First, we need to know what is iron on and sew on.
The back of the adhesive embroidery chapter is coated with a layer of hot melt adhesive. Under high temperature, the hot melt adhesive will melt. After cooling, the hot melt adhesive will solidify again to fuse the embroidery and the fabric. The bonded embroidery chapter , it is not easy to fall off under low temperature and normal washing.
For a completely secure patch, use a sewing machine or a needle and thread to secure the patch to the fabric. This greatly reduces the chances that the patch will fall off.