A introduction to fiber-reinforced fire-resistant PC plastics

Jun 10, 2022

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A introduction to fiber-reinforced fire-resistant PC plastics

PC plastic raw material refers to a compound material containing high molecular polymer polyester carbonic acid. PC plastic raw material is also called PC plastic. The Chinese name is polycarbonate, which is a thermoplastic compound with high strength. Today we introduce a kind of fiber-reinforced fire-resistant PC plastic obtained by adding other compounds on the basis of this PC plastic raw material.

Ordinary PC plastic raw materials also have good performance. First of all, its stability is not bad. In a normal environment, it has good stability. He is relatively good, light transmittance, which is an important component of plexiglass, but if it encounters ultraviolet rays, it will turn yellow or deteriorate, so this common PC plastic material is generally only used indoors. But what we are going to introduce today is a new material added with other compounds. On the basis of the excellent performance of traditional PC plastic raw materials, it has added other properties.

One of the outstanding performances is that its cold resistance and heat resistance have been improved significantly. The heat distortion temperature of traditional PC plastic raw materials is between minus 45 degrees and 135 degrees above zero. And this new type of fiber-reinforced fire-resistant PC plastic has a thermal deformation degree between minus 200 degrees and plus 500 degrees, which is a very big improvement. Even in the aerospace field, this high-performance PC plastic has begun to be used. raw material.

Let’s take a look at the main application range of this fiber-reinforced fire-resistant PC plastic. It has made a very prominent contribution in the automobile manufacturing industry. Some important parts and some more wear-resistant parts on the automobile are made of this material. It also has outstanding contributions in public pipelines, especially some heat pipelines, which have relatively high requirements on materials. This fiber-reinforced fire-resistant PC plastic is a good choice.

Introduction of fiber-reinforced fire-resistant PC plastic injection molding process:

1. Drying of raw materials

1. Raw material drying: the temperature of the ordinary drying box is 110-130, the time is 2-4 hours, the temperature of the top hopper drying box is 100-120, and the moisture content is required to be less than 0.03%.

2. Judging whether the water content is qualified: look at the condition of the injected material strip, the material strip flowing out of the nozzle after plasticization should be uniform and colorless, no silver wire and no bubbles; otherwise, the drying is incomplete. .

Second, the injection process

1. Adjust the molding parameters of the injection molding machine (depending on the molecular weight of the raw material):

Barrel Temperature: Front 250—310, Middle 240—280, Rear 230—250.

Nozzle temperature: 10 lower than rear.

Mold temperature: 70—120.

Injection pressure: 70-140MPa.

Screw speed: 30-120r/min.

Molding cycle: injection 1-25s, cooling 5-40s.

3. Matters needing attention

1. The injection temperature is adjusted according to the molecular weight of the raw material, the shape and size of the product, and the type of injection molding machine.

2. The injection speed should be multi-stage injection, using the slow-fast-slow method.

3. The injection pressure depends on the shape and size of the product. The plunger injection molding machine is generally 100-160MPa, and the screw injection molding machine is 70-140MPa.

4. The molding cycle depends on the wall thickness and injection volume of the product. Generally, the filling time is short, the pressure holding time is long, and the cooling time is based on the principle that the product will not be deformed when demoulding.

5. The mold temperature depends on the shape and thickness of the product. Properly increasing the mold temperature is conducive to demoulding and improving product quality.

6. Post-processing of products: For products with complex shapes, metal inserts, and very low or high temperatures, post-processing is necessary to eliminate or reduce internal stress.

Method: After the product is placed in the drying box, it starts to heat up, and when the room temperature rises to 100-105, the temperature is kept for 10-20 minutes, and the temperature is continued to rise to 120-125, and the temperature is kept for 30-40 minutes, and then slowly cooled to below 60 and taken out.