Stadium Grandstand Seats: Blow Molded Seats, Injection Molded Seats and Gas Assisted Injection Molded Seats

Stadium bleacher seats can be divided into injection molding (gas-assisted injection molding) according to the material, blow molding, wood, metal, soft bag, leather seat, among which the seats of wood, metal, soft bag, leather seat and other materials are very easy to distinguish and contrast. , but injection molding and blow molding are easy to confuse. Next, let’s introduce the difference between injection molding seats (gas-assisted injection molding seats) and blow molding seats in detail.

1. The manufacturing process principle of blow molding and injection molding (gas-assisted injection molding)

The blow molding process is to place the extruded molten plastic blank in a mold, inflate it with compressed air and stick it on the cavity wall, and then cool and harden it into a plastic part. More use of HDPE material.

mt stadium seating

Injection molding is to use the screw or plunger of the injection molding machine to make the molten material in the barrel, through the nozzle of the injection machine and the pouring system, inject into the cavity and solidify. Therefore, the compression resistance and toughness of the injection molding mold are better. Basically use PP particle material. Gas-assisted injection molding is to inject high-pressure nitrogen directly into the plastic being plasticized in the mold cavity through the main and auxiliary controllers (segment pressure control system), so that the inside of the plastic part expands and becomes hollow, but the product and shape are still intact. Since the gas is not injected into the plastic, no pores will be formed inside the finished product. Make the product remove finished product dents and keep the finished product surface smooth, reducing warpage deformation.


A brief summary of the understanding is: blow-molded products are hollow, and injection-molded products are solid. The injection molding mold has fine texture, precise size and better compression resistance. However, the traditional internal injection molding system directly injects gas into the middle of the melt, while the external gas-assisted injection molding system selects a specific product surface and injects air pressure between the mold wall and the melt, so that the gas directly pressurizes and cools the plastic surface, reducing the amount of plastic Dissolution streaks during cooling and warping due to hollow cavities. The product has better punching resistance, toughness, mechanical strength and chemical stability, so compared with pure injection molding products, gas-assisted injection molding products are more favored by customers.Rear-folding plastic seat YY-FT-P

Second, the advantages and disadvantages of blow molding and injection molding (gas-assisted injection molding)

Advantages and disadvantages of blow molding:

Advantages: simple structure, relatively light seat, affordable price.

Disadvantages: The function is relatively simple, the appearance is general, and the grade is relatively low. But a good blow molding seat is not low-grade, and the cost is relatively high.

Advantages and disadvantages of injection molding (gas-assisted injection molding):

Advantages: Accurate size, beautiful surface, the seat can achieve more functions, improved comfort, and enhanced pressure resistance, while the gas-assisted injection molding seat is more reliable and wear-resistant, and the flame retardant performance reaches B1 level, and has passed the SGS European fire protection mark. Hazardous substance discharge <E1.

Disadvantages: complex structure, high cost

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YY-ZT-P (2)

3. How to distinguish between blow molding and injection molding

1. Look at the material: PP material has the advantages of not easy to deform, good impact resistance, weather resistance, etc. This material is commonly used in injection molding, which is more beautiful and more expensive. Blow molding is basically made of HDPE material, and the price of this product is relatively economical.

2. Look at the price: Because the purchase cost of blow molding equipment is much lower than that of injection molding equipment, the blow molding process is simple, and the mold development cost is also low. Of course, the materials used are relatively economical. Therefore, injection molding seats are more expensive than blow molding seats.

3. Look at the surface: the surface of the injection molded product is smooth, the texture is relatively better than that of the blow molded product, and the compression resistance is also better than that of the blow molded product.

4. Look at the details: the blow molding structure is relatively simple, and there are not many places that can be adjusted, especially the inclination adjustment. The injection molded parts are assembled by multiple small molds, the structure is more complex, and it can realize many functions, such as multiple height adjustment and multiple angle adjustment.

5. The seat of gas-assisted injection molding is safer, more comfortable, more functional, and more high-end in appearance. Of course, the quality of good blow molding products is not low, and the cost is relatively high.

The journey seat produced by Yourease Sports is a typical gas-assisted injection molding seat. The shape and size of the seat are designed according to ergonomic principles. The overall shape of the seat is novel and unique, the surface is soft, delicate and generous. Stainless steel double spring folding and slewing mechanism, silent folding, strong reliability. The backrest and seat plate are designed according to ergonomic principles, which can fit the human body curve to the greatest extent. The material is made of pure PP raw material and formed by nitrogen gas. The seat is reliable, wear-resistant and comfortable. The flame retardant performance reaches B1 level, it has passed the SGS European fire protection mark, the emission of harmful substances is <E1. And the installation methods are various, it can be one of the best choices for indoor and outdoor sports venues.

In fact, whether you choose a blow molding seat or an injection molding seat, you must choose a professional manufacturer’s product. The brand that has passed the safety test can be purchased according to the project situation. Shenzhen Yourease Sports grandstand seats have many types and models. It is produced in strict accordance with the production process and production process, with comfortable sitting feeling, beautiful appearance, support for customization, and in line with various technical standards of the public seat industry in stadiums. It is your first choice!

Post time: Jul-12-2022