Cobalt Alloys as filler material for plungers in the glass industry


When it comes to glass, the first thing that pops to mind is definitely the finished product. We are therefore talking about bottles and glasses for food and beverage, perfume bottles, pharmaceutical and injectable containers and so on. When it comes to the welding in glass, however, only the few interested and experts in the field are able to recognize the importance of this process that, despite representing a tiny part in the entire cycle of creation of the artifact, directly and decisively affects productivity in the glass factory.

The Challenge

Nickel based alloys (Ni Cr B Si) with hardness from 30HRC to 60HRC have always been the natural choice for hardfacing, especially plungers for glassworks. Historically then, the deposition of these powdered alloys has always been done by means of the oxyacetylene flame (OFW) or because of the process called High Velocity Oxigen Fuel (HVOF). However a major Italian bottle manufacturer contacted us to try to solve the problems of high temperature erosion at which their plungers coated in Nickel were subject during the operating times; therefore it has been suggested the use of Cobalt based alloys, more tender and workable but at the same time much more resistant to high temperatures.


The problems of using such cobalt-based alloys were mainly related to their high melting temperature (1375-1400 °C). In fact, this temperature was very close to that of the fusion of Cast Iron and Steel and, if a welding was carried out with OFW or HVOF, the base material would also be melted during the remelting process typical of the two processes.

The Benefits

The transition to Transferred Arc Plasma (PTAW) technology with Cobalt powder filler material has led to several advantages not only in terms of workpiece performance that from an operating time of about 92 hours (Nickel) has increased to 325 hours (Cobalt) but also on the productive level in general and, therefore, economic. First of all, it was no longer a layer of molten powder projected towards the metal as was the case with the OFW and HVOF methods, but a total metallurgical anchor that solved the critical issues related to the cooling of the piece itself. In addition, the volume of powder deposited and thus the percentage of dispersion with PTAW technology plummeted from 70% (HVOF) to 3-5% while maintaining the same depositing time – about 5 minutes.

The Testimony

Thanks to the resolutive intervention of our technical staff and the performance offered by our ROBONEXT P (PTAW) plant , the bottle manufacturer was able to solve the problems of high temperature erosion at which their plungers were subject in operation, greatly reducing downtime and lengthening the life times of the plungers themselves.

SamuExpo 2022

Commersald will be present at SamuExpo, Pordenone/Italy from 31 March to 02 April 2022, reference trade show in the tools and technology sector for metal workings, mechanical and robotics.

We will introduce you our range of special welding consumables and some other complementary products, furthermore our robotized cartesian cladding systems with PTAW and LASER powder technology.

Come to visit us at Hall 3 booth 10 where our technical staff wil be glad to welcome you.

WNE World Nuclear Exhibition 2021

Commersald Impianti will participate in the WNE World Nuclear Exhibition 2021, Paris Villepinte from 30 November to 02 December 2021.
The latest news on cladding with wire and powder superalloys will be present, in particular we will present our proven robotized systems with Cartesian axes P.T.A. Plasma Arc Transfer and the new cells for Laser cladding.
Come and visit us at stand F17!

Koy Clean Plus

Koy Clean Plus is the professional pickling, passivation and polishing system designed for companies that need high productivity, the ideal solution for the instant ecological treatment of TIG, TIG welds with material addition, MIG / MAG, MIG pulsed arc, laser, resistance, orbital, plasma. The inverter technology guarantees a real and constant efficiency of 90%. In addition, the machine is equipped with a blow torch (patented) for the abatement of vapors and automatic delivery of the electrolyte connected, by means of an automatic pump, to the pickling solution tank with indicator of level.
It is possible to connect a second torch (patented) with built-in manual dosing tank, capable of working simultaneously with the large torch, doubling productivity and allowing you to reach the less accessible points more comfortably.

Article on GlassMachinery magazine - P.T.A. welding on plungers for the glass Industry

GlassMachinery Plants&Accessories magazine publishes an article interview televant to the study of Commersald impianti P.T.A. (Plasma Transferred Arc) welding with powder on blow Blow, Press Blow and NNPB plungers for the glass Industry. In particular focuses the attention on the process with Cobalt base powders and its several advantages in terms of performances.

Commersald Spa - Emergency communication Corona Virus

For reasons of transparency with our customers, it is our precaution to inform you that our production and logistics activities are in full swing, that our purchasing offices operate entirely without experiencing problems in finding material and that the transporters to whom we entrust the goods have no restrictions on collect at our facility and in circulating freely, confirming all the withdrawals of the next few days to the whole Italian territory.

The laser cladding of Commersald Impianti

Among the multiple applications of laser technology, cladding is emerging due to its high metallurgical quality, the limited heat input to the piece and the mixing contained to a minimum with the base material.

The deposits are perfectly anchored and the melting of the base metal is so limited that the analysis and characteristics of the filler metal are practically unchanged even in the area adjacent to the interface.

Under these conditions, the deformation of the pieces is almost zero. Often the piece can be welded without pre-heating even in the presence of hard or brittle filler alloys.

The high cooling rate of the weld beads also determines a fine grain structure of the deposit.

Samuexpo 2020 - Pordenone

Commersald will be present at SamuExpo 2020 (, Pordenone/Italy from 06 to 08 February 2018, reference trade show in the tools and technology sector for metal workings, mechanical and robotics. Come to visit us at Hall 3 booth 10, we are waiting for you!!



Monitoring kit - welding coordinators

The kit for controls made by COMMERSALD SPA is contained within a rigid case and includes all the instruments necessary to perform an accurate direct visual examination according to the requirements of the UNI EN 17637: 2011 standard.
This kit guarantees the operator the possibility of carrying out the visual test in the best way, because in a single kit there are all the measuring instruments suitable for checking any welding defects or other particular defects.
The kit contains different types of caliber - both manual and digital - for dimensional checks of welded joints and corner cords, brass and steel brushes for cleaning, sets of magnifying glasses, torches and magnifying mirrors, digital luxometer and thermometer.

IVS 2019 - Bergamo Italy, May 22-23

IVS - Industrial Valves summit is the meeting point for buyers and suppliers of valves technology and flow control solutions.
The event was created to attract the entire supply chain of the valve industry and will be held every two years.
Commersald Impianti will be present with its staff at booth 100 to update on last cladding solutions.
See you there!