What is setup time in injection molding?

What is setup time in injection molding?

• dry the material
• Set the mold in the molding machine
• Increase mold temperature
• Set molding conditions

It refers to the time for production preparation.

In plastic molding, the molding machine is stopped during material change and mold change, and production is stopped. In recent years, high-mix low-volume production is progressing, and in order to handle a wide variety of products, such setup time is on the rise.

This series of work, called "setup time", can lead to production loss if it is not done efficiently. In order to reduce lost time as much as possible and shorten the lead time, Shorten set up times in the molding factory has become an unavoidable issue.

In particular, "material change" and "mold change" are the processes that occupy most of the setup time.

material change

I think that the work of changing the color of the material or changing the material during molding is a common occurrence. For molded products that have many color changes, the setup time may be longer than the molding time. In addition, it is not uncommon to use a single mold to mold various parts with switching pins, etc., in order to reduce mold costs.

When changing materials, we would like to switch as soon as possible and start the next molding, but molding cannot be performed unless the material is properly dried. Drying of resin materials takes time, so it is necessary to plan and prepare well in advance.

Furthermore, when changing materials, it is also time consuming to dispose of and clean the materials left in the hoses and supply lines. If it is not done smoothly, the molding machine will be stopped for a long time, which will be a factor in the deterioration of efficiency.

mold change

Due to the increase in high-mix low-volume production, the time and effort required to replace molds at molding factory is on the rise. Replacing the mold requires the use of a crane or similar equipment, which is a time-consuming and labor-intensive task that is also dangerous.

Since the mold is hot after molding, you have to wait until it cools down before you can replace it. Also, even after replacing the mold, molding cannot be started until the mold temperature rises, so it is necessary to wait for the mold to warm up.

In addition, many molding factory operate with a small number of workers, and the number of workers is particularly low at night. If the timing of multiple mold replacement overlaps, replacement waits will occur and the molding machine will be stopped for a long time.

In this way, mold change is a process that inevitably takes a long time to set up.

What are the benefits of shortening the setup time?

By shortening the setup time and increasing the operation time of the molding machine, it is possible to produce more.

Even while the molding machine is stopped waiting for setup, standby power is still being used, so reducing the standby time will also reduce the loss.

Reducing the setup time in a molding factory directly leads to higher productivity and lower costs, which in turn leads to higher sales. This is important to improve factory efficiency.

However, it is difficult and time-consuming to schedule the entire molding machine, including the setup time, by hand. It is not uncommon for the molding machine to stop due to trouble, and it is not realistic to rearrange the schedule each time.

Introducing solutions that reduce setup time

So what are some ways to reduce setup time?

For each step, we will introduce a solution to solve the problem.

Efficient material change

If a dryer can be added and the resin can be kept in a pre-dried state, the setup time of waiting for the resin to dry can be reduced.

In addition, it is possible to increase work efficiency by using equipment that is easy to clean.

It takes a lot of time to remove and clean all the resin left in the hose, cylinder, and hopper.

A solution to this problem is the combination of a suction collector and a push damper. By sending the minimum amount of resin to the molding machine through batch processing, the amount of resin to be discarded can be reduced, shortening the setup time when changing materials and colors.

Automatic material changeover

When switching and molding multiple materials in one molding machine, or when using the same material in multiple molding machines, if the materials to be fed can be automatically switched, labor and time can be greatly reduced. .

That's where universal headers come into play. By preparing multiple pre-dryers and connecting the universal header and the molding machine, it is possible to easily switch materials by operating from the centralized controller. There is no need to move the dryer or replace the resin inside. There is no need to replace raw material hoses or air hoses, and the operating status of dryers can be monitored. By streamlining the work in this way, you can expect to Shorten set up times.

One of the features is that the structure is simple, so there is no material retention, and it can be freely configured according to each site.

Reduce the time and effort required to change molds

In normal setup work, even if the temperature is preliminarily adjusted, when attaching to the molding machine, it is necessary to remove all the piping once and attach it to the molding machine with a crane, which is a hassle. I will introduce a solution to solve this problem.

Fast and safe mold change

The normal setup to stop the molding machine and replace the mold is called "internal setup".

On the other hand, "outside setup" refers to making arrangements for mold replacement in advance without stopping the molding machine. By using "off-line setup" to prepare the molds for the next molding, it is possible to change the molds quickly and safely.

In the off-line setup, the mold to be used next is set in advance in the Mold Changer changer during production, and the pipes are connected and the temperature is preliminarily adjusted. After the previous production is finished, the mold can be replaced while the temperature is raised while the piping is still connected.

The positioning is also precise, and it is possible to start production immediately after replacement. Therefore, the setup time for mold change can be greatly reduced.

If you use a crane to move the mold, set it up, and complete the piping in advance when you have free time, you can eliminate the waiting time for mold setup. Worker safety is also improved because there is no need to rush to work.

It can be installed on existing molding machines, and the installation area is one of the smallest in the world, so there is no need for large-scale repairs or replacement of equipment.

Click here for details ⇒ Mold Changer changer SDC

Reduce mold maintenance time

If the gas component adheres to the molded product, it is necessary to clean the mold. Even during maintenance work like this, the molding machine has to be stopped, which is a big loss of time.

In the case of medium-heavy gas in particular, the mold must be removed from the molding machine once and cleaned, so it is necessary to change the mold and clean it. In such cases, using dry ice blasting makes it possible to clean the mold while it is still attached to the molding machine, reducing the labor and time required for attaching and detaching the mold, and ensuring the safety of workers.

Dry ice is carbon dioxide itself, which evaporates as soon as it is sprayed, so no waste is generated. After cleaning, molding can be resumed immediately, and work efficiency is greatly improved. One of the advantages is that it does not use solvents or abrasives, so it is friendly to the human body and the environment.

Summary

The shortest way to increase the productivity of a molding factory is to operate the molding machine as little as possible.

By eliminating wasted time and increasing production volume, sales will increase, and by achieving shorter delivery times, the reputation of the factory will also improve. Furthermore, by reducing the time and effort required for setup and making work more efficient, it is possible to operate with a smaller number of people, contributing to improved work safety.

MATSUI proposes various solutions to improve the productivity of molding factory. Please feel free to contact us.

CX Design Department Yasuhiko Iijima