Variety of materials safely managed

At the Louveira production plant located in the federal state of São Paulo in Brazil, Plasnova combines extrusion with injection molding under one roof. In WITTMANN, the plastics processor found a partner early on that offers the most suitable peripherals for both processes and also has injection molding ma-chines in its product range. With all-in-one solutions, the high level of consult-ing expertise of the WITTMANN team on site and the innovative strength of the WITTMANN Group, Plasnova ensures a high level of competitiveness.

Visitors meet the products made by Plasnova immediately on arrival. The way from the parking lot to the entrance of the building leads through a park-like garden with lush plant growth. “This is our testing ground, our open-air development lab”, ex-plains Eder, owner and CEO of Plasnova, while greeting us. And indeed, a closer look reveals the water pipes and sprinklers laid between the trees and bushes.

Plasnova specializes in horticultural and agricultural irrigation systems. Whether it be pipes or hoses, distribution systems, connection elements, couplings or valves, sprayers or sprinklers – all of these parts are manufactured in-house. Ever since its foundation almost 25 years ago, the company has seen continuous growth. Other sectors of industry, too, have already benefited for quite some time from the Plasno-va team’s extensive extrusion and injection molding experience. Additional product lines include monofilaments for 3D printing, microtubes for the fishing industry, cannulas for the chemical and pharmaceutical industries, and dosing caps for lubri-cant cans.

Simultaneous dosing and blending of six materials

The range of different plastic materials processed on site grows with the increasing portfolio of components being produced. In addition to standard materials such as PE and ABS, some plastic materials harder to process, partly with a high fiberglass content, are also being used.

“Safe handling of all these different materials is our daily challenge”, Eder reports while proudly presenting to us his most recent investment, which succeeds in cop-ing with this challenge: a large gravimetric blender from WITTMANN’s Gravimax se-ries. It feeds the extrusion lines, simultaneously metering and blending up to six dif-ferent materials. “The Gravimax provides a consistently high quality standard, to-gether with maximum material efficiency and a reduction in personnel costs. This leads to a higher margin”, says Eder, emphasizing that this is exactly what matters. For, as he says, the irrigation industry is a highly competitive market. Moreover, es-pecially extrusion with extremely small die diameters down to the micro level re-quires extremely high-precision metering, in order to achieve the necessary product attributes.

As a further trend, Eder also mentions that more and more often a proportion of re-cycled material is mixed in with the basic material, masterbatch and other additives. “For some pipes, we can already blend in up to 70 percent of regrind.” For example, PE waste – from sprue and scrap parts – is granulated on site and then re-processed.
Before the decision was made to add a large Gravimax to the range of auxiliaries in the extrusion hall, the formulations were mixed manually and the individual ingredi-ents weighed manually as well. “This clearly involves the risk of occasional mistakes happening”, says Eder. “Consequently, we wasted a lot of material in the past.” This is why Eder is so enthusiastic about the particularly precise dosing technology of-fered by the Gravimax system.

Extremely high material efficiency in dosing

Many conventional blending systems operate with time-based dosing algorithms, which set certain limits on the efficient use of materials. For either the system blends in too large quantities right from the start, or the machine operator calculates a mate-rial buffer to prevent system-related underdosing, which ultimately leads to exces-sive consumption, too. “Even if this involves only smallest quantities in each case, it is still a noticeable cost factor when expensive materials are being processed”, ex-plains Marcos Cardenal from WITTMANN BATTENFELD do Brasil. “With the Gravi-max, by contrast, it is possible to achieve extremely high levels of constancy in quali-ty standards while keeping the set weight down to the required minimum. In this way, the Gravimax already amortizes itself after just a few months.”

To achieve a highly accurate and consistent blend for every batch and simultane-ously be able to feed in the material very quickly, the Gravimax operates with the RTLS (Real Time Live Scale) technology developed by WITTMANN. Here, the first step is to approach the target weight by an extremely fast release of material within a minimum of time. Then, as a second step, the dosing system switches over to con-trolled high-precision dosing until the exact target weight is reached.

Since all valves inside the Gravimax are made of stainless steel, the appliance reaches a long service life even where materials reinforced with a high proportion of fiberglass are blended in.

Central material supply for injection molding and extrusion

Following the excellent results obtained in the extrusion process, the injection mold-ing department is now also getting a new, large Gravimax blender. “What has proven itself in extrusion, we adopt for injection molding”, is how Eder explains his strategy, which has already been put into practice for the materials handling system. Where-as for a long time each injection molding machine had its own Drymax dryer, the injection molding hall has now been equipped with a central materials handling sys-tem following the example of the extrusion department. “Now we have a separate dryer for each material, so we can change over from one material to another much faster and much more easily”, says Eder. 
The injection molding machine fleet includes 16 machines, among them several older models from Battenfeld, which became part of the WITTMANN Group in 2008. These machines are still functioning reliably to this day. The more recent machine models are servo-hydraulic SmartPower and all-electric EcoPower machines sup-plied by the WITTMANN Group. The largest injection molding machine comes with 200 tons clamping force. It is used to produce fittings and filters.

Everything from a single source enhances efficiency

For Plasnova, having both auxiliary equipment and processing machines from a single source means greater efficiency in planning new equipment and in after-sales service. “The responsibility lies in one hand, with the WITTMANN team”, Eder points out. “The WITTMANN technicians know all the systems here as well as we do, and they are on site very quickly when service is required. This is very important for us. We cannot simply stop an extrusion line whenever there is a problem with auxil-iaries. Those systems must always function reliably.”

Plasnova and WITTMANN BATTENFELD do Brasil have now been cooperating for more than 20 years. This close partnership has developed into friendship. “We meet regularly for lunch”, Eder discloses. “Of course, we discuss the current projects there, and often the future, too. We have to stay on top of things and are always on the lookout for innovative technologies for further optimization of our production.”

DC pioneers: uninterruptible power supply for injection molding

The topic of DC, the installation of a local DC grid in order to use energy obtained from photovoltaics directly for the operation of injection molding machines without conversion losses, was also discussed over lunch. When it comes to DC, WITTMANN is the pioneer in the injection molding world. WITTMANN is actually the first machine and equipment supplier to offer DC-compatible injection molding ma-chines, robots and temperature controllers, and has already presented these new possibilities and opportunities at several trade fairs, jointly with its partner Inesco.

 “We were immediately convinced by this idea”, says Eder. Here, the company owner not only considers the energy that can be saved by eliminating the current conver-sion loss. “The decisive factor for us is that we are gaining a bit of independence from the public power supply network here in São Paulo. With the DC machine and the salt storage battery from Inesco, we can continue our production without inter-ruption in spite of power failures.” In October 2024, Eder ordered a first DC-compatible injection molding machine for his plant at the WITTMANN booth during his visit to the Fakuma show in Germany, thus writing industrial history in Brazil.