Drying of Engineering Plastics a necessary criteria for achieving quality
Generally engineering plastics such as ABS, Polycarbonate, Nylon, Acrylic, SAN etc., used in automobiles have a high affinity towards moisture. They absorb moisture during manufacturing, transportation and storage prior to processing. Improper and inadequate drying of the resin leads to
1. Poor surface finish
- Silver streaking and splay
- Bubbles/Voids
- Peel-off of surface coating
2. Loss of physical properties
- loss of structural strength
- loss of tensile strength
- loss of impact strength
Parameters of drying
• Drying time • Air flow • Temperature • Dewpoint
While temperature, drying time, air flow are dependent on the resin type, if the dewpoint can be maintained at minimum –40ºC, then there is a huge difference in quality of molded component.
Dewpoint plays a very critical role in creating a lower vapour pressure around the surface of the resin. This lower vapour pressure forces the moisture in the molecular chain of the resin to dissipate out to its surface.
Only Bry-Air Dehumidifying Plastic Dryers can guarantee –40ºC to –65ºC as consistent dewpoint. The resins dried at –20ºC dewpoint retain 10 times more moisture than resins dried at –65ºC dewpoint
Saves money, Ensures clean shop floor
The handling of resins in the shop floor is a complex job. Employing labor to handle resins manually leads to spillage of resins, contaminates the shop floor with resin dust, result in not feeding right material to the right machine at the right time and delay in change over of material.
Resin Spillage
- Causes accidents on the shop floor
- Contaminates material
- Contaminates oil in machine
Resin Dust
- Creates barrel heater failures
- Creats problem in electrical components
- Contaminates the shop floor
- Creates problems in the tie-bar of injection molding machine
Feeding material continuously requires constant monitoring which becomes more tedious manually.
Automatic Conveying Systems will be a great support in case of quickly changing the dried material, saving the material, keeping shop floor neat and clean, protecting the shop floor and machines from resin dust.
Along with the Automatic Conveying System, Bry-Air offers centralized drying solution for quick change over of dried material and to avoid machine down time. Without Centralised Drying system, dryers have to be completely emptied and cleaned before change over of material. This results in loss of machine hours, wasting energy on drying and contamination of material.
