UL requirements for plastic parts can depend on material ratings, part thickness, and end-use conditions. Confirming how those requirements apply to a specific part can be challenging.
At American Plastics, we manufacture UL-approved plastic parts to approved customer specifications. Our documented production and inspection procedures provide defined controls for each manufacturing project.
Read on to learn more about UL-approved plastic parts and the factors that affect their production and use.
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Benefits of UL-Approved Plastic Parts
UL recognition can simplify component qualification when UL Solutions has already evaluated a plastic material or component. UL Recognized components are evaluated against specified requirements and include conditions that govern their use within an end product. That evaluation gives engineers documented information for component selection and end-product certification.
UL recognition can reduce or clarify several steps in component qualification and end-product certification:
Reduced Retesting: Using UL Recognized components can reduce retesting during end-product certification because the component has already been evaluated against applicable requirements.
Defined Use Limits: Conditions of Acceptability identify how a Recognized component may be used and can include limits related to housing, wiring, temperature, or other operating conditions.
Verifiable Certification Data: UL Product iQ gives engineers access to certification records and ratings that can be checked during component selection.
Ongoing Compliance Monitoring: UL Solutions monitors Recognized components during production to verify continued compliance with applicable requirements.
North American Recognition: The UL Recognized Component Mark indicates that a component complies with applicable requirements for the United States, Canada, or both markets.
American Plastics Provides UL-Approved Injection Molding
American Plastics provides injection molding for UL-certified parts and components through our ISO 9001-certified facility. We maintain UL-approved status for qualifying injection molding work. The molding operation works with commodity plastics and engineering thermoplastics specified for customer projects.
Thirteen injection molding presses operate from 55 to 400 tons of force. Tie-bar spacing reaches 36 inches, and shot sizes reach 54 ounces. This equipment supports both commodity plastics and engineering thermoplastics.
Additional manufacturing capabilities include:
Multiple Molding Methods: Available methods include scientific molding, traditional molding, conventional molding, and insert-over molding.
Design and Engineering Support: Engineering and design assistance is available for injection molding projects before tooling and production begin.
New and Existing Tooling: New molds can be produced through our regional tooling and machining company, or customers can transfer existing molds for contract manufacturing.
Flexible Production Volumes: High-volume production requests, blanket orders, and repeat orders are supported.
Post-Molding Services: Assembly, filling, printing, labeling, packaging, ultrasonic welding, and fulfillment services are available after molding.
UL 94 Ratings for Plastic Parts
UL 94 classifies how plastic materials behave when exposed to a controlled flame under specified test conditions. Each classification reflects factors such as test orientation, afterflame time, afterglow, and whether burning material ignites a cotton indicator. Part thickness also matters because a plastic can receive different UL 94 classifications at different tested thicknesses.
| Classification | Test Setup | Classification Difference |
| HB | Horizontal | Burning rate must remain within the specified limit |
| V-2 | Vertical 50 W | Afterflame can last up to 30 seconds, and flaming drips may ignite cotton |
| V-1 | Vertical 50 W | Afterflame can last up to 30 seconds, and flaming drips cannot ignite cotton |
| V-0 | Vertical 50 W | Afterflame can last up to 10 seconds, and flaming drips cannot ignite cotton |
| 5VB | Vertical 500 W | Flaming drips are not permitted, and a hole may form in the plaque specimen |
| 5VA | Vertical 500 W | Flaming drips are not permitted, and a hole cannot form in the plaque specimen |
UL 94 classifications apply to plastic materials tested under specified conditions and do not by themselves certify a finished plastic part. The tested thickness also matters because the same material can carry different classifications at different thicknesses. Part specifications should therefore identify the applicable material classification and thickness.
Injection Molding Process Controls
Producing UL-approved plastic parts to specified requirements depends on repeatable molding conditions. Temperature, pressure, and cycle time can affect consistency from one molding cycle to the next. Keeping these variables within established ranges helps control variation during production.
At American Plastics, we use statistical process control to monitor temperature, pressure, and cycle times. Documented process windows help maintain established molding conditions during production. These controls support repeatability between production runs.
Quality Inspection and Production Documentation
UL-approved plastic parts may also have customer requirements for dimensions, appearance, fit, function, and other part characteristics. American Plastics uses a three-tier quality system to establish inspection criteria and verify molded parts against approved specifications. The inspection sequence begins with first article approval and continues through production checks and final inspection.
First Article Inspection: Initial molded parts are measured and documented for customer review. Once approved, the first article report establishes the dimensional and quality benchmark for later production runs.
Customized Inspection Plans: Customer requirements and approved first article data define what we check during production. The plan can cover tolerances, appearance, fit, function, testing, labeling, and packaging.
In-Process Inspection: Production parts are checked against the approved inspection plan through dimensional, visual, and required testing procedures. For tight-tolerance work, we can use MicroVu video coordinate measurement equipment to verify dimensions along the X, Y, and Z axes.
Final Inspection and Records: Final checks are completed according to the established inspection plan before shipment. Required certifications and inspection records document the completed verification.
Applications for UL Approved Plastic Parts
American Plastics maintains UL-approved status for electrical, consumer, and construction components. Applicable UL requirements depend on the component and its use within the finished product. These three markets include many products that use injection-molded plastic components.
Electrical Components: We manufacture plastic parts for electrical products under UL certification. Injection-molded electrical and electronics components can include connectors, switches, protective casings, and similar parts.
Construction Components: Our UL-approved status also applies to qualifying construction components. Common injection-molded construction parts include electrical boxes, pipe fittings, fasteners, and building hardware.
Consumer Product Components: Our UL-approved capabilities extend to components for consumer applications. We also manufacture injection-molded parts for home goods and other consumer products.
American Plastics Manufactures UL-Approved Plastic Parts
UL-approved plastic parts must meet applicable material, production, and end-use requirements. Clear specifications and controlled production help keep finished parts consistent with those requirements.
American Plastics manufactures UL-approved plastic parts under established customer specifications. Our injection molding capabilities support projects from tooling and production through inspection and secondary operations.
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