Toy Assembly Isn’t Child’s Play
Assemblers at toy factories from the North Pole to the South China Sea usually breathe a big sigh of relief this time of the year. That’s because their assembly lines are winding down from the peak season.
However, the $84 billion market for action figures, building sets, dolls, games, play sets, puzzles, radio-control helicopters, slot cars, teddy bears, trains, trucks and other toys remains relatively steady throughout the year—not just in December.
Consumer demand for toys has been rebounding since the Great Recession and the future looks bright. In fact, the Toy Industry Association Inc. predicts that the number of kids in the United States under 17 years old will grow 9 percent annually over the next two decades.
A generation ago, the United States was the toy capital of the world, with thousands of manufacturers. Today, many toys are still designed domestically, but they’re typically assembled in Asia.
While some companies, such as industry giants Hasbro Inc. and Mattel Inc., operate their own plants in China, Indonesia, Malaysia and Thailand, many firms outsource production to contract manufacturers. But, toy manufacturing is slowly starting to return to the United States.
“Some production will shift back, although on a small scale,” predicts Carolyn Zulandt, an analyst at the Freedonia Group Inc. “A number of factors are supporting this[trend], including rising production costs abroad, ongoing safety concerns about toys produced in China, support for local industry, and demand for environmentally friendly toys.
“Local manufacturers can also provide a level of customization that is not usually possible with mass orders completed in foreign facilities,” Zulandt points out.
“The cost advantages in China are substantially less than they were a few years ago, so companies are going to be re-evaluating whether it makes sense to import toys vs. producing domestically,” adds Daniel Berch, director of Pell Research LLC. “Particularly, higher-end [production] processes and automation make U.S. manufacturing more feasible.”
One company that’s bullish on reshoring is Little Tikes Co., a division of MGA Entertainment that specializes in infant and toddler toys. It recently moved some production from China to a plant in Hudson, OH, where it mass-produces more than 200 different brightly colored products, such as the popular Cozy Coupe ride-on car.
To combat low-cost Chinese competitors, Little Tikes employs lean manufacturing and Six Sigma production principles. It has also implemented automation on the plant floor. For instance, robots are used to drill holes along 16 flexible assembly lines that are all capable of producing a wide variety of products.
“By producing our product in the United States, we are able to closely monitor production, [which improves] quality and productivity,” says Tom Richmond, Little Tikes’ general manager.
Once upon a time, tin plate and pressed steel were the predominant materials used to manufacture toys. But, most products are now made from durable, high-impact plastics that can be easily molded into numerous colors, contours, shapes and sizes. The material also allows toy manufacturers to use adhesives, screws and ultrasonic welding to assemble their products.
Polyolefins, styrene-derived polymers and plasticized polyvinyl chloride are commonly used by toy manufacturers. “Acrylonitrile butadiene styrene (ABS) is also frequently used in the toy industry,” claims Uwe Peregi, executive vice president and general manager at Herrmann Ultrasonics Inc.
“This plastic is light weight and is nontoxic,” Peregi points out. “In addition, it’s tear resistant, high tensile and allows for a glossy surface. These are all ideal characteristics for toys. ABS is a very good material for the ultrasonic welding process.”
Another material used for the production of toys is polystyrene, which also is compatible with ultrasonic welding.
“Because toy manufacturers typically operate at a very low margin, variable cost savings through material or labor are very attractive to them,” adds Andrew Scott, an application engineer at Henkel Corp. “Today, toys are commonly made out of the cheapest moldable plastics, which are types of olefin.
“Substrates in the polyolefin family, such as polypropylene, high-density polyethylene and low-density polyethylene, are very easy to work with and inexpensive; but, they have very low surface energy, which can make them challenging to bond without the right adhesive and primer combination,” warns Scott.
“Cyanoacrylates offer many choices for assembling these hard-to-bond plastics,” adds Scott. “They cure rapidly for high production environments, and are inexpensive and easy to process to control costs.”
Toy engineers must carefully balance material cost vs. assembly method. “Toys are typically lower cost products [that] must be assembled efficiently for the least amount of labor and cost,” notes Kevin Buckner, director of engineering at Design Tool Inc., which has supplied screwdriving equipment to Mattel and other toy makers.
One way to cut costs and simplify assembly is to design toys with fewer parts. “Simplify and do more with less is the key today,” says Bruce Lund, a veteran toy designer based in River Forest, IL.
“As one means of doing more with less, we have developed a technology that will give us movement and animation without using a motor and related gearboxes and controller circuitry,” adds Lund. “We struggle to get actions that once required two DC motors now with just one.”
Lund says wall thicknesses of some toy parts are also becoming thinner today. “We look at products designed years ago and are shocked to see how they were overbuilt and used far more plastic than was needed,” he explains.
“As the use of CAD software has become more prevalent throughout the toy industry, the shapes of plastic parts have become more complex,” adds Buckner. “For example, toys that transform from one shape to another by moving components into different positions have very complex shapes.
“As parts become more complex, access to fasteners becomes more challenging,” notes Buckner. “A fastener may be located in an area that has minimal clearance around the head of the screw, making automation very difficult. Also, fasteners are often located in deep recesses that limit screw access.
“Screw sizes used in toys are [also] becoming smaller today, as joint analysis and cost drive manufacturers toward using the smallest fastener that will achieve the desired joint integrity,” Buckner points out. “Smaller screws are often more difficult to automate, as the clearance area around [them] is usually more restrictive, leading to problems with access on automated systems. Smaller screws can also be more difficult to feed.”
“There has been a trend to reduce wall thicknesses [in toys] over the years in an effort to reduce material costs without affecting performance of the product,” explains Brian Gourley, North American sales manager at Sonics & Materials Inc., which has supplied equipment to Hasbro and other toy companies. “This has caused us to approach welding the product differently so as to not cause any diaphragming (creating an unintentional hole) to the assembly.”
“Most [toys], regardless of segment, are being designed today with complex shapes, curves and details, and are getting very small compared to similar products of the past,” claims Ken Holt, senior applications engineer at Dukane Corp. “The challenge in ultrasonic welding has been to fit the curvatures and shapes into the ultrasonic tooling and to minimize marking on the final assembly.
“Fortunately, advanced modeling software, as well as high-speed CNC machining centers, are embraced by the toy industry,” adds Holt. “So, these shapes can be accurately reproduced in the ultrasonic tooling even before molded parts [are] available.”
Joining Pros and Cons
Adhesive bonding, screwdriving and ultrasonic welding each offer challenges and opportunities to toy engineers searching for the best plastic joining solution.
Toys with electrical or mechanical motion components rely heavily upon screws. “Self-tapping screw designs, such as Plastite thread forms, tend to be the most popular with toy manufacturers,” says Buckner.
The biggest advantage to using screws is ease of disassembly in case of a defect or a mistake in the assembly process. “Other joining processes, such as adhesives, plastic welding or interlocking fits, are much more difficult to disassemble, leading to higher scrap rates,” says Buckner. “Fasteners also enhance the use of automated equipment in the assembly process.
“Hand held auto-feed screwdriving systems are widely used for toy assembly applications,” adds Buckner. “Robotic systems and XY Cartesian systems are used less frequently, due to the higher initial cost of these types of systems.”
“Advanced games, such as Xbox, where disassembly or upgrades are possible, rely on screws for their ability to be removed and reinstalled,” says Michael Mowins, president of global licensing at Phillips Screw Co.
“Pan head screw with threads that are good for plastics are the most popular [in the toy industry],” claims Mowins. “Our newer drive system and some tamper-resistant drive systems are gaining traction, as manufacturers look to minimize end user tampering but optimize assembly efficiency.”
According to Mowins, screw sizes used in the toy industry range from M2/#2 to M3/#10. However, some electronic toys require smaller fasteners.
“We’ve been working on some new micro screw [toy applications] that are down in the M1 range, [similar to what’s] found in cell phones and tablets, but they are not the norm yet,” says Mowins.
Adhesives are commonly used to assemble toys that don’t require servicing or disassembly, such as dolls and detailing on model trains. “Since most toys are intended to be thrown away if broken and do not require service or maintenance during their life, adhesives are a great fit for toy manufacturing,” claims Scott.
“Traditional assembly methods, such as mechanical fasteners and snap fits, can diminish the aesthetics and reliability of a toy,” argues Scott. “These assembly methods can also add significant material costs and complexity to part production.”
Instant adhesives and light-cure adhesives are popular for toy assembly, because they typically provide all-around adhesion to many types of plastics. “These technologies can bond many other substrates beside plastics, are easy to incorporate into high-speed automated manufacturing processes, are user friendly and require no mixing,” says Scott.
“By using rapid-cure adhesives, such as a cyanoacrylates, or light-cure technologies, toy manufacturers can simplify joint design, improve the aesthetics of their toys, reduce material costs, and improve assembly time and complexity,” adds Scott. “In addition, adhesives often provide superior strength and durability over mechanical fasteners.”
According to Scott, adhesives are a “one size fits all” solution, offering a single method of assembling multiple components and substrates without using fasteners or molded clips. “A single adhesive can be used for a very broad range of applications, joint configurations and substrates; whereas several types of screws may be required for a single toy and possibly dozens or hundreds for an entire line of toys,” he points out.
Ultrasonic plastic welding is another alternative. In fact, the first application for the technology occurred in the toy industry 50 years ago. Bob Soloff, president and CEO of Sonics & Materials, sold his newly invented assembly process to the Ideal Toy Co. The toy maker purchased an ultrasonic welder to assemble a Roy Rogers stagecoach cowboy kit. Ideal Toy was eager to replace its handheld gluing method with a more automated approach.
Today, ultrasonic welding is used to assemble a wide variety of toys, including boats, figurines and game pieces. The technology offers extremely fast cycle times, which appeals to toy engineers.
“Production has to be fast and efficient,” says Peregi. “Toy manufacturers are looking for a joining method that is fast, but also meets quality and safety requirements.
“The lifetime expectancy of the optimized tooling is also key,” adds Peregi. “Tooling for ultrasonically welded toys is typically made out of hardened steel, such as aluminum or titanium, with special coating that ensures long durability and complex contours.”
Because ultrasonic welding offers the fastest processing times, Peregi says it’s the most economical joining method per piece, even though it requires a higher upfront capital investment than alternative assembly processes.
“Due to special design geometry of the parts at the joining area and the optimization of the welding tool, it is possible to achieve optimized results, as well as a good visual appearance,” notes Peregi. “Results can be saved for tracking and are easily reproducible all over the world, due to an exact determination of all parameters at different production sites. Fast changeover time is another advantage of using ultrasonic welding for toy assembly.”
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