Abstract:

Objective The objective of this research is to develop far-infrared functional medical bandage products with excellent thermogenic effect. The functional bandage is expected to provide temperature to the wound surface hence accelerating the blood circulation of the skin around the wound surface, and make the blood vessels of the local skin dilate thus playing an anti-inflammatory and pain-relieving role and promoting the healing of the wound surface.

Method Based on the principle of far-infrared thermogenic radiation, tourmaline powder was selected as far-infrared thermogenic material. The best dispersion process of the carbide powder with sodium carboxylmethyl cellulose, sodium polyphosphate, sodium dodecylbenzene sulfonate were developed. The patterned bandage was prepared by patterned coating on polyester medical bandage, and the patterns include dotted, linear and radial configurations for the thermogenic bandage. Firstly, the optimal dispersion process of tourmaline powder was investigated by with settling time, settling height, average particle size and degree of polydispersity as indicators. Temperature rising of different patterned thermogenic bandages was evaluated by radiation temperature rise method, and the physical properties were compared with untreated bandage and fully coated bandage respectively.

Results When sodium carboxymethyl cellulose was used as dispersant with mass fraction being 1.0%, the tourmaline suspension has the best stability, the particles are more uniformly distributed and the dispersion effect was the best. The results of settling time, settling height, average particle size and polydispersity index of tourmaline dispersion with different dispersants and dispersant dosages were discussed. After 10 min of irradiation by infrared lamp, the surface temperature of pattern-coated bandages were higher than that of the untreated bandages, among which the temperature rise of the radial and strip coated bandages were 3.5 ℃ and 3.3 ℃, respectively. The temperature rise of dot coated bandage was 2.3 ℃, the temperature rise curves of the three pattern-coated bandages indicated that the tourmaline powder exert an excellent far-infrared thermogenic effect after the pattern-coating treatment on the bandage surface. Compared with the untreated bandage, the breaking strength, elongation at break and top breaking strength of the pattern-coated bandages increased, and the moisture permeability slightly improved. The air permeability was decreased, but still remained between 280-300 mm/s. The bending length and bending stiffness of the pattern-coated bandages was increased, but compared with the fully coated bandage, the softness of the bandage is significantly improved after the pattern-coating treatment, ensuring the comfort of the thermogenic bandage in the process of application.

Conclusion Tourmaline powder with 1.0% sodium carboxymethyl cellulose dispersion demonstrates the best and most stable dispersion effect, with uniform particle size, suitable for creating far-infrared functional finishing solution. Due to the excellent far-infrared radiation characteristics, the pattern-coated bandage containing tourmaline powder shows an excellent thermogenic effect, the thermogenic effect of different patterns of bandage varies. The combination of tourmaline and bandage with pattern-coating process can provide the bandage with far-infrared thermogenic function while ensuring the comfort of the bandage with good thermal effect. This work proved the feasibility of preparing thermogenic bandages by patterned coating process, thus providing a theoretical basis and practical foundation for the further exploration and production of clinically usable thermogenic bandages.

Key words: medical bandage, thermogenic bandage, pattern-coating process, tourmaline, far-infrared thermogenic, medical textile