black pvc injection moulding pellets

In addition, our company has established cooperative relationships with plastic raw material suppliers, printing manufacturers, etc. to ensure the supply of raw materials and printing quality. Through our rich experience and perfect supply chain, our company can provide customers with high-quality customized black pvc injection moulding pellets products to meet their specific needs. At the same time, we have 10 years of professional foreign trade service experience, understand the foreign trade process, and better serve our customers. For black pvc injection moulding pellets products, we can make corresponding plastic parts, which is mainly done through injection molds.

Professional technical analysis of black PVC injection molding (updated in 2025), combined with the characteristics of heat-sensitive materials and the influence of black pigments, systematically expounds from formula design, process control to cutting-edge technology:

I. Key points of material formula

1. Optimization of PVC substrate and black system

Resin selection: sanitary SG-5 type PVC (K value 65-68), whiteness ≥ 90% (reduces the difficulty of black covering).

Carbon black selection: highly dispersed gas phase carbon black (particle size 20-30nm, DBP absorption value 120-130cm³/100g), addition amount 0.8-1.2% (excessive amount leads to melt strength ↓30%).

Thermal stabilization system: calcium zinc composite stabilizer (3-4 parts) + epoxidized soybean oil (2 parts), inhibiting HCl release (decomposition temperature > 190℃).

2. Key points of additive compatibility (weight parts)

Processing aids, promote plasticization, 1-1.5 parts, insufficient plasticization will result in uneven plasticization

Internal lubricants, reduce melt viscosity, 0.8 parts, excessive amounts will result in difficulty in demolding

External lubricants, prevent mold sticking, 0.5 parts, excessive amounts will affect the gloss of the product

Impact modifiers, improve toughness (ACR), 6-8 parts, impact strength ↓50% when <5 parts

II. Special requirements for equipment and molds

1. Key points for injection molding machine modification

Corrosion-resistant screw: dual alloy coating (NiCrMo), aspect ratio L/D=20-22, compression ratio 2.4-2.6 (to prevent shear overheating).

Barrel temperature zone

graph LR

A[feeding section 150-160℃] --> B[compression section 165-170℃]

B --> C[metering section 175-180℃]

Clamping system: add hydraulic vacuum device (vacuum degree of cavity ≤-0.08MPa) to eliminate flow marks of black products.

2. Mold protection design

Surface treatment: cavity hard chrome plating (thickness ≥15μm) or S136H stainless steel (HRC 48-52).

Exhaust system: stepped exhaust groove (depth 0.015-0.02mm), total cross-sectional area > cavity projection area 0.05%.

Cooling water channel: ≤12mm from cavity surface, temperature difference ±2℃ (to prevent the surface brightness difference of black parts).

3. Precise control of process parameters

Process window and risk threshold

Melt temperature, 175-185℃, >190℃ causes degradation (yellowing↑), infrared thermal imager real-time monitoring

Injection pressure, 70-90MPa, too high leads to overflow (>100MPa), closed-loop control of pressure sensor

Screw speed, 40-60rpm, >80rpm friction heat accumulation ↑50%, inverter PID adjustment

Pressure holding time, wall thickness × 1.2s/mm, insufficient shrinkage depression ＞0.3mm, in-mold pressure curve analysis

Mold temperature, 40-55℃, >60℃ extends cooling cycle by 30%, multi-point thermocouple feedback

Special process application:

Two-stage plasticization technology: pre-plasticization at low speed (25rpm) in the front section → homogenization at high speed (60rpm) in the back section (plasticization efficiency ↑20%).

Delayed mold opening: mold opening is delayed by 0.5-1s after the end of pressure holding to eliminate air marks on the surface of black products.

IV. Defect analysis and solution strategies

Countermeasures for common defects (unique to black PVC)

Black spot impurities

Root cause: carbon black agglomeration or PVC degradation

Solution:

Use a high shear mixer (≥1200rpm, mixing time >5min)

Add a melt filter at the end of the barrel (mesh size 200→300 mesh)

Uneven surface gloss

Root cause: lubricant migration or mold temperature fluctuation

Solution:

Use oxidized polyethylene wax (OP wax) as external lubricant

Add pulse cooling function to the mold temperature controller (water temperature fluctuation <±0.5℃)

Insufficient weld line strength

Root cause: carbon black hinders molecular chain bonding

Solution:

Increase melt front temperature (mold temperature ↑10℃)

Use ultrasonic assistance (frequency 28kHz, amplitude 30μm)

V. Frontier technology and environmental protection upgrade (2025)

Application of recycled PVC

When the waste ratio is ≤25%, the performance is improved by reactive compatibilizer (MAH-g-PVC), and the cost is ↓18% (UL 2809 certified).

Lead-free breakthrough

New antimony-rare earth composite stabilizer (Sb/Ce=3:1), heat resistance↑15%, in line with EU 10/2011 food contact standard.

Digital twin process

Virtual injection molding system real-time warning of degradation risk:

Python

# Degradation prediction model core logic

def degradation_risk(temp, time):

return 1.8**( (temp-175)/5 ) * (time/60)**0.7 # Output＞1.0 triggers alarm

Cost optimization key formula

Comprehensive cost = [raw material×(1-recycled material%) + energy consumption×(1-servo energy saving rate%)] × defective product rate coefficient

Best practice: recycled material 20% + servo energy consumption↓40% + defective rate＜3% → total cost↓28%

Ultimate warning: The core contradiction of black PVC injection molding is the triangular balance of carbon black dispersion, thermal stability and fluidity. Three laws must be followed:

Temperature iron law: When the melting temperature is greater than 190℃, the degradation rate increases by 15% per minute

Pressure rule: When the injection pressure is less than 70MPa, the plasticization state needs to be checked

Time rule: When the barrel residence time is greater than 5 minutes, the material is forced to be purged

New direction in 2025: Nanographene modified black PVC (addition of 0.3%), the conductivity reaches 10⁻³ S/m, suitable for antistatic medical devices.

black pvc injection moulding pellets

We are a black pvc injection moulding pellets manufacturer, providing high-quality black pvc injection moulding pellets manufacturing. As long as you want to customize/develop black pvc injection moulding pellets products, you can find us. We have professional injection mold design and mature manufacturing technology, providing you with one-stop service, from product design-mold making-product production-product packaging-product transportation, we can help you in every link. As long as you come to us, we will provide you with the ultimate service and satisfy you in terms of product quality, production time, information dialogue, etc.

Plastic Injection Mould making

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Factory

We are Custom Plastic Mold factory. Our factory is plastic injection mold maker. we has 17 years of experience in professional custom plastic mold and 10 years of foreign trade experience. We are custom Plastic Mold supplier. We can provide custom Plastic Mold service. Our factory can make the Injection molded plastic parts, and the quality of the products will satisfy you.

We have more than 50 high-end machines and hundreds of engineers and designers. We can provide one-stop service, from product design - mold making - product production - product packaging - transportation. We have a complete production chain. We can meet all your requirements.

Services we provide:

Professional custom mold service, Plastic mold design and manufacturing .plastic product production, product design, mold design, blow mold customization, rotational mold customization, die-casting mold customization. 3D printing services, CNC manufacturing services, product packaging, customized packaging, shipping services.

We always adhere to the principles of quality first and time first. While providing customers with the highest quality products, try to maximize the production efficiency and shorten production time. We are proud to tell every customer that our company has not lost any customer since its establishment.If there is a problem with the product, we will seek a solution actively and take responsibility to the end.

FAQ

Q1: Are you trading company or manufacturer ?

A: We are manufacturers.

Q2. When can I get the quotation?

A: We usually quote within 2 days after we get your inquiry.

If you are very urgent, please call us or tell us in your email so that we can quote for you first.

Q3. How long is the lead-time for mold?

A: It all depends on the products' size and complexity. Normally, the lead time is 25 days.

Q4. I have no 3D drawing, how should I start the new project?

A: You can supply us a molding sample, we will help you finish the 3D drawing design.

Q5. Before shipment, how to make sure the products quality?

A: If you don't come to our factory and also don't have the third party for inspection, we will be as your inspection worker.

We will supply you a video for production process detail include process report, products size structure and surface detail, packing detail and so on.

Q6. What is your payment terms?

A: Mold Payment: 40% deposit by T/T in advance, 30% second mold payment before sending out the first trial samples, 30% mold balance after you agree the final samples.

B:Production Payment: 50% deposit in advance, 50% before sending out the final goods.

Q7: How do you make our business long-term and good relationship?

A:1. We keep good quality and competitive price to ensure our customers benefit for best quality products.

2. We respect every customer as our friend and we sincerely do business and make friends with them, no matter where they come from.