Winning through service excellence

Every maintenance engineer knows the situation well – everything is ready for the long overdue holiday, just a call from the mixer foreman and then that’s the lot. Or perhaps not? Mechanical breakdown! Bound to be easy to fix. However, visual inspection brings the extent of the damage to light. There is a broken shaft! No chance of an instant remedy. Every hour counts.

If a 50000 t/a mixing plant is brought to a stop caused by a broken mixing shaft then the fault has to be rectified quickly even if the plant is at some remote spot a thousand kilometres from the manufacturer of the machine. The stoppage has appeared unexpectedly and the operator is usually unprepared for this breakdown. In a modern plant every unit is interconnected with the others so the failure of one unit can lead to a shutdown. In this situation a partner is needed that has a sophisticated infrastructure and can react immediately with the right measures. A complex service organization is required – remote diagnosis, stock of spare parts for all sensitive wearing parts, first-class motivated fitters ready to be deployed.

The company m-tec has built up an international powerful service network based on more than 30 years of experience. Service is one of the company’s essential mainstays on which the success and satisfaction of the customer depends. 10  % of the staff work in the service sector. Fitters are permanently on the move to construction sites. Support for our customers from the planning phase to the documentation is provided by mother-tongue experts – Russian, Rumanian, Czech, Polish, Chinese, Spanish and further world languages.

The customers can count on a wide range of services to ensure that the defects do not occur in the first place. This includes the preparation of a repair estimate for an ageing mixer (Fig. 1). Only by professional examination of the actual situation it is possible to assess, calculate and take the requisite measures so that a machine can be used again after the shortest possible time. One precondition is naturally that a repair is cost-effective. The repair is therefore carried out in close agreement with the operator – at the weekend if necessary to minimize the downtime.

Back to the initial scenario: the mixing shaft was broken. Just 24 hours passed from the call from the Finnish plant operator to express delivery on site of a brand-new original m-tec mixer shaft. Inconceivable if the mixer shaft had not been in stock! Our policy is that if the worst comes to the worst our customers have to wait for the same length of time, maximum of one day but sooner if possible, until our fitter is ready to set off.

For years a customer, the operator of 2-flap mixer, had struggled with uncontrolled escape of material before he decided to use the self-locking m-tec “toggle system”. The m-tec service fitters have converted his old mixer to the toggle system (Fig. 2), a mechanical system developed by m-tec for opening and closing the mixer flaps. The flaps are opened and closed by pneumatic cylinders (in some circumstances also hydraulically). The special feature is that due to the dead centre position of the system the flaps cannot be forced apart, even by the strong mechanical forces that occur inside the mixer. Even if there is a sudden drop in pressure the toggle system holds the flaps securely closed. Mixers that were built before this development can be retrofitted with the toggle system.

The installation access had become successively obstructed over the previous years. Due to severe wear the mixer was actually scrapped after 12 years and a new one was due. Its removal was blocked by the complete mixer platform, the dedusting system, the GK scale and subsequently installed supporting braces. The cost was considerable. The m-tec fitters took a gamble: the complete reconstruction of a mixer for which there was no future. The mixer was fitted with an internally installed wear lining, the mixer shaft was replaced, the mixer shaft seals were renewed and spare seals were placed in store. The end walls were also reinforced by welding on cladding elements, and finally the flap sealing system was renewed. This was in 2004, the mixer is still in use.

The m-tec head office in Neuenburg received an emergency call at 15:00 hours on 22.07.2008: wear had caused holes in the end wall lining and immediate help was required (MR 220 mixer constructed in 1996). The m-tec fitters arrived at
12:00 hours on 23.07.2008. The repairs to the mixer end wall were carried out on 24. and 25.07.2008. The mixer end wall was renewed by positioning Vautid lining elements axially around the mixer shaft and welding them in place. This resulted in a virtually new end wall, the interstitial spaces between the cladding elements were filled with Sikaflex, a sealing compound. Production was resumed at 13:30 on 25.07.2008.

Changed mix formulations over the course of time and coarser particle sizes of new aggregates that were unknown when the mixer was designed meant that the mixer outer shell was being eroded away unusually rapidly. Even the Hardox steel of the mixer outer shell (Fig. 3) could not permanently withstand the increasing challenges. The operator was worried that sooner or later the mixer wall would no longer provide the necessary stability, so he turned to m-tec. Assistance was offered after only a brief design consultation. m-tec devised a scheme for the customer operating in the concrete industry that has now provided him with security for many years – a retrofitted lining for his mixer with a particularly abrasion-resistant Vautid internal wear lining. The size and curvature of the lining segments were calculated and prefabricated with the aid of the design drawings, while the customer continued to operate his mixer. A time was then agreed with the operator when fitters could modify the mixer. This has protected the plant against wear for many years and the quality of mixing has remained unaffected. Since then the operators of mixers from other ­manufacturers have also come to m-tec and asked successfully for linings for their mixers.

It is precisely the “small things” in life which can have painful effects. Even a humble solenoid valve of a butterfly flap can paralyse the dosing process and bring a plant to a standstill. It is particularly annoying if the manufacturer does not hold the requisite spare part in stock. It is precisely this risk that m-tec has minimized through carefully building up an enormous variety of spares that are always held in stock for all the possible sensitive and function operative component parts. After 30 years of building plants and constant contact with customers this experience makes it possible to anticipate the most likely sources of trouble as soon as a new supply contract is concluded. Customers can profit from this by having a package of spare parts made up for the project that contains sufficient replacement and wearing parts to provide for the particular unit for a certain period at minimum cost.

The expensive deployment of first-class fitters is often not really necessary. Everyone knows the situation where the modern electronics fail and a trained specialist solves the problem with a single touch. Expensive, if this specialist has had to make a long journey! Many customers are profiting from the m-tec breakdown hotline that can log locally into the customer’s programmable controller. This allows numerous faults to be located immediately. Only then is it necessary to decide whether a fitter has to be despatched or whether the fault can be rectified by technical staff with professional guidance through remote diagnosis. There are first-class diagnostic engineers on standby at the telephone around the clock at m-tec ready for immediate intervention.

Prevention of breakdowns can start right at the commissioning stage (Fig. 4). The customer decides whether he will have the machine installed on his own initiative, with the aid of supervising personnel or completely by m-tec staff. In all cases the operator will be given sufficient intensive training on the functioning, fault-prevention measures, maintenance periods and all other aspects to ensure that he can make optimum use of the performance of the plant or of the individual unit. But also later, when the knowledge gained during the commissioning may have become buried due to the great diversity of information, the knowhow can be re-activated by additional training.

A particularly popular service, but also a feature that can only be offered by a well-established leading company that has grown over the years on the purchasing side through partnerships, is the commissioning of machines manufactured by other companies. m-tec itself does not, of course, produce the entire range of products supplied. The company also profits from the increasing globalization by outsourcing the production of machines or relying on partnerships with specialized companies and integrating their range of services in the construction of complete mixing plants. The service personnel are also very well acquainted with these machines. During the difficult phases of planning, implementation and installation the plant operators do not have to concern themselves with coordinating the supplies and installation services of different suppliers. The entire installation is fully coordinated by a single committed first-class project manager. With over 220 completed plants (Fig. 5) and far more than 500 manufactured mixers (Figs. 6 and 7), m-tec is one of the world’s leading companies in the building materials industry with a continuous interchange of information with the operators associated with the group. This is an invaluable source of experience and provides indispensable support for many investors who have little experience in the construction of a new mixing plant. The range of competence covers everything that can be included in a mixing plant, from sand pre­paration, drying and grinding technology, and the dosing
(Fig. 8), weighing and mixing process (Fig. 9) to modern packing, palletizing and loading systems or the design engineering for a finished product plant.

This is where specialists can give help and advice to the customers when raw material properties, improvement of mix formulations, ready-mixed product quality, or optimization of the product by carefully controlled use of additives, fibres or pigments are involved. The centre keeps an impressive array of the gigantic, and still growing, range of additions for the ­dry mortar industry and a comprehensively equipped labora­tory.
This enables the customers to evaluate the quality of the raw materials that they use. Weak spots can be detected and eliminated. The customers are also keen to make use of the on-site presence of our technology personnel to create new mix formulations that are required by the market and the rising demands of the end users.

Here the m-tec professionals recourse to a big treasure of experience which is in fact neutral and completely free from dependencies and obligations to individual suppliers. If the operator does not have any analytical or laboratory equipment, then m-tec will be happy to support you with selection of necessary testing equipment in accordance to DIN/EN standards – suitable for each budget – and a quote can be produced for a basic or complete laboratory to satisfy the customers quality conrol system.