Web Coating Blog

AIMCAL Fall Technical Conference October 2008

AIMCAL Fall Technical Conference
October 2008
Edward Cohen
The AIMCAL Fall Technical Meeting was help in October in Myrtle Beach,
NC. It provided a forum for the exchange of Information between
technical personnel in the web coating Industry. Technical papers were
presented in four sessions as follows:
• Environmental Responsiveness
• Web Coating & Laminating
• Vacuum Web Coating
• EmergingT echnologies
• Advances in Web Coating Technology
In addition there were table to exhibits, which also provide an
opportunity for additional technical discussions.

I found all of the presentations were useful and relevant to the technology of importance
to the Converting Industry. While the Coating process is sold, there is
still a a lrge amont of new technology that is being developed.

Wide ranges of topics were discussed, energy concerns, coating methods, slitting,
barrier layers, Coating hardware etc.

The following are the titles and a summary of some of the key
presentation. Details of the papers and contact information can be
found in the Conference Proceedings available from AIMCAL.

A Paradigm Shift In Knife Holder Slitting Technology
David Rumson
Sigmala, USA

Conventional slitting systems, consisting of mechanically
mounted and pneumatically activated knife holders (Mech/Pneu) have been
in existence for approximately 60 years. Although shear knife holder
and positioning systems have advanced during this time, there are some
basic operating requirements that remain limited in efficiency and
usefulness relative to today’s computer controlling capabilities. This
paper will present a basic overview of the physical operating
differences of Mech/Pneu holders and Servo Motor-Computer Controlled
holders (Serv/Com).

Application Of Surface Analysis For Root Cause Failure Analysis
David Cole
Evans Analytical Group

X-ray Photoelectron Spectroscopy (XPS) and Time-of-Flight Secondary
Ion Mass Spectrometry (TOF-SIMS) are valuable analytical techniques in
determining the rooot cause of failure in multilayer films.

Breaking Thru A Paradigm:New Technology For Coating And Laminating
Mike Budai
TW Dynatec

The purpose of this presentation is to break thru a paradigm in
laminating nonwovens, textiles, and composites. This paper will present is to
introduce the latest technologies in coating and laminating utilizing
hot melt polymers.

Reducing Changeover Time on a Coating Line,
Larry Gogolin
Gogolin & Associates

This paper will cover the steps to consider in establishing a reduction in the changeover time. It will look at planning, data collection, analysis and what to do with this
information.

Optimizing Mix Performance”
Ken McCarthy

This paper presents a discussion of mixing time and its importance to
coating operations.

Stay Ahead of Static Problems in Film Conveyance
Kelly Robinson,
Electrostatic Answers LLC

Demands for static control in film conveyance are increasing because
products are more complex and sensitive to static discharges. Four keys
to staying ahead of static problems in web conveyance are presented T
he implementation of these four recommendations for a typical coating
operation is presented.

Primerless Heat Seal Coatings for Film Substrates
Virginia Cushing &Robin Cooper
Michelman

This paper presents a single pass, aqueous heat seal coating which
exhibits excellent hot tack and a wider operating window as compared to
conventional heat seal coatings and common extruded sealants.

Increasing Energy Efficiency in the Web Coating Process
Edward Cohen, Dan Bemi Megtec

This paper focuses on reducing energy consumption, by modifying the
overall coating process and to utilizie renewable resources in their
production in order to remain competitive in this climate of rising
energy costs.

Intelligent Process Cooling: Saving Money, Protecting the
Environment
& Curing Process Headaches
Steven Petrakis
Frigel

Process cooling with ambient air, closed loop cooling systems can save
up to 25% on energy and water consumption in addition to eliminating chemical
evaporation and the disposal of contaminated waste water.

Nanoparticulate Barrier Films and Gas Permeation Measurement Techniques
for Thin Film Solar and Display Applications
Senthil Ramadas*, Shwe Zin Ma, Mark Auch, Chua Soo Jin
Institute of Materials Research and Engineering.

This paper presents innovative approach to resolving the ‘pore effect’
by literally plugging the defects in the barrier oxide films using
nanoparticles. The nanoparticles used in the barrier stack have a dual
function – not only sealing the defects but also reacts with moisture
and oxygen. The result is an achievement of moisture barrier
performance of better than 10-6g/m2/day that surpasses the ideal
requirements needed for flexible applications,

Response to the question on Alliance EC

Question:

I believe Alliance is no longer in business. Does anyone know if they sold-out to anyone? Is their lab coater still available somewhere?

Effective Networking, A Path Through The Information Overload

                        Effective Networking, A Path Through The Information Overload
                                            Edward Cohen

Even though we live on large planet, with large physical dimension (a Volume of 1.0832073_1012 km_ and a  Mass of 5.9736_1024 kg); technologies such as the Internet, Information Sciences, World Wide Web, rapid digital communications ,easily accessible databases and search engines have made it a very small world. It now possible to instantly communicate with persons all over the world and to obtain technical information from most countries, businesses and Universities.

WEB COATING AND DRYING PROCESS TECHNOLOGY

The AIMCAl  Converting School is sponsoring  a course on Web Coating and Drying Proces Technology. The detaieled course outline is below. For more information and to register, see www.AIMCAL.org

                    WEB COATING AND DRYING PROCESS TECHNOLOGY
                    Edward Cohen, Ph. D Edward Cohen Consulting, Inc.
                E. J. (Ted) Light foot, Ph. D Dupont Fluoroproducts

CEMA Coating & Laminating Fundamentals

AIMCAl & CEMA will be sponsoring a Seminar on Coating & Laminating. The schedule is below. For more information and to register go to
        www.AIMCAL.ORG

Response to Question on Laboratory Coater Vendors

Response to Question on Laboratory Coater Vendors
Edward Cohen

IN response the question on the web coating blog, about sources for laboratory coaters. There are several companies that specialize in laboratory coating machines. The contact information is listed below

The Role of Contract Coaters

Contract Coater, also called Toll Coaters, are a very important part of the converting industry.  They specialize in manufacturing web coated products for other companies and have a wide range of coating, drying process and slitting equipment and significant expertise in these areas. Their technical capabilities include:
    • mixing and filtration equipment and technologies 
    • availability  and expertise in a wide range of coating techniques,
    • drying technology
    • optimizing process for quality, high yield and low cost
    • specialized web coating testing capability and testing capability.

In terms of facilities they have process capability from pilot plant coaters to full-scale manufacturing.

There are several technical and economic reasons for companies and laboratories who are using or will need to produce web coated products to consider the use of contract coaters.

AIMCAL Fall Meeting Technical Sessions

The Annual AIMCAL Fall Technical Meeting was held from October 16-19. There were sessions on three general technical topics, Web Coating and Laminating, Vacuum Web Coating and Advances In Technology. In addition there were two short courses and a tabletop exhibit.

This BLOG entry will discuss the Web Coating and Laminating session and the Advances in Technology Session. The Coating & Laminating session had four general topics as follows:

    • Coating Operations
    • Coatings & Adhesives
    • Drying and Curing
    • Converting Management

Mayer Rod Coater

Mayer Rod Coater is one of the most popular coating methods. It is widely used in both the laboratory and in production coaters to coat a wide variety of products such as adhesives, window film coatings release papers, food packaging laminates, pressure sensitive tapes, fax papers. It is also one of the oldest coating methods. The first use was by Charles Mayer in 1905 and a patent was issued in 1912. It has been in continuous use since then. A Mayer rod coaters is referred by several names all, Mayer Bar, Meyer Bar, Meyer Rod, coating rods, equalizer bars, doctor rods. Although, Mayer rod is the most frequently used name.

The Mayer rod is a stainless steel rod that is wound tightly with stainless steel wire of varying diameter. The rod is used to doctor of the excess coating solution and control the coating weigh. A typical rod is shown in figure 1. The wet thickness after doctoring is controlled by the diameter of the wire used to wind the roll and is approximately .1 times the wire diameter. Rods are available in a wide variety of wire sizes to give a range of coating weights. Table 1 gives the wire sizes that are available and the wet thickness that can be achieved. The dry thickness is determined by the solids concentration of the coating solutions.

The longevity of Mayer rod coating is a result of several improvements in the technology of the rod. Improvements in the fabrication techniques have given improved precision.  Wet coating thickness can be controlled to .1 mils. Several rod types are available to improve precision and to widen the range of coating weight and viscosities that can be coated. Figure 2 shows some of the types that are available. The gapped rod can coat higher viscosities and increased thicknesses. In the threaded rod, the grooves are machined into the roll to eliminate gaps between wires. The smooth rod with no wires is used to smooth the coating after the wire wound rod.

Upgrading the Laboratory Coating Process

While ongoing improvements have been made in the coaters used in the manufacturing coating process, the laboratory coaters have been virtually unchanged for many decades. A rudimentary process is used in which, sheets are coated by applying a puddle of liquid which is then spread to give the desired using some form of doctoring device, wire wound rod blade, die or knife. The coatings are then moved and dried with ambient air in an oven or on the bench top. There are several disadvantages to this method. The coating quality and reproducibility are poor. The results are very sensitive to operator technique. The productivity is poor and the cost per coating is very high. In addition, this process does not relate to the final coating process and significant reformulation and optimization is needed to scale-up up to commercial process.