Custom Ultrasonic Welding Fixtures for Plastic Parts

What Is an Ultrasonic Welding Fixture

An ultrasonic welding fixture, also called a support nest, holds and locates the plastic part while the horn 

applies vibration and pressure. Its contact surfaces support the part and help limit movement or deformation

during welding.

The fixture and horn perform different functions and should be reviewed together. The fixtures shown 

on this page are examples of application-specific tooling, rather than standard designs for every product.

Custom Ultrasonic Welding Fixture in Operation

See how the custom fixture positions and clamps the part during ultrasonic welding.

Designed Around Your Part and Process

Fixture design starts with the molded part and the intended welding process.

• Support near the weld area

  Contact areas are selected to support the part under welding force, with attention to thin walls

  and unsupported sections.

• Repeatable positioning

  Locating surfaces and stops are arranged to position the part while allowing for molded-part variation.

• Surface protection

  Contact materials and finishes are selected with the part’s cosmetic requirements in mind.

• Loading and machine access

  The layout considers loading, unloading, horn clearance and mounting to the intended machine or station.

• Clamping where required

  Manual or pneumatic mechanisms can be considered when the part needs additional restraint or controlled release.

Learn more about fixture support and positioning, or explore our custom ultrasonic welding horns.

Fixture Configuration & Design Inputs

Custom Fixture Development

1. Application review

Review part drawings or samples, weld locations, quality requirements and machine information.

2. Fixture design

Define support, positioning, clamping and mounting arrangements.

3. Manufacturing and fit checks

Manufacture the fixture and check part seating, clearances and mechanism movement.

4. Welding trials

Where agreed, evaluate the fixture with the horn, machine and actual molded parts.

5. Delivery and guidance

Confirm the supplied scope and provide setup information.

FAQ

Can you make a fixture for my existing welding machine?

We can review the design using your machine table dimensions, mounting-hole layout, available space 

and horn information.

Can one fixture hold several different parts?

Only when their geometry and support requirements allow it. Interchangeable nests may be considered 

for related variants, subject to design review.

Do you need actual molded samples?

Drawings and photos can support an initial review. Actual samples may be needed to check seating, 

molded-part variation, loading and welding performance.

Is a matching horn included?

A horn and fixture can be reviewed together. The quotation specifies whether the supply 

includes the fixture only or a complete tooling set.

Discuss Your Fixture Requirements

Show us how your part needs to be located and supported during welding. Helpful details include:

• Part drawings, photos and material

• Weld location and horn contact area

• Machine worktable dimensions and mounting details

• Loading method and surfaces that must be protected

If you have an existing fixture, share photos and describe any movement, deformation or loading difficulties.

Use the inquiry form below or contact us on WhatsApp: +86 159 8954 1416.