May 2008
By Justin Toland, Contributing Editor
Partnership between producers and suppliers is an essential component of product innovation. One aspect of this is product trials in pilot facilities. Pilot plants are normally associated with paper machine companies and other equipment manufacturers, but some suppliers of chemicals and additives are also keen to work closely with customers for the benefit of all parties.
Cargill Industrial Starches (see box) set up its Application and Development Center (A&DC) in Krefeld, Germany in the mid-1960s. Today, backed up by satellite operations in Vilvoorde (Belgium), Cedar Rapids (USA) and (later this year) Nantong close to Shanghai (China), the A&DC "is bridging the gap between research and the market," says global technical manager surface sizing and coating, Application and Development Center, Cargill Industrial Starches, Andreas Becker.
The center consists of pilot facilities, analytical services and starch preparation equipment and systems. "We are the only starch manufacturer that owns its own pilot coater," notes Becker proudly.
Starches are mainly used for printing and writing and industrial papers, so the Krefeld pilot plant has the ability to handle almost any kind of paper: "From vacuum cleaner paper to 300 g/m2 board," says Becker.
Some 35-40 people are employed at the AD&C, many with years of experience: "Some guys have been working on the pilot coater 10-20 years," points out Becker.
The pilot facility sees the pilot coater and calender in one room, with the coating kitchen located next door and a series of laboratories upstairs. Flexibility is the name of the game here and it provides different application units such as Combi Blade, Jet Coater and Size Press / Film Press.
The coating kitchen includes two mixing units (one standard and one rotostator), plus an inline dispersing unit for Cargill's C*iCoat product range – see below. The company is also looking ahead and exploring and experimenting with the latest technologies, including inline dispersing units.
The AD&C is able to conduct a wide range of paper property tests – bendtsen, tear, porosity, visco-elasticity, printability, etc. "We also have a microscopial lab which enables us to do micro analysis of the starch distribution in paper (which layer it is in, etc). This is much faster than a scanning electron microscope," says Becker.
The last big rebuild of the pilot coater (originally supplied by Jagenberg) was in 2002, but "we are constantly investing Euro 400,000-500,000/yr," explains Becker.
The right info to do the right things
Cargill uses the pilot coater for its own product development, to answer questions from customers and even to develop recipes with its customers and is available to rent by any interested parties.
The breakdown of usage is roughly 60% customer trials / 40% own product development, says Becker, "But it can vary a lot from year to year."
"It is very rare that customer trials take place without a customer," notes the global technical manager. "We need to have the right information from the customer in order to do the right things here," he explains. Becker also believes that it is, "Very important for customer trials if people from production as well as R&D from the paper company are here."
Optimizing starch properties and types
According to Becker, "Paper coating requires fine-tuning of multiple parameters to optimize runnability and performance , e.g. coating color rheology, water retention, blade adjustment." It is about taking a holistic view, rather than looking at the effect of starch in isolation.
One example of this is the development of high solids coating. "In the future, coating solids could be higher than 70%, but this requires cooperation and development with pigment suppliers," believes Becker.
High solids coating is said to offer the following advantages:
• Saves drying energy
• Reduces binder migration
• Decreases necessary total binder demand
• Increases smoothness and gloss
• Improves coater runnability.
At SPCI in Stockholm later this month, Cargill will officially launch a new high solids coating starch - C*iCoat.
The new product is designed to partially replace latex in binder systems for paper and board pigment coatings. It is added dry to the pigment slurry or coating colour and, according to Cargill, the product's rheology and binding power have been optimized for use in high-speed, high-solids applications.
In trials with woodfree precoat and single-coat wood-containing papers, the dry solids content was .4% higher using C*iCoat than with existing coating starches. "This allows the papermaker to use more UCC in the formulation, therefore saving energy and costs," notes Becker. Good runnability and gloss and reduced print mottling are other benefits cited by the supplier.
Simplicity of use is as important as the quality of the product. "Even if you have a very good product, if you bring additional complexity to the mill, no one likes it," says Becker. "We are pretty sure we will not add complexity."
According to the global technical manager, "The pilot coater was a very important tool in developing C*iCoat and – another range of coating starches - C* Film."
The next level
The A&DC and its satellites in Belgium, USA and China will also play an important role in Cargill's ongoing research and development activities. Areas under investigation include:
• High solids surface sizing
• 'Natural' binders for coating
• Starches for new application techniques (e.g. curtain coating)
• Testing the impact of different starch raw materials – e.g. tapioca rather than corn - on coating colour rheology and runnability
• Developing concepts for size press replacement (to allow the application of an additional coating step).
"We're not just looking for a simple starch or latex replacement: we are looking to improve the value proposition for the customer," concludes Becker.
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Founded in 1865, Cargill employs 158,000 people in 66 countries and had net sales of $88.3 billion in 2006/7. Cargill Industrial Starches, is committed to serving the paper industry and other industrial applications. The business unit processes 15 million tonnes of grains at 26 plants worldwide and employs some 7,000 people.
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