Polypropylene injection molding

Polypropylene injection molding

Connexions has more than 20 years experience in plastic injection molding industry. We pride ourselves in being one of the best plastic injection molding companies in term of designing and Polypropylene parts manufacturing. We can provide customized OEM/ODM service to meet all your requirements about Polypropylene injection molding.

Polypropylene injection molding

As one of processional Polypropylene injection molding companies, we are able to make variety of Polypropylene injection molding parts per your request. Our one-stop OEM/ODM services can just be started with your draft idea or concept.

Our custom Polypropylene injection molding services include

• 3D Mold Design
• 
• Mold Processing
• 
• Mold Trial and Inspection
• 
• Polypropylene Parts Injection
• 
• Injection Parts Finishing
• 
• PCB SMT
• 
• Product Assembly and Checking
• 
• Product Packing
• 
• Final Inspection
• 
• Delivery

Product Specifications for Polypropylene injection molding

Quality Assurance

The company always puts quality and the customer first. The factory has passed the ISO 9001-2015 quality system certification.To make quality thermoplastic injection molding parts and meet our customers requirement, we have strict quality control procedures:

1. Tool drawing Design review and update (Mould flow Analysis will be provided during the Polypropylene injection mold design period)

2. Design validation and verification

3. Strict IQC for all of raw material

4. First mold trial Inspection

5. Checking electrodes by CMM measurement machine before EDM

6. Full dimensions measurement report

7. Dimension adjustment inspection before next mold trial

8. Coordinate Measuring Machine (CMM)

9. Projector machine

Our custom plastic parts display for Polypropylene injection molding

FAQ

Q1: Are you trading company or manufacturer ?

A: We are a manufacturer specialized in plastic injection molding with more than 20 years of experience.located in Dongguan, China. Welcome to visit our factory anytime.

Q2:What is your minimum order quantity?

A: Generally 1000pcs, but a small amount can be accepted under some special circumstances.

Q3: Do you provide samples? Is it free or extra?

A: Yes, we can provide free samples, but not the freight.

Q4: How long does it take to have the first samples of plastic injection molding parts?

A: The first sample will be available once the plastic injection mold is completed. We will sent the sample to you via express service (FedEx, DHL or UPS). Normally, it will reach you within 3-5days.

Q5: What is your terms of payment?

A: 50% Mold cost deposit, the balanced mold cost and 50% production cost to be paid when sample is confirmed. And the balanced production cost is paid against copy of B/L.

Q6: What’s the technology process of Polypropylene injection molding?

A:Polypropylene, commonly known as PP, is a translucent, semi-crystalline thermoplastic with high strength, good insulation, low water absorption, high heat deflection temperature, low density and high crystallinity.

1. Treatment of the plastic

Pure polypropylene is translucent ivory white and can be dyed in various colors. Polypropylene injection molding generally does not require special drying before processing.

2. Selection of polypropylene injection molding machine

There are no special requirements for the selection of polypropylene injection molding machine. Because of the high crystallinity of PP, computerized injection molding machine with high injection pressure and multi-stage control is needed.

3. Mold design and gate design

Mold temperature is 50-90℃, higher mold temperature is used for higher dimensional requirements. The core temperature is more than 5°C lower than the cavity temperature, and the mold must have good exhaust. To avoid shrink marks, large and round sprues and round runners need to be used, and the thickness of the reinforcement should be small (e.g. 50-60% of the wall thickness).

4、Melting temperature

The melting point of polypropylene is 160-175℃, and the decomposition temperature is 350℃, but the temperature set during injection processing should not exceed 275℃, and the temperature of the melt section is preferably 240℃.

5、Injection speed

In order to reduce internal stress and deformation, high speed injection should be selected, but some grades of polypropylene and injection molds are not suitable (bubbles and air patterns appear). If bright and dark streaks appear on the pattern surface spread by the gate, low injection speed and high mold temperature should be used.

6、Polypropylene Injection pressure retention

Use a higher injection pressure (1500-1800bar) and holding pressure (about 80% of the injection pressure). Switch to holding pressure at about 95% of the full stroke and use longer holding time.

7、Product post-treatment

To prevent shrinkage and deformation caused by post-crystallization, the injection moulding products generally needs to be soaked in hot water.