Ultrasonic Welding for Automotive

Case Study: Automated Ultrasonic Welding for Automotive Applications

Your average automobile contains about 30,000 individual components put together into approximately 1,800 separate assemblies, all of which are just as important as the next. Assemblies are typically manufactured by “part suppliers” on the open market competing for the business of major auto manufacturers. The vehicle manufacturers then buy up these parts and aggregate them into finished vehicles. 

Clearly, the automotive parts supply industry is a massive market, with suppliers constantly looking for ways to win the next big contract. In this case study, we take a look at one part supplier’s search for an automated machine solution that would help them execute a large contract for an upscale vehicle. The problem was solved with the help of an AMS automatic ultrasonic welding for automotive parts machine.


A national automotive Tier 1 parts supplier recently won a contract to produce a high volume of pre-insulated wheel well shrouds, complete with attachment clips, edge molding, ID labels and insulation batting installed.  These liners would be sent to a luxury German car manufacturer for their upcoming line of SUVs.

The application called for a very specific insulation batting to be employed: 3M™’s Thinsulate™ acoustic insulation. Thinsulate is an engineered synthetic material designed to manage noise, vibration and harshness in motor vehicles (parameters so important, that they’re known as “NVH factors” in the automotive world). With seven available versions, Thinsulate™ series differ by base weight range, color, density, frequency target, temperature resistance and moisture sensitivity.  

The parts supplier needed an automated assembly solution that would attach the Thinsulate™ reliably and repeatedly, with minimal rejects. Also, the supplier needed the system to be up and running as soon as possible.


AMS was approached as a potential bidder on the design and build of automated machine stations that would affix the Thinsulate™ batting to the thermoplastic wheel well liner. Our objectives were straightforward: Present a cost-competitive, high cycle-frequency, low cycle-time, low cost-to-operate solution in a standardized, scalable platform. In addition, we were to provide onsite startup and training, and stay engaged for support over the course of the contract for any part changes or adjustments needed.  

Very quickly in the qualification process, AMS rose to the top of the pack by way of our experience in automotive plastic joining systems, as well as our expertise in bonding liner battings. Our approach focused heavily on cost-reduction elements, specifically answering the question of how to join the materials at the lowest possible cost and least possible complexity.  

We recognized right away that the manufacturer might need to change the Thinsulate™ series being installed over time, so we noted the importance of designing an attachment method that worked across all varieties. We suspected that spot welding would be the way to go, and with that concept in mind, went on to test out the perfect solution.  

Our inhouse lab directly tested samples and provided proof of our design, in which we experimented with multiple bonding methods on the customer’s sample materials. The result: ultrasonic acoustical welding of the Thinsulate™ directly to the liner was the way to go.  

With a solution physically in hand and a competitive proposal submitted, AMS received the contract to build the solution that would eventually support luxury German SUVs all across North America.


Using our existing PJ-401 plastic joining automated machine platform, we designed and built a robust solution to tackle this Mercedes-Benz Thinsulate spot welding application.  The drawer-load, semi-automated PJ-401 supports multiple joining methods, from spot welding to stake forming, to hollow boss staking and composite horn welding. AMS frequently deploys the PJ series into common automotive applications such as door panels, instrument panels, truck liners, floor boards and yes, even wheel liners.  

AMS’s design team made sure to employ the features that spoke directly to the customer’s needs on this project:

The PJ series is a semi-automated platform using a PLC and HMI control scheme. Once the part is loaded into the machine, the PLC automates the entire process, starting with final positioning, alignment confirmation, ultrasonic welding, weld confirmation and part release.  

Our customized ultrasonic welding process uses no consumables, additional hardware or special materials in the mold. The Thinsulate™ is positioned against the liner, and the acoustical weld heads use precise frequency generation that produces localized heat, fusing the two materials together. No glue, backing strips, fasteners, stake bosses or other materials are needed.  

Continuing with the upfront work performed in our test lab, we further dialed in acoustic frequencies and tool heating/cooling profiles to achieve the most efficient weld for an impressive total turnaround time, repeatable all day long, part after part.

We included quality control data gathering and reporting features, allowing the PJ-401 to document quality conditions and successful completion in real-time, as the parts were being processed. We customized the output of this information so as to comply with the end user’s rigorous documentation requirements. Our solution offered further time savings due to the parts manufacturer being able to offload this data-gathering work from their QC staff.  

Our plastic joining solution for this Tier 1 parts supplier continues to operate on the line of the luxury German car manufacturer’s  wheel shroud line without fail. We support the installation with ongoing preventative maintenance service calls written into a service agreement. 

This project shows just one way AMS applies automation solutions into automotive applications, on projects of any size and any complexity.  

How Can We Help You? 

AMS is an industrial automation integrator in Cincinnati, Ohio. We specialize in advanced automation solutions, including automated ultrasonic welding for automotive applications. Need to hit the accelerator on your next automated automotive assembly? Book a virtual meeting today to review your application.

AMS Automated Machine Systems Cincinnati

AMS Machines

Automated Machine Systems, Inc. (AMS) increases the productivity of manufacturers by helping them design, build and implement their factory automation systems.