FAQ

Processing FAQ

Q: 1. Why do silvery steaks exist despite the fact that the resins are pre-dried?
A: The key factor is depends on the pre-drying time, neither the time can be too short nor too long. Otherwise the color of the resins will be changed.
Here below is the calculation of quantity added:
Quantity Q (Unit: kg/hr) is added if M gram is produced after T second, Q = [(3600/T) X M]/1000

Q: 2. How to calculate the clamping force?
A: Clamping force is a very light force that holds the workpiece to prevent distortion, mould flash and sink marks. Commodity Plastic: 2 ton/in2
Engineering Plastic: 3-4 ton/in2
Reinforced Engineering Plastic: 4-6 ton/in2
Formula of Calculating the Clamping Force:
Clamping Force = Projected Area x Constant of resins

Q: 3. What is Ultrasonic Welding? What factors needs to be considered when choosing plastics for Ultrasonic Welding?
A: Ultrasonic Welding is a method of connecting thermoplastics by using high frequency-vibration. As heat is produced in the bonding area by the absorption of mechanical vibrations, the material will plasticize locally, forging an insoluble connection between both parts within a very short period of time. After the vibration has stopped, pressure is continuing added into the parts until the insoluble connection has solidified, thereof the whole process is completed.
When choosing plastics for Ultrasonic Welding, weldability should be noted. Since the molecules of Amorphous polymer are irregularly arranged, therefore it melts gradually while energy is easily transferred. However, the structure of crystalline polymer is uniformly arranged with a high melting point, thus additional energy is required. The important factor is that both of them have a near equivalent melting point and similar molecular structure.

Q: 4. What is Co-Injection Molding? Why do I use Co-injection Molding?
A: Co-injection process is characterized by its ability to completely encapsulate an inner core resin with an outer skin material.
The advantages of Co-Injection Technology:
-Improving quality and performance of molded part
*Able to combine various properties of materials; providing better decoration effects such as colour and soft-hard finishing and structural strength by using structural foam material
*By using adhering materials in Co-Injection Molding rather than chemical or mechanical methods, allowing better control
*Providing better chemical resistance on surface and better mechanical property in the interior
-Cost Reduction
*By using regrinds in the core, or using less expensive material on the skin layer, not only material cost will be largely reduced, but also post-processing labor and handling cost, including decoration and derived tooling
Co-Injection Molding is now commonly used in hard-soft material combinations products, ranging from personal care, lawn care to auto parts.

 

Raw Materials

Q: 1. What is the difference between SBS base and SEBS base TPE?
A: Both types of TPE, SBS base and SEBS base, have excellent processability and flexibility. Also, it is easy to process and is reprocessable. Special features of SEBS base TPE include high upper service temperature, excellent weatherability, excellent processing stability, and excellent solvent resistance. Hence SEBS base TPE is usually used in outdoor industrial & consumer goods while SBS base TPE is generally used in indoor and low-cost disposable products.

Q: 2. What is the difference between Acetal and Nylon used in producing gears?
A: Acetal is a very hard, durable material. It has good dimensional stability and is self-lubricating. Nylon is a softer material, and does not rate very high for stiffness. Its drawback is dimensionally sensative to both moisture and temperature variations.

Q: 3. Why is the product failing (break into small pieces) in the drop test despite glass fiber is added?
A: Although the stiffness of the product will strengthen when glass Fiber is added, its toughness is weaken which let the product goes into small pieces when dropped.
In that case, the product is not tough enough, tougher grade ought to be used but not by adding glass fiber.

Q: 4. What plastic material is suitable for making a light weighted, durable and high impact housing of the PDA?
A: * PA - light weight, strong and durable but the price is relatively high
* PC - light weight, strong and durable
* ABS - Very light weight but less strong

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