SURFACE TREATMENT, SIZING AND DRYING
CRITICAL FINAL STEPS OF CARBON FIBER PRODUCTION
During surface treatment, the surfaces of the fiber filaments are chemically etched through an electrolysis
process. Despatch’s surface treatment equipment provides consistent, uniform etching across all fiber filaments
and is designed to ensure that, post-etching, all electrolyte solution is efficiently and effectively removed
from the fiber prior to drying.
Contact drying takes place after surface treatment to reduce the moisture content on the fiber. Contact drying
involves weaving the fiber through a single series of stainless steel, heated rollers that apply direct, uniform
heat to the filaments for quick and efficient drying. Fiber exits the dryer with less than 1% moisture content.
Sizing is the final finishing process where fiber is passed through a liquid sizing solution that coats individual
fiber filaments and enables handling of the fiber without incurring filament damage. Despatch’s sizing equipment
is capable of processing various types of size fluid as required by the customer, and the equipment
provides an even distribution of size on the fiber. Recipes and fluid levels are conveniently controlled through
the PLC. Size fluid is continuously circulated via a pumped filtration system.
Non-contact drying takes place after sizing and is performed with a recirculation air dryer for complete drying
through uniform, low velocity airflow. This drying method maintains uniform amounts of size on the fiber
throughout the drying process. The temperature and airflow levels of the dryer are PLC controlled and the
dryer features a filtration system to capture debris.