德國巴斯夫TPU V2821、 

TPU(1) the weight of finished product, must be below 70% in the feed pipe forming capacity, such as the need for a level beyond the machine, so the material of high hardness, high viscosity, hydraulic motors usually need to increase the level of the driving torque.

(2) the resistance of raw material to flow in the pipe is small and the loss of pressure is less. The feeding tube group 0. 03-0. 04mm plating, increase hardness and smooth small resistance force |.

(3) its fluidity is not as good as that of ABS. It must be shaped by increasing injection pressure and velocity, and prone to sag and internal bubbles.

(4) melt speed may slow down about 40%-50%, to increase the heat of fusion, between the melt with 70~90kg/cm2 gauge more appropriate, which can adjust the temperature of material.

(5) when the shrinkage or vacuum bubble occurs, other conditions can not be solved, adding back pressure can be solved between 5kg/cm2~20kg/cm2. If the back pressure is too high, it will cause overheating and difficult driving.

(6) if it stays in a heated material tube for too long, it will cause too much gas. Sometimes it will not drive easily because of the resistance of gas. It can use continuous injection and loosening to eliminate gas.

(7) if not finished flesh to shorten the cooling deformation, can be slowly cooling by soaking in warm water, and skin temperature difference is not too large, so can shrink vacuum bubble.

(8) when the finished product has residual stress, the strength of the finished product will be reduced when it is exposed to the solvent. In order to eliminate the internal stress, hot mold production can be used, and the injection pressure can be reduced if the material temperature is increased. If the compression is used, the internal stress hardly exists.

(9) if the finished product has been produced many times, in order not to be scrapped due to too high internal stress, annealing treatment can be carried out, which can relieve the tension of the outer surface and relieve the internal stress.

(10) second material recovery, in order to clean the best material for the pipe, set about 240 C.

(11) as in the low temperature after molding, material tube temperature a little higher than the screw does not produce sharp sound.

Processing technologya2