Matching die and mould design parameters with parameters of injection molding machine is one thing that must be done. It is like you bought a very beautiful dress, while it is not suitable for wearing, no matter how good it is. Mold is same, check parameters of injection molding machine is the last step. Don't wait for problem to pay attention, it is already late!
There are many types of injection molding machines, such as horizontal, vertical turntable, two-color turntable, high-speed injection molding machine. According to product characteristics, product appearance and product dimensional stability to select appropriate injection molding machine. For example: 1. Product needs to be injection molded with 2 or more kinds of materials, and two-color machine is selected for injection molding. 2. Thin-wall products choose high-speed machine. 3. Material is PEEK, material temperature 400℃, mold temperature 180-200℃, machine with mold temperature machine is selected, 4. Rubber is PVC, which is corrosive select machine that its hopper and screw has anti-corrosion treatment.
After selecting type of injection molding machine, start to choose size of injection molding machine. Is it 120 T or 1000 T?
In short, parameters of injection molding machine should match size of product mold. In principle, it can be small, and it is necessary to not use a large injection molding machine to save costs.
Taking parameters of Haitian 470T injection molding machine as an example, factors affecting matching of product mold and injection molding machine are subdivided into 13 points one by one. Make it easier for everyone to understand, so that it is handy in practical applications.
1. Is clamping force enough?
2. Is finished product weight within 80% of shot volume?
3. Is spacing inside tie rod sufficient?
4. Is maximum thickness of mold allowed to exceed?
5. Does minimum thickness of mold meet requirements?
6. Is mold shift stroke (maximum mold opening stroke) sufficient?
7. Ejection distance (Is the mold product ejection time sufficient)?
9. Is spherical radius of nozzle correct?
10. Is maximum distance of nozzle from mold to allowable range?
11. Is positioning ring size (flange size) correct?
12. Is spacing and size of top stick holes correct? Is it convenient to mold trial by yourselves?
13. Is code template design correct?

 

 

When high-pressure injection of material melt into mold cavity produces force of mold, injection molding machine supports opening force of melt to mold and has to apply a locking force to mold, which is clamping force. Anti-locking of row position and large-mode original AB plate are based on prevention of insufficient clamping force.
Three methods are commonly used to calculate clamping force:
The first method is to calculate clamping force by mold flow analysis. Mold flow is used to analyze. As shown below, maximum clamping force is 258.2 tonne.

 

Second type: clamping force (T) = projected area of product opening and closing mode * plastic material pressure coefficient / 90% (rated clamping force)

 

For example: product 1 out 2, compound is ABS, average pressure coefficient: 0.32
Product projection area: 20X10=200 cm2
Flow path projection area: 0.7X10=7 cm2
Clamping force = (200 + 7) X0.32 / 0.9 = 73.6 T
Machine is to be selected to be larger than tonnage. For example, Haitian 86 T 120T machine
Third type: According to plastic material, clamping force of injection molding machine is calculated by in-mold pressure method.
Clamping force (F) = projected area of product opening and closing direction * number of cavities * in-mold pressure (P) (kg/cm2)
How to simply calculate in-mold pressure
Generally, ABS PS PE PP compound can be selected above 200 (kg/cm 2). PC PEEK and other engineering plastics with low viscosity and high viscosity. In addition, as well as thin-wall products and high-gloss products, generally 300-400 (kg/cm 2)
For example: product 1 for 2, compound is ABS, in-mold pressure: 200 (kg/cm 2)
Product projection area: 20X10=200 cm2
Flow path projection area: 0.7X10=7 cm2
Clamping force (T) = (200 + 7) *2*200 = 82800,
Unit conversion: 82800/1000=82.8 T
Machine is to be selected to be larger than tonnage. For example, Haitian 120T machine
Regarding calculation method of projected area, in menu list-help-command finder-input projection-calculation area, you can usually directly select product calculation. If product is large and too many areas, you can first make a cube and calculate it in the area of cube.

 

Regarding injection weight, taking parameters of Haitian 470T injection molding machine as an example, injection weight is 1296 g, which means that injection molding machine can only inject 1296 g at most each time. For safety reasons, weight of finished product needs to be 80% of injection volume. There is a misunderstanding that machine can put mold inside, injection molding is no problem, regardless of injection weight factor, it is partial and not desirable.

For distance between rods, for example, Haitian 470 T, horizontal and vertical is 820 x 800 mm, horizontal 820 mm is equivalent to width (W) of mold. Normally molds can be placed no more than 820mm (Figure 1), if mold width exceeds horizontal distance of machine, under premise that thickness of mold does not exceed horizontal distance of table, through transfer mold (in fact, mold is rotated 90 degrees before place, then back to 90 degree square) (Figure 2).
In short: width and thickness of mold should be less than or at least one side is less than horizontal spacing of tie rod

 

 

Taking parameters of Haitian 470T injection molding machine as an example, maximum thickness of mold is allowed to be 780 mm, and maximum thickness of mold is required to be less than 780 mm. It must be checked when drawing is checked. Before we made a mistake, customer specified same tonnage. Different brands of machine allow maximum thickness of mold to be different. Only one type of machine parameter is checked, which is considered to be same. As a result, when mold is finished, it is found that one can place, the other is no, customer is angry and stop all order.

Taking parameters of Haitian 470 T injection molding machine as an example, minimum thickness of mold is allowed to be 320 mm, and maximum thickness of mold is required to be no less than 320 mm. If it is to be thickened, it is recommended to increase height of square iron to save costs. Fourth and fifth points are summarized together, thickness of mold needs to be between mold thickness allowed by injection molding machine.

Taking Haitian 470 T as an example, maximum displacement stroke is allowed to be 780 mm (Fig. 3), which is calculated by subtracting maximum thickness. Actual stroke (S) = maximum displacement stroke of 780 mm + (allowing maximum thickness of mold - actual mold thickness). If product's ejection stroke is very high, it is simulation calculation, whether product is easy to take out, mold opening distance is at least 2 times ejection distance, it is not difficult to understand this, deep cavity product is the most obvious (Figure 4) . In additional ejector distance plus length of nozzle, while taking into account minimum spacing requirements of robot pick-up.

 

 

Ejector distance is very well understood. Haitian 470 T is 200 mm. It is necessary to pay attention to secondary ejector, which is sum of two ejector distances. Pay special attention when checking ejector distance of machine.

Taking parameters of Haitian 470 T injection molding machine as an example, minimum mold size (length * width) is 580 * 560 mm. This is not required for small machines. This is required when small mold is on a large machine.

Take Haitian 470 T as an example. Radius of spherical surface of nozzle is SR 15, and different machines are different. If customer does not give it, you can choose to do flat or do R 40. After confirmation, it can be processed twice. No need to replace.

Taking parameters of Haitian 470 T injection molding machine as an example, maximum distance of nozzle into mold is 50 mm. Distance on mold is calculated from panel without insulation board, and insulation board starts from insulation board (Fig. 5). Design check can not leak it.

 

Taking parameters of Haitian 470 T injection molding machine as an example, positioning ring size is Ø 200. Positioning ring is used for positioning mold on injection molding machine, which is convenient for quickly calibrating nozzle hole. Generally, dynamic mold and positioning are done. See customer requirements, normal positioning ring is 10 mm above die surface, diameter is 0.04-0.07 mm, and C-angle is used as installation guide.

There are 2 kinds of metric hole spacing: metric and inch. Domestic mold trial is mostly used in Haitian machine. Most of spacing is metric. If hole spacing of mold top holes is designed in inch, it is better to design it to be shared by metric and inch (see below), oval, easy to mold trial yourselves (Figure 8), top stick hole size is at least 35 mm in diameter. Top stick hole size is designed according to client table.

 

Stencil of code template is used for stencil. There are usually 2 kinds of stencils, coder (Fig. 9) and lock screw (Fig. 9). Lock screw is usually used in two-color vertical machine with turntables. Reason is that molds have to be rotated on turntable, and code is easy to loosen. There is also a magnetic code, suction magnet directly sucks and fixes, pays attention to water inlet and outlet position, Green column cannot interfere with code mode. At the same time, water transport design should be as far as possible in the middle, leaving 2 code space.