Rapid Mold Change Technology Reduces Downtime in Injection Molding

快速换模技术缩短注塑成型停机时间

Advanced quick mold change technology can help injection molding manufacturers reduce mold changeover time from hours to minutes, while also improving operational safety.

Plastic manufacturing companies use mature technologies to minimize downtime and enhance safety, thereby adapting to a production environment characterized by multiple varieties and small batches. The ejection system adopts the FasTie quick disconnect device, with a pneumatic disconnect structure that eliminates the need for mold technicians to reach into or enter the equipment.

In plastic injection molding production, efficiently completing mold changes is as important as a racing team's quick pit stop for repairs. Mastering the concepts of Mold Unit Design (MUD) and Single-Minute Exchange of Die (SMED) has significantly helped plastic manufacturing companies reduce downtime. Meanwhile, in conditions where production space is limited, a pull rod retraction device can greatly save working time when changing molds.

LS Mtron tie rod operation schematic, image source: LS Mtron

Small-Batch Production? Let Master Unit Die (MUD) Help You

Small batch production scenarios have a high demand for rapid mold changing.

“Manufacturers are under increasing pressure to take on smaller-batch orders, support a wider range of product variants, and shorten delivery lead times,” said Paul Shemanski, Product Sales Engineer at DME. “At the same time, labor shortages and rising operating costs are forcing machine shops to maximize equipment utilization.”

Paul Shemanski explained that MUD technology was developed decades ago with the original goal of standardizing mold bases and enabling interchangeable production inserts. Today, the technology “has evolved from a basic manual insert system into a precisely engineered quick mold-change solution, offering greater accuracy and durability while being compatible with automation equipment. Modern MUD systems are designed to streamline mold changeovers while delivering the precision and repeatability required for today’s injection molding production.”

DME’s MUD system enables quick mold changes, reduces equipment downtime, and supports cost-effective production of high-mix, low-volume parts.

“依据应用场景与自动化程度不同，新一代MUD系统能够将换模耗时从数小时压缩至短短数分钟。”Paul Shemanski继续说道，“该系统可实现可重复定位，减少调试调整工作，换模完成后即可快速恢复生产。近期技术升级聚焦于更严苛的制造公差、更长使用寿命、更简便的维护，以及和自动化注塑单元更高的适配性，最终实现设备开机时间提升，生产过程更加稳定。”

Multiple recent customer success stories of DME fully demonstrate the advantages of MUD technology.

Medical injection molding: An OEM factory that produces multiple types of medical components every day uses the MUD system to quickly change inserts, retaining the validated standard mold base and greatly reducing downtime between different orders.

Consumer products: A custom injection molding manufacturer serving multiple OEMs uses standardized MUD mold bases to accommodate dozens of product variants, reducing tooling costs and increasing equipment uptime.

原型与过渡生产：一家产品开发企业在通用MUD模架上使用可互换镶件，无需为每一轮产品迭代制作整套模架，就可以快速完成从原型试制到小批量量产的过渡。

Paul Shemanski mentioned that the DME system "integrates precision machining and standardized components, offering a wide range of sizes and configuration options, and is compatible with other DME mold solutions. It provides injection molding manufacturers with a mature and reliable platform that enhances processing repeatability, simplifies maintenance, and reduces the overall lifetime ownership cost of molds."

He summarized that as manufacturing enterprises move towards high customization, shorter product life cycles, and increased localized production, "the market demand for rapid mold change technology will continue to rise. With the ongoing popularity of automation and intelligent manufacturing, efficient and stable rapid mold change will become increasingly critical for maximizing equipment utilization and supporting flexible manufacturing. Systems like MUD for rapid mold change will continue to help injection molding manufacturers enhance their competitiveness while reducing downtime and lowering operating costs."

The path to Single Minute Exchange of Die (SMED)

The Single Minute Exchange of Die (SMED) concept in lean manufacturing aims to reduce the time required for tool changeovers. Although this technique offers significant value for injection molding, it has not been widely adopted.

“单分钟换模是提升设备综合效率（OEE）的有效手段。”密歇根州弗雷泽市PCS公司业务拓展经理Michael Stemm表示，“工厂成本最高的资产就是重型核心设备，也就是大型注塑机。保证设备持续运转至关重要。设备综合效率计算中的可用率，对应的就是设备开机时长，而模具更换正是消耗设备可用时间的因素之一。”

“In addition, single-minute die change is not just about speeding up changeovers; it can also free up valuable capacity and fully leverage the value of scarce skilled workers,” Michael Stemm added.

He outlined four steps for achieving efficient single-minute die changeover operations. The first step is to distinguish between internal and external operations and analyze the existing process: internal operations must be completed while the equipment is stopped; external operations can be carried out before the equipment is stopped or after production is restarted. Then make the following judgments in sequence:

1. Can this assignment be canceled directly?

Can it be completed in the form of external work during the equipment production operation?

3. Can the tasks be simplified, combined, or carried out in parallel?

4. 是否可以借助工具、标准规范或者控制手段，让作业更快、更安全、重复性更好？

Regarding point four, Steim listed a number of products that can shorten internal mold change time:

Magnetic template

Mold Transfer Cart

Quick Cooling Coupling

Quick Release Rod Connector Assembly

Smartflow冷却系统

Mold preheating device

归根结底，“设备可用时间是工厂成本最高的资源，单分钟换模就是用来降低设备停机带来相关成本的手段。”

However, improving mold changing speed must not come at the expense of worker safety.

Safety must be the top priority. Changing molds within a minute can usually improve operational safety, or at least not increase the risk of personnel injury.

The retractable rod device balances efficiency and safety.

With limited plant space and restricted headroom, installing large molds adds another challenge to fast mold changeovers. Some injection molding machine manufacturers have introduced tie-bar retraction devices, enabling safe and rapid access to the injection machine’s operating area under space-constrained conditions.

For example, LS Mtron's U.S. injection molding division equipped two custom machines for Stanford Manufacturing Company in Clemens, North Carolina, with a pull rod retraction device. The LS Mtron pull rod retraction device operates with a single button, completing the entire action in about 60 seconds, allowing molds to be loaded from the side of the equipment without the need for a crane or forklift to lift them from above.

“2024年12月这台1200吨LS设备投用至今，我们已经完成约85次模具更换。”斯坦福公司首席执行官Jack Elliott介绍，“普通模具平均换模时间约两小时；需要配套辅件的特殊模具，换模最长可达三小时。”

Elliott explained that the retractable drawbar device improved safety, allowing operators to “guide the die into position close to the ground, rather than hoisting it at height. We hang the die on an overhead bridge crane, move it alongside the equipment, with the die about two feet off the ground, and then feed it into the machine. Once inside the machine, the die is lifted about 10 feet.”

俄亥俄州阿什塔比拉 Zehrco-Giancola公司同样面临车间层高的限制。

“Our largest molds could not be lifted into the equipment from above the tie bars,” said Raffaele Giancola, Vice President of Operations. “The ceiling height in that area of the plant and the lifting capacity of the crane were insufficient, so the mold had to be split into two halves, loaded into the equipment separately, and then assembled inside the machine. This process was extremely time-consuming, and every mold change required precise assembly.” He added that this cumbersome procedure also posed safety risks.

Split-die installation requires more crane lifts, and workers must operate inside the equipment while the die is suspended, with their hands close to pinch-point hazard zones when aligning the two die halves. Loading the die as a single assembled unit in one operation eliminates all of the above risks.

该企业在ZGC热塑性材料工厂的LS Mtron LSG‑1800H注塑机选用可缩回拉杆，“缩回拉杆之后，模具整体从侧面装入，省去上述繁琐步骤。同时拓展了我们可承接的业务范围，以往不得不拒单的大型模具，现在可以报价接单。”这台设备承担ZGC最大规格模具的生产任务，几乎每周都要换模，每套模具更换能够节省数小时工时。拉杆缩回装置带来的其他优势也很快显现。

"Energy consumption under high-output production conditions is a significant expense, and savings in energy consumption can be reflected in our quotations, helping us to be more competitive. The equipment is easy to operate, allowing technicians and operators to quickly get the hang of it. The mold change process is simpler than before, and the assembly and adjustment of large molds no longer rely solely on a few employees."

The ZGC factory covers an area of 100,000 square feet and is equipped with 21 injection molding machines with capacities ranging from 60 to 1800 tons. "The group has a total of 13 factories with over 220 injection and compression molding machines, covering both thermosetting and thermoplastic molding." The company processes a large amount of nylon, flame-retardant ABS, and various general-purpose resins, while also focusing on small-batch projects across multiple varieties for the electrical, automotive, consumer, and industrial sectors, processing the vast majority of engineering plastics. ZGC holds ISO 9001:2015 certification.

“Currently, the LSG-1800H is producing a four-cavity fitting mold for large-diameter high-density polyethylene and polyvinyl chloride pipes. This mold is loaded from the side after the tie rods are retracted.”

Raffaele Giancola summarized: "In the past, some molds were simply too large to be loaded onto the machine as a whole, as they could not be hoisted from above the tie bar and their weight exceeded the crane's capacity. By enabling side mounting of the mold on the framework, mold changes are faster and safer, allowing us to take on orders that we were previously unable to fulfill."