Research & Development
Research & Development

Research and Development Policy

Closures are like “time capsules” that deliver the contents of beverage and food manufacturers’ products to the home without sacrificing freshness or flavor.

Nippon Closures has three core technologies that we have developed over the 80 years since our founding: “Sealing Technology” to protect the contents, “Tamper Evident Technology” to clearly indicate the safety of the contents, and “Easy Opening Technology” for ease of use and ease of opening. With these technologies as our three pillars, we all continue working to develop closures that encompass safety, security, and ease.

We have also long been committed to the development of environmentally friendly products that are “eco-friendly.

We are continuously working to reduce the use of metals and plastics, have added a sorting function to seasoning & condiment caps, and have recently developed and deployed products made from biomass.
To achieve a sustainable future and contribute to the well-being of people and society, Nippon Closures will continue to take on the challenge of creating new value.

Our R&D

28 Hook TC

Project vol.1 Supporting the strong carbonation boom: Lightest cap in Japan Product Development Department Group 1 Shin Nakamura

We are constantly striving to improve our products to meet the demands of our customers.This time, the three requirements we received and were able to fulfill at the same time were: (1) weight reduction (2) compatibility with highly gaseous carbonated beverages and (3) opening sound.Reducing the weight of the cap can lead to a reduction of several thousand tons of CO2 emissions per year, including a reduction in the amount of raw materials required for its manufacture.
In addition, the new cap has a seal that withstands the recent “strong carbonation” boom, while maintaining the easy-opening of the conventional cap.And yet, there were a wide variety of factors required, such as the opening sound that gives a sense of carbonation.

▲ 28 Hook TC

Maximized pressure resistance performance while reducing weight

Among the various challenges, the first thing we set out to do was to reduce the weight of the cap.
Since the band at the bottom of the cap has little effect on performance, we focused on weight reduction there.On the other hand, the screw in the middle of the cap has been strengthened to prevent the cap from lifting due to the increase in internal pressure caused by strong carbonation.During the development process, we encountered a problem with a reduction in the cap opening noise.After a year of repeated trial and error, we were finally able to determine the cause of the problem and designed a sealing profile that allows gas to escape all at once when the bottle is opened.This is how we were able to develop the lightest carbonated beverage cap in Japan.

▲ Cross-section view of 28 Hook TC

Project Review

Product Development Department Group 1
Shin Nakamura
At the beginning of development, we thought it would be a simple matter of reducing the weight of the band portion of the existing cap.However, it was unexpectedly difficult and time-consuming to establish a mold structure for this cap and a shape that would satisfy all performance requirements; but after repeated trial and error we managed to successfully commercialize the product.
Product Development Department Group 1
Satoru Inoue
There were various issues from the beginning of development, and in particular, the cause of the low opening sound remained unresolved until the end of the project.Finally, after a year of repeated trial and error, we were able to elucidate the mechanism and commercialize the product.We would like to thank our customers who patiently waited for the completion of the specifications and our colleagues who supported the development.

29 Screw hinge valve

Project vol.2 Cost reduction and improved functionality achieved by two-color molding technology Product Development Department Group 2 Satoru Shimada

In recent years, the seasoning & condiment industry has been seeking to improve the usability of caps, such as ease of pouring and dripping performance, in addition to sealing, which is an essential role of caps.For this reason, silicone valves are increasingly being used for spouts. But the unit cost of the cap is high due to the high cost of the silicone material, the need for a separate part to secure the silicone valve, and the need for a separate device to incorporate the cap. So we changed the valve material from silicone to elastomer, and dissimilar material molding(co-injection,double-shot injection) technology was adopted to enable integrated molding of the valve and cap.This has resulted in the productization of a new valve cap with stable performance and greatly reduced production costs.

▲ Cross-section view of 29-screw hinge valve
(①1st material injection, ②2nd material injection)

Achieves both pourability and dripless performance

A valve cap with a thin wall thickness facilitates valve deformation during dispensing, resulting in a smaller dispensing force and better dispensing performance.On the other hand, thicker valves allow the liquid to be shut off more quickly, resulting in better run-off after dispensing.In order to achieve both of these contradictory abilities, the base of the valve is made thinner and only in the center and where the liquid is cut is made thicker, thereby achieving both discharge and dripping performance requirements.

▲ Good pouring and dripless performance make it easy to pour contents and prevents dripping

Project Review

Product Development Department Group 2
Satoru Shimada
The newly developed technology is highly versatile as a technology for adding valves to closures, and we believe it can be applied to a wide range of products.In the future, we intend to apply this technology to other new developments.
Product Development Department Group 2
Jun Wakishima
It was the first large-scale development project I was involved in after joining the company.At first I was puzzled by the differences from the way we had been working, but I was happy to see that we were able to come up with a product that had never existed before by sharing ideas.
Production Promotion Department
Keitaro Hayashi
In the lead-up to production equipment for cross-slitting products, I spent every day thinking about what “cutting” means. In the end, I never thought it would work that way…!
DIE&MOLD Technology Department
Yuji Takayama
For the first time in our company, we were able to design and manufacture a dissimilar material core-back structure. Based on this experience, we would like to continue to challenge new mold structures to add value to products and improve productivity.

Torshear plastic Cap

Project vol.3 Nut attachment for both efficiency and safety Product Development Department Group 3 Ryuta Kobayashi

Recently, Nippon Closures’ technology is helping customers in the civil engineering and construction industries.
Since the Kasago Tunnel collapse accident in 2012, safety awareness has increased at construction sites, and we are checking to see that nuts are tightened to the proper torque.However, this reduced work efficiency and there were cases of forgetting to tighten the bolts due to human error.
Therefore, we were asked if we could develop an attachment that would break when tightened to the proper torque and disengage from the nut.The development of the attachment was started based on the concept that if the attachment was removed, it would prove that the proper torque had been applied and prevent forgetfulness.

▲ Inspecting to see if it is broken by proper torque

Torque management and prevention of forgetting to tighten with a single cap.

It was a completely new industry, and development was also a process of exploration.First of all, the product was to be used outdoors, and the material used for standard caps is fundamentally insufficient in terms of durability and strength.More than 10 different materials were tested to find the best fit, and dozens of product shapes were tested.
Through this process of gradually accumulating know-how, the decision was finally made to commercialize a product that fulfilled the required functions.However, the decision to commercialize the product was short-lived, and a glitch occurred.After about a week of setting the nuts, about 1% of the time, the nuts were damaged without the proper torque.The cause was too strong of a mating* with the nut.We urgently and radically re-looked the mating methods, and at the same time, we constructed a severe test in which the frequency of defect occurrence was more than 90%.After optimizing the mating until zero breakage was achieved in a severe test, the product was successfully productization.

*Mating: A relationship in which various parts of a machine fit together, as in the case of a shaft and bearing. Also, its condition.

▲ Some of the prototypes leading up to completion

Project Review

Product Development Department Group 3
Ryuta Kobayashi
This was my first experience in commercialization, and it gave me a lot of confidence.When I drive on the freeway, I wonder “Is it used here?”
Product Development Department Materials Group
Masataka Murai
As the product is used in a harsh outdoor environment, we had difficulty in selecting materials and establishing evaluation methods that approximated the harsh conditions.The product was made possible through the cooperation of all three groups.
Product Development Department Group 3
Katsuhiro Muramoto
I joined the project in the middle of development, but I have fond memories of how we all worked together to investigate the product cracks caused by low frequencies and reproduce them through trial-and-error testing.
Sales Department West Group2
Yuki Sato
Although we had never worked with a customer in the civil engineering and construction industry before, it was a great experience for both the customer and our company to be able to work together to launch a product.


Project vol.4 Improving ease of opening by optimizing seal shape Product Development Department Customer Satisfaction Group Koji Hosono

As a recent trend of the bottle can market, caps are required to possess the following performance characteristics: (1) ease of opening, (2) impact resistance, and (3) liquid spurts prevention (*1). Especially in Japan, a society with an increasingly aging population, there is strong demand for “easy-to-open” caps. Conventional P.P. caps for bottle cans are usually made by bonding a single layer of liner material to the “aluminum shell” on the top surface (which forms part of the exterior) to protect the interior. However, with this conventional adhesive method, the force required to open the cap is determined by the degree of mating force between the liner material and the bottle opening. This means reducing the mating force in pursuit of ease of opening will lower the sealing performance, resulting in a trade-off between the two.
*1. Liquid spurts: The phenomenon of liquid accumulated inside the cap spurting out when the cap is opened.


Dual layer structure to ensure both ease of opening and sealing performance

Using our proprietary liner mold technology(*2), we have created a liner structure (dual layers) that is easy to open and seals well. By making the aluminum shell and the first-layer liner non-adhesive, the bottle cap would require less force to open. Furthermore, by using a soft, heat-resistant material for the second-layer liner, we succeeded in developing a cap that is easy to open while maintaining high sealing performance. By optimizing the profile of the second-layer liner to reduce the amount of liquid accumulating inside the cap, we successfully managed to reduce liquid spurting when the cap is opened.
*2. liner mold technology: Technology to mold the liner according to a clearly defined profile

▲ Cross-section view of 38PP-M CAN RWeA P.P.CAP

Project Review

Product Development Department Customer Satisfaction Group(at the time:Product Development Department Group 1)
Koji Hosono
Being our first attempt to create a dual-layer liner inside the cap, there were many challenges along the way requiring repeated trial-and-error to overcome. However, with advice from other groups in the company, we eventually managed to commercialize the product. We would like to thank everyone involved in this development project.
Product Development Department Group 1
Shunya Yoshida
This is my first participation in new product commercialization since I joined the company, which turned out to be a wonderful experience. I would like to make the most of the experience gained and continue to do my best in my position as a designer.
Product Development Department Group 1
Hidenori Kondo
Being the first time for me to handle resin material for liner molding purposes, it was difficult at the beginning. However, I was able to establish an efficient production method by commuting to the production site every day and working together with team members onsite.

26&30 Hook Spout Set Carton

Project vol.5 Spout caps easily opened in one touch without a pull ring Product Development Department Group 2 Shinji Omori

In recent years, there have been increasing applications of paper carton containers with a spout plug attached. In their early days, the majority of these containers used to have a pull ring to open the spout. In order to improve convenience and reduce environmental impact, we began developing a spout without a pull ring yet maintaining the same sealing performance and ease of opening. In response to customer requests, we also emphasized the touch sense and sound when the bridge (the component connecting the band and cap body which is detached upon opening) detaches. This is to enhance the container’s tamper-evident characteristics which help to clearly verify that the cap is opened for the first time. Following the launch of this new type of cap with a standard diameter of 26 mm, we moved on to develop the product with a medium diameter of 30mm. For this purpose, it was necessary to reduce the height of the spout plug so it would not protrude from the carton body. Therefore, the grooves on the side of the cap were shaped to enhance gripping performance.

▲ Enlarged cross-section view of seal part

Unique seal profile to ensure both ease of opening and sealing performance

For paper cartons with a roof-like profile at the top (gable top), the spout plug is attached to the “roof” section and hence cannot be opened by gripping the entire cap as in the case with PET beverage bottles. Therefore, they required a cap that is even easier to open by pinching with fingertips. To ensure good sealing performance without a pull ring, we adopted the inner ring sealing method widely used by us for PET beverage bottles. However, introducing a sealing structure similar to a conventional cap would require greater force to open. To overcome this challenge, we have adopted a unique sealing mechanism with the cap contact ring adjacent to the spout pushing against the top surface of the spout nozzle and deflecting the latter upon closing the cap. This sealing method helped to achieve both ease of opening and sealing performance at the same time.

▲ Cross-section view of set product

Project Review

Product Development Department Group 2
Shinji Omori
Through this development, we believe that we have established a fundamental technology in the area of paper carton spouts for chilled products. We will continue to work on developing products with higher added value.
Sales Department East Group 2
Go Yamamoto
I would like to thank all of our customers and related departments within the company for their strong support. We will aim for further sales expansion, keeping in mind our determination of “never give up” and a sense of responsibility.
Production Promotion Department
Keitaro Hayashi
To allow maximum industrial variation, we have adopted the latest and unique electrical controls literally to the capacity limit. We will continue to pursue reliable production equipment without waste as our eternal theme.
Quality Assurance Department(at the time:Product Development Department Group2)
Ryo Tomabechi
As a developer, this is my first time being involved in the commercialization of a product. Although designing and conducting the leakage test for paper carton containers turned out to be a challenge, I was able to gain valuable experience by overcoming it through repeated trial-and-error processes.