A. Mixing process
Insufficient mixing time, high or low discharge temperature; simultaneous addition of acidic and basic compounding agents (such as stearic acid and scorch retarder ESEN with zinc oxide and magnesium oxide); insufficient mastication; compounding agent addition Inappropriate order; fillers are added too late in the mixing cycle; small particle size carbon black and resin or viscous oil are added simultaneously; metal oxides have not had enough time to disperse; liquid accelerators are added after the compound has torn or broken agent; batch size is too large or too small

B. Craft
The compounding procedure established was not followed; agglomerates of oily and dry materials stuck to the top pin and hopper sides; improper rotor speed; compound was unloaded from the tablet press too quickly; pressing was not applied correctly Glue turning device on tablet machine

C. Equipment
Internal mixer temperature control failure; insufficient pressure on the top bolt; wear transition of the welding layer in the mixing chamber; failure of the roll temperature control of the tablet press; failure of the overhead rubber turning device on the tablet press

D. Material
Expired and partially gelled rubber; EPDM or butyl rubber too cold; frozen natural rubber; insufficient pre-mastication of natural rubber; excess moisture in fillers (clumping); viscosity added at temperatures below pour point Compounding agent; Compounding agent used inappropriately

E. Recipe design
The Mooney viscosity of the elastomer used is too different; the selection of plasticizer and rubber is not appropriate; too much hard particle compounding agent; too much filler with small particle size; resin with too high melting point; insufficient liquid plasticizer; filler and Excessive plasticizer