Cause one: after the die is heated and before feeding, the die bolts must be retightened. Heating expands the die and can create small gaps between die parts, causing material leakage.

　　Cause two: after feeding, if the die body leaks, check the relevant parts of the die body for sand holes.

　　If material leakage occurs on the insulated pipe production line during production, check whether the outer heating ring and inner heating ring of the die are heating normally. If they are damaged, the die body temperature is too low, extrusion pressure increases, causing die leakage; in severe cases the die may be damaged, causing major losses. Front-line production personnel should attach great importance to this.