Screw is an important part of injecφ♠δtion molding machine. Its function is to tra∞γ¥nsport, melt, compact, mi♠<∑∏x and press plastic. ≠•€All these are completed by the rotatio→♣n of the screw in the barrel, which showλ↕€s that the screw plays an important role i₽σ×€n the plastic machinery.

When the screw rotates, the plastα↑§ic will produce friction and≠←π  mutual movement on the inner wall o§λf the barrel, the bottom sur★​ face of the screw groove, the advancing surface o₽γf the screw edge and between the plastic and ←​£the plastic. The forwar  αd movement of plastics is ≠↕the result of this combination of δ÷'←movements, and the heat generated by®→ friction is also absor¥≥bed to raise the temp₹₹erature of plastics and melt them. The structure λγ↔←of the screw will direc &$tly affect the degree of these effeαπε×cts.

At the same time, the rotation of tπ β‌he screw makes the film between the solid bed and δ the inner wall of th™€e barrel shear, so that the solid between th≈★e film and the solid bed interface melts.§¥ As the spiral shape of the solid bed ≤σ∏moves forward, the volume of the solid b€∑©ed decreases gradually, while the volume of✔₩• the molten pool increases gradually.

If the decrease speed of the soli÷✘β d bed thickness is lower than that of the sha ®llow depth of the spiral groove, the ✔αsolid bed may partially or completely block the §₹spiral groove and cause the plast★α$βicization to fluctuate, or because of the loca♠£l pressure, the melting speed, the±♠β melt viscosity, the melting temperature rang↓↕e, the sensitivity of the viscosi•↔→₩ty to the temperature and shear rate,>↕₹Ω the corrosiveness of the hig&㮧h temperature decomposition gas, and the γ♦≥friction system between theβγ↔ plastic particles There is a great dif>₽‌ference in the number. Generally speaki≈​♦‍ng, the phenomenon of high sh✘Ω≈∞ear heat will appear when the generγ₽al screw processes some pl↕∑‌astics with outstanding melt characteristics. Th¥☆ is phenomenon can be eliminated by reducing the★•÷ screw speed, but it will inevitably af∞↕>≤fect the production efficiency.