Classification and Types of crowd control barriers
The crowd control barriers are a product derived from the bike racks. At the initiative of the barriers, products appeared all crowd control barriers were made of steel. With the development of the times, the progress of science and technology, and the improvement of people’s requirements for products, various crowd control barriers appeared in the market. If distinguished by materials, they can be divided into the following three types of crowd control barriers.

STEEL CROWD CONTROL BARRIERS

PLASTIC CROWD CONTROL BARRIERS

ALUMINUM CROWD CONTROL BARRIERS
CROWD CONTROL BARRIERS CLASSIFICATIONS
What is galvanizing?
Before we understand the difference between pre galvanizing and hot-dip galvanizing, we need to understand the meaning of metal galvanizing. Galvanizing is a process of coating zinc protective coatings on metals such as steel or iron. The zinc coating can prevent rust and corrosion and effectively improve metal’s durability or service life.
Although galvanizing does not prevent corrosion indefinitely, the service life of galvanized steel is much longer than unprotected steel under the same conditions.
Steel crowd control barrier with the most extended history, mature development, and widely used. We know that the character of iron products is that it is easy to oxidize and produce rust, resulting in a discount on the service life of products. Therefore, all-steel crowd control barriers products must be galvanized as the surface treatment to resist oxidation better and prolong the service life. Here we introduce two concepts.
Hot-dip galvanized
Before introducing the difference between the two galvanizing methods, let’s conclude: hot galvanizing is the best surface treatment method for crowd control barriers. However, it is also the main reason for the high price of products. Therefore, due to the price reason, in many cases, We will recommend customers to purchase pr-galvanized crowd control barrier or pre-galvanized then powder coated.
Galvanized steel is one of the most commonly used materials in the crowd control barrier industry. You may have seen silver crowd control barriers around your city. If you are engaged in construction, you may have used them in the project. But do you know there are different kinds of galvanized steel? How does its processing affect the durability of your crowd control barriers panels? Read on to learn the difference between pre-galvanized steel and hot-dip galvanized steel and why crowd control barriers are better.
What is the difference between pre-galvanized steel and hot-dip galvanized steel?
The process is the difference between pre galvanizing (or “pre galvanizing”) and hot-dip galvanizing. First, let’s separate the two.
Pre galvanizing types of crowd control barriers
When steel components manufacture more complex finished products, they can be galvanized before assembling the final product. This is called pre galvanizing or “pre galvanizing.” It can also be called “online,” “continuous,” or “rolled” galvanizing. In essence, steel components – plates or wires – are galvanized by an automated process before cutting to a specific size.
The automation process will vary depending on the type of galvanized parts. Generally speaking, steel members are immersed in the “galvanizing tank” of molten zinc for a short time. Once the steel is removed from the groove, use mechanical wipers, air knives, or steam to remove excess zinc. This leaves a relatively thin zinc coating.
Hot-dip galvanizing
The batch hot-dip galvanizing process immerses the finished steel or “steel products” in pure zinc solution. This ensures complete coverage of the product, including the inner surface of any hollow area (e.g., inside the pipe). Hot-dip galvanizing also usually results in a thicker zinc coating than pre galvanizing. Metallurgical bonding is formed between steel products and zinc coating to provide anti-corrosion protection.
If you search for pictures of hot-dip galvanized steel, you are likely to find photos of steel products with unique surface patterns, called “flash.” After Hot-dipped Galvanized, The Crowd Control Barriers will produce zinc spots once the molten zinc is attached to the steel and cooled below the melting point. Once this temperature is reached, randomly arranged atoms in liquid zinc begin to set into an orderly crystal pattern.
Which is better: pre-galvanized steel or hot-dip galvanized steel?
The winner of the battle between pre galvanizing and hot-dip galvanizing depends on your unique requirements and the intended use of the steel. We provide galvanized crowd control barriers for various applications at boss metal, including buildings, special activities, outdoor retail, and storage space.
Crowd control bars are made of several different steel members and are expected to withstand severe weather, so it is best to use hot-dip galvanized steel. Hot-dip galvanized steel is most suitable for temporary fence panels for several reasons.
Coating continuity
Immersing the entire crowd control barriers n a hot zinc bath ensures that every corner and gap is coated – including the areas most vulnerable to corrosion. For example, molten zinc enters the inside of the crowd control bars tube and is covered from inside to outside. This is critical because the square pipes will experience a lot of wear due to continuous insertion and removal of the base. After hot-dip galvanized treatment, the crowd control barriers plate also ensures that all welds are coated to provide additional protection.
Compare it with pre-galvanized components in the crowd control bars structure. If the pre-galvanized steel pipe is cut into a certain length during the manufacturing of the fence plate, the cut end will form an uncoated surface that is easy to corrode. Similarly, welding broke the zinc layer after welding, so without zinc will not protect any weld fixing pre-galvanized steel wire mesh to the crowd control barriers frame.
Coating thickness
As mentioned above, pre-galvanized parts are usually soaked only in the galvanizing bath for a short time to form a relatively thin coating. Compared with pre galvanizing, the thicker zinc coating produced by hot-dip galvanizing can provide better rust and corrosion protection. This is an essential feature of crowd control barriers because it is usually used outdoors and exposed to snow, ice, rain, and salt.
Metallurgical bonding
The resulting zinc coating consists of four layers when steel is hot-dip galvanized. The topmost layer is pure zinc coating. The remaining three layers are alloys of zinc and iron, which are more complicated than the base steel and form a metallurgical bond between steel and zinc. This means that they become an integral part of the steel, not just the coating.
The metallurgical bonding produced by the hot-dip galvanizing process has better wear resistance than the thin coating formed by pre galvanizing. This is critical because of the degree of abuse and wear that crowd control barriers, as a leased item, have endured throughout its life cycle. As a result, crowd control barricades will be subject to a lot of wear during transportation, installation, and removal.
Pre-galvanized pipe, also known as rolled galvanized pipe, hot-dip galvanized pipe, or continuous hot-dip galvanized pipe. Pre-galvanized steel pipe refers to the pipe galvanized in the form of a plate before further manufacturing. After the rolling mill galvanizes the plate, it is cut to a specific size and rewound. The pipe thickness shall be at least 12 µ M. Compared with hot-dip galvanized steel, one of the advantages of pre-galvanized steel is its better appearance. Therefore, it is common to use pre-galvanized materials for crowd control barriers.
Hot-dip galvanized crowd control barriers have the advantages of long service life but a high price. In contrast, the pre-galvanized crowd control barrier has a low cost, beautiful appearance, and short service life.