IV bags, otherwise known as medical fluid bags, have been in widespread use in the medical and healthcare field for a wide variety of applications. Uses can vary from collection and transfer of blood, collection of various fluids, and collection of urine, to the collection and transfer of diverse biological media. In all these different applications, an IV bag needs to be fully compliant to a number of strict regulations, including being tamper-free. They must also be recyclable and compliant with regulation standards for safe disposal of plastic materials. The following is a closer look at how IV bags are manufactured, and how they are sealed to meet federal regulations and those of the medical world in general.
Radio Frequency (RF) sealing
For many decades, RF sealing technology has been used in manufacturing IV bags designed for various applications in the medical sector. As the healthcare industry’s growth has kept pace with the global population’s growing health needs, there has been a great demand for medical bags produced using RF sealing. The origin date of this technology is debatable, however, it is estimated that it traces its origins to the mid-1940s.
At this time, some of the very first products manufactured using RF sealing began to surface in the consumer market, including plastic raincoats, 3-ring binders, assorted automotive products, swimming pool liners, to mention a few. Later, this technology began to be applied in the medical field to produce medical bags that were superior to all other alternatives on the market.
In the context of how RF sealing works, it is quite simple. Radio-frequency waves are employed to fuse together two or more layers of plastic materials, which are commonly PVC, polyurethane, Saran, or even EVA, to fashion containers or pressure devices. These products have numerous applications in the healthcare industry besides holding blood and IV fluids, including in chemotherapy, urology, enteral feeding of patients, laparoscopy, ileostomy, ostomy, and fluid filtering to name a few. Despite the fact that these medical products are extremely varied in their applications, the sealing method remains basically the same. Essentially, the RF sealing process works in much the same way food can be heated in a consumer microwave oven. One of the common characteristics of RF sealing technology and microwave oven technology is that not all plastic materials can be heated in either of these processes.
The RF sealing process
RF sealing technology uses radio waves that are conveyed through the layers of dielectric plastic materials. When this process is combined with pressure on the plastic materials, the various molecules that make up the material become fused together, once they turn into a molten state. The radio waves penetrating the materials causes the polarized molecules of the polymers to vibrate. In turn, this reaction triggers friction at the molecular level, culminating in considerable heat production. When sufficient energy is produced, the heat buildup transitions the plastic materials to a molten state, and as pressure continues to be exerted on them, the layers get fused together.
Once this has been accomplished, the RF energy source is then deactivated and for a short time, the tooling will hold the plastic sheets and cool them, still maintaining the pressure exerted on them.
The end result are seals that possess the same or greater strength as the original plastics materials. These seals are acclaimed for their consistency, uniform appearance, and measurement and are almost clear to the naked eye. A thin, raised exterior edge is then added to the die, creating a tear seal that the operator can then strip the exterior waste material from the edge of the seal. The end result is an RF sealed medical bag.
RF welding has major advantages over sewing and the use of adhesives to form a seal. RF welding creates an airtight seal and does not allow fluid out or debris into the container like a sewn seam. Using glue or adhesives to form the seam introduces new and sometimes hazardous chemicals into the medical product, and these seams can deteriorate or fail over time. RF welding creates an airtight seal, does not introduce any new materials, stays consistent over time, and is a cost-effective manufacturing process.