Spin-Welding

One of the Midwest's Leading Specialists in Thermoplastic Spin Welding

At Secondary Solutions Inc. (SSI), spin welding is more than another manufacturing process—it's one of our core specialties.

Since 1996, SSI has provided precision spin welding services for manufacturers requiring exceptionally strong, repeatable, and leak-resistant thermoplastic assemblies. While many manufacturers have shifted away from spin welding in favor of other joining methods, SSI has continued investing in the knowledge, equipment, and process development required to produce high-quality spin-welded components.

Today, relatively few contract manufacturers offer production spin welding. Fewer still have decades of hands-on experience developing reliable welding processes for demanding applications.

For customers requiring the strength, reliability, and repeatability that only spin welding can provide, SSI remains a trusted manufacturing partner.

Why Spin Welding Still Matters

Over the past several years, many manufacturers have transitioned toward ultrasonic welding because of equipment availability and changing manufacturing trends. While ultrasonic welding is an excellent process for many applications, it is not the best solution for every plastic assembly.

Spin welding continues to provide significant advantages for rotationally symmetrical components where weld strength, joint integrity, and manufacturing robustness are critical.

Rather than trying to redesign your product around a different joining method, SSI helps customers take full advantage of the proven benefits of spin welding.

Exceptional Weld Strength

Spin welding creates a true friction weld by generating heat through controlled rotational motion between compatible thermoplastic components.

Because the joint is created through frictional melting across the entire weld interface, spin welding often produces exceptionally strong structural joints for circular components.

For many applications, this results in:

• Outstanding mechanical strength
• Excellent leak resistance
• High burst strength
• Superior vibration resistance
• Long-term durability
• Permanent molecular bonding
• Consistent production quality

When product performance depends on a strong, permanent thermoplastic joint, spin welding remains one of the industry's most dependable manufacturing processes.

Greater Manufacturing Robustness

One of spin welding's greatest advantages is its ability to accommodate normal molding variation more effectively than some alternative joining processes.

Because heat is generated through friction across the complete mating surface, spin welding can often produce highly consistent welds on molded components that exhibit typical manufacturing variation.

This can provide manufacturers with:

• Greater process stability
• Improved production consistency
• Reduced sensitivity to minor molding variation
• Improved long-term repeatability
• Lower scrap potential
• Reliable production performance

Successful results still depend on proper joint design, material compatibility, and process development—areas where SSI's experience provides significant value.

A Specialized Manufacturing Capability

As demand shifted toward other joining technologies, many manufacturers chose not to invest in spin welding equipment or process development.

The result is that relatively few contract manufacturers today offer true production spin welding services.

SSI has continued supporting this process because we believe certain applications still deserve the advantages that only spin welding can provide.

Our long-term commitment allows customers to partner with an experienced manufacturer rather than searching for a specialty capability that has become increasingly difficult to find.

Engineering the Process

Successful spin welding is not simply pressing the cycle start button.

Every project is evaluated to optimize:

• Joint design
• Material compatibility
• Rotational speed
• Weld pressure
• Weld time
• Hold time
• Cooling characteristics
• Part alignment
• Fixture design

Developing the proper welding process is essential to achieving consistent weld strength, dimensional accuracy, and long-term manufacturing repeatability.

Custom Fixturing

Proper part alignment is critical to weld quality.

SSI designs and manufactures custom fixtures that ensure every component is accurately positioned throughout the welding cycle.

Our fixtures improve:

• Concentricity
• Weld consistency
• Dimensional repeatability
• Cosmetic appearance
• Production efficiency
• Operator consistency

Every fixture is developed around the specific geometry and performance requirements of the customer's product.

Process Development & Validation

Every successful production program begins with a proven process.

SSI supports customers through:

• Prototype welding
• Engineering evaluations
• Process optimization
• Validation builds
• First Article Inspection (FAI)
• Pilot production
• Long-term production support

Our collaborative approach helps reduce risk while ensuring dependable manufacturing performance throughout the life of the program.

Why Manufacturers Continue Choosing SSI

Spin welding has always been one of SSI's core manufacturing specialties.

For nearly three decades, we've continued refining our processes, developing custom fixtures, and helping customers solve difficult plastic joining challenges that many suppliers are no longer equipped to support.

Customers choose SSI because we provide:

• Manufacturing experience since 1996
• Decades of spin welding expertise
• Precision process development
• Custom fixture engineering
• Prototype through production support
• Experienced manufacturing technicians
• Responsive customer service
• Competitive pricing
• Minnesota-based manufacturing
• Consistent, repeatable weld quality

When your product depends on a strong, permanent thermoplastic weld, experience matters.

Looking Beyond the Weld

At SSI, we don't simply weld plastic components—we help customers develop reliable manufacturing processes that support long-term production success.

Whether your project is a new product launch, a supplier transition, or a legacy program requiring continued spin welding support, our team has the experience to deliver dependable results backed by decades of practical manufacturing knowledge.

Industries We Serve

Spin-welded thermoplastic assemblies are trusted across a wide range of industries where strong, leak-resistant joints are essential:

• Automotive & transportation
• Filtration & fluid handling
• Medical & laboratory devices
• Industrial & consumer products
• Agricultural & outdoor equipment
• Water treatment & irrigation

Typical applications include filters, float chambers, reservoirs, sensor housings, valves, and other sealed circular components that must hold pressure or resist leaks over a long service life.

Quality & Process Control

Consistent weld quality comes from disciplined process control. SSI validates every spin-welding program and monitors it throughout production to protect strength, dimensional accuracy, and appearance.

• First Article Inspection (FAI)
• Documented, repeatable process parameters
• In-process visual and dimensional checks
• Leak and burst testing to customer specifications
• Material compatibility verification
• Full traceability and process documentation

Production Experience

Since we began tracking, SSI has spin-welded more than 600,000 parts. Our deep experience with joint design, fixture development, and process control allows us to produce strong, leak-resistant welds on circular thermoplastic components. These figures are only what we have recorded since we started keeping track; actual production totals are higher.

Frequently Asked Questions