In order to reduce the number of gates, each gate shall be located at where the melt is able to cover maximum part area based on the largest melt flow length/thickness ratio.
(A) (B)
W 1.5WD 1.2WD
2.5W
W
0.5W
肋的设计 (1 )
Rib Design ( 1 )
A
C t
B D E F
A t = wall thichness B = 0.5t C=3t D=2B E = 0.13 mm(radius) F = 1.5 - 2 deg
假如需要更大的强度,可增加肋的数目 假如需要更大的强度 可增加肋的数目 If more strength is required, add additional ribs.
电子零件置物箱 材料 Material:ABS 原始设计 Original Design
四浇口设计
4 Gate Design
电子零件置物箱 材料 Material:ABS 修正设计 Revised Design
电子零件置物箱四浇口 和十二浇口设计比较表
浇口数目 充填时间 (s) 最大射压 (MPa) 锁模力需求 (Ton) 产品重量 (g) 流道系统重量 (g) 原始设计 12 2 58.4 950 4136 294 修正设计 4 2 61.8 820 4136 98Leabharlann 如何快速平衡众多模穴之流道
How to Balance Flow In A Multi-cavity Mold Multi 首先调整一排支流道内之次支流道尺寸,使此支流道内 之各模穴可平衡充填. First, adjust runner size in one branch to make flow balanced in this branch. 再调整各支流道前段之尺寸,使各支流道可平衡充填. Then, adjust the first section's runner size in each branch to make flow balanced in all branches.
在型腔能够完满充填的前提下,浇口数目是愈少愈好.
As long as the cavity is able to be filled appropriately, gates are the less the better.
为了减少浇口数目,每一浇口应就塑流力所能及的流长/壁厚 比之内,找出可以涵盖最大产品面积的进浇位置.
Typical Filling System
竖浇道
Sprue
浇口
Gate
成品
Part
主流道
Main Runner
冷料井
Cold Slug Well
支流道
Branch Runner
壁厚不均
Non-uniform Wall Thickness
壁厚不均是注塑成型中最大的麻烦制造者. 这对薄壁 产品尤然. 这些麻烦包括了迟滞现象,短射,凹陷, 发赤,喷流,翘曲及长冷却时间等;目前都可用CAE 以直接或间接的方式预测.
18 gates pressure: 76 MPa
冷气通风饰罩冷气通风饰罩-修正设计
AirAir-conditioner Grille - Revised
8 gates pressure: 75 MPa
分析结果比较表
Comparison of Analysis Results
十二浇口设计
12 Gate Design
熔接线冷料井 Weld Slug Well
熔接线冷料井 [Weld slug well] 对头熔接线 [Butt weld]
积风
Air Traps
排气
Vent
A'
进料流道
Feed Runner
塑胶成品
Plastic Part
A C A'
排气孔
Vent
D
B SEC. A'-A'
大部份热塑性塑胶
Most Thermoplastics A 0.08 mm B 3.18 mm C 12.7 mm D 0.25 mm
浇注系统设计的优先顺序
Priorities of Filling System Design
产品设计 (Part Design) 型腔设计 (Cavity Design) 浇口设计 (Gate Design) 流道设计 (Runner Design) 喷嘴设计 (Nozzle Design)
典型的浇注系统
Reinforcement Tensile Strength Type Retention (%)
0%GF 20%GF 30%GF 0%GF 30%GF 0%GF 10%GF 30%GF 0%GF 30%GF 0%GF 10%GF 40%GF 0%GF 10%GF 30%GF 86% 47% 34% 80% 40% 99% 86% 64% 100% 62% 83% 38% 20% 83-100% 87-93% 56-64%
改进 [Improved]
气泡或/ 气泡或/和凹陷的形成
Void or/and Sink Mark Forming
气泡 ( Void )
凹陷 ( Sink Mark )
肋厚和内圆角半径的影响
The Effect of Rib Thickness & Fillet Radius
肋的底部厚度
Bottom Thickness of Rib
肋的设计 (2)
Rib Design ( 2 )
肋的设计 (3)
Rib Design ( 3 )
热塑性塑胶) 与侧壁相连之凸毂 (热塑性塑胶)
Boss at Wall ( Thermoplastics )
L H A'
A' E
K J D F A
I C B
G
A = 凸毂附著处壁厚 wall thickness B = 凸毂外环直径 dia. of boss over radii C = 0.5 A D =2B E = 1 ~ 2 deg F = 0.13 mm ( radius ) G =D H = 0.8 A I =A/4 J =2B K = 0.3 ~ 1 J L = 0.5 A
原设计 [Original] 更改设计 [Revised]
材料 [Material] : PC-GF50
典型对头熔接线伸张强度保留值
Typical Butt Weld Tensile Strength Retention Values
Material Type
PP PP PP SAN SAN PC PC PC PSF PSF PPS PPS PPS PA66 PA66 PA66
I
H G
E
F C B
F A
D
外侧凸毂
Outside Boss
A ( DIA )
A'
A'
B=A B= 2A ( max. )
B
Section A'-A'
Flexural Rigidity
1 r = M EI
挠曲刚性
Where 1/r : 梁的曲率 curvature of the beam M : 弯曲力矩 bending moment E : 弹性模数 modulus of elasticity I : 断面积对中立轴的惯性矩 moment of inertia of the cross- sectional area with respect to the neutral axis EI : 挠曲刚性 flexural rigidity
熔胶波前推进
MeltMelt-Front Advancement
充填模式,积风和熔接线
Filling Patterns, Air-Traps and Weld Lines Location
熔接线
Weld Lines
更改浇口位置以重新定位熔接线
Weld Lines Can Be Relocated By Changing Gate Location
壁厚设计
Wall Thickness Design
差 [Poor]
较好 [Better]
最好 [Best]
掏空设计 (1)
Coring Out Design (1)
原设计 [Original] 改进设计 [Improved]
掏空设计 (2)
Coring Out Design (2)
差 [Poor]
Non-uniform wall thickness is the biggest trouble maker in plastic injection molding. This is especially true to thinwall part. The troubles, including hesitation, short shot, sink mark, blush, jetting, warpage and long cooling time etc., can be predicted, directly or indirectly, by using CAE.
Section A'-A'
热塑性塑胶) 远离侧壁之凸毂 (热塑性塑胶)
Boss Away From Wall ( Thermoplastics )
A =凸毂附著处壁厚 凸毂附著处壁厚 wall thickness B =凸毂外环直径 凸毂外环直径 (含底部修整圆弧半径 含底部修整圆弧半径) 含底部修整圆弧半径 dia. of boss over radii C = 0.5 A D=2B E = 1 - 2 deg F = 0.13 mm ( radius ) G = 0.95 D H = 0.3 G min. to G max. I = 0.5 A