Problem: Industry Existing
What problems does clamping force of injection molding machine directly affect?
What are reasons for broken column of injection molding machine and how to repair it?
How to solve problem of product size being thick on one side and thin on the other?
How to solve persistent problem of rough edges?
Why do I need to repair my crank regularly?
Injection molding machine product consistency problem?
Existing problems in domestic injection molding industry
Precision of injection molded products is not high, and high-precision products need to be produced with imported equipment.
Ignoring importance of parallelism of injection molding machine mold plates leads to low product qualification rate
Improper use of equipment affects service life of equipment
Reason why stress issue of Corinthian pillars has not been taken seriously by manufacturers:
Manufacturer does not understand this technology and cannot use it. In addition, price of imported instruments is very high, which is unacceptable to machine manufacturers. In addition, they do not understand importance of using instruments to adjust force on four Corinthian pillars.

Production is unstable
Unbalanced shot
Product has rough edges
Broken Corinthian Pillars
Small molding window
Insufficient clamping force
Clamping force is one of important factors affecting product quality

1. Clamping force is an important technical parameter of injection machine/die-casting machine. Clamping force displayed on operation panel of injection machine/die-casting machine is usually measured by a pressure sensor to measure oil pressure in oil cylinder or oil line as clamping force. This method cannot reflect actual clamping force. To obtain actual clamping force, a sensor needs to be installed on tie rod to measure actual force on tie rod. Sum of forces on four tie rods is actual clamping force.

 

2. Clamping force is an important technical indicator of injection machine/die-casting machine. Injection machine/die-casting machine manufacturers must use clamping force sensors to detect actual clamping force of each machine and correct clamping force displayed on operation panel. Third-party inspection agencies also need to use clamping force sensors to inspect clamping force of injection machines/die-casting machines.
3. Size of clamping force and whether clamping force is evenly distributed on four tie rods are important indicators for evaluating performance of injection molding machine/die casting machine. If clamping force is evenly distributed on four tie rods, it means that clamping mechanism of injection molding machine/die-casting machine is reasonably designed; if actual force deviation of four tie rods is large, it means that there is a problem with mold clamping mechanism of injection molding machine/die-casting machine and further inspection is required. reasons and improvements. Only when clamping force is evenly distributed on tie rods can product quality be ensured, service life of mold and injection molding machine/die casting machine be extended.

 

4. For manufacturers of injection products and die-cast products, the first step in mold testing is to check whether force on each tie rod of injection machine/die-casting machine is uniform. Only by measuring force on each tie rod can we know actual force on each tie rod and whether four tie rods are balanced; if force on tie rods is uneven, it will cause movable mold and fixed mold to be non-parallel. After mold is closed, a mold closing gap will appear, causing flash problems.

 

Practical measurement applications
Therefore, flash phenomenon during mold trial may be caused by imbalance of clamping force, rather than clamping force being too small. This reason is often ignored. Especially for injection machines and die-casting machines that have been used for many years, as well as large-scale injection machines and die-casting machines, it is strongly recommended to check clamping force before mold trial.

5. Reasons for breakage of tie rod. Due to interaction of forces, clamping force will inevitably react on four tie rods, that is, clamping force will be shared among four tie rods. Whether clamping force is evenly distributed on four tie rods is easily overlooked. When four tie rods are stressed unevenly, if one of tie rods bears main clamping force, this tie rod is most likely to break. This is also main reason why a tie rod of many injection machines and die-casting machines breaks.

 

Injection molding machine clamping force tester
Moreover, when product flash is caused by uneven distribution of clamping force, we often mistakenly think that it is caused by insufficient clamping force, so we mistakenly increase clamping force. Sometimes, although it can solve problem of product flash, it sharply increases risk of breakage of the largest tie rod. Tie rod breakage often occurs at root where stress is most direct.
For normal adjustment of injection machine, correct adjustment and reset after maintenance, usual method is to use a dial indicator, dial indicator, other simple tools and measuring tools to make a rough estimate manually. Accuracy cannot be calibrated and error is too large. Current standard use is to use a new type of mold force tester, also commonly known as Gorin Pillar Tensile Force Tester.
Test of new machines is generally relatively simple because each component is processed with standard tool error values, while old machine has been used for a period of time and relevant dimensions of each component have deviations.

 

2# (Haitian 250T injection molding machine):
Machine is about 3-5 years old, and product have batches seriously. Difference in clamping force (maximum value - minimum value) before improvement is 12.3T (ton), and balance degree is 76.4%;
Supplement: Because Corinthian column nut and Corinthian column fit too tightly, it cannot be adjusted on site and cannot be improved.

 

 

On-site guidance and correction
2# machine clamping force detection data before improvement (23.6% before improvement) ▲

15# (Jiaming PD328 injection molding machine):
On a machine that is about 3-5 years old, product may have batches. Difference in clamping force (maximum value - minimum value) before improvement is 9.5T (ton), and balance is 88.5%;
After improvement, difference in clamping force (maximum value - minimum value) is 4.3T (ton), and balance is 93.7%, which is within standard range (feedback effect is good).

 

On-site guidance and correction

 

15# machine clamping force detection data before improvement (11.5% before improvement▲

 

15# machine improved front clamping tension detection data (6.3% after improvement) ▲

26# (Garmin PD468-KX injection molding machine):
Machine is about 3-5 years old, and product has a tendency to have batches. Difference in clamping force (maximum value - minimum value) before improvement is 13.4T (ton), and balance degree is 87.5%;
After improvement, difference in clamping force (maximum value - minimum value) is 5.1T (ton), and balance is 96%, which is within standard range (feedback effect is good).

 

On-site guidance and correction

 

26# machine clamping force detection data before improvement (12.5% before improvement) ▲

 

26# machine improved front clamping tension detection data (4% after improvement) ▲

Suggestion:
Note (reference): Adjust clamping force of machine repair machine. Generally, clamping force difference of injection molding machine is less than 10%, or balance is more than 90%; precision products require a higher balance;
Regularly correct balance problem of Corinthian column. It is best to perform inspection and maintenance once every six months;
Clamping force equipment is easy to operate, and it takes about 10 minutes to complete test of one machine on-site; if it is operated by a mechanic, it can handle all problematic injection machines, which is beneficial to communication between mold department and injection molding department;
Reduce machine wear, mold wear, and injection machine life, improve product qualification rate, injection machine efficiency, and production stability;
Nowadays, injection molding machine factories must have a clamping force instrument that can detect imbalance of Corinthian pillars. It can be used with a standard mold base to detect imbalance of Corinthian pillars. Suggestion: Reduce unbalanced interaction between mold and injection molding machine; there are screws at the end of collin column to adjust balance by yourself, which can save unnecessary maintenance costs;
Unbalanced Corinthian pillars can also cause mold to be unbalanced.
In order to avoid situation that Gorin column and nut are too tight and cannot be tightened, regular maintenance is required so that they can be adjusted smoothly during maintenance.

After injection machine and die-casting machine are assembled, size of clamping force directly affects whether customer's mold can be produced on this machine. One of reasons is whether clamping force of machine meets theoretically calculated clamping force. Adjust force of four Gorin columns to keep force consistent.
During operation of machine, wear caused by uneven force change of four Gorin columns, and wear caused by side change of force change point of crank arm affect machine's non-parallelism during mold clamping operation. Machine swings greatly and mold clamping sound is loud; otherwise, legs of crank arm are worn, affecting alignment between machine and mold.
Use of testers on injection molding machines and die-casting machines can effectively solve problem of being unable to judge whether clamping force of machine and parallelism of machine are correct. In production, Corinthian column tester can basically determine whether one side of product is unqualified, has burrs, or is short of material on one side.

 

Before fixing
Parallelism is mistakenly 18%, which does not meet standard requirements. Cracks occur, thickness is uneven, and product is unqualified.
Adjusted
Parallelism error is 96.3%, which meets standard requirements, saves materials, and improves product qualification rate.

 

Before fixing
Parallelism error is 89%, which does not meet standard requirements. Cracks occur, thickness is uneven, and product is unqualified.
Adjusted
Parallelism error is 98.3%, which meets standard requirements, saves materials, and improves product qualification rate.

Through above cases, we understand that machine manufacturers waste a lot of materials every day and can only make some ordinary products. High-precision products can only be produced using imported equipment. If equipment is used for a long time without understanding parallelism error, it is extremely easy to cause wear and tear on clamping part of machine, affect service life of equipment. It is recommended to establish usage standards:
1. Confirm balance of Corinthian pillar before trying out mold.
2. Regularly correct balance of Corinthian columns
3. In production of precision products, problem of balance of Corinthian column should be detected at any time.