Development of automotive coatings: The pump makes the difference!

In recent years the market for automotive coatings has experienced extremely dynamic development. Technological progress and the awareness for high-quality paints have resulted in an increasing variety of coating options. In the course of this development not only did the complexity of production increase, the requirements imposed on quality and manufacturing processes also increased. Today in particular, automobile manufacturers, OEMs and suppliers expect high flexibility. For series-production paint manufacturers fast response times with short-notice adjustments of the paint formulation are crucial for market survival. "The paint must meet the requirements of the painting lines – not the other way around", emphasises Susanne Richert, Project Manager for Site Development at BASF in Münster. "Consequently, suppliers must demonstrate a comprehensive knowledge of all coating technologies in use, and ideally they must be capable of delivering all series production automotive coating products – including, cathodic dip painting (CDP), as first coat, fillers, base coats and clear coats." BASF launched the Lean Lab modular laboratory concept in order to quickly and flexibly meet current and future market requirements, and also to make work processes more efficient, less complex and more transparent. "Thanks to the Lean Lab we have been able to implement several innovative concepts. For example, collaborative process structures within paint labs, as well as digital recording and control of all manufacturing processes", says Richert. Using a special software, BASF networks all integrated work areas of the lab, where practical sample manufacturing occurs, and thanks to this network the entire raw material supply can be centrally coordinated and controlled. This considerably accelerates the work flows, since the raw materials are always available at their prescribed stations at the right time.

Process automation in paint development

Formerly, to a great extent, paints were developed by hand. To create a paint, lab employees added specific amounts of raw materials to the overall mixture via pipette. Today this is done with a high degree of automation. "In the Lean Lab, a laboratory dosing device, especially developed for this purpose, is used, which automates the recurring work steps", explains Alexander Blaser, Head of Automation and Digitalisation in the Lean Lab at BASF in Münster. Specifically this means: On the system, the employees select a certain stored product, the system calls up the appropriate recipe and automatically mixes the raw materials together in a precise ratio. Thus the quality of the output mixture is uniformly high. Efficient double diaphragm pumps from Timmer GmbH make this automation possible – they are the heart of the system and are elemental for its functionality. The central raw material supply for the more than 300 dosing points via the automated dosing machine occurs by means of the Timmer pumps. The materials are delivered, dosed, and regularly circulated by these pumps. For development of the coatings BASF works with several hundred raw materials that have different properties. "The materials to be dosed vary greatly in their flow behaviour and wide range of viscosities. Without constant pump capacities, dosing that is accurate to the gram cannot be realised", states Blaser.

 

Space-saving, energy-efficient pump technology

With the Timmer pumps BASF can pump virtually all materials. Two great advantages offered by the Timmer pumps are their compact design and ease of use. The double diaphragm pumps are only about half the size of conventional variants. BASF has several hundred of these pumps in use and they are installed in close proximity to each other; this means that the company saves a significant amount of space. At the same time the Timmer solution enables simplified access. If specific pumps must be inspected, they can be removed, i.e. dismounted, quite quickly and easily. Another advantage: The double diaphragm pumps have an extremely low start-up pressure. Conventional variants on the market require a start-up pressure between 1.5 and 2 bar for the pump to even run at all; the Timmer solution requires only 0.5 bar to operate reliably even at 1 bar pressure. This results in significant medium-term and long-term energy savings, since less compressed air is required. "Basically a high start-up pressure is like driving a car with the parking brake engaged – the consequences are high energy consumption and wear. Therefore, start-up pressure should be as low as possible", points out Stefan Anstöter, Market Development at Timmer. Moreover, this has a positive effect when purging the lines. BASF is able to completely purge the system at a low pressure. This procedure is necessary to remove even the most minute residues, such as pigment particles, from the pipelines. Because the pumps are so small and compact, fewer residues are deposited. In addition, loss of raw materials due to emptying the system of residues is correspondingly low. This advantage reduces costs for BASF, since some raw materials, such as complex special paints, are very expensive.

Maximum process reliability

Furthermore the possibility of pump standstill is excluded. This is ensured by a special, low-wear ceramic over-centre valve. "As a rule, the diaphragm is the part of a pump that is subject to the most wear – like the brake pads of a car. If a diaphragm change is necessary, usually the valve and the entire gasket must also be replaced. This isn't necessary for our products", says Anstöter. All moving parts in the heart of the Timmer pump are made of ceramics in conjunction with precision-ground, high-performance plastics. This results in minimum wear in the valve itself. In addition a short-stroke principle is used; the membrane executes shorter strokes and therefore it is subject to less wear. Shorter strokes also mean less pulsation – fewer pressure surges in the line. High pulsation can falsify measurements of the raw material quantity. Since in some cases BASF fills in the milligram range, this is an important factor. The Timmer solution has a so-called rest function. If the delivery rate is too low, frequently conventional pumps come to a standstill, and then do not start up autonomously. In contrast, with the Timmer pumps BASF can pump even in minimal quantities with no problems. The digital networking in the Lean Lab, where the powerful pump technologies are an important component, quickly led to the desired results: BASF was able to optimise the quality of the paint samples, and leverage the efficiencies to increase the speed for the customer. "The high product quality and dosing quality, as well as the minimal service and maintenance requirements of the Timmer pumps, convinced us" said Richert. Moreover, in addition to its products the company also brought the necessary technical expertise into the development process of the Lean Lab. At the Timmer site in Neuenkirchen, the company trained BASF employees in operation and maintenance of the pumps, and thus imparted specialised knowledge in all aspects of the products. "Our pumps are extremely easy to maintain and they are quite simply structured. You don't need engineering expertise to take them apart and maintain them", reported Anstöter. In addition, Timmer experts and service employees continue to support BASF in an advisory capacity for all questions concerning pumps and pump technology. The successful collaboration of the companies should also be continued and expanded in the future.