Micro switches are widely used in precision electronic components such as automotive electronics, smart home appliances, industrial control, etc. due to their small size, sensitive triggering, and high reliability. However, due to its compact internal structure and sensitive electrical contacts, it is prone to switch failure, contact oxidation, and sensitivity reduction in humid, vibrating, or chemical environments. Therefore, waterproof sealing protection has become a key link to ensure the long-term stable operation of micro switches.
Application challenge: PP shell+long-term sealing, failure to stick firmly is ineffective protection
The housing of micro switches is often made of PP (polypropylene) material, which has low surface energy and strong inertness. Even after plasma treatment, many adhesives still exist:
✅ Insufficient adhesion, cracking occurs under slight stress
✅ After solidification, it becomes hard and brittle, and after fatigue aging, it peels off
✅ The waterproof layer is discontinuous and cannot form a sealed structure
At present, some factories use Weifu 500 adhesive, but there is still a risk of bonding fatigue and sealing degradation under long-term humidity and external forces.
Therefore, it is crucial to choose a highly reliable adhesive that can tightly bond with plasma treated PP and has a flexible sealing effect.
Recommended product: PUR 1680 Micro Switch Special Waterproof Sealing Adhesive
PUR 1680 is a single component moisture curing polyurethane reactive adhesive, particularly suitable for bonding low surface energy materials such as PP, PE, TPE, and sealing and packaging electronic devices.
Core strengths
Performance Characteristics and Advantages Explanation
After plasma treatment, PP has high adhesive strength and is firmly bonded without breaking or delamination
Excellent waterproof sealing performance can effectively block the infiltration of moisture, dust, and oil stains
After curing, the flexibility does not crack due to vibration or falling
Easy to operate, dispensing friendly, can be automated or manually applied, suitable for large-scale production
Strong temperature resistance and environmental adaptability, maintaining stable performance in environments ranging from -40 ℃ to 120 ℃
Application effect demonstration
After encapsulation and curing, PUR 1680 forms an integral protective layer between the PP shell and internal contacts, which can achieve:
Waterproof level up to IP67-IPX8 application requirements
Maintain sealing without cracking under long-term humid and hot conditions (85 ℃/85% RH)
No detachment or powdering after mechanical vibration/external impact
Applicable scenarios
✅ Car door lock/window lift switch
✅ Motorcycle handle micro motion trigger
✅ Electric tool trigger micro switch
✅ Home appliance control button micro switch
✅ Intelligent device and sensor module switch protection
For the water vapor protection and structural bonding scenarios of micro switches, the selection of adhesive should not only focus on initial bonding strength, but also on long-term sealing retention, moisture and heat resistance, and low surface energy bonding ability.
PUR 1680 provides a reliable, waterproof, and durable overall protection solution for micro switches through its flexible packaging and strong adhesive dual function, making it a more suitable solution to replace the Weifu 500.
Tags: PP adhesive · pur 1680 · Switch sealing solution · Micro switch sealing adhesive · Electronic waterproof packaging · Waterproof sealant
