Controlling Static in Fiber Processing

Dr. Thomas W. Theyson

Goulston Technologies, Inc., Monroe, North Carolina

The issue of static generation and control continues to be a major issue at all levels of fiber and fabric manufacture.  Static is of particular concern in systems where there is a high level of friction contact and/or fiber to fiber movement in the process.  This, together with ever increasing processing speeds and higher process demands, continues to makes anti-static agents and static control a critical component of future fiber finish technology.

Static generation was observed and noted by the pre-Socratic philosophers and studied systematically as early as the 1700’s.  With the expansion of the synthetic fiber industry in the 1950’s and 1960’s, static control in fiber processing became a major issue.  Goulston Technologies and other fiber finish companies made major commitments to the development of testing capabilities for characterizing the generation and dissipation of static under a variety of typical textile processing conditions.  

In addition to testing capabilities, Goulston and other fiber finish companies made a commitment to the synthesis and development of static control agents (anti-static agents).  The development of the primary chemical technology of phosphate ester salts and quaternary salts was carried out in the 1950’s.  This was followed by 50 years of product design and improvement that provided the industry with a selection of highly functional anti-static products for use in a wide variety of fibers and applications.  These products were traditionally thought to function largely through their ability to provide fiber surface conductivity and thus, allow the conduction of generated static change to ground.  However, work in the 1990’s clearly demonstrated that the selection of an anti-static agent for a finish system also played a significant role in determining the amount of static charge generated during fiber processing.  This opened a new approach to controlling static, not just through enhancing conductivity and the rate of dissipation, but through formulation to control the amount of static generated in a process.

Goulston Technologies continues to carry out significant research programs in the area of agents for static control.  Recent developments include:

• Special additives that function to control static generation on spandex fibers
• Hygrophobic anti-static technology for non-wovens and wet lay fibers
• Durable antistatic systems for nylon based on special phosphate esters
• Melt additive anti-static packages for nylon and polypropylene

Goulston’s ongoing research and development programs will continue to provide innovative static control technology for the full range of modern fiber processing conditions.

Goulston also supports fundamental research in this critical area.  Over the last 20 years, the focus of deep research activities in this area of static generation and control in non-conducting materials has moved from fibers to technology driven applications.  Copiers and powder coating, both of which use static charge to place pigmented materials, are examples of areas where the control of static is critical to product performance.  Clean room and medical materials, along with electronics packaging films are areas where static reduction is a critical performance parameter.  Applications of this type, along with a limited amount of basic work on materials, have provided the basis for most of the recent significant developments in our understanding of static charge generation.   

In spite of these efforts to understand static electricity, its generation and control, and the work done in characterizing fiber based static electrical phenomena, there is still no systematic understanding of a range of critical static electricity related issues:

• The physics and surface chemistry of static generation on non-conducting polymers
• The impact of lubricating systems (fiber finishes) on the static generation process
• The often observed phenomena that finish composition and/or minor finish components can have a major impact on the static generation process
• The physics and surface chemistry of the static dissipation process, particularly in the context of fiber finish distribution and  fiber structure
• The mechanism by which humidity plays such an important role in static generation and control

Goulston has worked with the American Fiber Manufacturers Association’s (AFMA) Fiber Finishes and Surfaces Group and NC State University’s Textile Department to support the funding of a project designed to expand our understanding in this area.  The project is now underway and interested researchers from the fiber industry are encouraged to join in advising and support the program.  Interested parties can learn more by contacting Bob Barker at the AFMA (email address: rbarker@afma.org, 703-875-0432).