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

The five major technology changes in mobile phone shells must be known (Part 2)

3.IML technology The outstanding features of in-mold insertinjection molding (IML) technology are: the surface is a hardened transparent film, the middle is a printed pattern layer, and the back is a plastic layer. Because the ink is sandwiched between, the product can prevent the surface from being scratched and resistant. It can rub and keep the color vivid for a long time. IML technology production process: IMLtechnolog y product effect: 1）   Diversification of printing appearance effects: By combining soft-touch transfer printing with printing technologies such as color and electroplating, various appearances can be realized. 2 ） The research and development of ultra-thin IML, the thinnest can reach 0.80mm, and the deformation is less than 0.5mm; the deformation of 6-inch battery cover is less than 1.0mm; the thickness of local glue reduction can be 0.6mm. development trend: In the existing equipment and process flow of IML technolog...
Post a Comment
Read more

Why will TWS become the mainstream of headphones?

What are TWS Bluetooth headsets? Why is TWS headsets a lifestyle in addition to wearable? From a macro perspective, wireless and multi-device collaboration is the mega trend. On the micro level, the arrival of Bluetooth 5.0 has enabled TWS headsets to be upgraded with the underlying technology; global smartphones have gradually eliminated the headphone jack, which has accelerated the development of TWS headsets. The emergence of TWS headphones can be said to be a necessity. TWS headsets are not accepted by consumers and the market from the beginning. There are many problems such as battery life, transmission, sound quality, and price, which have not been completely resolved so far. As more and more consumers begin to pay attention to TWS headsets, demands such as voice assistants, health monitoring, and noise reduction modes also begin to emerge. TWS will become the mainstream of mobile phones in the future.Why? 1, AirPods have sparked the TWS craze, As we known, the Air...
Post a Comment
Read more