PET bottles use slices for bottle-to-bottle technology, food and non-food grades. It is processed directly into PET bottles of grade A using waste PET bottles.
Multi-layer PET beverage bottle It is a three-layer sandwich process with a middle layer of recycled PET and FDA-required 0.025mm Class A PET on both sides. HUSKY has developed this equipment.
A-PET sheet PET cast sheet used to produce packaging materials that are in direct contact with foods such as drinking water cups, soft food holders, and the like. Recycling PET Bottles Made from Beverage Bottles The packaging trays made of PET are bright and have a high impact strength and tensile strength. Recycling PET from beverage bottles can be processed into a scoop, and Procter Gamble (USA) has produced some products.
Films containing recycled PET have been produced under the registered trademark ECOTM (ICI Films, Wilmington, USA). The ECO813G film contains 25% recycled PET and has been approved by the FDA for use in food contact applications.
Composite Extrusion Multilayer Films In North America and Europe, a thermoformed food packaging tray is now in production. The outer layer is pure PET and the inner layer contains a certain amount of recycled PET.
Non-contact food containers If performance permits, single-layer PET bottles can be made with 100% recycled PET, and can also be made with recycled PET and pure PET. This product is mainly used as a detergent and daily necessities.
PET tapes with PET have high toughness and can replace steel tapes, with IV values ​​ranging from 0.78 to 1.10 dl/g.
C-PET slice It is an abbreviation for crystalline PET. It is mainly used for the production of food trays that can be placed in a microwave oven. It can withstand high temperatures when the oven is heated, and can withstand very low temperatures when stored in the refrigerator.
PET-Engineering Plastic Injection Molding Process Introduction 2006-07-25 15:36 PET Chemical name is Polyethylene terephthalate, also known as polyester. At present, GF-PET is the most used among customers, mainly for bottle preforms.
The rheology of PET in the molten state is good, and the pressure has greater influence on the viscosity than the temperature. Therefore, the fluidity of the melt is mainly changed from the pressure.
1. Treatment of plastics PET macromolecules contain a lipid group and have a certain degree of hydrophilicity. Pellets are sensitive to water at high temperatures. When the moisture content exceeds the limit, the molecular weight of PET decreases during processing and the product is colored. Become brittle. For this reason, the material must be dried before processing. The drying temperature is 150°C, more than 4 hours, usually 170°C, 3-4 hours. Air ejection can be used to check if the material is completely dry.
The proportion of recycled materials should not exceed 25%, and the recycled materials should be thoroughly dried.
2. The injection molding machine uses PET because of the short time after the melting point is stable and the melting point is higher. Therefore, it is necessary to use more injection molding systems with more temperature control sections and less self-heating during plasticization, and the product (water-containing mouth material) is actually used. The weight should not be less than 2/3 of the injection volume of the machine. Based on these requirements, Ramada has developed a small and medium-sized PET special plasticizing system in recent years. The clamping force is greater than 6300t/m2.
3, mold and gate design PET preforms generally use hot runner mold, the mold and the injection molding machine template between the best insulation board, the thickness of about 12mm, while the insulation board must be able to withstand high pressure. Exhaust must be sufficient to avoid local overheating or fragmentation, but the depth of the exhaust port generally should not exceed 0.03mm, otherwise it is prone to flash.
4, melt temperature can be measured by the air injection method. Different from 270-295°C, the reinforced grade GF-PET can be set to 290-315°C.
5, the injection speed Generally faster injection speed, can prevent premature coagulation during injection. But too fast, the high shear rate makes the material fragile. The shot is usually completed within 4 seconds.
6. The lower the back pressure, the better so as not to wear out. Generally does not exceed 100bar. Usually do not need to use.
7. Retention time Do not use excessive residence time to prevent the decrease of the molecular weight. Try to avoid temperatures above 300°C. If the stoppage is less than 15 minutes. Only air shot processing is required; if it exceeds 15 minutes, it is cleaned with viscosity PE and the barrel temperature is lowered to PE temperature until it is turned on again.
8. Matters needing attention (1) Recycling materials can not be too large, otherwise it is easy to produce "bridging" at the blanking area and affect plasticization.
(2) If the mold temperature control is not good or the material temperature is not properly controlled, it is easy to produce "white fog" and not transparent. The mold temperature is low and uniform, the cooling rate is fast, and the product is transparent when the crystal is low.
Reprinted from: China Waste Net