How Gel Filled Products are Made for the Medical Industry

There are many types of liquid and gel filled products on the market designed to provide protection, pain relief, impact resistance, and hot and cold compression to the body.

Most of these products are made by safely encapsulating silicon or silicate gel with flexible vinyl or coated fabric materials that can protect the skin. The outer material used for gel products require a high tensile strength that will not rip or break apart, and can withstand the pressure and compression of the gel inside.

Many liquid or gel filled products would not be safe if it wasn’t for radio frequency (RF) welding being used to seal the edges of the product with strong, impervious leak proof seams. Radio frequency welding is a manufacturing process that uses electromagnetic energy to temporarily soften the material, and pressure to fuse the material at the seam. The welded seam is strong enough to prevent ripping, punctures and bursting.

gel pack
Radio Frequency Welding is used to seal gel filled products.

Liquid & gel filled products are used for patient care

Flexible products that require liquid or gel filling are widely used in the medical industry because they conform easily to the contours of the body and can maintain a temperature consistency that benefits the patient. Some gel filled therapy pads and therapy wraps can be used for hot or cold applications on the body. Since gel temperatures can fluctuate, it is critical that the welded seams can withstand these hot and cold variations without causing degradation to the shell material or the seams. There is no need for chemicals or bonding glue to contain the gel because RF welded seams consists of the original material only, making it stronger, more pliable, and softer to the touch.

How are liquid & gel filled products made?

Flexible containment products that require a liquid or gel filling need tooling dies to create the design, shape, and functionality of the product. The tooling die is used to hold the material in place while the fluid is added. When the complete tooling die set is combined, the fluid is inserted and then the rf welding takes place, sealing the seams for containment in one motion. The result is a uniform welded seam that is formed to the shape of the product with the gel contained inside.


Tooling dies are used to create form & functionality

The use of tooling dies is necessary not only for the shape of the product, but also for the functionality that is required of the product. Section chambers, inlet tubes and portal hoses can also be RF welded to the material. These multi-purpose products of containing or removing liquids rely even more on the strong and flexible seals to provide secure, leak free seams that can withstand pressure changes. Tooling dies can be expensive to make, but if made properly, can be reused for many manufacturing runs of the same product. It is recommended to create a prototype of a gel or liquid filled product with inexpensive temporary tooling dies that are made for this purpose. After the product has been successfully tested for its function in the environment it is intended, an all metal tooling die would be required so that the die can withstand repeated use in high volume production runs.

gel containment
Containing liquids requires strong, RF welded seams.

Clean seams that won’t leak is the reason RF welding is used to make gel filled products

Radio Frequency Welding bonds two or more pieces of like materials together without any additional bonding agents. This is an important attribute to the medical industry because the rf welding process does not create pockets or gathered areas that can collect bacteria and microbes. RF welding is a clean sealing process that fuses the material only, and because of this, there is less likelihood of contamination, which is exactly why the medical industry relies on radio frequency welding for the fabrication of the many products used for patient care.

To find out more about creating a gel or liquid filled product using radio frequency welding, call SealWerks and talk to an expert!