Dramatically improves the molding defect rate due to insufficient drying.

Dramatically improves the molding defect rate due to insufficient drying.|HARMO Co.,Ltd

The defect rate will be reduced drastically to 0 to 3%. We attempt to improve the defectiveness of resin molded products that occurs due to a lack of drying with the use of Hot Air Dryer.

Potential causes of defects using Hot Air Dryer

Aren’t you being troubled by weather and humidity that increase the defect rates of resin molded products?
The reasons for such defects are a lack of strength and resistance caused by hydrolysis and poor appearance due to bubbles and silvers.
Insufficient drying leads to measurement errors and they occur more frequently when the following materials are being used.

Materials that easily generate measurement errors due to insufficient drying


The reason is considered moistures left due to a lack of drying.
HARMO’s Dehumidifier Dryer aims to solve this problem and improve defectiveness.

Hot Air Dryer fails to properly control humidity and dryness, resulting in the defect rate of nearly 10%

Some may develop a concern like this; the regularly used Hot Air Dryer for drying resin molded products performs poorly depending on weather and humidity, causing defects.
For these issues, we have suggested Dehumidifier Dryer that can improve the quality of resin molded products and minimize defects.

As a result, we succeeded in largely decreasing the defect rate to 0 to 3%. We confidently recommend the use of Dehumidifier Dryer for automobile components like PC and PBT too, as there is an increasing demand in this area.

Concerns & Problems

  • Hot Air Dryer doesn’t perfectly dry resin molded products, causing a poor product quality
  • Silver streaks occur when molding PA.
  • A lack of strength like cracks is detected when molding PBT.
  • The transparent part of PC gets foggy with Hot Air Dryer.


1. A shift from Hot Air Dryer to Dehumidifier Dryer optimizes drying condition

Hot Air Dryer takes times drying thus leads to defects due to over-drying. On the other hand, Dehumidifier Dryer will improve the defect rate as it infuses low dewpoint drying air at -45 degrees, leading to stabilize moisture content and minimize measurement errors of products. Besides, the overall processing time will be shortened as the drying time is short with Dehumidifier Dryer,

2. The perfect dehumidification and drying solve moisture problems

As mentioned previously, the bubbles and silver streaks of resin molded products that lead to poor appearance, weakness, and measurement errors may be due to moisture left on the product. This problem can be eased by thorough dehumidification and drying. To achieve stability and improve productivity, we have deployed a dehumidification dryer unit.

3. Low dewpoint air at -45 degrees prevents hydrolysis and maintains strength

The strength of resin molded products decreases due to hydrolysis which occurs from the scientific reaction of moistures on the resin materials. Since the dewpoint air represents the amount of water in the air, it’s been known that the lower the dewpoint air, the drier the condition will be. By infusing dehumidified, dried air into the resin materials, the defect rates of resin molded products will be improved with fewer moistures.

4. Maintaining the moisture content will minimize measurement errors of molded products.

There is a substantial difference in drying quality between MDR II and Hot Air Dryer. With stabilized water content, the measurement errors of molded products will be minimized. Also, its fast dehumidification and drying save two hours thus improve productivity.

The implementing effect of Dehumidifier Dryer

The defect rate of 10% will be reduced to 0 to 3%.

While Hot Air Dryer is easily affected by external conditions like weather and humidity that result in silver streaks, a lack of strength, and a fog of transparent parts, Dehumidifier Dryer performs thorough temperature controls and drying, leading to stabilize the quality of molded products.

Solved/improved points

The stabilized quality of molded products with Dehumidifier Dryer’s perfect temperature control and drying technique The drastic reduction of the defect rate to 0 to 3%

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