Ultrasonic Welding of PET Plastic: From a Challenging Application to a Stable Production Solution
For PET packaging, trays, and components, weld quality depends on the material, product geometry, weld location, welding horn, fixture, and operating parameters. VietSonic evaluates actual samples, conducts application testing, and designs a system tailored to each manufacturer’s production requirements.
No added adhesive at the weld
Clean and consistent joints
Automation-ready
When Staples and Adhesives No Longer Meet PET Product Requirements
PET is widely used for transparent boxes, thermoformed packaging, trays, and sheet components. However, many PET products are still secured with staples or adhesives because manufacturers have yet to find a sufficiently stable welding method.
Staples can create sharp edges, reduce visual quality, or introduce a risk of metal contamination. Adhesives require additional consumables, curing time, and dispensing control. As production volume increases, these methods also make it more difficult to maintain consistent quality and implement automation.
Eliminate Additional Consumables
Join the material directly at the contact interface, reducing the need for staples or adhesives during assembly.
Cleaner Joints
Concentrated energy is ideal for spot-weld locations that require a clean appearance and minimal impact on the rest of the product.
Fast Cycle Times
Energy is applied only during the weld cycle, supporting production lines that need higher speed and fewer manual operations.
Easy to Standardize
Operating parameters can be saved as process recipes to control results consistently across production cycles.
From a PET Product Sample to a Production-Ready Welding System
The welder is only one part of the solution. To achieve the required PET weld quality and repeatability, VietSonic provides an integrated process covering product assessment, sample testing, welding horn design, and weld-cycle optimization.
Sample Evaluation
Identify the material, thickness, geometry, weld location, and the manufacturer’s inspection criteria.
Application Testing
Test multiple combinations of amplitude, weld time, energy, pressure, and hold time.
Welding Horn Design
Calculate the contact geometry and manufacture a welding horn suited to the PET product.
Fixture Design
Hold the product in the correct position, minimize movement, and distribute force consistently during welding.
Machine Completion
Evaluate repeatability, provide operating guidance, and adjust the system to the actual production rate.
The Difference Lies in Application Expertise
Although all may be made from PET, films, sheets, thermoformed packaging, and injection-molded components transmit energy differently. Parameters developed for one product should therefore not be applied unchanged to another. Results must be verified directly on the manufacturer’s sample.
Ultrasonic Spot Welding on PET Packaging
This video shows VietSonic conducting a spot-welding test on a PET product. The result demonstrates that ultrasonic technology can create a direct bond, giving manufacturers an alternative to stapling or adhesive bonding.
Factors That Determine PET Weld Stability
During welding, the horn transmits mechanical vibration into the part. Energy concentrated at the interface softens and locally melts the material. Pressure is maintained while the material solidifies to form the bond.
| Control Factor | Engineering Solution | Value for the Manufacturer |
|---|---|---|
| Material Composition | Evaluate single-layer PET, laminated materials, coatings, additives, and compatibility between the two surfaces. | Avoid selecting equipment based solely on a generic material name. |
| Thickness and Geometry | Assess the energy path, distance from the horn to the joint, and the part’s tendency to deform. | Reduce the risk of incomplete welds, surface marking, or product distortion. |
| Welding Horn | Design the contact profile around the required weld shape and select a horn material suitable for the operating cycle. | Deliver energy to the correct location and form the required weld pattern. |
| Fixture | Provide secure positioning, support the weld area correctly, and prevent the part from moving when the horn is applied. | Improve consistency between products and reduce dependence on operator technique. |
| Cycle Parameters | Optimize amplitude, weld time or energy, pressure, and post-weld hold time. | Balance joint strength, appearance, and cycle time. |
| Production Rate | Select a manual unit, standalone machine, multi-horn system, or integrated production-line solution. | Invest in the appropriate level of automation and simplify future capacity expansion. |
What Does a Manufacturer Receive Beyond the Welding Machine?
The objective is to deliver a production-ready welding process that matches the product and the factory’s operating capabilities.
- Direct weld testing on PET samples supplied by the manufacturer.
- Weld-location assessment and design-adjustment recommendations when required.
- Welding horn design and manufacturing based on the product geometry.
- Fixture design for part positioning and support during the weld cycle.
- Machine configuration based on output requirements and the required level of automation.
- An initial parameter set for the tested product sample.
- Guidance on operation, changeovers, and weld-quality inspection.
- Maintenance, repair, and process-optimization support when the product changes.
A Solution That Can Be Developed for Various PET Products
Depending on the product structure, ultrasonic spot welding can be evaluated for applications that require a fast, clean joint without added staples or adhesives.
PET Boxes and Packaging
Secure edges, folding tabs, or locking points on thermoformed PET packaging and transparent boxes.
PET Sheets and Films
Create spot bonds on sheet or film products when the structure allows energy to be transmitted and concentrated effectively.
Assembled Plastic Components
Join small areas, attach tabs, secure components, or create temporary locating points before subsequent operations.
What Manufacturers Should Know Before Testing PET Welding
Can the same parameter set be used for every PET product?
Can ultrasonic welding completely replace staples or adhesives?
What should a manufacturer provide for sample testing?
Can the welding machine be integrated into an automated production line?
Send Us Your PET Sample to Evaluate Weldability Before Selecting Equipment
VietSonic receives samples, analyzes application requirements, and tests a suitable welding method. The sample-test results provide the basis for determining the welding horn, fixture, parameters, and machine configuration required for production.
Hotline: +84 938 49 33 66 – Mr. Hai
Email: info.vietsonic@gmail.com
Website: https://vietsonic.vn