Sofia Martinez
Lubricating plastic parts is essential to reducing friction and wear and increasing their lifespan. However, it is crucial to choose the right lubricant to avoid damaging the plastic. Incompatible lubricants can cause stress cracking, discolouration, and loss of structural integrity. To determine compatibility, manufacturers assess the plastic's physical properties, such as volume, weight, and hardness, before and after exposure to the lubricant. The lubricant's chemistry, viscosity, and resistance to aging are also key factors. Synthetic lubricants with high aging resistance are ideal for long-term use, while PTFE solid additives can provide dry lubrication and reduce startup friction. For plastic bearings, WD-40 can be useful, despite its high viscosity, to silence temporary squeaking noises. Other recommended lubricants include gun oil, sewing machine oil, PTFE spray, and silicone grease or oil.
| Characteristics | Values |
|---|---|
| Importance of lubricating plastic parts | Lubricating plastic components reduces friction and wear, lowers power consumption, and increases part life. |
| Choosing a lubricant | The most important factor is the lubricant's compatibility with the plastic material. |
| Factors contributing to compatibility | The lubricant's chemistry (base oil, thickeners, and additives), viscosity, and resistance to aging. |
| Chemistry | Silicone-based lubricants, PFAE, synthetic hydrocarbons (SHC or PAO), and mineral oils typically work well with plastics. Esters and polyglycols generally do not. |
| Viscosity | High-viscosity oils are less likely to penetrate and degrade plastic. Greases with an NLGI of 1 or 0 reduce friction and grease-induced noise. |
| Aging resistance | Synthetic lubricants have high aging resistance and are suitable for long-term applications. Mineral-oil-based lubricants are also suitable for plastic lubrication. |
| Additives | Solid additives like graphite and molybdenum disulfide can weaken plastic parts. PTFE solid additives can provide dry lubrication and reduce startup friction. |
| Specific lubricants | WD-40, Teflon lube, Krytox, Dow Corning Molykote 55 Oring lube, dielectric grease, silicon grease, and powdered lubricants (hexagonal boron nitride, titanium disulfide, powdered PTFE, etc.) are some specific lubricants mentioned. |
Explore related products
What You'll Learn
Choosing the right lubricant for plastic parts
Lubricating plastic components is essential to reducing friction and wear, lowering power consumption, and increasing part life. However, choosing the wrong lubricant can cause the plastic to crack, become discoloured, or lose structural integrity.
The most important factor when choosing a lubricant for plastic parts is compatibility. Manufacturers determine compatibility by monitoring changes in the physical properties of the plastic material, such as weight, volume, hardness, strength, and elongation, under various conditions of speed, load, and environment. The allowable change in these properties is typically within a range of 7% to 10%.
Lubricants based on silicone, perfluorinated PFAE, mineral oils, and synthetic hydrocarbons (SHC or PAO) are generally compatible with plastics. PAOs, in particular, offer high aging resistance and can operate within a wide temperature range. Silicone-based lubricants are also highly compatible and suitable for low load applications and a broad temperature range.
On the other hand, lubricants based on esters and polyglycols are typically not recommended for use with plastics, although exceptions may depend on the specific type of plastic material.
Additives in lubricants can also cause unintended reactions with plastic. Solid additives like graphite and molybdenum disulfide can weaken plastic parts, while PTFE solid additives can provide benefits such as dry lubrication and reduced startup friction.
It is worth noting that synthetic lubricants are generally recommended for long-term applications due to their high aging resistance. Outgassing byproducts of plastic, such as formaldehyde and styrene, can accelerate the aging process in lubricants, so this should be considered when choosing a lubricant.
In summary, when choosing a lubricant for plastic parts, it is crucial to prioritise compatibility by considering the specific type of plastic, the anticipated operating conditions, and the potential for any adverse reactions or negative effects on the plastic's structural integrity.
Creating a Sturdy Plastic Sign: A Step-by-Step Guide
You may want to see also
Explore related products
$16.03 $18.59
Testing lubricants for compatibility with plastics
When choosing a lubricant for plastic parts, the most important factor is the lubricant's compatibility with the plastic material. Incompatible lubricants can cause the plastic to develop stress cracking, become discoloured, or lose dimensional stability or structural integrity.
To verify compatibility, manufacturers monitor changes in physical properties of the plastic material under conditions of speed, load, and environment. These properties include weight, volume, hardness, strength, and elongation. Each manufacturer determines the limit on allowable changes, but typically the range is 7% to 10%. When evaluating these tests, ensure they reflect your worst possible conditions because both lubricants and plastic materials are more prone to change in high temperatures and adverse environments, particularly with high dynamic loads.
Lubricants based on silicone, perfluorinated PFAE, mineral oils, and synthetic hydrocarbons (SHC or PAO), typically work well with plastics. Synthetic lubricants are the best choice for long-term applications as they have high aging resistance. PAOs are compatible with most plastics, have high aging resistance, and offer long-term lubrication within a temperature range of -60º to 320ºF. Silicone-based lubricants also show excellent compatibility and are a great choice for low load applications and a wide temperature range (typically -90º to 425ºF).
Compatibility testing is generally carried out at high temperatures, simulating an accelerated life and poor or stressful conditions for the plastic. A relatively simple test, the criteria of the test varies depending on the grease manufacturer. The test involves exposing the necessary plastic pieces to the relevant lubricant at elevated temperatures using a laboratory oven. The higher temperatures and durations are considered a type of accelerated ageing process. The duration of the test is normally a maximum of 168 hours.
If you do not have access to a testing facility, it is possible to carry out your own test. Although not as thorough as the above process, a good indicator of any possible lubricant and plastic compatibility issues could be shown by conducting your own test at ambient/room temperature; simply immerse a piece of the plastic in the appropriate oil or grease and leave it in your office/workspace for an extended period of time. Remember to weigh and measure the parts before and after the test.
Plastic Ceiling Fan Blades: Worth the Outdoor Investment?
You may want to see also
Explore related products
Using WD-40 as a lubricant
Lubricating plastic components is essential to reduce friction and wear, lower power consumption, and increase the life of the plastic parts. While WD-40 is commonly believed to be a universal lubricant, it is actually a solvent with some lubricating properties. As a penetrating oil, WD-40 can enter small openings and cavities and get under corroded surfaces, driving out corrosion, dust, and grease. This makes it useful for unsticking plastic parts. However, due to its high viscosity, WD-40 does not provide long-lasting lubrication.
WD-40 can be useful as a temporary lubricant for plastic bearings, especially during the initial "run-in" period when the smooth injection-molded surface of the bearing starts to wear off, making it easier for solid lubricants to spread between the shaft and bearing. This process can sometimes cause temporary squeaking noises, which WD-40 can help silence. While WD-40 can improve running capabilities and friction in the short term, it is not suitable for prolonged lubrication, especially for mating parts in constant motion and varying temperatures.
When choosing a lubricant for plastic, it is essential to consider compatibility to avoid stress cracking, discolouration, and loss of dimensional stability or structural integrity. Lubricants based on silicone, perfluorinated PFAE, mineral oils, and synthetic hydrocarbons (SHC or PAO) typically work well with plastics. Synthetic lubricants, such as PAOs, are ideal for high operating speeds, high temperatures, or long-term applications as they have high ageing resistance and offer long-term lubrication within a wide temperature range.
While WD-40 can provide short-term relief for stuck plastic parts and improve initial friction, it is not a substitute for a dedicated lubricant designed for long-lasting lubrication of plastic components. It is important to select a compatible lubricant that meets the specific requirements of the application to ensure optimal performance and longevity of the plastic parts.
Plastic Seals: Bryers' Ice Cream Security?
You may want to see also
Explore related products
PTFE solid additives as a lubricant
Lubricating plastic components is important to reduce friction and wear, lower power consumption, and increase the life of the plastic part. When choosing a lubricant, it is important to consider the compatibility of the lubricant with the plastic material. Using an incompatible lubricant can cause the plastic to crack, become discoloured, or lose structural integrity.
Polytetrafluoroethylene (PTFE), trademarked as Teflon, is a solid synthetic fluoropolymer that is widely used as an additive in lubricating oils and greases. PTFE has a very low coefficient of static and dynamic friction and repels water and resists heat. PTFE solid additives can be beneficial in providing dry lubrication and reducing startup friction. PTFE particles can also be compounded in plastics to form a PTFE film over the mating surface, resulting in reduced friction and wear.
PTFE solid additives are particularly useful in extreme conditions of temperature, pressure, and chemical and environmental contamination. PTFE can be applied directly as a topical coating or used as an additive to a fluid lubricant. PTFE-based lubricants are also compatible with a wide temperature range, typically operating up to 260 °C.
In certain industries, such as the bearing pad industry, PTFE has become the standard due to its toughness and weatherproof properties. PTFE-based lubricants can also be sprayed on parts that are inaccessible for lubrication after assembly.
It is important to note that while PTFE is a popular choice for solid lubricants, other options such as graphite, molybdenum disulfide, and mineral oil-based lubricants are also compatible with plastic parts and may be more suitable depending on the specific application and operating conditions.
Welding Plastics: Combining Two into One
You may want to see also
Explore related products
High viscosity oils as a lubricant
Lubricating plastic parts is important as it reduces friction and wear, lowers power consumption, and increases the life of the plastic part. When choosing a lubricant, it is important to consider the chemical structure of the lubricant and its compatibility with the plastic. Using an incompatible lubricant can cause the plastic to develop stress cracking, discolouration, or loss of structural integrity.
High viscosity oils are those with an ISO VG of 100 or more. These oils are less likely to penetrate, crack, or adversely affect plastic materials. The viscosity of a lubricant refers to its resistance to flow and shear. It is influenced by factors such as contamination with water, particles, or other lubricants, as well as the ageing of the oil. The viscosity of a lubricant is also affected by temperature; as the temperature increases, the viscosity decreases.
When selecting a high viscosity oil, it is important to consider the specific application and operating conditions. High viscosity oils are suitable for higher loads and can maintain a lubricant film from start to stop. However, if the oil is too thick for the operating conditions, it can create unnecessary wear and tear on the machine due to increased heat and energy usage. Therefore, it is crucial to choose a lubricant with the appropriate viscosity for the intended application to ensure proper circulation and adequate film strength under pressure.
For applications requiring high operating speeds, high temperatures, or long operation, synthetic lubricants such as hydrocarbon (PAO) types are recommended. PAOs have high ageing resistance and offer long-term lubrication within a wide temperature range. Another option is silicone-based lubricants, which are compatible with plastic and suitable for low load applications and a wide temperature range.
Plastic Toxins and Your Fridge: What's the Truth?
You may want to see also
Frequently asked questions
First, you need to determine what type of plastic you are dealing with and choose a lubricant that is compatible with it. For example, silicone-based lubricants, synthetic hydrocarbons (SHC or PAO), and mineral oils work well with most plastics, while lubricants based on esters or polyglycols generally do not. Once you have chosen a suitable lubricant, apply it to the plastic and work the stuck parts free.
Some common lubricants that can be used on plastic parts include WD-40, gun oil, sewing machine oil, PTFE spray, and silicone grease.
Lubricating plastic parts helps to reduce friction and wear, lower power consumption, and increase the life of the parts. For example, studies have shown that lubricated plastic sliding bearings last up to five times longer than non-lubricated ones.
In addition to compatibility, other factors to consider when choosing a lubricant for plastic parts include the lubricant's viscosity and resistance to aging. High-viscosity oils are less likely to penetrate and degrade plastic, while synthetic lubricants have higher aging resistance and are better for long-term applications.
![WD-40 Original Formula, Multi-Use Product with Smart Straw Sprays 2 Ways, 14.4 OZ [2-Pack]](https://m.media-amazon.com/images/I/61jav-v2rYL._AC_UL320_.jpg)
