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How to choose a three-in-one dehumidifying and drying machine for the injection molding industry?
Views: 553 Author: Site Editor Publish Time: 2022-05-19 Origin: Site
The three-in-one dehumidifying and drying machine is mainly used for dehumidifying, drying, and conveying of engineering plastics. With the wide application of engineering plastics, the three-in-one dehumidifying and drying machine is becoming more and more popular among customers. Most engineering plastics, such as PA, PLA, PP, PET, etc., have strong moisture absorption. When the plastic is taken out of the moisture-proof sealed bag and exposed to the atmosphere, it begins to absorb moisture from the air. If a conventional hot-air drying machine is used, which uses moist external air to dry the plastic, the plastic will continue to absorb moisture.
The optical-grade dehumidifier is a three-in-one machine, consisting of three parts: suction, dehumidification, and drying. The benefits of using this type of dehumidifying and drying machine are as follows:
(1) It can remove the water from the plastic material, eliminate bubbles, and improve the product forming rate.
(2) The dehumidifying and drying machine uses low dew point air for dehumidification, which can shorten the drying time and save working hours.
(3) It can prevent the production of defective products.
(4) The air pipeline of the dehumidifying and drying machine adopts a closed loop system and is equipped with a filter, so it is not affected by external weather and can prevent dust from causing pollution in the factory, improving the working environment.
This machine has high cost-effectiveness and strong practicality. You can choose according to the requirements of your material.
This section examines the key parameters of the venting section in vented extruder screws. Venting effectiveness depends primarily on venting section length L, melt residence time, shear rate, and the fill factor F (the ratio of melt cross-sectional area to channel area). To ensure good performance, the venting channel should be partially filled; experiments suggest L ≥ 3D, F ≤ 0.5, and a shear intensity K > 100 for optimal degassing. For screws with L/D ratios of 24–30, the venting section length is typically 4D, and its channel depth is 2.5–6 times that of the first metering section. Design verification must include fill factor, shear intensity, and screw strength.
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