THIẾT TRÌNH THIẾT KẾ CHẾ TẠO KHUÔN MẪU ĐỦ 25 BÀI_13_EN

(Hot runner) Presentation: How to calculate, design hot channel system for computer mouse shell Mission Putting hot plastic into the cavity when hot plastic line comes out from presses and keeps the molten plastic in the channel system Hot asphalt supply system Technical requirement • Temperature distribution uniformity • Must minimize the potential loss of pressure • - Ability to control the status as a valve vents the heat (thermal): Structure • - Silver spray stem (sprue bushing) • - Funnel plastic distribution to the nozzle (Manifold) • - Nozzle (Nozzle) • - Oral Spray (Gate Bạc cuống phun (Sprue bushing) • If the temperature of this area is too low for sensitive materials at high temperature, the surface of the product is not quality So to heat the stem silver spray Here is a more detailed standards and large firms produce very good quality The silver-stemmed type spray in hot channel 1- Kênh dẫn Manifold • Manifold is used when spraying indirectly through multiple vents, manifold acts as a distributor of plastic sheet from the hot arm of the machine to the cavity Design Manifold good, not good Mold structure for Manifold - Firmly grip Plates containing nozzles (Nozzle cavity plate) must be made with niches containing Manifold and must have clearances of at least 10mm shell clamping bolts quanh.Cac Manifold must close as possible to ensure the grip The size of a Manifold important Size M: thickness of the manifold M1 Dimensions: width of manifold Size J2: the canal diameter plastic in the manifold Calculation of thermal expansion LR = LF (1 - α (TR - TF)) (mm) Inside: LR is the size of the manifold (mm) LF is the size of the manifold in the mold (size when expanded) (mm) TR is the manifold temperature (° C) TF is the temperature of the mold (° C) α is the coefficient of thermal expansion (1 / ° C) Nozzle) (1) Nozzle tip (2) Gaskets (3) Closing the valve (4) Heating equipment (5) Thermocouples (6) Body Nozzle • - Sprinklers are the most important details, difficult choices and fabrication of an HR system, it must meet several demanding • Nozzle is heated from inside or outside Heated nozzle in Heated nozzle OUT Nozzle type isolation Calculation of Nozzle length expansion • Actual length = L +? L of Nozzle + q • L: the length of the selected type Nozzle (mm) • ? L: is the thermal expansion value of Nozzle (mm) • q: the vent openings (mm) Giá trị ΔL xác định sau: ΔL= LF – LD = LD x α x (TR – TF) (mm) Gate Style vent valve Style vents vancore Kiểu ứng dụng để ép sản phẩm có dạng lỗ chi tiết bánh nhựa, chi tiết dạng ống,