Plastic chain moulding

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 plastic chain moulding 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 plastic chain moulding products, we can make corresponding plastic parts, which is mainly done through injection molds.

The injection molding process for plastic chains requires extremely high part precision, consistency, and wear resistance. They are typically constructed from identical links meticulously overlapped, so the quality of each link directly determines the performance of the entire chain.

The following is a detailed process for plastic chain injection molding, highlighting the key aspects of these moving parts.

Plastic Chain Injection Molding Process

Phase 1: Design & Material Selection

This is the foundation for ensuring the chain's flexibility and strength.

Link Design:

Overlap Structure: Design the hinged joints between the links, which are the core of the chain's flexible bending. The clearance between the shaft and the hole must be precisely calculated to ensure flexible rotation without excessive clearance.

Uniform Wall Thickness: Ensure uniform wall thickness across all chain links to prevent internal stress and deformation caused by uneven shrinkage, which can affect the chain's straightness.

Rounded Corner Transitions: Use rounded corners at all stress-concentrated areas to prevent breakage during use.

Design for Material Function (DFM) Analysis: Conduct a design and manufacturing feasibility analysis to optimize draft angles, ejector locations, and other factors.

Material Selection:

Nylon (PA66 or PA6): The most popular choice. It offers excellent wear resistance, high strength, and good self-lubrication, making it ideal for chain applications requiring repeated flexing and friction. Glass fiber (GF) is often added to enhance rigidity and heat resistance.

Polyoxymethylene (POM / DuPont Delrin®): Another excellent choice. It offers extremely high rigidity, low friction, and excellent fatigue resistance, resulting in quieter operation and is commonly used in precision transmission chains.

Polypropylene (PP) and Polyethylene (PE): Used in low-load, low-cost applications such as decorative chains and lightweight conveyor chains.

Phase Two: Precision Mold Design & Manufacturing

Plastic chain molds are the epitome of high-precision, multi-cavity molds.

High-Cavity Mold:

A single mold typically molds dozens or even hundreds of chain links at once, achieving high production efficiency. All cavities must be absolutely identical to ensure interchangeable chain links.

Hot runner system: Highly recommended and almost standard.

A needle-valve hot nozzle reduces scrap (no sprue), saves expensive engineering plastics, and shortens molding cycles.

Ensures balanced filling of each cavity, ensuring highly consistent weight and dimensions of each chain link.

Sliders & Core Pulls:

Because chain links often have lateral holes and overlapping structures, the mold must use multiple slides to handle lateral undercuts and ensure smooth demolding. This is the most complex and delicate part of the chain mold.

Ejector system:

Ejector pins must be carefully positioned on non-working surfaces to ensure uniform ejection and avoid white ejection or deformation.

Cooling system:

The design must be efficient and uniform to ensure fast production and dimensional stability.

Exhaust system:

Precise exhaust is crucial to prevent trapped air from causing burning or underfill.

Stage 3: Injection Molding Process

The goal of process tuning is to achieve products with dimensional stability, low internal stress, and excellent mechanical properties.

Material Handling:

Thorough drying is essential! Both nylon (PA) and POM are hygroscopic. Drying at 80-100°C for at least 3-4 hours before injection molding is essential. Failure to do so will result in brittle parts, surface silver streaking, and a significant decrease in mechanical properties.

Injection Molding Parameters:

High mold temperature: Using a higher mold temperature (e.g., 80-100°C for nylon) helps increase crystallinity, thereby achieving optimal mechanical properties (strength, toughness, and wear resistance) and dimensional stability.

Medium-to-high-speed injection: Ensures that the melt quickly fills the mold cavity.

Appropriate holding pressure: Apply sufficient holding pressure to compensate for shrinkage, but excessive holding pressure can increase internal stress.

Stage 4: Post-Processing, Assembly & QC

Post-Processing:

De-gating: Automatically performed by a robotic arm.

(Optional) Annealing: For high-precision applications, annealing can be performed to eliminate internal stress and further stabilize dimensions.

(Optional) Humidity Conditioning: For nylon materials, humidity conditioning can be performed to balance moisture content and prevent dimensional changes due to moisture absorption during use.

Assembly:

The molded individual links are assembled into a chain manually or using dedicated automated equipment. The assembly process should be smooth and free of jamming.

**Rigorous Quality Inspection**:

Dimensional Accuracy: Key chain link dimensions (shaft diameter, hole diameter, pitch) are randomly inspected using a 2D image measuring instrument or tool microscope to ensure interchangeability.

Appearance Inspection: Check for defects such as flash, missing material, and burnt material. Flash must be zero, otherwise it will seriously affect the flexibility of the chain.

Functional Testing (Core):

Flexibility Test: Manually test a section of chain for smooth and flexible bending and for any jamming.

Tensile Strength Test: Tensile strength testing is performed on the finished chain to measure its breaking strength to ensure it meets the required breaking strength.

Wear life test: Test the durability of the chain under simulated working conditions.

We are a plastic chain moulding manufacturer, providing high-quality plastic chain moulding manufacturing. As long as you want to customize/develop plastic chain moulding 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

Plastic molding specifications

Mold design:

Transaction process:

Mold testing:

Product packaging

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.