Yoga, has become more and more people's fitness preferred project, for the women in the city of white-collar workers, the choice of yoga mats and the choice of sports items, high quality is the best choice, now on the market yoga mat Variety, it is easy to make people pick the eye, a lot of yoga beginners to buy yoga mats, will ask such a sentence, what kind of yoga mat is better, what material to do.
Now on the market yoga mat material mainly PVC, TPE, EVA, NBR, etc., there are saying cloud: the so-called TPE foam on the market are also EVA foam pad, or part of the TPE + part of the EVA foam , No matter how kind of material is that we often met in the selection process, no matter how the salesman said hype, a good yoga mat should meet the following two requirements:
1, because the yoga mat is in direct contact with the practitioner's body skin, itself is a chemical, is absolutely not toxic and tasteful. Toxic and taste of the mat because it has not been non-toxic and tasteless treatment, just opened when the smell is great, smoked people eyes, after a long time to scrub the water or on the dry place flat about 20 days or so the smell will be smaller, but uncomfortable smell forever There will be, practitioners after a long period of time there will be intermittent dizziness, neurological headache, nausea and fatigue and other adverse reactions.
2, good yoga mats require moderate weight material, mat long shop is not easy to deformation.
PVC foam system is composed of PVC resin, stabilizer, lubricant, modifier, foaming agent and other components, the material mixed evenly by the hopper quantitative by adding the groove, by the screw power forward, barrel heating The action and the shearing action of the screw make the material plasticized and melted, and the foaming agent is decomposed at this temperature to produce gas which is dissolved in the melt. The cross-sectional area of the cavity from the groove to the mouth is gradually reduced, so that a certain back pressure is formed under the action of the screw, so that the gas produced by the decomposition of the foaming agent can remain in the melt to form many foamed foams. When the melt away from the die, the external pressure suddenly reduced, the rapid expansion of dissolved gas to form bubbles, resulting in foam products. At present the plastic industry generally use AC (azodicarbonamide) foaming agent. AC foaming agent is organic foaming agent, light yellow or orange crystalline powder,PVC Yoga Mat decomposition temperature of about 180 ~ 200 ℃, slightly ammonia decomposition, non-flammable, self-extinguishing, stable storage at room temperature, non-toxic. The biggest advantage for the unit mass of the amount of gas, decomposition of the release of gas and decomposition of non-toxic, harmless, and the melt compatibility. The main factors that affect the foaming performance of AC foaming agent in the material are the decomposition temperature and the amount of Ac foaming agent. In the PVC extrusion process, the decomposition temperature of AC is between PVC plasticization temperature and decomposition temperature (140-180 ℃). Decomposition temperature is too low, premature release of gas and foam, difficult to control; decomposition temperature is too high, deflated difficulties, need to add the right amount of activator to be adjusted.
The amount of foaming agent has the greatest influence on the foaming quality. The amount is too large, foaming products, large cell, uniformity decreases, the mechanical properties of products decreased;PVC Yoga Mat dosage is too small, the foam effect is not obvious. Experiments show that with the increase in the amount of AC blowing agent, the amount of gas increased, the product density decreased. When the AC amount at a certain value, PVC products, low density, and the surface is smooth but with the amount of AC continues to increase, the apparent quality of products decreased, other performance is also affected.