The Milling Report

By Kerry Pianoforte, Ink World Associate Editor | 02.01.08

Milling equipment manufacturers are seeing particular interest in process improvements and new technologies, including nanotechnology.

Due to challenging economic conditions facing their industry, ink manufacturers might not choose to

Premier Mill’s QMAX Supermill.
purchase entirely new milling machines. However, milling equipment manufacturers have seen an increased interest in upgrading and improving existing equipment to improve their processes.
“There is always interest in improving production and product quality, and to reduce production costs by introducing new equipment technology in a downturn or upturn,” said George Murphy, national sales manager, Hockmeyer Equipment. “However, it comes down to whether or not purchasing the equipment is justified at the time.”
“We are working with many ink companies with interest in new equipment and modifications to existing equipment,” said Stewart Rissley, national sales manager – Premier Mill Operation, SPX Process Equipment.
Buhler Inc. reported an increase in the latter half of 2007. “We are also hoping that 2008 will continue with this upward trend,” said Rene Eisenring, GD sales manager, Buhler Inc.
“We have not seem much growth in ink manufacturing in the U.S., but we have seen a lot of interest by companies looking to improve their ink processing,” said Dave Peterson, president, CDC Microtron USA, Inc. “In particular, inkjet and this type of printing seems to be growing as formulation and inkjet application technology gets better.”
“The consolidation continues, and with excess equipment, we see a lot of spare parts and service work for the existing machines,” said Harry Way, technical director, Netzsch. “There is always a steady requirement for machines in the ink industry, replacing older machines with better technology.”

Hockmeyer Equipment’s Immersion Mill.
The decision to replace existing milling equipment with newer technology is not to be taken lightly. Customers have high expectations of their milling equipment. Cost and ease of operation are the top of the wish list.
“It is foremost the initial purchase price, followed by the safety of the equipment. Now we also see that customers care, more and more, about the quality and the operational cost of the equipment,” said Mr. Eisenring.
“Our customers are looking for the right equipment to do an efficient quality job. Easy and minimal maintenance, simple operation and reliability are often mentioned,” said Mr. Rissley.
“Customers are always looking for ease of operation, reduction in costs in all areas and maintaining or improving product quality,” Mr. Murphy said.
According to Mr. Peterson, customers are also looking for the ability to produce lightfast pigment dispersions and move away from dye-based inks which tend not to be waterfast or lightfast. “The use of pigmented inks gives longer color life to photo prints and printed materials,” he noted.
As fuel costs continue to rise, finding ways to increase energy efficiency is also important when purchasing milling equipment.
“We have seen interest in equipment that helps reduce production time, as our customers look to become more energy conscious and lower their operating costs,” said Cathy Strahan, marketing director for Myers Engineering. “We are also seeing interest in sophisticated control systems that automate the milling process.”
A definite bright spot for milling equipment manufacturers is the field of nanotechnology.

CDC Microtron USA’s Microtron bead mill.

Nanotechnology is an exciting area for nearly all industries,” said Mr. Way. “In fact, it seems that nanotechnology in the ink industry is not as much of a buzzword like other industries, possibly due to the fact that fineness of pigment dispersions for inks could already be classified as a nano pigment dispersion.”
“We see interest in nanotechnology frequently in a variety of markets,” said Mr. Murphy. “This is not new to our industry; however, the process gets more technical when the D-90 has to be below 200 nanometers. You need a more advanced media mill for running the smaller grinding media – .3mm, .2mm and .1 mm. You also need to run at higher tip speeds while keeping the media fluidized and maintaining product temperature.”
According to Mr. Eisenring, the company is seeing growth in digital nanotechnology, UV and printed electronics. “We have seen interest, especially since we have introduced the new MicroMedia line of bead mills, which are capable of using grinding media down to 20 µm,” he said.
“All ink jet systems have to be dispersed with particle sizes of less than 400 nm and typically in the 100-200 nm range,” said Mr. Peterson. “Being able to produce nano inks will result in superior properties in the electronic printing industry.”
Customer service and technical assistance are of paramount importance to a milling manufacturer.
According to Mr. Peterson, service is extremely important because most companies now only make products to order and stock levels are kept low. “Therefore, it is important for all machinery suppliers to be on top of their after sales service,” he added.

Buhler’s MicroMedia Mill.
Buhler also recognizes the need for superior customer service. “This is why we have added additionalpersonnel in the service area in 2007 and we will add more in 2008,” said Mr. Eisenring. “Buhler also has started years ago to relocate service technicians to the field so that we have service technicians available in different markets and locations around the U.S.”
“A mill company without good service will not be around long,” said Mr. Murphy. “Service is of the utmost importance before and after the sale. When we take an order from a customer, we are entering into a partnership. In most cases the media mill is the backbone of that specific process, meaning that if the mill goes down, production stops. So as a mill supplier, we have to be there for the customer by constantly checking up on the performance of their mill and making sure they are maintaining a spare parts inventory, ensuring a quick recovery should a failure occur. We as the mill supplier also maintain a spare parts inventory for all our mills, creating immediate availability. As a mill supplier, we also continually look for new ways to improve our customer’s processes through our own R&D department or using joint efforts. This keeps our customers informed of new technology as it becomes available allowing them the opportunity to improve their process. Because if we are not doing it, someone one else will.”

New Products in the Milling Industry

Milling equipment manufacturers are developing new products to help meet the needs of ink companies.
Buhler has a new line of recirculation mills, called MicroMedia Mills. The new mills are based on the traditional DCP platform, but with a new grinding chamber that allows high throughput rates with very fine grinding media, down to 20 µm.
CDC’s Microtron mill is specifically designed to produce nano particle dispersions and it is able to consistently use the smallest grinding media (0.1 mm diameter) available. It can produce dispersions of 50-200 nanometers with very high production rates. The resulting products are of the highest standard ensuring the most economical use of raw materials and power consumption is also very low. Due to the engineering design, the machine is virtually maintenance-free.
Netzsch has launched its PSI-Mix, whose guiding principle is that effective wetting of solid particles by high-quality dispersion improves quality and enables unmatched operation of the machine at high production rates.  The company also introduced its  Zeta RS, which offers significant energy savings while enabling gentle dispersion, even down to nanoparticle size. The Zeta RS has a patented design that creates uniform compression throughout the chamber’s length. The result is total utilization of the media charge and mill capacity for greater efficiency in particle size reduction. Netzsch also offers its Total System Solutions, the company’s full turn-key engineering offering.
On its HCP-II, Hockmeyer Equipment added a Rotec bearing to its standard mill design, giving the customer the option of adding either a single arm scraper for scraping the tank wall utilized with temperature sensitive or tacky products, or adding an anchor sweep with single helical blade for processing higher viscosity products that have poor flow characteristics, as the helical helps circulate the product from the bottom to the top of the tank.
Additionally, Mr. Murphy noted that customers have the option of adding an upper auger to the upper draft tube. This allows the processing of high viscosity products that were never able to be processed on a basket type milling system. The added auger acts as a pump, feeding the material into the mill. It is capable of processing material as high as 400,000 CPS. The auger  will force feed the mill yet it will never over-pressurize the mill. The auger will slip or cavitate within the upper draft tube allowing the product to pass through the mill at its own pace, without causing a high pressure shutdown. The auger also seals off the upper draft tube eliminating the concern or possibility of media escaping from the mill during operation.

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