high speed injection ,thin wall
Thin-wall injection molding to injection molding machines, molds, plastic to a requirement. Seminar on the features, benefits and equipment for thin-walled design.
In addition to wall thickness outside, processes, can be impact injection molded plastic viscosity and thermal conductivity of thin-walled.
Thin-wall injection molding requires remaining between mold wall before the runner has not cured fill the mold cavity, high injection speeds involved, such as 300-600 mm/s. Injection time are under 0.2 km/s.
The nitrogen bottle can provide power for high-speed injection. Shoot low inertia, machine frames and moulding, injection oil higher rigidity of servo valve to be installed to implement closed-loop control, computer react faster, higher plasticizing capacity in order to meet the requirements of thin-wall injection molding.
Period should be short, value for money. High clamping speed and tooling sides of ejection is necessary.
high speed injection mold
Templates for die steel higher cavity and core to be able to lock, lower relative movement.
Higher melt index of plastic, add a lubricant to increase liquidity.
Sprue to the finished product the farthest point from the mold the process l, divided by the product of the wall thickness t, called the process/thickness ratio. When L/t>150 is called thin-walled. Such as the density of the flow is inconsistent, can be calculated as indicated in Figure 1.
Figure 1 flow viscosity coefficient of PP/wall thickness ratio is 1. A process 135mm of disposable food containers, wall thickness of 0.45mm, process/thickness ratio = 300. PC 2 is the coefficient of viscosity. Cell phone battery casing process 38mm,t=0.25mm, process/thickness ratio = 152. Multiplied by coefficient of viscosity is 304, comparable with the boxes.
Why the thin-wall injection molding? Plastic costs usually account for a large proportion of the cost of finished products, such as 50-80%. Thin-wall helps to reduce this margin. Due to consumer electronics devices such as mobile phones, MP3 players, digital cameras, handheld computers, compact and light, plastic part design, more and more related to the thin-walled nature of filling mold walls are cold, melting when filling cavities, die wall frozen layer will be set up, thereby reducing the thickness of the mobile channel. This condition is more severe when the wall thickness as thin as. 1mm thickness 0.2mm thickness of the frozen layer, flow-top left 0.6mm. 0.5mm thickness 0.2mm thickness of the frozen layer, flow-top left 0.1mm. When filling is not complete disappearance of flow channels for solidification layer too thick, finished it filled.
