Improved Methods, Better Parts

By Liz Stevens, writer, Plastics Business

Texas Injection Molding, Houston, Texas, provides custom plastic injection molding for OEM manufacturing and consumer goods. Operating 30 injection molding machines, the company serves the business electronics, food and beverage, sports and outdoors, medical and pharmaceutical, energy, and industrial and safety markets. Recently, the company earned first place in the MAPP Innovation Awards Labor Solutions category and submitted a noteworthy entry in the Smart Manufacturing category.

Plastics Business talked with Texas Injection Molding’s CEO Jeff Applegate about the impetus for the changes, the methods used in tackling the challenges and the lessons learned from the experience.

A Labor Solution
Texas Injection Molding’s award-winning labor solution revolved around building an O-ring quick install and quality check apparatus. A valued customer asked the company to take on the assembly task of adding two O-rings to an over-molded product already in Texas Injection Molding’s production line. “Our customer was manually installing O-rings in limited quantities and was planning to increase production volumes,” Applegate explained. “We initially began the project using hand tools similar to the ones used by our customer.” The company tried adding the O-rings manually and even created a specially designed tool to facilitate the work. The manual method, however, was cumbersome for assembly workers and introduced ergonomic strain. “As the volumes increased,” said Applegate, “we needed a new solution to keep up with the quantities required, prevent employee injury from repetitive motion and ensure quality of production.”

In this customer’s important part, a defective or missing O-ring can be extremely costly to its operation. To find a solution, Texas Injection Molding’s crew sought out and evaluated other methods. “Our continuous improvement team researched automation options,” Applegate said, “and collaborated with a supplier to design and build a machine to feed, install and inspect O-rings. The Keyence vision system in the machine includes examination of O-rings for any cracks, even those not visible to the human eye.”

The O-ring installation equipment includes a bowl feeder to align and deliver O-rings to a loading station, a fixture to hold a brass pin, pneumatic jaws that stretch the O-rings and an internal mandrel to position the O-rings onto the over-molded product. The inspection element scans the O-rings with better-than-human optical precision. Minimal maintenance is required for the new machine. “It requires five minutes of cleaning after eight hours of production,” said Applegate, “There are clear, simple work instructions and training is provided to all employees operating the machine; there was no need to introduce maintenance technicians as all that is required is cleaning and inspection. The only wear-and-tear aspect is the mandrel, which is fabricated in our tooling shop.”

To gauge the success of the project, the company used production rates to calculate the return on investment. “The project is presented with an estimated ROI based on a standard production rate,” said Applegate. “We work to ensure that we execute to the plan and, once in production, we track hourly production rates and report throughput to standard.” For this assembly and inspection task, the company had three operators working three shifts, adding up to nine people. “We were able to reduce to one operator on one shift to complete all of the monthly production requirements,” Applegate said. “The labor savings applied across each unit, multiplied by the number of units shipped annually, saves us about $265,000 per year over our manual assembly process.”

During this project, Texas Injection Molding learned a macro lesson: Being scrupulous about cleaning the bowl feeder machine is imperative since even a normal accumulation of dust in a day can be enough to affect the proper functioning of the machine. And a broad lesson learned: “O-ring installation machines, if appropriately designed,” said Applegate, “will greatly reduce the training time for employees and greatly improve the quality and consistency of the hand-operated devices. But, more importantly, a successful implementation of these machines can dramatically enhance the quality and precision of the product.”

This labor solution relieved workers of the highly important but laborious task of adding O-rings to a part, delivered the volume of parts on the production timeline, upped the company’s quality to near-zero defects and allowed for the freed-up workforce to transition to more productive work at Texas Injection Molding. “The manual process was hard on employees’ hands and arms,” Applegate explained. “The new process is much safer for the employees to use. The manufacturing process now is more reliable. The automated vision inspection system is far superior to human inspection, and it eliminates judgment calls made by humans.”

Next up for Texas Injection Molding in this area is production expansion for additional products for the O-ring customer. “The customer is adding new products with different lengths,” said Applegate, “but they will use the same O-rings and our machine was designed to accept this anticipated additional product.” After that? “The next step is to install the machine next to the injection molding machine,” Applegate said. “Currently, the metal inserts are hand loaded by an operator; we are programming a robot to pick up the metal components and insert them into the cavity of the mold.” In a best-case scenario, one operator will be able to run and monitor the molding, O-ring assembly and inspection for this production line.

An Example of Smart Manufacturing
The smart manufacturing submission from Texas Injection Molding was focused on implementing a new way to post Master Control Plans (MCPs) at each molding press. The MCPs are a set of documents – each of them an entire binder’s worth of documents – that are the bible for each part manufactured at the company. This includes the operation layout, packaging instructions, the audit plan, quality criteria and the process plan. Also found in the MCPs are photos and diagrams illustrating the parts, quality notes and more. The existing MCP methodology was to have a physical binder at each press, available for the operators to thumb through to find information.

The downsides of the existing method were that binders were not attached to a press, the documentation had to be refreshed with replacement pages to keep the information current, and it sometimes was difficult to see the fine aspects of the parts’ photos. The impetus for starting the project, according to Applegate, was, “to address the effort to constantly update files, reprint paper and insert it into notebooks – notebooks that were sometimes misplaced or damaged, and expensive to reproduce.”

In finding a solution to this dilemma, it was important to Texas Injection Molding to retain the company’s investment of time and energy to build a repository of Master Control Plans. “We had invested a tremendous amount of time,” said Applegate, “in collecting, standardizing and maintaining paper manuals. We needed to have all Master Control Plans for every part available at every work center. Then, when there was a change, we could simply update the file and the change would be immediately available.” Producing digital versions of the MCPs and making them accessible via a tablet computer on every machine looked like an obvious advantage, but that, of course, would require the time and energy of someone to manage and implement the project.

Applying the broad concept of smart manufacturing – Industry 4.0, automation, networking – the company tackled the project of digitizing each part’s specs, creating an MCP document library, and installing networked tablet computers at each press for access to the Master Control Plans. “Everything was originally produced with PowerPoint,” Applegate explained, “so we continued to provide access to PDF versions of our PowerPoint files. We purchased inexpensive tablet holders and custom machined panels to cover inexpensive tablet computers.”

The content of the MCPs, now that they are available on tablet computers, is consistent and comprehensive. “Each file is standardized,” said Applegate. “It contains virtually all information needed to run the job and is accompanied by photos.” The information is in narrative format, and in tables, photos and scanned data sheets from material suppliers. “Work instructions are in English and Spanish,” Applegate said. “Photos are included and continuously updated to provide the most current information and answer almost any question an operator may have.”

“The tablet computers are wirelessly connected to our network, where the files are protected and maintained by Engineering,” said Applegate. “They have touch screens so operators can select a file, quickly swipe through pages and zoom in on images.”

With this plant-wide upgrade, operators now have access to the specs in a computer tablet that cannot walk away from the work cell. Information is refreshed whenever a change is made to a part’s specifications, and it is easy to zoom in on the fine details. As a result, quality and efficiency are dramatically improved, and operator training and productivity have improved now that team members have an easy-to-use reference for ensuring top-quality parts.

Operators have embraced the new MCP system. “Our people are using the MCP information,” said Applegate. “Previously, employees were instructed to first look to the MCP to answer their questions, as supervisors are not always immediately available.” The paper manuals were cumbersome to thumb through and employees often just waited for a supervisor, quality auditor or other support staff to arrive to answer questions. “With the digital versions mounted at the presses, employees can easily see and flip through the files. Operators are readily using the system, and this has reduced their dependence on supervisors and support staff.”

One lesson learned during this project was in gauging how much information to include in the Master Control Plan files. “It can be easy to include too much information,” said Applegate, “so it is important to decide where to draw the line, especially in compiling FAQs. We can’t cover every question that could be asked about every part, but we had to make sure all of the truly necessary information was covered.”

“This was a big project,” said Applegate, “Every time we successfully identify, implement and see benefit from our investment, it promotes further investment.” He explained that at Texas Injection Molding, there is no “flavor of the month” that pops up as a good idea but is never implemented. “Finishing what we start ensures success with the next project.”

Texas Injection Molding has a game plan for what’s next in digitizing knowledge at the company. “We utilize IQMS as our ERP system,” Applegate explained. “Every area of the company must have goals to expand the use of IQMS, as part of the measurable goals in the business plan and their personal performance goals.” The company is looking at ways to streamline workflows and fine-tune processes and documentation, to eliminate the paper required for hard copies and to convert to digital files in every area of the company.

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