What are the factors influencing the bonding strength of the welded type extruded profiles during the production process?

What are the factors influencing the bonding strength of the welded type extruded profiles during the production process?

②)Preheating temperature and uniformity of the main profile. If the hot air duct is too wide and the gap is too large during preheating, the air in the hot air duct cannot be further heated before being blown onto the base profile extrusion, resulting in poor hot melt effect of the profile and poor bonding effect between the post-co-extruded material and the base profile extrusion. If the hot air duct is too narrow and the gap is too small, although the hot air temperature is sufficient, the wind speed is too low, and the heating and melting of the main profile are not sufficient, the bonding effect between the post-co-extruded material and the base profile extrusion is also poor. In severe cases, it may even cause the heating fan to overheat and burn out; 

③)Post-co-extrusion process. The process temperature and die head pressure of the production line have a significant impact on the production of welded post-co-extruded products. If the die head temperature is too low, the surface gloss of the soft material is poor, and plasticization deficiency and incomplete material mixing are prone to occur, resulting in material burning in the flow channel and poor continuity of the material output from the die head. If the die head pressure is too low, the bonding between the post-co-extruded material and the main material is poor.