How to select dust-free cloth correctly has always been a headache for users of dust-free cloth. Here, we will discuss how to select dust-free cloth materials, which should also be used as a guide. Dust free wiping material, commonly known as dust-free cloth in China, is a special cleaning cloth for dust-free room. Compared with ordinary civilian wiping cloth, it has similarities and differences. What's common is that they are all decontamination products, which require strong decontamination ability and no reverse pollution. The difference is that the dust-free room cloth focuses on the removal of trace pollutants, requires to be able to withstand the erosion of various solvents, with ultra-low dust generation, while the civil dishcloth only requires the general non falling wool and water resistance.
Dust free wiping materials have been widely used in various high-tech industries, From general consumer electronics to biopharmaceuticals, from general laboratories to satellite factories, all places with dust-free rooms need dust-free wiping materials. It is the wide application of dust-free wiping materials that forms a variety of dust-free wiping materials on the market. At present, there are mainly the following categories of dust-free wiping materials on the market:
1. Polyester knitted wiping cloth
2. Polyester brocade knitted wiping cloth
3. Polyester brocade woven wiping cloth
4. Wood pulp / viscose and polyester composite non-woven wiping cloth
5. All polyester non-woven wiping cloth
6. All wood pulp non-woven wiping cloth
7. All PP non-woven wiping cloth
8. Pu sponge wiping cloth
9. PVA sponge wiping cloth
10. Cotton woven knitted wiping cloth
According to many years of practical experience, the correct selection of dust-free wiping materials should follow the following steps:
1. Clarify the objects to be clear and the requirements of cleanliness;
The so-called clean objects, we need to determine what we mainly remove? Is it a general grease fingerprint, or some residual glue? Or is it easy to remove dust? Is there high temperature in clean watch? How hard is the cleaned surface? Is there any requirement to prevent scratching? How clean is it? Are there any requirements for organosilicon pollutants? Is it sensitive to polluted ions?
2. Determine the compatibility with the solvent used;
As we all know, dust-free wiping materials are all polymer materials, and in the process of cleaning, we should use organic solvent for cleaning, but there is a problem we must pay attention to, that is, to what extent can our wiping cloth tolerate our organic solvent? How soluble is our wiping material in solvent? This is the problem of solubility parameters of polymer materials. It is recommended to check the solubility parameters first when choosing a better wiping cloth. The closer the solubility number of wiping cloth is to the solubility parameter of solvent, the easier the wiping cloth is to be dissolved by solvent!
3. Determine the type of dust-free materials;
Before choosing the wiping cloth, we need to determine the advantages and disadvantages of various dust-free wiping materials, which are limited to space. The following is only a brief introduction
① Polyester knitted wiping cloth
Advantages: wear resistance, strong decontamination ability, high cleanliness.
Disadvantages: it has no water absorption and weak ability to remove sewage. It is usually treated with hydrophilic agent, which will dissolve into the solvent we use.
② Polyester brocade knitted wiping cloth
Advantages: wear resistance, strong ability to remove grease, fingerprints and other pollutants, fast drying of solvent after wiping, high efficiency.
Disadvantages: high cost.
③ Polyester brocade woven wiping cloth
Advantages: strong ability to remove residual gum.
Disadvantages: the ability to remove granular dirt and dust is weak.
④ Wood pulp / viscose and polyester composite non-woven wiping cloth
Advantages: non-woven structure, strong macro decontamination ability, suitable for removing a large number of pollutants.
Disadvantages: the cleanliness is not high, the solvent is broken and crumbs are removed, so it can not be used in a very clean environment.
⑤ All polyester non-woven wiping cloth
Compared with wood pulp polyester non-woven wiping cloth, it is clean and durable, but it is not suitable to remove water pollution, because the hydrophilic ability of polyester is not strong.
⑥ All wood pulp non-woven wiping cloth
Advantages: resistant to organic solvents, strong decontamination ability.
Disadvantages: the cleanliness is not high. At present, in addition to Japan's M-3, the cleanliness of other wood pulp non-woven fabrics made in China is very low, and it is easy to fall debris, so it is not suitable for use in dust-free rooms above 1000 levels.
⑦ All PP non-woven wiping cloth
It is a good helper for oil pollution removal, but its cleanliness is not high and its water absorption is not good.
⑧ Pu sponge wipe
Large amount of decontamination, but not durable, easy to break off fiber. And it is not resistant to solvent with strong solubility.
⑨ PVA sponge wipe
Absorption capacity and decontamination capacity are large. They can only be used with water, otherwise they are hard blocks and cannot be wiped.
⑩ Cotton woven knitted wiping cloth
High temperature resistance, strong ability to remove water and sewage, very low cleanliness, not suitable for use in dust-free room above 10000 level.
According to the actual needs of our application, we can determine the type of wipes we need. If the main purpose is to remove grease or fingerprints, polyester / nylon composite microfiber wiping materials are more suitable, because this kind of materials have more contact with the surface, and the wiping effect is higher than that of ordinary fiber wiping materials. If it is to remove the residual glue that adheres tightly to the surface, woven wiping materials will be more appropriate. If the surface temperature is high, 100% wood pulp or 100% cotton cloth is suitable. If there is a requirement for organosilicon, it is required that the wiping material shall not contain organosilicon. If the volume of dust and residual glue is large, it is suitable to use knitting materials with large pore diameter. The higher the requirement for surface cleanliness is, the more we need to find clean cloth.
4. To determine the evaluation method of dust-free materials in the factory. For the evaluation of wiping materials, we should establish the method of combining the cleanliness evaluation with the actual effect. Generally, whether the dust-free cloth is suitable or not should be summed up from the previous point. After that, we should put forward the requirements for the cleanliness of the wiping cloth. The cleanliness of dust-free wiping material is one of the key aspects of its abnormal quality. The cleanliness directly affects the ability of wiping cloth. Generally, the cleanliness of dust-free wiping materials is defined in the following aspects: dust emission, including dust particle emission in air (APC) and dust particle emission in liquid (LPC). Many people think that shaking to remove the chips is an intolerable problem of the dust-free cloth. In fact, it's not the case. On the contrary, shaking to remove the chips is a physical property of the dust-free wiping material itself, just how much is it.
NVR (nonvolatile matter quantity) in the solvent, which is usually used, is evaluated. The amount of residue is usually measured by a sophisticated weighing device, but, The user can also determine whether the residue of the wiping cloth is within the required range by testing whether it is foggy (special attention: the strength of the inspection lamp will have a great impact on the test results, if under a very strong light, all the wiping cloth will find foggy residue). The amount of ion precipitation is mainly to check the metal ions and non-metal ions with high activity. If you wipe the surface with precision metal materials, it is recommended to take ion precipitation as an important inspection item, because active ions can easily damage the surface of precision metal through battery reaction.