Skip to main content

What is the injection molding-part1

Firstly, let us learn the basic structure of the injection molding machine:
No alt text provided for this image
No alt text provided for this image
No alt text provided for this image
Secondly,we learn some basic theoretical knowledge of injection molding (questions were asked by interviewers frequently)
1,what is the runway effect:The runway effect can be called a high movement along the runway and a regular rhythm of movement. Before filling the thinner part, the fluid passes through the thicker part of the cavity quickly, and the runway effect will appear
2, what is the shear rate:The rate of intense movement of molecules produced by the melt during the filling process is called the shear rate, that is called the shear rate, the motion trajectory generated during molecular motion, such as stretching, extrusion, bending, friction, and the like. The intense movement of the molecules produced during the filling process also causes the temperature of the melt itself to heat up again. Therefore, if the speed of injection is too high, the product will burn. This is another explanation of why the product is burnt down and the injection speed is slowed down。
3, what is internal stress：When an object does not have an external factor, the stress inside the object that still maintains its own phase is called the internal force. When the plastic melt enters the rapidly cooled cavity, the temperature drop rate of the surface of the product is much faster than that of the inner layer, and the surface layer is rapidly cooled to solidify. Due to the poor thermal conductivity of the solidified plastic, the internal solidification of the product is very slow. When the gate is closed, it cannot be The center cools and shrinks to feed, then the inner layer is stretched due to shrinkage, while the surface layer is in the opposite state of compressive stress. These stresses are left in the product after the mold is opened and disappeared. We call it residual stress. 
4, what is stress：The resistance experienced when an object flows is called pressure, and the pressure physically refers to the force acting perpendicularly on the surface of the object. The force object is the support surface of the object, and the action point is on the contact surface, and the direction is perpendicular to the contact surface
5, what is traffic：The flow volume that passes through the unit time is called the flow rate, and the flow rate is the speed of the speed. The amount of fluid passing through a cross section of a river, canal or pipe in a unit of time. Generally refers to the volume flow, expressed in cubic meters per second
6, the five major elements of injection molding：（1）Temperature: (forming temperature, cavity temperature, product release temperature, etc.)，（2） Pressure: filling pressure, low pressure, high pressure, etc.（3）Speed: injection speed, storage speed, opening and closing speed, etc. (4) Time: filling time, holding time, cooling time
7，The role of injection pressure：（1）Reduce the surface shrinkage of the product caused by cooling during the molding process；(2) Preventing warpage of the product after demolding；（3）Stabilizing product size；（4）improve the surface quality of the product
  • Grandshine is specialized in electronic plastic moulding/commodity plastic moulding/Industical plastic moulding/mobile phone cases/tablet cases/ manufacturing
For more information please visit our company website: www.grashine.com

Comments

Post a Comment

Popular posts from this blog

How to select to phone case that is fit for you

We don’t pay the insurance for our phone, but we will add some extra protection for it ， a phone case is one of the protection for your phone .So what case should we select for our smartphone ? When it comes to buying the case for our phone, we have met some problems more or less, such as “It scratches very easy” "The buttons are way to stiff when using this cases" "The color is   beautiful and it’s easy to pop on but the material is NOT durable.” Actually, most of these problems are related to the material that the phone case is made from, every material has its own advantage and disadvantage,after we know the performance of the material, we can choose a better case that is fit for you. Silicone phone case: Silicone phone case is a typical application of silicone protective cover. It’s softness is   between 35-80A Shore hardness and a slightly slippery feel . It has been popular in the market for many years. Silicone rubber, commonly known as silica gel, is a h...
Post a Comment
Read more

5 Ways to help you remove the scratch from your mobile phone

Now everyone has a big screen smart phone,  but  if you do not buy a protective shell or cover , it is easy to   scratch  at the back rear  cover or the screen , even if  it was covered by  the whole wrap protective  case , there will inevitably be some scratches on the screen .  Here are some tips that you can DIY to  remove  scratch es on your phone , the effect is magical, have a  try ! 1, toothpaste Toothpaste can be used in many occasions to scratch, toothpaste contains solid calcium carbonate, silica and other ingredients have the effect of grinding, and because of the hardness and screen glass similar, often can have a good  effect on removing scratch. But don't use children's toothpaste to clean your phone screen. Just use regular toothpaste.First, squeeze a little bit of toothpaste on a cotton swab or a clean cloth, then paint a circle around the scratched area and wipe gently until the scratch is g...
Post a Comment
Read more

TWS headset market will be the focus of the AI ​​era

In October last year, Apple launched the third-generation TWS (True Wireless Stereo) headset, AirPods Pro, on the official website for $ 249. This price is higher than the previous two generations, but it has not hit consumer enthusiasm in the slightest. Earlier, the two generations of TWS headphones released by Apple reversed the decline in sales after the release of ordinary electronic products, and became absolute benchmarks for the TWS headphones industry. The TWS headset is not just a sound transmission tool. Its more important role is an AI assistant based on voice interaction technology. As a smart wearable device, the TWS headset is designed to provide a better human-machine interaction experience. For consumers of TWS headsets, the instant automatic connection can be achieved after the initial setting, so a smooth user experience is more important than sound quality. This can also provide some explanation for "why AirPods can produce word-of-mouth effect...
Post a Comment
Read more