Technology
In order to construct a waterproof/airtight outer shell, the outer shell fabric need to be coated or laminated.
There are 4 different methods for making a waterproof seam.
High Frequency Welding
Localized High Frequency electromagnetic waves heat up the molecules exceeding its melting point. The melted molecules then be bonded between fabric surfaces. Also known as Radio Frequency welding.
Heat Sealing Welding
Hot tooling, with a shape that matches the welded joint geometry, is pressed over the fabric. Heat is transferred to melt the interface. The tooling is pressed until the welded joint cools and re-solidifies to create a permanent bond.
Ultra Sonic Welding
Ultra Sonic Acoustic vibrations are locally applied to fabric being held together under pressure to create a solid-state weld. Welded seam is reinforced by Heat Sealing for maximum strength and reliability.
Seam Taping
Fabrics are joined by sewing. The thread holes are sealed by an adhesive tape on the back side.