We are aware of the incompatibility of oil and water. In actual daily work, due to the poor waterproof seal of a water-contacting component, there are many restructuring materials for project engineering to be stationed in the factory in batches. In fact, it must be used as a waterproof seal. There are a few parts, and there are various types of structures and products, such as sanitary products, home appliances, various waterproof rings, waterproof piston positions and waterproof sleeves, etc., which are in contact with water. Because the above positions will often come into contact with water and steam or various alkaline or weakly acidic waters, the requirements for lubricating grease are particularly strict and demanding!
Sealed and waterproof grease is used in many household appliances, from electric toothbrushes and tooth cleaners, to household vegetable washing machines and washing machines, and is widely used in the industry.
Therefore, waterproof sealing grease plays a vital role in the design of developers.
01
What is waterproof sealant
Waterproof sealing grease is a food-grade sealing grease made from refined synthetic oil as the base oil thick inorganic thickener, and added with structural stabilizers and anti-corrosion additives. The common application equipment is mostly small household appliances and beauty equipment. It has good waterproof, waterproof, solvent resistance and creepage resistance, does not corrode metal, and has good adaptability to rubber. It is designed for sealing and lubricating pressure valves and drinking water valves, and can also be used for metal/ Lubrication and sealing of friction parts of plastic, plastic/plastic, ceramic/ceramic, ceramic/plastic. Common application equipment is mostly small household appliances and beauty equipment
As a waterproof sealant, it should have the following properties:
1. Excellent water resistance and airtightness, resistance to cold and hot water, resistance to environmental aging;
2. Excellent high and low temperature performance and anti-oxidation performance, the consistency changes little with temperature;
3. Excellent oil resistance, corrosion resistance and most chemicals resistance, extremely long service life;
4. Excellent adhesion and lubricity, good compatibility with most plastics and elastomers.
02
How to choose waterproof sealing grease
One. Consider working temperature and usage load
Use grease with good temperature change properties. Grease with poor high and low temperature stability will drop sharply in viscosity when the temperature rises and become liquid, making the grease unable to provide lubrication and waterproofing, and cannot dissipate heat and wear parts.
two. Consider the material compatibility of the application product
The compatibility of lubricating grease may be complicated even by lubricating oil technicians with general knowledge. If the composition of the two lubricating oils is not clear, just relying on whether they have similar performance to judge, it is likely to produce adverse consequences. Because two lubricants with similar properties, their ingredients may not be compatible. Another point worthy of our attention is the compatibility between polyurea grease and lithium-based grease. Polyurea thickeners have many ingredients, some of which are compatible with lithium-based greases, while others have poor compatibility.
three. Consider the oil's water resistance and acid and alkali resistance
If it is a liquid lubricating oil, it should be emulsifying. A certain amount of water is mixed with the lubricating oil. Observe the oil-water separation time. The shorter the oil-water separation time, the better the water separation, that is, the better the demulsibility. If it is a solid grease, one is water-washing resistance, a certain pressure and temperature of water-washed grease, observe the amount of grease retained, the more the better; there are also water-rolling water mixed with water into the grease How much and the consistency of the grease change to judge its water resistance.
03
What grease can effectively seal against water?
Having said that, how to choose a waterproof sealing grease! ! !
First of all: consider that the grease will not corrode the sealing ring and plastic parts. The viscosity of the grease should be adjusted according to the hardness of the sealing ring to ensure that the grease is not absorbed by the sealing ring.
Second: Consider safety requirements, such as NSF H1 food grade, RoHS, REACH, etc.
Third: it is the waterproof and sealing function requirement.
Finally: through USDA/NSF H-1 level certification, it can be used for equipment and machinery that accidentally come into contact with food. When using, ensure that the greased part is clean. Do not mix with other greases. This grease is easily soluble in aromatic hydrocarbons and chlorinated hydrocarbons Solvent.
Lubricating grease is composed of base oil, thickener and additives. It is the thickener that determines the waterproof and sealing function of the grease, with composite aluminum and composite calcium being the best. The complete TDS will have the technical parameters of the waterproof erosion test, which is the key parameter of the waterproof seal, such as ASTM D-1264 <5%, or DIN 51807 0-90.
