The Differences Between Nylon, Aluminum & Chrome Office Chair Base
There are three main types of office chair bases: nylon, aluminum and chrome. You may wonder:
- What are the differences between them?
- How to choose?
- What are their advantages and disadvantages?
In the following content, we are going to talk about these issues one by one.
First of all, let’s get a preliminary understanding of the differences between these three types of chair base through a simple table.
Nylon + Glass Fibre
1.15g / m3
2.7g / m3
Chrome + Iron
7.8g / m3
* The material
Some people may be confused about the relation between plastic and nylon. They may wrongly think the nylon has become the standard and wonder why.
Actually, plastic is a generic name, while nylon is a subclass of it. Nylon is one engineering plastic, which is often used to take the place of metal. What we use for making office chair base is modified nylon with glass fibre which is of outstanding bearing and wear properties.
In order to further reduce costs, some manufacturers on the market use PP and glass fibre as raw materials, but the office chair bases made of PP are poor in the wear resistance.
The biggest problem for plastic and solution
Both Nylon and PP belong to the category of plastics. And for the plastic, its biggest problem is oxidation and ultraviolet rays.
A chair is placed indoors, though with the relatively small effect of ultraviolet rays, the oxidation problem is still inevitable.
Therefore, it is necessary to add antioxidants to the raw materials in the production. Since nylon chair base is made by injection molding, it’s very important to accurately grasp the ratio of raw materials.
In addition to adding necessary antioxidants, it is also important to note that the proportion of secondary materials cannot be excessive. Otherwise it will affect the load-bearing capacity and service life of the base.
More production details please visit our article “The Injection Molding Process of Nylon Office Chair Bases”
* The specification
The density of nylon material is 1.15g / m3, which is smaller than 2.7g / m3 of aluminum alloy and 7.8g / m3 of metal iron. Therefore, only when the diameter of nylon base is large enough, can it stably support the entire chair and maintain a stable balance of the chair.
The diameter of 560MM is the minimum specification we recommend. The commonly used NYLON base diameters are 600MM, 640MM, 700MM.
Nylon Chair Base NPA-A Detail Display
Although the nylon base cannot resist hard impact like the polished aluminum or chrome base, it still can stand over a pressure of 8ookg. What’ more, even with that pressure, it still can stand firmly and stably. The higher standard one can meet the BIFMA request , with a load-bearing capacity reaching up to 1136kg .
* The color
Black is the standard color for nylon bases. White and grey are popular too. But since they require more pure raw material and more steps in the production, price is higher except black.
With the hot sales of gaming chairs, a unique style has been created in the design of nylon base to complement the colorful cushions of the chair. The pictures below show some of the customized Colorful Gaming Chair Nylon Base of our customers.
Advantages of nylon chair bases:
+ Suitable for max production, belonged to injection molding industry, simple production process, about cycle time 1.5 mins per pcs, may realize full auto production for 24 hours / 7 days.
+ More color options
There are more details about the advantages of nylon chair base.
Nylon Chair Base NPA-B Detail Display
Disadvantages of nylon chair bases:
– Less duration. Because nylon is one kind of plastic, which will always faces the problem of oxidation once open to the air. With years passing, it will become fragile.
– If it is not maintained properly after use for years, scratches will be obvious on black nylon base.
– It looks like not so high-end.
The aluminum chair base is made of aluminium alloy. It is more durable, which makes it the first choice for office chair manufacturers.
* The Production
Aluminum alloys usually contain alloying elements such as copper, zinc, manganese, silicon, and magnesium, and were invented by German Alfred Wilm in the early 20th century.
The production of Aluminum Chair Bases is die casting.
The production of aluminum alloy profiles includes three processes: casting, extrusion and oxidation.
1. Casting is the first process of aluminum production.
According to the specific alloy grades to be produced, the amount of addition of various alloy components is calculated. And a variety of raw materials are reasonably matched and melted in the melting furnace.
2. Extrusion: Extrude to the BASE mold.
3. Oxidation grinding and polishing
The smallest size we have is R240-R280.
But after the aluminum alloy base come out from the machine, it still needs to be polished to shining. And the majority job is still by hands in China. The scratches and rust will be cleaned during the polishing. The polishing paste is necessary to impart gloss, with which a clear, shinning coat is made up to protect the finish.
In the production process, DIE casting and Polishing may not be carried out in the same place. Some specialized polishing workshops can concentrate on polishing aluminum alloy bases from many factories. However, scratches are prone to occur during transportation. This requires careful inspection when receiving the goods.
Compared with ordinary carbon steel, aluminum alloy is lighter and more resistant to corrosion. In a clean, dry environment, a protective oxide layer will form on the surface of the aluminum alloy.
A experiment also proved that the bending strength of aluminum alloy is three times that of ordinary steel.
So aluminum alloy base is the best among these 3 types of office chair bases: nylon, aluminum and chrome.
* Causes for the cracking of aluminum alloy base
Cracking – Aluminum chair base
But this does not mean that the aluminum alloy base will not break. The following factors are likely to cause the aluminum alloy base to crack:
- Improper proportion of other metals fused in the production
- Poor control of casting temperature
- The aluminum alloy baseis thin and the materials used are insufficient, which makes the product quality poor. Then, it may be bent and broken due to insufficient bearing capacity during use.
Therefore, the final process of aluminum alloy base production is usually the load-bearing test to ensure its superior quality.
(At the end of the article, we will summarize some common problems appearing on the office chair base and the corresponding solutions ).
Advantages of aluminium alloy office chair bases:
+ High class and great looking.
+ Good shock absorption ability.
Disadvantages of aluminium alloy office chair bases:
– High cost.
– Easy to get scratches during the use. If you are not careful, scratches will be made of the chair bases. Moreover, the gloss will disappear after a period of time for the wear of the clear coating.
Our Aluminum Chair Base NBW06 Detail Display
Our Aluminum Chair Base NAL-D01 Detail Display
There are other article will explain from other view about the aluminium office chair “ The Advantages of Aluminum Office Chair Bases ”
Chrome-plated chair base is made of iron. Normally it is called metal base or steel base.
Raw material is iron tube or iron sheet, produced by stamping machine, then welded together and assembled with some other parts.
Chroming is actually the process of impregnating or electroplating a thin layer of chromium on the surface of the iron. The shiny finish you see on the iron chair base is what we usually call the “Chrome” finish.
Comparison with Aluminum Base
Chromium is not expensive and less resistant to corrosion and wear than aluminum base. But its surface shows a brighter luster than aluminum, almost like a mirror.
When choosing Chrome chair base, we should pay attention to the thickness of the following two materials:
In the market, the iron thickness of the chrome chair base is in this range: 0.8 / 1.0 / 1.2 / 1.5 mm.
The different thickness will make the load-bearing capacity vary greatly. Among them, the thickness of 1.2mm or above is the most stable.
For Chromium Layer
Since iron pipes are prone to rust when exposed to moisture in the air, the Chromium layer must be thick enough to prevent BASE from oxidizing and rusting.
But it’s not that the thicker the better. Because a too thick layer is not only costly, but also the adhesion of the electroplated layer will be insufficient. This will cause the surface to delamination and fall off.
You can distinguish by looking for a smooth, and the mirror-like shine. Under this chrome coat, it is iron tube or sheet. The thicker of the two determines the strength of the chrome-plated base.
The chroming process is not really easy. In other words, it places particularly high demands on the manufacturer’s equipment.
The entire process poses a hazard to the environment and must be supervised under strict guidelines. If not handled properly, metals can enter natural water sources and streams. And it have been shown to be toxic and dangerous to health.
In China, for easily to supervise and disposal the hazardous water, electroplating plants will be centralized. And Most iron office chair base manufacturers will send out the naked iron base to these professional electroplating factories for processing. For the other hand, it is increasing the cost.
Advantages of chrome-plated steel office chair bases :
+ Shining looking.
Disadvantages of chrome-plated steel office chair bases :
– Easily get scratches.
Application Considerations for Chair Bases
As you have noticed, each kind of chair base has it own characteristics that are decided by material and production process.
Among all these elements, the cost plays the main role, as you move from nylon to chrome plating to polished aluminum, you are likely to see product prices are increasing. Although it is tempting to buy or specify these for each product, your budget may not allow it at all.
In terms of quantity, task chairs with nylon base are no doubt to be a leading position. Most of the new companies will disappear in 3 years, which is no longer than the life of the nylon material.
Polished aluminum and chrome finishes are usually used in administrative offices and board of directors. Compared with ordinary employees, their number is limited in a company.
(1) Deformation and cracking
☞ For Nylon Chair Base
– Replace the cracked one with a firmer and stronger nylon chair base.
☞ For Aluminum Chair Base
– Replace the damaged one with a new and high-quality aluminum chair base.
☞ For Chrome Chair Base
If there is cracking at the weld.
– If you have welding tools, you can weld the cracks by yourself and be careful.
– Replace with a more stable and good quality chrome chair base.
☞ For Nylon Chair Base
– The appearance defects don’t affect the actual use.
☞ For Aluminum Chair Base
– Return it to the factory to re-grind and polish
– Polish it with a suitable sandpaper
☞ For Chrome Chair Base
– The electroplating layer is easy to fall off due to scratches, and the internal iron part is easy to rust. It is recommended to replace it.