In recent years, with the development of resin industry, mold industry, and machine automatic control component manufacturing industry, the application scope of injection products has been widely promoted and popularized.
With the widening application of various modified plastics, engineering plastics, and composite plastics, people have higher requirements for the precision and complexity of plastic products. It is particularly important to choose a suitable injection molding machine. FCS will show you how to choose the right injection molding machine. It only takes two to three minutes to gain a better understanding of the injection molding machine to facilitate your purchase.
Photo/ Rotary Table Two-Component Injection Molding Machine (FB-R Series)
1. Factors affecting the selection of injection molding machines:
Usually, the important factors affecting the selection of injection molding machine include the weight repetition accuracy of products, mold opening position, and cycle time. Therefore, the following information must be collected or possessed before selection:
Size (length, width, height, wall thickness), net weight, and total weight.
The proportion of raw materials or granulated materials and other materials and crushed materials.
Photo/ FCS diversified product applications
2. How to select the type of injection molding machine:
After obtaining the above information, you can follow the following steps to select an appropriate injection molding machine:
The model and series are determined by products and plastics.
When the customer selects an injection molding machine, first of all, according to the taking-out direction of the product and the mold structure, it is necessary to determine the structural form of the injection molding machine: Vertical injection molding machine, angular injection molding machine, or horizontal injection molding machine.
There is little difference in the structural form of glue injection molding machines from major manufacturers, and the structural difference mainly lies in the mold clamping structure.
Photo/ Advanced Servo Hydraulic Injection Molding Machine (FA Series)
3. Selection of clamping force of injection molding machine:
The "clamping force" tonnage is determined by the design and construction of the product mold and the plastic. Clamping force is an important parameter of the injection molding machine. When the high pressure plastic melt fills the cavity, a large expansion force will be produced in the cavity, which will make the mold expand along the parting surface. If expansion is not allowed, the injection molding machine must provide a force larger than this expansion force to lock the mold, otherwise, it will produce the phenomenon of overflow and material running, and this force is called clamping force.
Photo/ Mode clamping device of injection molding machine
If the clamping force is too large, it will not only increase the purchase cost of customers but also increase the wear of molds and the difficulty of exhausting in the cavity, which will lead to the phenomenon of burning or lack of materials. More importantly, when the machine is stressed, it will aggravate the wear of machines, shorten the life of clamping mechanisms and hydraulic systems, and also cause waste of energy.
Therefore, when calculating the clamping force, it is necessary to calculate accurate clamping force through the projection area of customers' products, the ratio of process length to wall thickness, materials, and cavity pressure of molds. Clamping force, like injection quantity, reflects the capacity of machining products to a certain extent, and is often used as the main parameter to express the size of machine specifications.
4. Select the appropriate injection molding machine based on the mold:
Photo/ Diagram of injection molding machine
◎ Connecting post (also known as guide post):
The inner spacing determines the width of the external dimensions of the mold, and the mold that can be accommodated with a large inner spacing of the guide post is also large, and the mold that can be accommodated with a small inner spacing of the guide post is also small.
The minimum contact area between mold and template should not be less than 60%, and the maximum effective area of mold should not exceed the area of spacing in connecting columns, otherwise, the engine template will be stressed unevenly, the product will produce flash locally, and the template will be easy to crack.
◎ Mold size:
The template is a ductile iron plate supported behind the mold, and the mold should not exceed the inner distance area of the template. To prevent the mold from bending during injection. If the mold is too small, it will produce too high bending stress on the template, and even make the template break.
When injecting thin-walled products, the injection pressure is high, the injection speed is fast, the cycle time is short, the template should be thickened, and the strengthening rib plate should be strengthened to increase the stiffness.
◎ Capacitive modulus:
The difference between the minimum and maximum molds accommodated by the injection molding machine is the modulus of the injection molding machine.
The available mold thickness should be larger than the minimum modulus so that the injection molding machine can open and lock the mold. Otherwise, special works are added (the effective thread of the guide post is increased, and the minimum value of the program should be changed).
When the same available mold thickness is greater than the maximum modulus capacity, special works (lengthening of the frame and guide posts and their threads, lengthening of the steel strip with the moving two plates of the frame clamping, and changing of the maximum value of the program should be considered.) However, there is an upper limit to increase the modulus, and the bearing capacity of the guide post (the maximum bearing weight of the mold) should be considered.
Maximum and minimum modulus of twisted injection molding machine are the distance between moving and fixed templates when the machine twist is straightened and the mold is adjusted to the maximum and minimum respectively. This parameter determines the size of mold opening space and the depth of products.
The larger the modulus, the deeper the depth of the product; on the contrary, the shallower the depth of the product. The full hydraulic large-scale two-plate injection molding machine has a larger modulus and mold opening stroke than the same level of a twisted injection molding machine and is more suitable for products with a deep cavity and high height.
Tips for you to choose a proper injection molding machine!
Knowing The Types Of Injection Molding Machine
5 Minutes To Understand “Multi Injection Molding”