Quality guarantee period of lighting sector is normally one year from the date of ex-works. According to our market investigation, at present the damage rate of market digital tube is as high as 8% - 15%, stability of quality has become the biggest headache of the customer and the hindrance for the city lighting expansion. How to solve this realistic problem has become an issue bewildered the sector.

Do normal protection measures ring the bell?

The prevention measures in LED digital tube sector, in a whole, remains basically in two ends. Analyzed from the working conditions of the digital tubes, however, due to various adverse conditions in different areas as high temperature, frostiness, solarization, drenching, dryness and moisture etc. in which the tube must endure, the so-called perfect protection measures before ex-works meet with continuous challenges during the using of the product, what is the source for it? In fact, many enterprises neglect the following details before production:

I. During the guarantee period, the defective rate of the components in early stage is around 0.3% - 1%. Actual defective rate varies with the quality control of each enterprise.

II. The defective rate of digital tube is about 2% - 3% due to the erosion, following the change of the temperature, of water inside the tube and acid and alkaline matters.

III. The defective rate due from water entering caused by the sudden crack of shell and sealing end degumming is around 6% - 11%, specific defective rate is slightly different according to shell sealing mode of each enterprise. From the above we can see a “Special Protection” of the circuit board in the tube is essential for solving the problem, normal measures which protect only external water from entering can not protect the tube at all, nor slow down the high annual defective rate of digital tube.

Three Normal Kinds of Protection Measures in the Sector

Normal protection measures are as following:

First, adhere the sealing end and shell by ultrasonic wave, this is the most unreasonable way and the worst way. The product looks relatively beautiful by ultrasonic wave adhering, and the protection effect of the finished product looks also good, but material in adhering position has been injured by ultrasonic wave, and what is worse is that, after working in adverse conditions for about 3 months, the tube material in adhering position may result in a leakage as high as 30% - 40% due to the tension and cracking by expansion with heat and compaction with cold, this is quite severe a consequence.

Second, adhere the sealing end and tube with glue, this is a way the manufacturers adopt for saving cost, provided proper glue is used and details are paid attention to during production, this protection measure can have relatively good external protection effect when there is not big temperature change. However, if under high temperature, the increased air pressure in the tube will cause the cracking or sealing end degumming, this may also damage the inside circuit board with a defective rate as high as 5% - 10%.

Third, connect the sealing end and the tube with silica gel ring. This is with beautiful appearance, it can prevent water from entering but also exhaust the expanded air inside the tube when in high temperature, it is with relatively external protection effect; it solves the protection problem in the joint of the sealing end and the tube, however, it does not solve the problem of the damage of water to circuit board upon a failure of the external protection, thus it has not solve the protection of LED digital tube essentially.