PROCESS® is an innovating process of chemic nickel-plating, which allows to obtain on treated surfaces an even deposit, non-porous with high corrosion proofness; essentially it differs from traditional electrolytic processes for the perfect evenness of the thickness of the deposit, aside from the geometry of the parts.
The main characteristics can be resumed as follows:
Evenness of thickness, apart from the geometry of the items, which allows to obtain:
- First-rate adhesive power
- Full protection of inner surfaces (hollows, bores, etc…)
- Absence of "crest" effect
- Absolute observance of ground roughness
- No final machining required (grinding)
- HARDNESS: very high surface hardness. In compliance with the basic material and respective heat treatments, we can obtain hardness from a minimum of 500/550 to a maximum of 950/1050 Vickers. It can be compared with that of hard chrome
- RESISTANCE: high corrosion proofness and high resistance to wear. This thanks to the phosphorus content alloy, which gives to NIPLOY PROCESS® characteristics of:
- SELF-LUBRICATING power, giving a low coefficient of friction and water-proofing.
It was proven that this deposit has an higher corrosion proofness than electrolythical nickel-plating. This property is due to its amorphous structure and to presence of phosphorus.
It can be applied on ferrous materials, stainless steels and carbon steels. This treatment can be employed in the food industry instead of stainless steel.
The application of this process is recommended when one or more of following properties are required:
- Corrosion profness
- Improvement in friction
- Resistance to wear
- Increase of surface hardness
All that provides important and various, even economic, advantages to the user, such as:
- Longer life of the chain
- Decrease of costs, because of the possibility of replacing stainless steel with a less expensive material
- Resistance to thermal shocks: excellent resistance to thermal shocks with range between +200°C to -192°C, without crumbling.
5) LATEST TEST ON CHAINS WITH HARD CHROMIUM PLATED PINS
Unlike chromising, “hard chromium” is a chromium coating. Therefore the hard chromium underneath doesn’t undergo chemical alterations during the process. For this reason the component (pin) can be, and it is, casehardened. Therefore the hard chromium adds the exellent characteristics of the chromium coating to the already good characteristic of a casehardened pin.
During the useful life of the chain, wear and tear will be quite limited because first of all, there’s the particularty hard layer of the chromium and then the casehardened layer. The layer of hard chromium reaches 40 - 50 micron with hardness of 1000 - 1100 HV. Underneath, the casehardened layer reaches a hardness of 700 - 800 HV for the depth of useful casehardening.
The hard chromium adds to the exellent characteristic of resistance to wear and tear, an anti-corrosive protective power which makes it particularly suitable even for the applications in the open; the importance of the coating thickness enables the pin to resist with greater easiness to eventual abrasive and/or corrosive inclusions.
During the useful life of the chain, first the coated chromium will be consumed and successively and partially the casehardened layer. The max. stretching of the chain will take place before this last layer will wear away.
The Hard Chromium coating is being used by ROSA CATENE S.p.A. for several years now in the agricultural field with considerable satisfaction and recognition on behalf of the national and international clientèle.
