The need to lubricate gear mechanisms is obvious. This reduces friction, wear, and increases the performance of mechanisms. Depending on the version of the unit (crankcase or “dry”), the lubrication method also changes.
In the first case, the node is filled with liquid oil, in the second, grease is used, which is held on the gears.
Just like on metal components, lubricant for plastic gears can be thick or thin. There is an opinion that gears made of fluoroplastic or Teflon are themselves anti-friction.
Is there a special lubricant for plastic gears?
Almost all manufacturers lubricants have in their assortment compositions for plastic and composites based on it. In theory, standard greases can be used for universal use. However, not all of them interact normally with plastics.
- When in contact with conventional lubricants, the plastic may lose strength and crack. The teeth are destroyed and the transmission unit fails.
- The material of gears and racks swells when interacting with certain compounds. Jamming occurs.
- Adhesion on the surfaces of plastic gears is too weak, so standard lubricants are not retained and splash out during intense rotation.
It is interesting that some traditional lubricants, which have proven themselves in metal gearboxes, have a destructive effect on plastic gears. For example, when using, the teeth wear off, as if using an abrasive paste.
For this reason, special adapted compounds are produced for plastic gears of gearboxes and worm gears. 
Another technical nuance: plastic gearboxes heat up more than metal gearboxes. This occurs due to the low thermal conductivity of plastic: heat is not removed from the working area.
In this regard, high-temperature lubricant for plastic gears must maintain basic properties, both in cold and in heated states.
Using lubricant for gears made of plastic
- multimedia equipment using outdated storage media (CDs, cassettes) that use rotation mechanisms;
- computers, servers (CDs);
- computer peripherals: scanners, printers, game controllers;
- printing equipment: plotters, large-format printing devices, duplicating equipment;
- office equipment: copiers, MFPs;
- cash registers;
- food preparation mechanisms: for example, coffee makers;
- Medical equipment;
- aviation modeling.
Given the applications, specialized lubricants must meet more than just mechanical requirements. Medical and food units require health and hygiene certification. Therefore, such compositions, by definition, cannot be cheap.
Common lubricants for plastic mechanisms
Silicon Fett by Liqui Moly
adheres well to the surface and repels water. Properties are maintained over a wide temperature range. Thanks to good stickiness, it does not splash at high speeds.
This composition has a long service life: replacement is not due to aging; after several years of use, the lubricant dries out naturally.
It interacts neutrally with both pure plastic and transmission pairs made of various materials: plastic + metal, plastic + rubber. 
note
The only limitation: cannot be used in the food and medical industries if the gearbox mechanisms are not in a sealed area.
Another product from Liqui Moly
Thermoflex Spezialfett. This is a universal grease that can work in both metal and plastic gearboxes. The undoubted advantage of this composition is the preservation of viscosity at low temperatures.
However, with strong heating, the lubricant is poorly retained on the surface of the gears. Therefore, it is not suitable for high-speed gearboxes. Not a food product. 
Silicone grease SI-180
Not a bad option domestic production. It is used mainly for aircraft modeling, so the release form is quite compact. 
This lubricant can withstand high temperatures and rotational speeds. In addition, it adheres well to the teeth and does not splatter. The limitation is traditional: the lubricant is not food grade.
Food formulations
For example, OKS 1110. The instructions indicate the application: sealing mechanisms. In fact, such lubricants also work great on gear pairs.
Bottom line
If your plastic gearbox or worm pair works sporadically, you can get by with inexpensive silicone grease or simple.
And at high temperature and speed loads, it is necessary to carefully select the composition of the lubricant according to its characteristics.
The world of printer lubricants is currently a mess. Lubricants for printers are usually sold by spare parts sellers who have no idea what they are doing or why, so they can simply sell lubricant for old Xerox copiers under the guise of lubricant for thermal films of modern Hewlett Packard printers. At the same time, prices for lubricants border on prices for precious metals.The Oltar company, together with the representative office of the world-famous manufacturer of lubricants Molykote, decided to bring order to the issue of sales of lubricants for printers on the Russian Market. All lubricants offered are tested and recommended by experienced Molykote technicians, not home-grown parts salesmen..
You can be confident in your choice The main types of lubricants used in laser printers
1.
Hewlett Packard.
2. Lubricants of gears of gearboxes, where the latter rotate at medium speed at temperatures up to 80 °C. The load on the gears is uniformly rotating. In this regard, HP lubricant works perfectly. This lubricant is not commercially available. Instead, various lubricants are sold that satisfy the assigned tasks by 50 - 70%. As a rule, sellers have no idea what they are selling, what properties and durability their product has. Thermal film lubricants. HP uses a unique lubricant that is perfectly matched to the application. The lubricant does not flow, has negligible viscosity, does not evaporate, and does not lose its mechanical and chemical properties . The thermal film rotates solely due to the pressure of the Teflon-coated rubber shaft and does not have any gears. Works at temperatures up to 240 degrees, has several main types. Lubricant for thermal films is a separate issue. It's not possible to buy it . On They present either mediocre lubricants that can work for a limited time at temperatures up to 200 degrees or simply an outright surrogate, after which blurred images appear, paper jams in the oven, image repetitions, and others. Typically, after 700 - 1200 copies, such a lubricant turns brown, becomes sticky, viscous and slows down the rotation of the thermal film.
3. Lubricant used in heater gears (image fusing units). This is the most difficult case. Gears operate with vector or directional load. In addition, gears operate under sudden temperature changes and at speeds much higher than average. From 20 to 120 degrees. HP uses the same lubricants as in paragraph 1. This approach is fundamentally wrong. The lubricant is squeezed out from the teeth and the gears operate no more than 50 - 70,000 copies. The problems with these lubricants are clearly shown in Fig 1, Fig 2.
4. Lubricants for bushings, bearings, Teflon-rubber shafts of stoves. Hewlett Packard, as a rule, does not use any lubricants in the bushings of fusing units. In modern high-speed laser printers, this leads to the fact that after 30 - 60 thousand copies, the bushing is eaten away by 1 - 2 mm, the rubber shaft sags, the film falls to one side and eats up its edge. The gears begin to work at the edges of the teeth with a lot of noise, turning into a loud crack. The printer breaks down and requires repair.
The Oltar company offers the following types of lubricants for printers.
1.
For lubricating gears of gearboxes, as well as for lubricating oscillating units of stoves and gears of rubber shafts of fusing units - Molykote EM-50L grease.
Unlike conventional lubricants, the proposed lubricant works up to 150 degrees Celsius, does not thicken over time, is not afraid of temperature changes and does not lose its properties over time. This lubricant can be used on both plastic and metal gears.
2.
Lubricant for thermal films of printers, both polymer and aluminum. Lubricant type - Molykote HP-300 Grease. The lubricant works at temperatures up to 280 degrees, does not evaporate, and does not change physical and chemical properties over time. The lubricant does not become sticky and does not slow down the movement of the thermal film, the image is not blurred. The lubricant is universal and can be used both in home-class printers such as HP LJ 1012, and in powerful modern printers such as HP LJ P4515 with a printing speed of 45 sheets per minute. The lubricant is also good because even if the thermal film is punctured, it continues to work. Then, under the influence of toner, other lubricants begin to crystallize and cut the rotating film from the inside.
The lubricant is excellent for bushing rubber shafts of printer stoves; it does not corrode plastic bushings and does not introduce additional heating into the aluminum printer shafts rotating under the influence of high temperatures. The lubricant does not destroy the protective layer - aluminum oxide!
Modern types of plastics and polymers make it possible to use them not only as seals, but also to make gears from them. This presents engineers with many opportunities, but also many challenges. The main problem became the absence suitable lubricants. Conventional products intended for metal are not suitable, as they can corrode the plastic, change its structure and physical properties. Therefore, special types of funds have been developed. Lubricant for plastic gears allows you to achieve the necessary lubricating properties and protect the material from external factors and provide minimal friction.
Features of using lubricant for plastic gears
Many people believe that if gears are made of plastic, they do not require lubrication. Unfortunately, this often leads to damage and premature wear of the mechanisms. Plastic lubricant should be used for almost all types of plastic gears, as it provides the following functions:
- provides a long service life of plastic gears and prevents premature wear;
- ensures stable operation of mechanisms without interruptions;
- prevents the occurrence of unpleasant noises and squeaks, ensuring virtually silent operation;
- keeps the working surface of rubbing parts intact, without roughness and abrasions;
- prevents deformation of the working elements of gearboxes and the occurrence of cracks;
- protects components from the influence of external factors, especially high and low temperatures.
There is a misconception that plastic gears can be lubricated with conventional lubricants. This is strictly forbidden, as there may be negative consequences.
Even universal formulations cannot guarantee high efficiency. Exposure of plastics to conventional mixtures may have the following effects:
- Under the influence of ordinary lubricant, the plastic loses its strength and small cracks appear on its surface. This quickly leads to damage to the gear teeth, which causes the entire mechanism to fail. Then it will not be possible to restore the gear pairs using lubricant.
- Some types may cause the surface of plastic parts to swell. This leads to the gears jamming, which can lead to breakage of the teeth and the entire assembly as a whole.
- Plastic surfaces have poor adhesion. Because of this, classic lubricant does not adhere to the gears and scatters to the sides during rapid rotation.
- Some types, such as solid oil, act as an abrasive. During operation, gear teeth can wear out before your eyes. This usually renders the parts completely unusable.
- Classic lubricants cannot provide the necessary heat transfer. Plastic gearboxes differ from metal gearboxes in that they become very hot during operation. Conventional oil melts and loses the desired consistency, which leads to overheating of the plastic and changes in its shape and physical properties.
Today, plastic gears are used in various fields:
- computer equipment, especially servers;
- office equipment, including printers and scanners.
- multimedia equipment, the operation of which is based on rotational mechanisms;
- printing equipment, copying equipment and devices for large format printing;
- in some parts of cars;
- cash registers;
- food equipment, including conveyors, mixing and handling equipment.
- kitchen appliances;
- medical equipment;
- children's toys, radio-controlled models of airplanes and cars.
Lubricants for plastic gears intended for medical and food equipment require special attention, since they are subject to not only mechanical requirements, but also hygienic ones.
How to choose?
Before buying oil, you need to study all the varieties, determine what it is needed for and make sure that it meets the following requirements:
- Inertness to polymers (the lubricant should not react with plastic so as not to harm moving parts; even universal mixtures can damage the plastic surface).
- Composition stability (lubricant for plastic gears should adhere well to the plastic surface and not change viscosity and thickness at low and high temperatures).
- Versatility (very often, driving mechanisms use elements not only of plastic, but also of metal and rubber, so the product must be suitable for different materials).
- Compatible with fluoroplastic (most plastic gear mechanisms are made from this material, so if there is no information about the material, this lubricant will almost certainly work).
- Non-flammable (plastic gearboxes get very hot, so the lubricant should not spontaneously ignite due to high temperature).
- Environmentally friendly (it must be safe for humans, since plastic friction pairs are often found in kitchen and other appliances with which humans come into direct contact).
- Resistance to moisture (it should protect the mechanism from water and not be washed off by it).
- Good adhesion (the plastic surface is very smooth, so ordinary oils do not adhere well to parts).
When choosing a lubricant, it is important to consider the type of operating mechanisms and the conditions under which they operate. Taking this into account, several types can be distinguished:
- For mechanisms with plastic and metal parts (the lubricant must adhere well to the surface of various materials, protect the metal from corrosion and dissipate heat well).
- For mechanisms operating at high temperatures (the lubricant must retain its properties and structure at extreme temperatures)
- For mechanisms that operate at low temperatures (regular oils in winter or refrigeration equipment harden, therefore you should select a lubricant that can maintain basic viscosity, regardless of temperature).
- For gear transmissions operating under increased loads (conventional lubricant under high load is squeezed out of the working area, as a result of which the protective film is destroyed and the service life of the mechanisms is significantly reduced).
- For food industry equipment and plastic parts household appliances(food production involves direct contact of working mechanisms with food, so conventional lubricants are not suitable for such purposes because they contain substances harmful to humans).
Common formulations
To lubricate plastic gears, it is best to choose compounds from global brands that have specialized in developing compounds for many decades. Among the most common are the following:
- Silicon Fett. A universal lubricant for plastic that has excellent adhesion and water-repellent properties. Can operate in a wide temperature range, both low and high. When working at high speeds, it does not scatter, but holds well on the surface of the plastic. It has a long service life, it does not require replacement until it practically dries out, which happens after several years of operation. It can be used in mechanisms that combine plastic with metal or rubber.
Cannot be used for food processing equipment or in open gearboxes. An analogue is Silicot silicone grease. - Thermoflex Spezialfett. It is also a universal one, which can be equally used not only in plastic mechanisms, but also in metal ones. It differs in that it retains its properties and structure at low temperatures. But it is not suitable for tall people, as it begins to melt and spread, as a result of which the protective film is destroyed and friction increases. Also cannot be used for food processing equipment.
- SI-180. Domestic silicone grease. Sold in small volume syringes, as it is used to lubricate small mechanisms. The white grease adheres well to the plastic surface without changing its properties at high temperatures. It does not belong to the food group.
- Lubricants for food equipment. This is a separate group, the price of which is much higher than usual, and is used in household equipment and in production. The most popular is OKS 1110, which is used not only for lubrication, but also for sealing. You can also highlight Loctite food-grade lubricant for plastic and rubber, made on a silicone basis.
The service life of plastic mechanisms directly depends on their care. Choice high-quality lubricant will allow you to achieve optimal uninterrupted operation and save money on repairs.
