For EVA sponge manufacturers, it is very important to pay close attention to the maturing and storage procedures of EVA sponge. For the production of polyurethane sponge, the maturing process of new sponge is the high occurrence period of fire accidents. Strictly control the measurement accuracy of each component, reduce the measurement error, and pay attention to the water quantity in the formula. If the production process parameters of EVA sponge are not adjusted properly, it will flood at the bottom of EVA sponge Start a small yellow coking line, because the internal temperature of the large sponge is high and the heat dissipation lasts for a long time, usually the time to reach the internal temperature is 30-60 minutes, and it can start to slowly decline within 3-4 hours or longer. In this period of time, the new foam has left the EVA sponge production line and entered the aging storage stage which is easy to be ignored. If there is no good monitoring measures, it will It is very easy to cause fire. In the production of continuous block EVA sponge, it is necessary to adjust the discharging speed of materials at the mixing head and the running speed of the conveyor belt to make them coordinate. It is necessary to avoid the undercurrent phenomenon that the materials that have not started to flow into the bottom of the starting materials due to the slow speed of the conveyor belt or the excessive discharging amount, so that the materials can not start to flow normally and collapse, and the collapsed materials are not easy to generate local "gas seed", so as to make the materials unable to start to flow normally and collapse Local heat accumulation increases the risk of scorch.

Adjust the formula and control the water consumption not to exceed 4.5 phr. If necessary, use low boiling point liquid compound auxiliary foaming agent to replace the Department water. In order to prevent the spontaneous combustion of EVA sponge, the sponge manufacturer shall store the newly foamed EVA sponge in a mature way, which shall not be more than 3 layers, and the spacing must be more than 1 meter, and it shall be placed separately. When EVA sponge is found to smoke or self ignite, water spray or fire extinguisher shall be used to put out the fire. It is not allowed to move EVA sponge or open the doors and windows at will to avoid the expansion of the fire caused by the increase of air flow. For the EVA sponge that may produce high temperature, the large EVA sponge should be cut horizontally (such as 20cm thickness) according to the needs to facilitate the heat dissipation of EVA sponge. The maturing storage section shall be equipped with full-time staff to strengthen monitoring, such as measuring the internal temperature of EVA sponge every 15 minutes, monitoring time shall be at least 12 hours, or even longer, and then normal storage. The highest temperature rise safety point of high density EVA sponge is 160 ℃, but not more than 170 ℃.

It is necessary to avoid the deformation of EVA sponge under external compression. The reason is that when EVA sponge is not fully matured, the external compression will affect the sponge network and sponge structure. At the same time, it is also to avoid the heat accumulation caused by compression and increase the risk of spontaneous combustion of EVA sponge. Especially in the most sensitive stage of EVA sponge's rising response, any misoperation code and vibration, such as the jerky movement caused by the too tight conveyor chain, the too much folded separator paper and the bumpy conveyor belt, will cause the mature EVA sponge to compress and burn. It has been reported that when using polyether polyol with molecular weight of 5000, 4.7 phr of water, 8 phr of F-11 and isocyanate with TDI of 1.07 to produce EVA sponge with density of 22kg / m3, a small amount of light yellow smoke was found after EVA processing for 2 hours, and the surface temperature of EVA sponge was not high, but the inside of EVA sponge was in a very dangerous initial stage of decomposition, and the temperature was about 200 ~ 250 ℃, and it began to self ignite.