Spin welding is a pretty straightforward process. You spin one plastic component against another and the friction between them causes the material in the weld joint to melt. Even with a welding process this simple, it’s easy to make design mistakes that will cause headaches later. Here are three common mistakes that you should always avoid.
About two years ago, Mark, a manufacturing engineer at AutoTrim, was researching equipment to assemble a new, high-volume door panel they were hoping to win from an OEM. Mark recalled seeing a demo of Extol’s InfraStake technology a few months prior and was drawn to InfraStake’s built-in clamping feature that ensures tight stakes. Mark was hopeful that InfraStake would be a good fit for the door panel line, but wanted confirmation that the technology could meet the cycle time, strength, and assembly tightness requirements. That’s when our Applications Lab, the first of Extol’s wide array of customer-supporting service groups, stepped in to help.
How many times have you stared at a plastic staking machine and wondered how long of a cool time is necessary to prevent the material from sticking to the forming tool when it retracts? Will the settings need to be adjusted after the machine has been running for a while? You need to make good parts, but you also want to optimize the machine cycle time. And naturally, the staking modules need to be small enough to fit your application. Automotive lighting and electronics manufacturers especially need a staking process that fits in tight spaces, keeps up with production, and is simple to set up and operate. Enter nanoSTAKE®, a patent-pending, revolutionary new staking technology that fits the bill.
What if I told you that you can reduce weight and space of a headliner assembly while attaching B-side headliner components? It must be expensive, right? Wrong. In one application, cost was reduced by $3.27 while saving 1.46 lbs and 1 mm stack height per vehicle. Most automakers look for ways to save a few ounces per vehicle, let alone almost a pound and a half! These savings were achieved using a process called InfraWeld®, which uses zero consumables and can change the way you manufacture headliner assemblies.
Several months ago, while spending some time in our Innovation Group, one of our company’s founders (or I can say engineers) asked me to come and take a look at something. Standing in our innovation area, Chip walks me over to a workbench where I see an unassuming setup with a small pneumatic cylinder which holds a pencil-shaped device, only shorter. It’s small with what appears to be undersized wires and a hose coming out of the top. It’s hovering over one of Extol’s plastic test coupons which I’ve staked or riveted using ultrasonic and InfraStake modules hundreds, if not thousands of times. Nearby there is a start button waiting to be pushed.
When welding parts in production, you want to have reliable and consistent assemblies. You may have been churning out ‘good’ parts for years, but suddenly you are finding part inconsistencies and failures when none of your parameters have changed! What happened?
The origins of the verb “trend” mean “revolve or rotate” which has become “change or develop in a general direction”. It is appropriate that we discuss trends with respect to the auto market as the wheels revolve and the axle rotates, so do the trends change. Jabil recently commissioned a survey of the automotive and transportation industry seeking to understand trends from OEM’s and Tier 1’s in this market sector.
The moment is here, the process is set, the machine has cycled. How does it look? “GASP!” My staked part has FLASH!!! If you are not familiar with flash, I’m referring to the displaced plastic material from a staking or welding process that extrudes outwards and does not contribute to the strength of the joint. Flash may be observed as fine dust surrounding the joint, thin strands of plastic material in a disorganized clump, or even smooth rounded material adjacent to the weld joint. So why does flash occur in plastic staking and how can you optimize stake appearance?
Recently, we’ve been discussing conventional vibration welding and hybrid or ‘clean’ vibration welding. Vibration welding, a linear frictional weld method, you probably know all about. Hybrid – the introduction of an infrared preheat function prior to the conventional vibration weld process, is a relatively new method of welding plastic parts.
A quick review: The intent of the IR preheating prior to the introduction of frictional energy is fairly obvious – elevate the temperature of the weld joint. The anticipated result of this preheating is improved flash (plastic displacement from the joint) control and the potential in certain applications to reduce the necessary amplitude and/or force to achieve the ideal weld performance and assembly appearance.
Occasionally people will confuse vibration welding and ultrasonic welding because both processes use vibratory energy to weld plastic assemblies. However, both processes are very different from each other. Let’s look at the differences between the two processes and how you can use them to your advantage.