Modern appliance manufacturers must work continuously to improve the efficiency of their operations in the face of stiff competition domestically and abroad. Producing household or commercial appliances—like dishwashers, washing machines, or televisions—requires a faster pace and greater accuracy than ever to meet the market’s demands for speed and volume.
At the same time, lightweight, inexpensive plastic fasteners are more prone to damage than heavier, costlier metal screws and bolts. So, how can a manufacturer work faster and harder while simultaneously protecting their plastic assembly fasteners? The answer is soft-stop electric torque screwdrivers.
The Case for Protecting Plastic Assembly Fasteners
Plastic fasteners have taken the place of metal screws and bolts in appliance assembly because they’re cheaper and lighter. While most plastics used in these assemblies aren’t as strong as their metal counterparts, they don’t need to be—after all, they aren’t subjected to heavy stresses.
For the most part, these fasteners are stationary. As such, they aren’t required to stand up to dynamic loads. If a screw or bolt is expected to handle a heavier load than an inexpensive plastic can handle, then the appliance designers will specify that it be made of another material, like steel or an aluminum alloy. But for the inexpensive, lightweight plastics commonly used to hold appliances together, manufacturers are unlikely to hear about product failure in the field. Rather, these fasteners are more likely to be damaged during the manufacturing process itself.
These small, plastic fasteners don’t typically require high amounts of force to hold themselves in place. Yet, even the small amounts of force their assembly demands can damage the fastener if applied with a sudden, jarring motion. Forcing the screw sharply against its substrate can also cause damage to soft or brittle plastics.
If undetected before being sent to their distributor, broken screws in appliances can result in decreased customer satisfaction and increased replacement costs under warranty. If detected during the quality assurance phase, these screws can prove costly due to the time spent replacing them. Even if noticed right away, during manufacturing, rework still slows production and replacement screws eat into margins. These screws are cheap, yes, but they’re not free.
Overcoming Plastic Assembly Fasteners’ Narrow Torque Tolerances
The best way to protect plastic assembly fasteners from damage caused by the rapid application of torque is to slow down. The fastener’s threads will still hold their tension if the right amount of torque is applied quickly or slowly.
Of course, an entirely different type of pressure—economic pressure—forces manufacturers to produce their appliances as quickly as possible. Which means tightening fasteners as quickly as possible. Which means broken screws. Fortunately, there’s a solution.
Most rapid assembly operations working with plastic fasteners already employ electric screwdrivers to deliver the precise, repeatable amounts of torque they need to hold their appliances together. Electric screwdrivers can be connected to screw counters and automated control systems, allowing for maximum rapidity and accountability in manufacturing. However, not all electric screwdrivers are the same.
For the assembly of delicate fasteners, electric screwdrivers with current-controlled motors are preferred. These motors, which operate at variable revolutions per minute based on the amount of current used, can be programmed to start soft, speed up, then stop soft. This level of versatility allows assembly line engineers to specify and program the ideal speed, torque, and procedure into each tool or many tools in combination. They can be operated by human workers or programmed to run automatically, even in complex sequences.
Whatever the specific needs of the fastener are, these tools can deliver in the most efficient manner possible. Among current-control electric screwdrivers, those with brushless motors return more value than older-style screwdrivers with brush motors due to significantly decreased maintenance needs.
To successfully manufacture modern appliances, speed, precision, and efficiency are of the utmost importance. Lightweight plastic fasteners are more practical than costlier metal screws, but they can easily be damaged by the aggressive application of torque. Electric torque screwdrivers with current-control motors are the best solution for companies fastening plastic assembly screws and bolts due to their ability to deliver the right amount of torque exactly as quickly as the fastener allows.
