Research On Several Key Problems In The Production Process Of Gymnastics Leather

Gymnastics palm products take an important part in gymnastic and it is the protective sports equipment all over the world.However,China has not developed an authority production process for producing gymnastics palm materials.The properties of gymnastics palm products in domestic are unsatisfactory and can only be used for the amateur training of unprofessional athletes.The gymnastics palm products used by professional gymnasts rely on imports.This paper expounds the characteristics of the gymnastics leather including mechanical properties,appearance color and comfort feeling.Owing to the requirements of safety,the gymnastics palms should have very high tensile strength and low elongation.Meantime's,the color of the gymnastics palm should be lighter thereby the appearance will be better;Taking into account long time using of athletes during competition training,gymnastics palms should be comfortable as much as possible.Based on these requirements,leather is considered as a good choice,with the irreplaceable advantages as a bio-natural materials.In this research,the leather-forming characteristics are firstly analyzed,and cattle hide is selected for producing gymnastics leather.In beam-house operations,the soaking process was firstly investigated and it showed that the optimal soaking time should be controlled at 20 h.In unhairing-liming process,the condition influence was studied.It was found that the optimal lime dosage was 4.0%with 24 h,and the ideal unhairing-liming effect can be achieved.In the deliming process,the organic acid deliming agent should be applied which provided excellent deliming effect and the decalcification rate was high.In the pickling process,it presented that application of moderate amount of sulfuric acid dispersed the collagen moderately,which is beneficial to mechanical strength of leather.In the tanning and wet finishing operations,the modified aldehyde tanning agent is suitable for gymnastics leather production.It should be mentioned that,the softness and extensibility of gymnastic leather are incompatible.In fatliquoring process,the anionic fatliquor and the amphoteric fatliquor should be used compositely.In drying,vacuum drying and toggling drying were combined and it will be more effectively.Through these operations,the final tensile strength of the gymnastic leather reached 34.16MPa,while the elongation rate was 45.74%.The finished leather color was white,with excellent hand-feeling,which meet the requirements of gymnastics palm material.In order to analysis the safety of gymnastic leather,some physical and chemical parameters were measured.The results showed that the hexavalent chromium and formaldehyde residues in the gymnastics leather accorded with the national standard.Therefore,this production process can meet the chemical and physical requirements of the gymnastics palm,while the gymnastics leather possess excellent safety.