Enterprise name: Zongsheng Precision Mould Co., Ltd.
Contact: Mr. Nie 13923298099 (Wechat same number).
Miss Jia 15820657628 (Wechat same number).
Tel: 0757 2226 9630.
0757 color 22269276.
Fax: 0757 2226 9631 22269276.
Web site: en.fszongsheng.com.
Add: no. 1, Rongye 6 road, Fengxiang industrial zone, Daliang, Shunde district, Foshan city, Guangdong province
With the continuous progress of science and technology, PET bottle embryo gradually into our days, more and more people begin to know, but some people still inadvertently understand it, in view of this situation, we collected a lot of relevant materials for us to consult. Below we on the "PET bottle embryo in the homework to pay attention to the main points and related common sense of science popularization" to understand in detail.
[what are the points for attention of PET bottle embryo during injection molding]. PET chemistry is called polyethylene terephthalate, also known as polyester. Now in the customer uses many is the GF-PET, is mainly hits the bottle embryo. The rheological property of PET is better in the melting state, and the effect of pressure on viscosity is greater than that of temperature. Therefore, the fluidity of the melt is mainly changed from the pressure.
1. Treatment of plastics.
Because PET macromolecules contain lipid groups and have certain hydrophilicity, the granules are sensitive to water at high temperature. when the water content exceeds the limit, the molecular weight of PET decreases, and the products become colored and brittle.
Therefore, it is necessary to monotone the material before processing, the monotonous temperature is 150 ℃, more than 4 hours, generally 170 ℃, 3 Mel 4 hours.
The aerial shooting method can be used to check whether the material is completely monotonous.
Generally speaking, the proportion of recycled materials should not exceed 25%, and the recycled materials should be thoroughly monotonous.
2. Selection of injection molding machine.
Because the PET is stable after the melting point for a short time, and the melting point is higher, it is necessary to choose the injection system with more temperature control sections and less self-contradictory heat generation during plasticizing, and the practical weight of the product (water-containing material) can not be less than 2max / 3 of the injection volume of the machine.
According to these requirements, Funeng has developed a small and medium-sized series of PET special plasticizing system in recent years.
The clamping force is greater than 6300t/m2.
3. Mold and gate planning.
PET bottle embryo is generally molded with a warm runner mold between the mold and the injection molding machine template * there should be a heat insulation plate whose thickness is about 12mm and the heat insulation plate must be able to withstand high pressure.
Exhaust is necessary to avoid partial overheating or fragmentation, but the depth of the exhaust port is generally not more than 0.03mm, otherwise flying edge will occur simply.
4. Melting temperature.
It can be measured by air-shooting method.
The enhanced GF-PET can be set to 290mur315 ℃, etc.
5. Injection speed.
Generally, the speed of injection should be fast, which can avoid premature solidification during injection.
But too fast, high shear rate makes the material fragile.
The injection usually ends in 4 seconds.
6. Back pressure.
The lower the better, to avoid wear and tear.
Generally do not exceed 100bar.
Generally speaking, there is no need to use it.
7. Length of stay.
Do not use too long stay time to avoid the decrease of molecular weight.
Try to avoid temperatures above 300 ℃.
If the downtime is less than 15 minutes.
Only need to be air-shot treatment; if more than 15 minutes, it is necessary to use viscosity PE cleaning, and reduce the barrel temperature to PE temperature, until the restart stop.
Foshan Shunde Zongsheng Precision Mould Co., Ltd.
Tel: 0757 Tel: 22269630 / 13923298099 (Mr. Nie).
Web site: www.fszongsheng.com.
Add: no. 1, Rongye 6 road, Fengxiang industrial zone, Daliang, Shunde district, Foshan, Guangdong
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