For over 40 years, our expert staff at Dal-Bac Manufacturing Co., Inc. has provided a full range of services, working with the industry’s most challenging and demanding applications to help our customers save costs and increase yields. In the project illustrated below, a client in the aerospace industry needed processing for a thin, clear, and expensive proprietary PTFE film. This film was to be utilized in a contamination free environment and required that no VOCs were to be emitted above a certain level. This requirement could not be fulfilled at film extrusion, and we were enlisted to cure the film so that it would achieve an acceptable level of emissions.

The curing process of this 0.009” film was relatively simple: raising the film to an elevated temperature for a period of time and allowing significant airflow to draw off the VOCs and discharge them. To accomplish this, the film was run roll-to-roll through one of our large convection ovens. This oven, typically used to cure wet coatings, isolated its heat source and air movement to the top side of the web, requiring the film to be run through twice—once for each side. While this process was successful in eliminating VOCs, the elevated temperatures made the film extremely difficult to work with. The film became very soft and malleable, making it stretch, rope, and wrinkle throughout the unwinding and rewinding process. This problem caused yields to be dramatically compromised. A solution needed to be found in order for this process to be a viable method of drawing off VOCs.

Our team of engineers found a solution that was at once simple, intuitive, and elegant. We employed an inert paper stock that measured slightly wider than the film. This paper was used to bear the pressure of the web tension; it remained stable under processing conditions and easily tracked during the unwind and the rewind procedure using edge guides. The film was fed onto the paper with its leading edge attached with conventional splicing tape, with the angle of the feed achieving a modest static bond that kept the film in contact throughout the airflow’s turbulence in the oven. After the first pass, the end of the film was attached to the opposite side of the paper, and the paper and film combination was fed through the oven a second time with identical processing parameters. Both passes resulted in a flat, wrinkle-free roll that supported the cured, relaxed film, which held all the properties the customer required. The condition of the film was dramatically improved, allowing our customer to significantly increase their yield.

In this project, we provided an innovative solution that surpassed our customer’s expectations, increasing yields while completely maintaining the quality and integrity of the film. This client was impressed with our results, and has returned to us for additional processing jobs. To learn more about this project, please see the table below or contact us directly.