The Milling Report

By David Savastano, Ink World Editor | 02.06.06

With the ink industry showing some growth in 2005, mill manufacturers have seen some improvement in terms of capital expenditures.

Capital expenditures is a key indicator of whether the ink industry is moving forward. From all accounts, 2005 was a mixed year for the ink industry. Sales were up slightly, but margins were impacted by higher raw material and energy costs.


Above, Premier Mill’s AP discs.

Below, Charles Ross & Son’s MegaShear Inline High Shear Mixer.
With the printing ink industry showing some growth in the past year, mill manufacturers saw improvement in terms of capital expenditures in the ink industry.

“We have experienced an increase in equipment sales for standard equipment as well as sales for our patented Axial Pin Disks,” said Stewart Rissley, national sales manager for Premier Mill Operation of SPX Process Equipment.

“Our unit sales were approximately double in 2005 compared to 2004,” said Christine Angos, application engineer at Charles Ross & Son.

The reason for increased expenditures are most likely two-fold. First, there are growth areas in ink, such as digital and UV, where companies are looking to make investments. Second, ink companies are looking at ways to become more efficient, and are concluding that new equipment will pay off in the long run.

“Certain segments of the market show improvement and have room for spending on new capital equipment,” said Kerstin Grosse, industry specialist for Buhler Inc., USA’s Grinding & Dispersing Division. “Also, traditional accounts seemed to ‘awake’ and have a need to optimize their production.”

“We have seen some significant investment in capital equipment from the ink industry in the past calender year, not only in North America but globally,” said Harry Way, technical director, Netzsch Fine Particle Technology, who added that China has also seen very strong growth. “We attributed this to not only an improving U.S. economy but fundamental programs to improve efficiency due to programs like Six Sigma.”

“There has been a lot of changes and movement in the ink industry over the past year,” said George J. Murphy, national sales manager for Hockmeyer Equipment Corp. “We have seen increased interest in upgrading older milling technology to more advanced, more productive and user friendly technology.”


Growth Areas

The ink industry has seen solid growth in a number of segments. For example, Korkmaz Oz, Draiswerke, Inc.’s sales engineer, noted that UV and ink jet inks have been particularly strong growth areas. Mr. Rissley said there has been growth in all ink segments in North America. Mr. Way has seen good growth in UV.

Ms. Grosse said that growth is occurring in the Midwest, East Coast and South, with ink jet, UV curable products and flexo showing the strongest growth. Ms. Angos pointed to growth in the Midwest and Northeast, with water- and solvent-based flexo inks used mostly for packaging, jet inks, UV and offset inks showing the most growth.

Mr. Murphy said he has seen growth opportunities throughout the ink industry.

“We here at Hockmeyer are seeing growth and activity in all geographical regions and segments of the ink industry,” Mr. Murphy said. “Ink manufacturers are searching for better and easier ways for manufacturing to produce the same or a better product, to be price competitive or to offer a superior product which demands better margins.”

Key Requirements

There are a number of areas that ink manufacturers are emphasizing when they are purchasing new mills, including process improvements, finer particle sizes and service.

“Process improvements and finer particle sizes are definitely trends we believe will continue,” Ms. Grosse said. “Our customers seems to appreciate complete packages that start with product development, process engineering and design, reliable, efficient equipment, after sales service and training on a global scale. We refer to that as the worry-free one-stop-shopping convenience for our customers so they can focus on their core competencies in a challenging market.”

“Customers are looking for process improvements and finer grinds,” Mr. Murphy said. “Mostly we see customers looking for process improvements that will keep them in front of their competition along with getting the most out of their pigments and offering a superior product. They are also looking for a equipment company that they can count on for service and support.”

“Customers are seeking a reduction in the time required to media mill a product, as well as higher production rates, process improvements, finer particle sizes, better results from high shear mixers, reduction of cycle time and to get away from milling through single pass equipment,” Ms. Angos said.

Mr. Oz said that customers are looking for finer particle sizes, down to nanometer range, easy cleaning for quick product changeover, and the ability to use the same mill for various formulations and viscosities.

Rebuilt Machinery Market

Considering the state of the ink industry, there remains a sizable market for rebuilt machinery. Ms. Grosse said that there is interest in rebuilt equipment, especially in markets where customers are looking to cautiously fill gaps in their existing production or where they need a solution fast.

Above, Draiswerke’s DCP Mill; below, Netzsch’s PSI-Mix.
Mr. Murphy noted that Hockmeyer has a used equipment division, which will buy back or trade in any used disperser, mixer or tank, rebuild it with original parts when available from the original manufacturer, and offer it for resale with warranties.

“Our stock of used equipment is constantly turning over with great success,” Mr. Murphy said. “In many cases it just makes sense to buy a used disperser or mixer. Buying a used mill is very risky if you are not buying it from the original manufacturer, and even then it could be risky and end up costing you a bundle. Replacement mill parts are not inexpensive, so by the time you rebuild one replacing the mechanical seal grind chamber and milling shaft, you are back up to the price of new, so you would be better of looking a new milling technology that offers you more. In my 20 years of servicing and selling grinding equipment, there are rarely good deals on used mills. There are some, but few.”

“Everyone would like to purchase a rebuilt machine to save money,” Mr. Rissley said. “The problem is a lack of machines to rebuild. Most companies are rebuilding what they have.”


New Products And Technologies

With the need for more efficient production and finer particle size in the forefront of the minds of ink companies, mill manufacturers have been hard at work to develop new technologies to meet these needs.

Draiswerke’s DCP technology sets new standards in wet grinding of high tech products down to nanometer range with no metal contamination.

In the newly developed multiple grinding zone of DCP mills, the product successively flows through multiple grinding zones where different grinding and dispersing principles prevail. Initially, the product is pre-dispersed in a pre-grinding/pre-dispersing zone. Subsequently, product and grinding media flow into the area of an intensive impact grinding, which results from the interaction of rotor and stator pegs. In the following inner rotor and inner stator section, the mixture of product and grinding media flow upward, where it is exposed to intensive turbulent and shear forces where further homogenization and polishing takes place.

DCP mills coated with special polymer compound or ceramics ensure zero metal contamination for applications where metal contamination is a major concern.

According to Draiswerke, DCP Technology offers high energy density milling, internal true-media recirculation and the most efficient grinding media/product separation by centrifugal force. High flow recirculation followed by shorter residence time provides high energy density milling even for mills coated with special polymer compound or cCeramics as there is minimum temperature build-up in the mill. Therefore, simple cooling on the premix tank for mixing the product prior to milling is mostly sufficient for processing temperature sensitive products. Low processing temperatures can easily be maintained in the DCP Mills.

SPX Process Equipment introduced the development of Premier Mill’s patented AP disc configuration, only available for Premier Horizontal Media Mills (existing and new). The higher media/product interaction and shear level obtained with this patented disc agitator system results in a significant and substantial increase in the rate and quality of product dispersion due to the more efficient acceleration of media.

Test data conducted in Premier Mill’s laboratory shows an increase in dispersion quality up to 300 percent of those achieved in fine media mills with conventional disc systems operated under identical process conditions. This newly developed and patented disc system will significantly increase products performance, efficiency and productivity. The application of this disc configuration is based on customer product characteristics and system configuration.

“Our patented Axial Pin Disks are giving improved quality and throughput in new mills as well as retrofitting older mills,” Mr. Rissley said.

Netzsch’s PSI-Mix achieves homogeneous, fine dispersions with a controlled process that ensures exact reproducible quality. The complete dispersion procedure occurs in an enclosed process chamber, preventing any dust and emissions. The wetting or dispersing process uses low shearing. The PSI-Mix was designed for both continuous dosing operation and operation with batch tank. The PSI-Mix can be integrated in a fully automated plant, and can process high-viscosity products.

“We think one of the most important improvements in milling is our introduction of the PSI-Mix premixing system,” Mr. Way said. “This system addresses improved pigment wetting during the premix stage and can increase milling efficiency by 20 percent or eliminate passes over a three roll mill, or eliminate pregrinding through a shot mill prior to three roll milling for paste inks. We have also recently introduced our Zeta RS system for using grinding beads as small as 50 microns in a low shear process for dispersing nanoparticles.”

Hockmeyer’s latest work on its Immersion Mill Technology has made the system capable of handling virtually any product or process.

“We have made many improvements to the Hockmeyer Immersion Mill,” Mr. Murphy said. “These changes offer a superior milling process never available before and unheard of. We can now offer ink manufacturers and just about any manufacturer doing grinding a dispersion a single machine that can process almost any viscosity material, that will disperse, mill and de-aerate utilizing one machine, one vessel with no pumps or hoses or delicate mechanical seals. We can also offer cascade milling in one machine by introducing a second mill with a smaller media than the first mill. There are many process configurations available that can improve and shorten process times and add money to the bottom line.”

Immersion Milling technology can offer the entire process in on machine, according to Hockmeyer. There are many configurations, making the system more versatile in larger batch sizes up 1,500 gallons. All of the configurations are available to customers in Hockmeyer’s R&D/ Customer Service Laboratory for product testing.

The Ross MegaShear Inline High Shear Mixer is the first High Shear Mixer to combine high flow rates up to 500 gpm without an auxiliary pump, high tip speeds up to 18,000 fpm, and ultra high shear rates, all in a single pass. The advantage of the MegaShear is its ability to disintegrate large particles and droplets in a single pass. By eliminating the need for inline recirculation, the mixer also delivers an important improvement in process control.

Unlike recirculation systems, in which passes through the rotor/stator were estimated statistically, the MegaShear operates with exactly one pass through the rotor/stator – a statistical certainty. With virtually 100% particle/droplet disintegration on the first pass, the MegaShear produces an exceptionally uniform particle/droplet size distribution, which is critically important for many fine emulsions and dispersions.

“We continue to showcase our high shear rotor/stator mixers where applicable, as they offer the greatest possibility of process improvement to our clients,” Ms. Angos said.

Ms. Grosse said that some of the technological improvements mills are utilizing included smaller grinding media, automated processes and parameter trending availability to avoid human errors and trace production records. She also noted that Buhler customizes mills to meet specific needs.

“Besides state-of-the-art equipment, we try to work out customized solutions,” Ms. Grosse said. “With our product and process expertise, we try to prepare the right set of equipment and services to make our customer’s production unique and most efficient.”

As ink companies continue to emphasize the importance of process improvements, mill manufacturers are developing new approaches to help their customers meet their goals.

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