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What Is Difference Between OCA And OCR For Touch Panel?


Generally, what’s bonding way for touch panel?Today,let us talk about the what is OCA and OCR for touch panel?

OCR and OCA for touch panel

What is OCR for Touch Panel?

OCR Optical Clear Resin is a special adhesive designed for bonding transparent optical components. The optically transparent resin can fill the gap between the panel and the transparent protective layer and the liquid crystal module to improve the contrast of the display. Compared with the traditional air gap method, this optical resin can suppress light scattering caused by external light and backlight. The optically transparent resin formed by rapid response to UV irradiation has a refractive index and light transmittance similar to glass, resistance to yellowing, softness, and can withstand the expansion and contraction rates of a variety of different substrates, so that it can withstand high and low temperature changes during bonding problem. This product is suitable for the lamination and assembly of touch screens, large-size glass substrates or other soft and hard boards.


OCR Optical Resin Product Characteristics

Curing method: ultraviolet light UV curing, combined with point and surface light sources;

Chemical system: acid-free colloid and compatible with ITO;

Ease of use: You can select the dispensing or other corresponding coating methods

Repairability: It has the characteristics of being reworkable before being completely cured;

Optical characteristics: high optical penetration characteristics and matching refractive index;

Other characteristics: low hardness, low shrinkage, low haze (Haze)


What Is OCA For Touch Panel?

OCA (Optical Clear Adhesive), the optical acrylic adhesive is made into no substrate. And then a layer of release film is laminated on the upper and lower bottom layers. It is a special layer of optically transparent double-sided adhesive without substrate.

Its advantages are clarity, high light transmittance (total light transmittance> 99% or more), high adhesion, high weather resistance, water resistance, high temperature resistance, UV resistance. What’s more,it will not produce yellowing (yellow) after long-term use, peeling and deterioration issues. Completely different from acrylic transparent glue, some mermaid mixed beads pretend that these acrylic transparent glues are OCA (generally, the light transmittance of PMMA is still around 95%). However, its high temperature resistance, water resistance, and UV resistance are very poor. And it also will turn yellow in a short time, which has a huge impact on light transmittance.


The Advantage of OCA for Touch Panel

1.High bonding and peeling strength, suitable for bonding many transparent film substrates to glass, resistant to high temperature, high humidity and UV light. It can be cured at room temperature or medium temperature with low curing shrinkage.

2.Controlled thickness, providing uniform spacing;

3.Good durability, no yellowing, no delamination or degradation.

4.Light transmittance>92-99%

5.Refractive index 1.48

6.Haze 0.1%, low acidity,

7.Bonding smooth or textured surface with strong adhesive force.


The Disadvantages of OCA for Touch Panel

Similarly,after we know about the advatange of OCA. What’s disadvatange of it?However,there have six disavantages of OCA for touch panel,let us discuss about them.

1.The surface of the OCA film is sticky. When you peel off the release film , it is easy to leave marks on the surface, and it is easy to produce bubbles when bonding. Easy to adsorb dust and impurities to cause secondary pollution.

2.In the process of lamination of OCA film and FILM, uneven manual lamination pressure is easy to wrinkle and produce bubbles. For G+G lamination, use a vertical press combination machine, and the air under heating and pressure is difficult to remove, which is very easy to generate air bubbles. However, the effect of the deaerator is not great.

3.OCA has poor flow performance,  it is difficult to fill the ITO line gully or ink when Sensor or cover glass attache it

4.The bonding performance of OCA is not strong, and the product that fits well has the risk of rebound.

5.OCA is not conducive to large-size lamination, low production efficiency, and high labor cost. It is difficult to perform OCA bonding for G+G for medium size (about 10 inches). What’s more, for large size bonding (such as 15.6-inch 48-inch 72-inch).Firstly, it becomes more difficult as the size increases. Secondly, the production efficiency is low.And thirdly, the yield rate is also low.

6.OCA cannot effectively increase the strength of the screen and the ability of explosion-proof. Especially for OGS, it must need to attached the explosion-proof film . After fitting, the screen has poor anti-explosion effect, is not resistant to falling, however,  the screen is easily damaged.


Storage Conditions

  1. Environment: It is best to store directly in a clean room, however, cover each roll of material with film
  2. Temperature: Temperature: 22±4
  3. Humidity: 40%-60%
  4. Placement: Place it upright or hang it to avoid poor indentation caused by heavy pressure on the OCA.

In conclusion, we know there have 4 way of storage conditions for OCA.Therefore, we need to pay attention to it.


Nine Tips for Optical Adhesive OCA Defoaming

When we use optical glue OCA for bonding, sometimes bubbles may appear.  Therefore, here are 9 ways to defoam

  1. The bonding process is in a class 10,000 clean room;
  2. Use a precision laminating machine;
  3. Adjust the pressure, speed and angle of the laminating machine;
  4. The cutting and punching process of the optical adhesive explosion-proof film are all placed vertically;
  5. Defoaming treatment with heating and pressurization
  6. Machine rolling. Pay attention to the flatness of PC (PMMA);
  7. If the alignment is not correct,we can make special tools ;
  8. Adopt the method of heating while laminating:
  9. Or use Uninwell’s liquid optical transparent glue 7070-5, UV curing type, light transmittance 99.99%, yield rate above 95%, which can solve the above problems

Above all, theser 9 way will help you to defoam on the touch screen.

In conclusion, Dingtouch as a professional touch screen panel manufacturer.We are welcome to customize your own touch screen panel for your project.In other words, we will sincerely listen to your detail requirement.Send us your drawing and then let us get start the business together now.We also have professional engineer team for you if you have any question of touch screen panel.We can solve your every question as we can. Come on! Contact with us!

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