Difference between hot air dryer and dehumidification dryer

        With the widespread use of engineering plastics, dehumidification dryers have gradually replaced traditional hot air dryers (ovens). What are the differences between a hot air dryer and a dehumidifier dryer?

        1. The water in the plastic raw material can be taken away to eliminate the generation of bubbles, making the product achieve ideal mechanical, electrical, dimensional stability, and smooth and beautiful appearance.

        2. Prevent the generation of defective products and return losses, greatly reducing the generation of waste materials.

        3. Because dehumidification dryers use very dry air for dehumidification, they can shorten drying time and save labor hours.

        4. The air pipelines of the dehumidification dryer adopt a sealed circulation system and are equipped with filters, so they are not affected by the external climate, and can prevent dust from causing pollution in the factory, improving the working environment.

        A good drying efficiency is determined by the following four factors: drying temperature, residence time, air flow, and dew point. These four factors are closely linked, and any change in conditions will affect the drying effect.

        Drying temperature refers to the temperature of the air entering the drying bucket. Due to the physical properties of each raw material, such as molecular structure, specific gravity, specific heat, moisture content and other factors, the temperature during drying has certain limits. If the temperature is too high, some additives in the raw material will volatilize, deteriorate or agglomerate. If the temperature is too low, some crystalline raw materials will not reach the required drying conditions, such as PC/120 ℃, ABS/80~95 ℃. In addition, insulation is required for the selection of dry barrels to avoid drying temperature leakage, resulting in insufficient drying temperature or energy waste.

        "Residence time" refers to the pre drying time of raw materials before molding. Too long a drying time can cause deterioration or caking of raw materials or waste of energy, while too short a drying time can cause excessive moisture content. ". For example: PC/3-4 hours, ABS/3-4 hours.

        Air flow is the only medium that removes moisture from raw materials, and the amount of air flow can affect the effectiveness of dehumidification. Too much air volume can cause excessive return air temperature, causing overheating and affecting the stability of the dew point. Too little air volume can not completely remove moisture from the raw material. Air volume also represents the dehumidification ability of a dehumidification dryer.

        Dew point refers to the temperature at which a gas cools to condense the moisture it contains into water droplets. It is a unit for measuring the degree of dryness (wetness) of a gas. The less moisture in the gas, the lower the dew point temperature. A good dehumidification dryer should have a dew point temperature of - 40 ℃.

        The use of dehumidification dryers can be divided into single machine and centralized type. Single machine dehumidification dryers usually include a dryer host, a drying barrel, and a suction machine. The use of a single unit is suitable for a small amount of diverse drying, with the advantage of high drying efficiency and convenient and rapid material replacement. The centralized dryer includes a dryer host and several drying barrels. Each drying barrel has an independent heating controller that can simultaneously dry several different raw materials, and is equipped with an air volume regulating valve to control the air volume of each drying barrel. www.jiashengsz.com