前面说了常用的可移除压敏胶系，而不常用的压敏胶有UV压敏胶系和有机硅压敏胶系这两种。这两种胶为什么不常用？小编为您解答，今天先说说UV压敏胶系。

什么是UV压敏胶？

　　UV压敏胶是通过不同的UV波段（紫外线光）进行光照固化的压敏胶。

UV压敏胶的优缺点

　　之所以不将UV压敏胶当做常用可移胶，除了成本原因，也是由于它的胶体性质决定它很难达到可移除的性能。

　　UV压敏胶系的优点十分突出，它的胶体非常透明，生产车速快，还是100%的固含量。


　　但它的缺点也十分突出，因此给许多厂家带来一定门槛。

• 相比水胶系、热熔胶系的气味大多了，相比有机硅压敏胶系的气味，就要看个人接受程度了，总之两个气味都不会小
• 生产车速快慢，跟UV灯组的功率及数量多少有直接关系，从而使产线的投入和生产的成本会非常高， UV 压敏胶胶水的成本也比亚克力胶系高的多，比有机硅压敏胶水的成本会稍低一些
• 虽然100%固含，但因为UV单体树脂气味较大，有较强的刺激性，容易造成过敏现象
• 耐高低温性能和高低温兼容性差，低温环境胶面粘性急剧变弱
• 胶面对各种材质长时间内的粘贴可移除性能不会太好，个别材质（玻璃/烤漆/大理石）在特定的环境（常温环境）下有短时间（6个月左右）的可移除性

如何改善可移除性

　　由于UV压敏胶的可移除时间短和限制较多，为了改善可移除性能，通常会采用加专用稀释剂或者调整光引发剂的方法，具体原理如下。

　　方法1：当设备精度不够或涂胶厚度不变的条件下，便可以通过加专用稀释剂来调整原胶体的有效含量，使干胶后降低了胶的初粘力，来提升一定的可移除性能。

　　方法2：通过调整更为匹配的光引发剂，以及光照时间，增加了胶体的有效固化率换来了更好的内聚力，从而也会大大减低了胶水的初粘力。

　　需要提醒的是，因UV压敏胶胶系本体树脂的原因，胶体的持粘力要么在以上的调整下，来实现好的可移除性，但同时持粘力及初粘力都会大幅度减低或像消失了一样。




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Useful tips | Understanding the pros and cons of UV pressure-sensitive adhesive, you will get it after reading this article!

    I mentioned the commonly used removable pressure-sensitive adhesive earlier, while the less commonly used ones are UV pressure-sensitive adhesive and silicone pressure-sensitive adhesive. Why are these two adhesives not commonly used? Let me explain, starting with UV pressure-sensitive adhesive.

What is UV pressure-sensitive adhesive?

   UV pressure-sensitive adhesive is a pressure-sensitive adhesive that cures through exposure to different UV wavelengths (ultraviolet light).

Pros and cons of UV pressure-sensitive adhesive

   The reason UV pressure-sensitive adhesive is not commonly used as a removable adhesive, besides cost, is due to its adhesive properties, which make it difficult to achieve removable performance.

   The advantages of UV pressure-sensitive adhesive are remarkable. It has a very transparent adhesive, fast production speed, and a 100% solid content.

   However, its disadvantages are also significant, which pose certain challenges for many manufacturers.

   Compared to water-based adhesive and hot melt adhesive, it has a stronger odor. Compared to silicone pressure-sensitive adhesive, it depends on individual tolerance for the odor. In any case, both odors can be strong.

   The production speed depends on the power and quantity of UV lamps, thus resulting in high investments and production costs. The cost of UV pressure-sensitive adhesive is much higher than that of acrylic adhesive and slightly lower than that of silicone pressure-sensitive adhesive.

   Although it has a 100% solid content, the strong odor of UV monomer resin can cause irritations and allergies.

   It has poor resistance to high and low temperatures and compatibility. The adhesive strength of the adhesive surface weakens significantly in low-temperature environments.

   The performance of long-term removable adhesion to various materials is not excellent. Certain materials (glass/paint/marble) can have a short duration of removability (around 6 months) in specific environmental conditions (room temperature).

How to improve removability

   Due to the short removal time and limitations of UV pressure-sensitive adhesive, special diluents or adjustments to photoinitiators are commonly used to improve removability. The specific principles are as follows:

   Method 1: When equipment accuracy is insufficient or the coating thickness remains unchanged, the effective content of the original adhesive can be adjusted by adding a special diluent. This reduces the initial tackiness of the adhesive after curing, enhancing its removability to a certain extent.

   Method 2: By adjusting a more suitable photoinitiator and exposure time, the effective curing rate of the adhesive is increased, resulting in better cohesion. This significantly reduces the initial tackiness of the adhesive.

   It should be noted that due to the nature of the UV pressure-sensitive adhesive resin, the adhesive's holding power and initial tackiness will be greatly reduced or even disappear when achieving good removability through the above adjustments.