In the automotive industry and specialized industries glass-glass most often called acrylic or polycarbonate, if we are talking about modern optical elements, or "polishing", when we mean polished stainless steel. Users wonder about the terminology when they are faced with replacing a reflective element in a machine that doesn’t break into sharp shards on impact, or are looking for an alternative for decorative overlays. Understanding the exact name of the material is critical for the correct selection of spare parts, since the optical properties and methods of fastening the material are not very important. squirrel and steel They're very different.
If you are looking for information about this, The mirror is not glass as it is called.It is important to clarify the context: is it a functional reflector in the side mirror of the rear view or a decorative element of the interior? In the first case we are talking about polymer composites, in the second case about metal. Incorrect choice of material can lead to distortion of the picture on the road or rapid failure of the element due to vibrations and temperature changes.
Modern technologies allow you to create reflective surfaces that are not inferior in quality to the classical amalgamated glass, but have increased impact resistance. That is why manufacturers are increasingly switching to use. polycarbonate and acrylic resins in the complete set of cars. Let’s take a closer look at what materials are hidden behind the term “non-glass mirror” and where they are used.
Acrylic mirrors: properties and applications in cars
The most common answer to the question of which mirror is not glass is: mirror. This material, technically called polymethyl methacrylate (PMMA), has high transparency and excellent reflectivity when applied special coating. In the automotive industry, acrylic is valued for its lightness and ability to avoid forming dangerous shrapnel in an accident, making it ideal for safety systems.
The production of such elements involves the process of vacuum spraying aluminum or silver on the back side of the acrylic sheet. This creates a thin layer that forms the image. Unlike glass, acrylic You can easily cut and drill, which simplifies installation in non-standard designs, for example, in tuning side mirrors or interior elements of the cabin.
- 🚗 High impact resistance - the material withstands stones and small hail without cracking.
- 💧 Moisture resistance – acrylic is not corrosive and does not become cloudy from condensate inside the housing.
- 🛠 Ease of processing – the ability to give any shape without the use of high temperatures.
- ⚖️ Low weight - reduces the load on the electromechanisms of mirror regulation.
⚠️ Attention: Despite their strength, acrylic mirrors are sensitive to aggressive chemistry. When washing your car, avoid using solvents and abrasive pastes as they can damage the reflective layer.
It is important to note that the optical purity of acrylic can degrade over time under the influence of ultraviolet light if the material does not have a special protective coating. Therefore, when choosing spare parts, it is worth paying attention to the presence of a UV filter in the structure of the polymer. Quality phosphore It lasts for years without losing its properties.
Technology of production of acrylic mirrors
The creation process involves extrusion or casting of acrylic mass, followed by polishing the surface to perfect smoothness. Only after that, a metal layer is applied by spraying in vacuum, which guarantees uniformity and the absence of image defects.
Polycarbonate reflectors: strength and flexibility
Another popular material that is often confused with glass is polycarbonate. It is a polymer that is characterized by exceptional tensile and bending strength. If acrylic is fragile with a strong point impact, then polycarbonate is almost impossible to break with conventional methods. In the automotive sector, such mirrors are used in special equipment and cars operated in extreme conditions.
The main feature of polycarbonate is its flexibility. Thin sheets of this material can bend without cracking, which allows you to create streamlined shapes for side mirrors of complex configurations. However, this material has its drawbacks related to the hardness of the surface. Polycarbonate is easier to scratch than glass or acrylic, so it is often applied to additional pacifying (hard coat).
When installing polycarbonate elements, it is important to take into account their thermal expansion coefficient, which is higher than that of glass. This means that with sudden temperature changes, the size of the reflector can change, which requires special methods of fastening with gaps. If you fix it. polycarbonate It's too hard, it can be driven, and the image will be wavy.
- 🛡️ Extreme impact resistance - withstands hits of large objects.
- 🌡️ Wide temperature range - retains properties from -60 ° C to +120 ° C.
- 🔄 Flexibility – the ability to install on curved surfaces.
The cost of polycarbonate mirrors is usually higher than acrylic mirrors, due to the complexity of production and the high cost of raw materials. However, for certain tasks where safety comes first, this is the only right choice. Truck and SUV drivers often prefer this material.
To clean polycarbonate mirrors, use only soft microfiber fabric and special sprays for plastics. Conventional windshield wipers can leave microcracks on the surface.
Polished stainless steel: classics of “non-glass” mirrors
When it comes to decorative elements or retro cars, “non-glass mirror” is often meant to be a “non-glass mirror.” polished stainless steel. It is not an optical element in the literal sense, but a metal surface polished to the state of a perfect mirror. Such details can be found as overlays on the body of side mirrors, door handles or interior elements.
The technology of creating such surfaces is multi-stage polishing of metal with abrasive pastes of different grains. As a result, the surface The stainless steel becomes smooth enough that it begins to reflect light like glass. However, the image quality in such a “mirror” will always be lower due to the microrelief of the metal, but for decorative purposes this is quite enough.
The main advantage of steel mirrors is their absolute indestructibility. They don't beat, crack, or fade. The only enemy of polished steel is corrosion when the protective oxide layer is damaged and scratches appear. You can restore the shine with the help of polishing pastes, returning the details to their original appearance.
| Characteristics | acrylic | Polycarbonate | Stainless steel |
|---|---|---|---|
| Strength | Medium | Very high. | Tall. |
| Optics | Great. | Good. | Low (decor) |
| Weight. | Lightweight | Lightweight | Heavy. |
| Price. | Low. | Tall. | Medium |
The use of steel linings allows you to give the car a premium look without the use of chromium, which can climb over time. Modern alloys allow you to achieve a deep black or matte shade, which can also perform the function of a mirror in a certain lighting.
Comparison of optical properties of materials
When choosing a replacement, it is important to understand the difference in optical properties. Glass. It gives the clearest and most undistorted image, but it is fragile. acrylic and polycarbonate may have a lower reflectance if the spraying technology has been impaired. This is because the picture seems a little dimmer, especially at night.
Distortion (distortion) is another important parameter. Cheap plastic mirrors often have the effect of “curve mirrors” where straight lines on the horizon look curved. This is due to uneven cooling of the plastic during molding or defects in the thickness of the reflective layer. Quality. mirror The geometry of the surface must be carefully monitored.
Color reproduction is also different. The glass does not change the color of the reflection. Plastics can go into a bluish or yellowish hue depending on the additives in the polymer. For the driver, this can be critical when evaluating distance and speed at dusk.
- 👁️ The clarity of the image is higher in glass than in polymers.
- 🌈 Color rendering is important for a correct assessment of the situation on the road.
- 📉 Distortion is a critical safety parameter that is tested in the workplace.
⚠️ Attention: Never use a bathroom mirror to replace a car. They do not have the necessary heat resistance and can burst from heating by the sun or vibration.
How to distinguish plastic from glass by touch and sound
Often there is a situation when you need to determine the material of the mirror already installed on the car, and there are no documents at hand. There is a simple diagnostic method based on thermal conductivity. Glass. It is always colder to the touch than plastic, as it removes heat from the finger faster. If you touch the surface, acrylic or polycarbonate will seem more “warm”.
The second method is acoustic. Light tapping with the nail or plastic handle of the instrument gives different sounds. The glass makes a loud, high-pitched sound. Plastic sounds deaf and quieter. This method requires some practice, but allows for quick identification of the material without dismantling the part.
You can also pay attention to the edge. The edge of the glass is always sharp and transparent (if there is no black edging). In plastic mirrors, the edge often has a slightly rounded shape or visible cut structure if the part is not cast. Pollen steel It is recognizable by the metallic luster from the end.
☑️ Verification of mirror quality
Installation and replacement of non-glass mirrors
Replacement acrylic or polycarbonate Mirrors have their own nuances. The main feature is the use of glue compounds. Unlike glass, which is often held on mechanical latches or specific glue, plastics may require adhesive primers for reliable fixation.
When installing it is important not to pull the fasteners. Plastic does not have such rigidity as glass, and at high pressure can be deformed, which will lead to the appearance of a “lens” and distortion of the picture. The mounting should be uniform throughout the contact area.
If you are changing the mirror on a heated car, make sure that the conductive layer of the new element is compatible with your wiring. Some polymer mirrors have built-in heating elements that require gently connecting the contacts to avoid melting the base.
Choosing the right mirror material is a balance between safety, cost and image quality. For daily driving, it is better to choose certified analogues with glass or high-quality acrylic.
FAQ: Frequently Asked Questions
Can I polish the scratches on an acrylic mirror?
Yes, small scratches on acrylic can be removed by polishing. For this purpose, special pastes are used for plastic (for example, polyrene for headlights). However, deep scratches are difficult to remove, since polishing can disrupt the geometry of the surface and spoil the reflection.
Why does a plastic mirror turn yellow over time?
Yellowing is the result of degradation of the polymer under the influence of ultraviolet radiation from the sun. Cheap plastics don’t have enough UV stabilizers. High-quality car mirrors should have protection from ultraviolet light.
Is it safe to use a stainless steel mirror as the main one?
No, polished steel gives a strong distortion and low definition. It can only be used as a decorative element. Use only certified optical elements to control the traffic situation.
How to clean a mirror of scotch marks without damaging the coating?
Use special glue cleaners (Remover) on a citrus basis or isopropyl alcohol. Do not rub hard and do not use blades or sharp objects to avoid scratching the soft polymer layer.
Are there any fully unbreakable mirrors for your car?
Absolutely non-breakable materials do not exist, but polycarbonate and special films on glass (anti-shatter film) are as close to this ideal as possible. They can crack in extreme impact, but will not crumble into fragments.