What are the general problems of plastic products, and where do the problems generally appear?

Common defects in plastic products mainly include the following problems:

1. Shrinkage and deformation.

2. Surface pores.

3. Flow marks.

4. Underinjection & overflow flash.

5. Black bars, burnt & bubbles.

6. Cracking and whitening.

7. Bending and deformation.

8. Silver wire strip & weld mark.

9. Poor demoulding.

Water streaks, air streaks, bubbles, shrinkage, etc.

Streaks, top white, shrinkage, surface ** paste.

High-temperature resistant plastics: generally PPS, LCP and high-temperature nylon. PPS is 260 degrees, LCP is 300-350 degrees, high temperature nylon is 260-290 degrees; Teflon operating temperature 280, maximum temperature 380.

Among them, polyimide (PI) has a long-term working temperature of more than 350 and a short-term temperature of up to 450, which is the engineering plastic with the best high temperature resistance among engineering plastics. PTFE polytetrafluoroethylene has high corrosion resistance, temperature resistance between -80 degrees --- 250 degrees, and is also very powerful, known as the king of plastics.

Repeated use of plastics: It depends on what it is used for, most of them are not used for drinking, and there are still many cases of repeated use. Many plastic products are scrapped due to appearance at the time of production, and the company usually restores the failed finished product to the material and remolds.

However, if the water cup we drink has been used, it is currently believed that it will cause cancer if it is re-used.

How to choose safe plastics: you can pay attention to the water bottle, the number identification within the triangle at the bottom of it, according to the ** classification label 1 7, number 1: drink bottles made of pet:

It can be filled with room temperature water in a short period of time, but it cannot be filled with high-temperature water, and it is not suitable to fill acid and alkaline drinks, so it is recommended not to reuse it, and do not put the drink bottle in the car to expose it to the sun. Figure 2: Plastic containers made of HDPE high-density polyethylene:

It is commonly found in medicine bottles, cleaning products, bath products. These products are not easy to clean thoroughly and should not be recycled. Numbers 3 and 4:

Products made of No. 3 PVC (also known as "V") polyvinyl chloride and No. 4 LDPE polyethylene: commonly used in raincoats, building materials, plastic films, plastic boxes, etc. Because these two types of materials have excellent plasticity and low price, they are more commonly used.

However, they are rarely used in food packaging because they have a low heat-resistant temperature and may release harmful substances when they decompose at high temperatures. Figure 5: PP polypropylene:

It is the only plastic box that can be put in the microwave oven and can be reused. Figure 6: PS Plastic products made of polystyrene:

It cannot be used in high temperature, strong acid, or strong alkali environment. Figure 7: AS acrylonitrile-styrene resin:

Kettles, cups, and baby bottles that have been mass-produced with this material have a history of more than 10 years, and they are highly safe. The cups made of this material are highly transparent and resistant to falls, but they are less durable.

The speed of softening has a lot to do with whether it is crystallized or not.

The crystallization is that the TM melts quickly at the fusion point, and the difference between crystalline and amorphous polymers when melting can be seen from the surface.

Heat deflection temperature of HDT plastic: show whether the plastic material can maintain the same shape at high temperature and under pressure, generally the heat deflection temperature is used to represent the short-term heat resistance of the plastic, for amorphous plastics, HDT is smaller than TG 10 20; For crystalline plastics, HDT is close to TM.

The crystals melt quickly at the TM temperature and do not soften.

The amorphous ones begin to soften at TG.

It is useless to say so much, that is, the heat deflection temperature, regardless of crystalline polymers and amorphous polymers, will have a heat deflection temperature. Low temperature for fast deformation and softening.

There are many types of plastics, and each type of plastic has a different melting temperature.

That was a film made of what I don't know.

But I know that it's easy to tear and it's easier to tear.

The problem that plastic factories often face is that there are many bad habits formed in management and operation, or negligence causes a lot of waste of energy. In fact, as long as we pay attention to the correction in all aspects, we can effectively save energy, improve energy efficiency, and thus reduce production costs.

Here are just a few examples of energy saving measures.

1. It is necessary to choose the appropriate size of the injection molding machine for production.

2. It is necessary to develop good operation and maintenance habits of injection molding machines.

1) Shorten the time it takes to get ready to boot up.

2) Cover the insulated mask on the barrel.

3) The hydraulic oil should run normally.

4) Mold cooling control.

5) To improve the mold design.

For some products, if possible, the wall thickness is appropriately reduced, which can also reduce the cooling molding time and the energy consumption of the melt.

Your question is very vague,I don't know how you.

Generally, the impact of receiving international plastics is relatively large, especially the change of the old price, and the other is environmental protection issues. It's basically the price. It depends on what kind of plastic you're producing.