Products frangible large part is due to the stress caused. Many causes brittle hair products, are:
Equipment:
(1) barrel are dead or obstacles, easy to promote melt degradation.
(2) machine plasticizing capacity is too small, plastic barrel in plastics is not sufficient; too much capacity plastics machinery, plastic barrel by the shear heat and time is too long, plastic easy to aging, so that products become crisp.
(3) the top of the device is tilted or unbalanced, dry top small cross-sectional area or improperly distributed.

Molds:
(1) gate is too small, you should consider adjusting the gate size or the addition of auxiliary gate.
(2) shunt is too small or improperly configured, a reasonable balance should be arranged or increased shunt size.
(3) mold caused by poor molding cycle unusual structure.

Technological aspects:
(1) barrel, nozzle temperature is too low, raise it. If the material is easily degradable, it should raise the barrel, nozzle temperatures.
(2) reduce the pre-plastic screw back pressure and speed, so that the material slightly loose and reduce degradation of plastic due to overheating caused by shear. (3) The mold temperature is too high, stripping difficulties; mold temperature is too low, plastic premature cooling, poor weld fusion, easy to crack, especially high-melting plastics such as polycarbonate even more so.
(4) cavity core have appropriate stripping slope. When stripping the core difficult to raise the temperature of the cavity, shorten the cooling time; when the cavity impunity, to reduce the cavity temperature, prolonged cooling time.
(5) minimize the use of metal inserts, such as Polystyrene hematocrit cold brittle plastic, but can not join the insert molding.

Raw materials:
(1) raw materials mixed with other impurities or doped with inappropriate or excessive solvent or other additives.
(2) Some plastics such as ABS, etc., in the damp heat condition can occur with moisture catalytic cracking reaction, the occurrence of large parts of the strain.
(3) plastic recycling too many times or recycled materials content is too high, or in the machine barrel heating time is too long, can cause brittle parts. (4) The plastic itself is poor quality, such as molecular weight distribution of a large, non-uniform structure containing ingredients rigid molecular chain possession excessive; or contaminated, poor additive pollution, dust and other plastic doping impurity contamination is caused by brittle the reason.

Product design:
(1) products with sharp corners prone to stress cracking, or the thickness of the gap very different parts. (2) product design too thin or too hollow.