WITTMANN machines are the most economical

Short setup times contribute substantially to the high competitiveness of Krona in Brazil. In view of the company’s product range, not a matter of course. This group of companies ranks among Latin America’s leading manufacturers of pipes, pipe sections and fittings. With particularly large and bulky molds, how-ever, the MacroPower injection molding machines from WITTMANN fully prove their worth. For 23 years now, WITTMANN BATTENFELD do Brasil has not only been a supplier, but also an important development partner for Krona.

Founded in 1994, Krona stands for a continuous success story. Today, the Krona Pipes and Fittings Group comprises Krona Joinville, Krona Northeast, Krona Central East, Krona Ultra-Therm, Krona Acessórias, Viqua as well as the Linear Group of companies and remains on course for further growth. “We are growing faster than our competitors”, says Valdicir Kortmann, Sales and Marketing Manager and mem-ber of the company’s Management Board, proudly during our visit in Joinville, Southern Brazil – the location of the corporate headquarters and production plant for both injection molding and extrusion.
In the sanitary equipment sector, the Krona Group is one of the top 3 brands in Latin America, currently producing 2,500 different products. These include pipe segments and molded parts for cold water, hot water and sewage systems, as well as fittings and drainage systems. Additional business segments are irrigation technology and electrical installations. “The electrical sector is growing particularly fast”, says Kort-mann, and Krona has prepared for it accordingly. During the Fakuma in Germany last October, Krona ordered three additional MacroPower injection molding ma-chines from WITTMANN for the production of covers and housings of fuse boxes.

The Fakuma is a regular fixed date for the Krona managers. “We are always on the lookout for new technologies to become more efficient”, says José Armecides Gon-çalves, Production Director of the company and also a member of the Board. “If we are targeting higher competitivity, we must boost our efficiency.” Here, the large 
MacroPower machines make a substantial contribution. At the production facility in Joinville alone, Krona is operating 75 injection molding machines from WITTMANN, or WITTMANN BATTENFELD, as WITTMANN’s machine division was called until recently. MacroPower machines are taking the lion’s share of this equipment.

Fast setup in spite of many core pulls
Price pressure is high, and the product portfolio is extremely demanding. Fitting pro-duction requires elaborate molds with many core pulls and other mechanical fea-tures for injection molding production. The core pulls often protrude laterally far out of the steel block. Accordingly, the molds take up a lot of space. Of course, the core pulls can be removed for clamping the mold, but that takes additional time, which reduces the machine’s availability.

This is where the MacroPower machines prove their strengths. Even large, mechan-ically complex molds can be clamped efficiently without being taken apart. “The 
MacroPower machines offer a particularly large distance between tie-bars”, empha-sizes Cássio Luís Saltori, Managing Director of WITTMANN BATTENFELD do Brasil, to explain one of their advantages. “The very large dimensions of the mold clamping platens were the decisive reason for Krona to invest in WITTMANN machines from the very beginning.“
Another aspect is that the clamping system permits a large distance between the ends of the tie-bars and the moving platen, thanks to the short length of the tie-bars and a large platen stroke. This enables mold insertion and mold clamping laterally from the rear end of the machine, using a crane.

“35 minutes is our target for mold changes”, explains Israel Almeida Furtado, Tech-nical Manager at the Joinville facility. “This is what we need on average for cost-efficient production.” Without the special features of the MacroPower, the bulky molds could not be set up within such a short time.

An additional gain in efficiency is achieved by the fact that extremely large molds fit on comparatively small machines. In this way, the machine size can be chosen on the basis of the clamping force required for the injection molding process rather than based on mold dimensions. “The door-opener for WITTMANN at Krona was a ma-chine request for a special fitting mold”, Marcos Cardenal from WITTMANN BATTENFELD do Brasil remembers. “We finally delivered a machine two clamping force sizes smaller than the one originally requested. This size was perfectly ade-quate for the mold and led to an increase in overall efficiency.” After all, smaller ma-chines not only reduce the investment costs. They also come with lower energy consumption and a smaller footprint.

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