Bonding plastic that will run hot is a two-part problem: the adhesive has to grip a low-energy surface, and it has to keep gripping it at 100°C and above. Heat-resistant glue for plastic has to solve both, and Incure Heat-Resist™ 328 is formulated for exactly that combination.
The Two Failure Modes to Design Around
Plastic-to-plastic bonds that fail hot usually fail one of two ways. Either the adhesive never wet the surface properly, so the bond is weak from the start, or the cured film softens as temperature rises and the joint creeps under load. A general-purpose cyanoacrylate is vulnerable to both. Heat-Resist™ 328 addresses the second with a modified cyanoacrylate chemistry that holds a large fraction of its strength through sustained heat, and the first is handled with correct surface preparation.
It is a single-component, medium-viscosity adhesive that cures at room temperature through ambient moisture, with no mixing and no pot life.
Incure Heat-Resist™ 328 at a Glance
- Chemistry: single-component, room-temperature-cure cyanoacrylate
- Viscosity: medium, for controlled placement and small gap filling
- Fixture speed: seconds to tens of seconds depending on substrate and humidity
- Bond strength: up to roughly 5,200 psi on suitable rigid plastics
- Thermal behavior: engineered for thermal-shock resistance and elevated continuous service
- Chemical resistance: withstands alcohols, aliphatic fuels, aromatic hydrocarbons, and dilute acids and bases
Matching the Adhesive to the Plastic
Surface energy drives everything. ABS, polycarbonate, PVC, acrylic, and most filled engineering resins bond well after a solvent wipe. Nylon and acetal need light abrasion and often a primer. Polyethylene, polypropylene, TPO, and PTFE are low-energy and require a dedicated polyolefin primer before the adhesive will hold. Glass-filled grades bond more like the base resin but benefit from a slightly thicker film to fill surface texture.
For dissimilar-plastic joints, thermal expansion is the hidden load. A rigid plastic bonded to a flexible one over a wide temperature range puts continuous stress on the bond line even when the assembly is doing nothing, so review how CTE mismatch causes adhesive bond failure during joint design. If you are also weighing chemistry options, UV glue versus epoxy for transparent bonding covers the trade-offs on clear plastics.
Application and Cure Control
Clean both faces with isopropyl alcohol and let them flash off. Apply one thin drop or bead to a single face, mate within the open time, and hold light fixture pressure until handling strength develops. Full strength and peak heat resistance build over 24 hours; a short 80–100°C post-cure accelerates that on production lines. Keep shop humidity between 40 and 60 percent, and use an activator on primed polyolefins or wider gaps. Meter each dispensed shot on automated equipment so film thickness stays repeatable.
Where Heat-Resist™ 328 Fits
- Automotive: under-hood plastic housings, ducts, and clips near heat sources
- Appliance manufacturing: plastic components in ovens, dryers, and cooktops that see cyclic heat
- Industrial equipment: plastic guards, covers, and fixtures in warm process areas
- Consumer electronics: internal plastic structure near power supplies and processors
- Lighting: plastic housings and lenses adjacent to LED drivers and ballasts
Testing the Joint Before Production
Qualify the bond on production plastic, not on generic coupons. Mold conditions, regrind content, colorant, and release agent all shift the surface chemistry of an injection-molded part, and a bond that passes on a clean test plaque can fail on a greasy production run. Prepare a sample set using real parts and the intended cleaning step, cure fully, then split the set: test one group at room temperature and put the other through a thermal-cycle profile that brackets the service range before testing. Record failure modes. Substrate tear or adhesive left on both faces is the target; a clean release from one surface signals contamination or incomplete cure and should be traced before the process is released.
Handling and Storage
Store unopened bottles refrigerated at 2–8°C and bring them to room temperature before opening to avoid condensation inside the bottle. Reseal after every use and follow the label shelf life. Keep the adhesive off skin and eyes, work with ventilation, and cure spills with water or activator before disposal.
For help pairing a Heat-Resist™ grade with a specific resin and service temperature, Email Us with your material and load details.
Frequently Asked Questions
Q: Which plastics are hardest to bond?
A: Polyethylene, polypropylene, and fluoropolymers. All need a polyolefin primer, and even then the joint should be designed for shear, not peel.
Q: How hot can the finished bond run?
A: Well beyond standard cyanoacrylate. Confirm the specific ceiling for your resin and stress state with Incure before qualification.
Q: Does it fill gaps?
A: Small ones. For gaps beyond about 0.2 mm, use an activator or a higher-viscosity grade.
Heat-resistant glue for plastic only works when surface prep and chemistry both do their jobs. Incure Heat-Resist™ 328 supplies the chemistry for hot-running plastic assemblies. Contact Our Team to request samples and a technical data sheet.
Visit www.incurelab.com for more information.