Of the three items in the fator4 fractional formula, the last item, "Increase added value," is difficult to quantify. However, our goal is to improve molding quality and to increase the value of the molded product itself by innovating molding methods and new technologies.

Our solution themes are the following three. Here is an overview of each of them.

1. Improve dimensional precision

2. Lighter molded products

3. Enhance surface quality and value

1. Improve dimensional precision

For many of you, improving dimensional precision of molded products is not so much about whether or not you can produce the targeted shape and dimensions, but rather about how you can minimize deformation after the molding process. Swirls, strains, and sink marks are all problems that appear over time after the molding process.

Why does the deformation occur later? It occurs because the temperature of the melted resin gradually drops and it hardens, and it is pulled toward the hardening side and stress remains. That means, that to suppress this deformation, the temperature of the entire molded product should be lowered uniformly.

So how do you achieve uniform cooling? Methods that have been used for a long time include annealing and multi-zone temperature control that sets the temperature of the medium according to the distance between the mold water pipe and the molded product. Recently, 3D metal printers have been used. Recently, 3D metal printers have made it feasible to design water pipes that match the shape of molded products.

2. Reduction in part weight

Reduction in part weight can be said to be the most important issue, especially for parts for automobiles. In recent years, weight reduction has been promoted by using resin molded products as a substitute for metal parts, but now there is a demand for further weight reduction of resin parts themselves. How can you meet both of these trade-off requirements of being strong and light?

Foam molding is one of the technologies we can propose and provide. If the shape is the same, the strength will decrease as the resin density decreases due to foaming, but it should be matched with the design of the molded product considering that the resin filling characteristics in foam molding are different from those in normal molding. Therefore, we realize weight reduction while maintaining the required strength.

3. Enhance surface quality and value

When molded products are used as-is as appearance products, even if they are painted, plated, or decorated in subsequent processes, better surface quality is required because it leads to a reduction in the process of preparing the substrate. For many molded products, surface quality can be increased by setting the mold temperature higher, but at the same time, this results in a longer cooling time, reducing productivity.

Therefore, heat & cool molding is a method to improve the quality* without extending the molding cycle time as much as possible. It is a method to control the temperature of the mold up and down according to the molding process, that is, the temperature of the mold is high at the time of injection and it is actively chilled water after injection. There are various methods for heating, such as warm water, steam, heaters, and electromagnetic induction heating.

In addition, we can also provide oil medium type heat & cool that enables the high-temperature range required to achieve beautiful metallic surface quality without painting.

* In heat and cool molding, the molding cycle tends to be longer, and unfortunately it is not quite the same as the cycle time of normal molding. Thick-walled molded products may shorten the cooling time, but in most cases, the cycle time is 1.1 times or more as a guide.

Improving the surface quality and value of contract-produced molded products is likely to be difficult to directly lead to profits, but it is important to connect heat-and-cool molding to the next job in the future. We have been contacted by many companies that have positioned this as an important initiative to connect to the next job.

We have an alliance (3D weldless alliance) consisting of companies with technology, so we not only manufacture and sell equipment, but also support you in total, from resin flow analysis in advance to mold design, molding start-up support, and consultants.

Global Solution Promotion Department Yasuhiko Iijima