Comparison of aging resistance between LOCA and OCA
Vehicle mounted/outdoor/wide temperature equipment (damp and sun exposed) → LOCA water-based adhesive, aging resistant roller OCA; Indoor room temperature small-sized consumer terminals (mobile phones/tablets) → OCA sheet adhesive, meeting room temper
Comparison of aging resistance between LOCA water-based adhesive and OCA sheet adhesive (key selection for industrial wide temperature screens, compatible with AU/Innolux industrial control screens)
1.Damp heat aging (85 ℃/85RH high temperature and high humidity test, industry standard)
LOCA liquid water-based adhesive
✅ Better resistance to moisture and heat
UV cured epoxy/silicon-based LOCA cross-linking is dense, with a water absorption rate of less than 0.5%. Long term exposure to 85 ℃ and 85 RH for thousands of hours results in minimal whitening, delamination, and fogging;
Car mounted and outdoor industrial control screens are preferred for humid environments all year round, and 90% of the original industrial assembly is glued with water.
Shortcoming: Poor quality acrylic water-based adhesive may undergo slight yellowing due to prolonged high temperatures.
OCA solid sheet adhesive
Weak resistance to moisture and heat
Most of them are made of acrylic adhesive, with a high polymer structure that easily absorbs water. In a long-term humid and hot environment, the edges absorb water and turn white, gradually defoaming and layering;
Suitable for indoor use at room temperature, not recommended for long-term use outdoors or in vehicles with high humidity.
2. High and low temperature thermal shock (-40 ℃~105 ℃ cycle, wide temperature industrial screen core indicators)
LOCA water-based adhesive
After solidification, the colloid has good elasticity, and the coefficient of thermal shrinkage and expansion is close to that of glass. It does not crack or shrink after repeated cycling at -40~+105 ℃, and is suitable for wide temperature scenarios of engineering machinery and low-temperature equipment (standard for wide temperature screens such as G085VW01).
OCA sheet adhesive
Significant low-temperature shrinkage and high-temperature creep:
High temperature>85 ℃: adhesive layer shrinkage, edge curling and delamination;
Low temperature<-20 ℃: The colloid becomes hard and brittle, and bubbles are prone to rebound at the screen frame; Narrow temperature consumer screens are suitable, with obvious shortcomings in extreme wide temperature.
3. UV weathering aging (exposure to sunlight and ultraviolet rays)
Silicon based LOCA: Top grade UV resistance, resistant to direct sunlight for 3-5 years without yellowing, preferred for charging stations and outdoor touch screens;
Ordinary acrylic LOCA: mid-range, suitable for indoor/semi outdoor use, with slight yellowing after long-term exposure to sunlight;
OCA film adhesive (all acrylic): has the worst UV resistance, and overall yellowing and decreased light transmittance due to long-term sun exposure, making it unsuitable for outdoor equipment.
4.Long term natural aging (3-8 years of overall machine service life)
LOCA: Strong chemical stability after curing, no small molecule precipitation of colloids, and rare touch failure and screen watermarking in industrial equipment for 5-8 years;
OCA: Adhesive additives gradually precipitate over time, and local watermarks and fog spots may appear on the screen within 2-3 years. It is commonly used for mobile phones and tablets that require 2-3 years of replacement.
5. Selection Summary (for your 8.4-inch AU industrial screen)
Vehicle mounted/outdoor/wide temperature equipment (-40~85 ℃, humid and sunny) → LOCA water-based adhesive, aging resistant roller OCA;
Indoor room temperature small-sized consumer terminals (mobile phones/tablets) → OCA sheet adhesive, meeting room temperature aging standards, with high cost-effectiveness.
