1.Optical lens
From cameras / DC / DV in life; to various professional cameras / cameras / telescopes / microscopes used in the workplace, all kinds of expensive and precise optical measurement, inspection, detection, health diagnosis, automated production and other related instruments / equipment / Supplies ... These are lenses that will absorb moisture and mold.
According to Japanese photo industry experiments, optical coatings on precision optical lenses are prone to mold after long-term absorption of moisture, especially in environments above 60% RH. Once the lens grows mold, it is not easy to detect with the naked eye, even if it is sent for repair, The original sharpness is restored, causing discrepancies in recording / testing / research and loss in maintenance and repurchase. Therefore, it is necessary to fully control humidity at 30-50% RH.
2. Magnetic recording materials
Magnetic recording materials are made of polymer materials with tape bases. The plasticizers and dispersants contained in them are suitable for decomposition and absorption by molds, although various magnetic recording material companies have added more or less antifungal agents in their production. However, the so-called "mildew-resistant disk" does not guarantee that the disk will not grow mold at all, it is just the difference in probability and speed. Sometimes, a disk suddenly cannot be read or written, and a certain track is broken. The main reasons are mold growth and moisture. Moisture of the magnetic recording material will also cause the magnetic powder to fall off; the mold will cause the tape base to be eroded, and both will cause the loss of recorded data signals. The falling magnetic powder and mycelium can also block the magnetic heads of computers, camcorders, and recorders, making the machine unable to work properly and even damaging the magnetic heads. In addition, mold can be transmitted through magnetic heads.
At present, the information recorded on magnetic recording materials is usually re-copyed regularly to prevent moisture and mold from causing loss of data signals, but it is time-consuming, troublesome, and limited. If the encrypted disk cannot be copied; the quality of the audio and video will be reduced after the audio and video tape is copied, and the quality of the audio and video will be very poor after repeated copying, which can not meet the requirements. To ensure the safety of magnetic recording materials, magnetic recording materials should be stored in an environment with a relative humidity of about 30-50% RH.
3.Image film
The film information carrier is composed of a polymer material base and an organic photosensitive material coated on the surface, which is suitable for mold decomposition. In particular, the photosensitive film on the surface is most susceptible to mold attack. The photographic film of the photographic film latex layer is also extremely susceptible to moisture and hydrolysis, which damages the image of the film. After the mold grows, the oxalic acid excreted by the mold can attack the silver shadow particles and dye images. Dye images also hydrolyze themselves under high humidity conditions. High humidity also causes residual chemicals on the film to damage the picture. Harmful gases in the air, such as sulfides and peroxides, can have harmful effects even at low concentrations. Peroxide is the main reason that causes the silver image particles to be oxidized, causing the colloidal silver to form colored deposition spots. Others such as paint vapors and active compounds can damage the substrate and the image.
Low-humidity environment can avoid mold growth and slow down the fading of image dyes, but low humidity or frequent periodic changes in humidity will reduce the adhesion of the film base and the emulsion layer, causing film edge peeling, curling, and emulsion layer cracking. And other phenomena. The high temperature environment will make the film gray and lose its gradation.
National Standard for Photographic Film Preservation:
Photo archive management specification GB / T 11821-89
6.1.1 The suitable temperature and humidity for storing negatives are: temperature 13-15 ℃, relative humidity 35-45%.
6.1.2 The suitable temperature and humidity for storing photos are: temperature 14-24 ℃, relative humidity 40-60%.
Article 6.4.3 The change of day and night relative humidity in the warehouse is not more than ± 5%.
Storage technology of processed film security film GB 9049-88
4.Paper, wood, silk and leather products
Paper products are widely used in archival materials, literature, cultural relics, calligraphy and painting, stamps, photos and various important bills, filter papers, test papers and so on. Wood products, silk products, leather products, etc. are widely used in all aspects of life and art and antiques. They all contain a large amount of cellulose. Long-term moisture absorption will swell and deform and affect the quality of precision printing. Moisture will stick to dust and stain, and will change with the effect of color. It will interact with the backing of stamps and photo albums to adhere. , Will form water marks, mold, etc. and cause damage to the value of the article. Chemical test strips also fail to indicate properly due to changes in composition. Therefore, it must be stored in a relative humidity environment of 30-50% RH to ensure safety.
5.Tobacco, grain, tea, medicine, etc.
From home tea, coffee, milk powder, Snack, dry goods, dry food, grains, Chinese and western medicinal materials, nutritious food; to catering industry, medicinal materials, baking materials, additives ... Caking, discoloration, discoloration, deterioration, mildew, and even carcinogenic toxins (such as aflatoxin in peanuts, ochratoxin in coffee, etc.), in daily life, affect the taste and health of eating, and for the industry, Will affect the quality of its products. In particular, once a large area of moldy and rotten warehouses of the above-mentioned items are stored, the losses caused are even more alarming. It can be stored in a relative humidity environment of 30 to 50% RH and turned over in time to ensure safety.
6, research and development supplies
Samples, reagents, standard products (pieces), filters, powder materials, pure metal materials, optoelectronic semiconductor components, hardware tools, electronic parts (materials), crystals, seeds, spices, adhesives, special sampling and samples Processing supplies, precision instrument accessories / consumables, backup circuit boards ... These supplies are very expensive and not easy to obtain immediately. Once they interact with trace moisture, various possible qualitative changes will occur, which will affect the results and progress of precision R & D / testing. Therefore, it must be controlled at <40% RH for a long time to effectively solve this problem.
7. Precision metal products:
From watches, precious metal jewelry, silverware, metal crafts, model cars, knives, gold coins ... collection; to industrial precision molds / tools / measuring tools / manufacturing tools / tools (pieces) ... ... the precision machining (carving) of metal surfaces Easily absorb moisture and oxidize (especially above 35% RH), loss of gloss / rust, and dust contamination, which affects the value of storage; its precise function will also be distorted due to aging of the machine, affecting accuracy or poor contact , Can not work normally. Therefore, it must be controlled at <40% RH for a long time to effectively solve this problem.
8. Precision electronic equipment
From DC / DV / Mobile phone / MD / ipod and other digital electronic supplies; to R & D / Lab / Engineering / Processing / Maintenance / Military police / Education / Medical / Testing / Computerized / Audiovisual and other related units' precision instruments / equipment / weapons / Computer network management host / Audiovisual equipment ... ... its precision numerical control IC chip / Electronic contacts in the circuit board are susceptible to moisture absorption and oxidation for a long time, resulting in poor contact, which may cause time to time or even downtime. Its precision sensing components are degraded and deformed by the action of moisture. (Quality) changes, resulting in distortion, deviation and even failure, must be controlled at <40% RH for a long time to effectively solve this problem.
9. Precision electronics manufacturing processes such as SMT / PCBA / LED / LCD / IC packaging ... etc.
Existing IPC / JEDEC J-STD-033B strictly regulates that its moisture sensitive materials / semi-finished products (MSD) must be stored in <10% RH or <5% RH Fast Super Dryer to prevent such as popcorn, Occurrence of poor quality such as welding, peeling, oxidation, etc.
10.All research industries / manufacturing industries that need upgrading
Must improve its precision contact (combination) / compression / mixing / injection / encapsulation / printing / adhesion ... processing / process technology, its key materials / semi-finished products must also be classified as MSD and fast Only low-humidity storage can improve the yield.
