• WEB CONVERTING SYSTEMS

          Custom Coating and Laminating Equipment Line

          Coating, Laminating and Embossing Systems for a wide range of Industries and Products

          Learn More

          UNWINDS

          Turret Unwind Equipment

          Unwind Systems with Automatic Tension Control, Guiding and a Range of Chucking Options

          Learn More

          WINDERS

          Turret Winder with Zero Fold-over transfer mechanism (carousel winder)

          Winding Systems with Automatic Tension Control, Guiding and a Range of Chucking Options

          Learn More

          COATERS

          Modular, Cartridge Style Gravure and Offset Gravure Coating Station

          A Variety of Hot Melt, Water & Solvent Based Web Coating Station options for both Dedicated Coating or Modular Systems

          Learn More

          LAMINATORS, EMBOSSERS, AND CALENDERS

          Calender Station with Roll Bending

          High and Low Pressure Nip Sets for Combining or Calipering a Range of Materials

          Learn More

          WEB HANDLING EQUIPMENT

          Web Cooling Roll Station

          Web Conveyance Equipment Including Pull Rolls, Heating & Cooling Stands, Flips and Turns

          Learn More

          ROLL HANDLING EQUIPMENT

          Custom Roll Handling Carts for Unwinds and Winder

          Custom Roll Handling Equipment for Unwind and Rewind Equipment

          Learn More

          NARROW WEB

          Narrow web battery coating & drying line

          Narrow web Coating, Laminating & Embossing Equipment for Pilot Scale or Production Environments

          Learn More

          DRIVE & CONTROL SYSTEMS

          Allen-Bradley Multi-Bay Drive Panel

          Drive & PLC Cabinets, HMI’s, SCADA Systems and more

          Learn More

          CLEANROOM EQUIPMENT

          Cleanroom Coating, Laminating and Embossing Line

          Cleanroom Coating, Laminating and Embossing Systems and Components

          Learn More

          DRYERS & APPARATUS UNITS

          Four Zone, Electrically Heated Air Floatation Dryer

          Fully Integrated Web Drying Systems for a variety of Web Coating Applications

          Learn More

          SPECIALTY

          Solution Pumping and Mixing System

          Specialty Equipment and Ancillary Systems for Web Handling and Converting Systems

          Learn More

          EQUIPMENT BROCHURES – PDF

          Downloadable Brochures in PDF Format Learn More
  • Facilities
  • Services
  • Technology
  • News
  • Contact
News

Advancements in Wax Coating: Thinner, Faster – Part 1 of 3

The following is part one of a series of 3 blogs that will go through a white paper written by New Era Converting Machinery’s Bob Pasquale. The white paper is titled “Advancements in Wax Coating – Thinner, Faster.”

Part 1 will offer an overview of the entire paper and what to expect in coming blogs, as well as some brief background on wax coating and typical operating speeds and coating weights. Part 2 will go through improvements that have been made in roll and web handling, closed loop moisture control, and pre- and post-heating and cooling. Part 3 will wrap the series up with an explanation of recent drives and controls, coating application methods and design, and a brief conclusion.

—–

Part 1: Abstract and Background

ABSTRACT:

Over the past few years there has been a concerted effort by converters to reduce the cost of wax coated paper by applying thinner coatings at higher line speeds with better quality. This paper will explore the changes and improvements in equipment design that are being utilized to help achieve these goals, focusing on both wet and dry single-sided coating. We will cover changes and improvements being made in the equipment used in the application of coatings, namely the coating head, which allows for the thinner laydowns and higher speeds. Improvements in web treatment including removal of excess moisture prior to coating, pre-heating of the web (dry waxing) and post-heating (dry waxing)/cooling will be covered. We will also address the improvements in drives and control systems and how they are being applied to this goal. Additionally, we will cover improvements in paper roll and web handling as they relate to increasing speeds.

BACKGROUND:

Wax coating of papers is a technology that has existed for many years. While this paper will focus on single-sided wax coating, much of what is discussed will also apply to two sided wax coatings.

Wax coating is typically divided into two categories, “wet” wax coating and “dry” wax coating. In “wet” wax coating the goal is to have the coating remain on the surface of the paper with as little penetration into the web as possible. These papers feature a smooth, high-gloss finish and are typically used on products where release is important (e.g. candy wrappers, soap liner paper). Waxes used for “wet” waxing tend to be applied at higher viscosities and lower temperatures. Successful “wet” waxing requires the substrate to be kept at or below room temperature, the hot wax to be applied at temperatures as close to the melting point as possible and the rapid cooling of the product after application of the wax.

In “dry” wax coating the desire is to have the coating penetrate or saturate the paper, leaving a matte finish (e.g. meat wrapping paper, drinking cups). The ability to successfully “dry” wax coat is aided by pre-heating of the web, applying the wax at elevated temperatures, post-heating the web (after coating application) and a slower cooling cycle.

TYPICAL OPERATING SPEEDS:

Through the years improvements in the design and control of wax coating machines have allowed for increases in the speed of the coating operation. The table below shows the typical maximum operating speed for such systems at various times:

TABLE 1 – MAXIMUM OPERATING SPEED

YEAR MAXIMUM OPERATING SPEED
1970 1000 FPM (300 MPM)
1984 2000 FPM (600 MPM)
2010 3000 FPM (900 MPM)

We will explore the changes and improvements that have allowed for this increase in speed.

TYPICAL COATING WEIGHTS

In addition to increases in the speed of the coating system, advancements in equipment and system design, in conjunction with changes in the coatings’ properties, have allowed for a decrease in the required coating application. The table below shows the typical minimum coating weight for such systems at various times:

TABLE 2 – MINIMUM COATING WEIGHT

YEAR MINIMUM COAT WEIGHT
1984 1.84 #/REAM (3 GSM)
2010 0.75 #/REAM (1.22 GSM)

We will explore the changes and improvements made that have allowed for this decrease in coating weight as well.

###

*Continue to part 2, or skip to the final blog in the series!*