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

The molding process for injection molded buckets (typically industrial buckets with handles, trash cans, food cans, etc.) is a typical application for injection molding large, thick-walled products. The core challenge lies in overcoming product shrinkage and deformation while ensuring sufficient strength and sealing.

The following is a detailed, professional process for injection molded buckets.

The Complete Injection Molding Process

Phase 1: Product Design and Material Selection

This is fundamental to determining the final product quality and cost.

Key Structural Design Points:

Rib Design: Radial or grid-like ribs are designed on the bottom and body of the bucket. These ribs are crucial for ensuring rigidity and compressive strength, while also guiding shrinkage and reducing deformation.

Draft Angle: A sufficient draft angle (typically at least 1.5°) is required to facilitate smooth ejection from deep-cavity molds.

Stacking Design: Stacking ribs (anti-slip ribs) are designed on the sides of the bucket to facilitate secure stacking and transportation when empty.

Handle Mounting: Holes are reserved for the handle pivots, ensuring precise dimensions and smooth assembly.

Material Selection:

High-density polyethylene (HDPE): The most commonly used material. It offers excellent impact and chemical resistance (suitable for cleaning agents and chemicals), processability, and is reasonably priced.

Polypropylene (PP): Higher stiffness and better heat resistance (suitable for microwaveable containers), but its low-temperature impact resistance is inferior to HDPE.

Additives: UV stabilizers (used in outdoor trash cans), antistatic agents, or masterbatches are often added.

Phase Two: Mold Design & Manufacturing

Injection barrel molds are large and complex, and their design directly impacts production efficiency and product quality.

Large mold base: Due to the large size of the product, a large mold base (such as the LKM standard mold base) is required.

Hot runner system: Almost standard. For large barrels, multiple hot nozzle injection points (such as a center injection point or several side injection points) are typically used to ensure that the melt quickly and evenly fills the large cavity, reducing flow marks and internal stresses.

Cooling system: This is a crucial aspect of mold design. Efficient and uniform cooling water circuits must be designed, especially in thick-walled areas such as the bottom and barrel. Uneven cooling can lead to product warping and deformation. Bubblers and baffles are often used to cool the core areas of the mold.

Venting System: Adequate venting slots must be provided at the final melt filling point to prevent trapped air, which can cause burning (yellow streaks appearing on the product surface) or underfill.

Sliders: Used to form lateral undercuts such as handle holes.

Ejector System: A large number of evenly spaced ejector pins or ejector plates are required to provide smooth and uniform ejection force to prevent whitening or punch-through.

Stage 3: Injection Molding Process

The key to process tuning is controlling shrinkage and deformation.

Material Processing: HDPE/PP do not absorb water well, but drying at 80°C for 1-2 hours is recommended to remove surface moisture and ensure optimal quality.

Injection Molding Machine Selection: A large-tonnage (usually over 1,000 tons) and high-shot-volume injection molding machine is required.

Core Process:

Injection Stage: Use medium-to-low injection speeds. High-speed injection can easily generate high shear stress and molecular orientation, increasing the risk of deformation later in the process.

Package Stage: This is the most critical step in controlling shrinkage! A low but prolonged hold pressure is required to slowly compensate for shrinkage during plastic cooling and prevent sinking (shrinkage) in the barrel, especially behind the ribs.

Cooling Stage: Sufficient cooling time is essential. Due to the thick barrel body, a longer cooling time is required to ensure complete set. Insufficient cooling time can easily lead to deformation after ejection.

Fourth Stage: Post-Processing & Quality Control

Post-Processing:

De-gating: Separate or manually trim the sprue during automatic part removal by the robot.

Annealing: Products requiring extremely high dimensional stability or exhibiting high residual stress can undergo annealing (heating the product in hot water or an oven followed by slow cooling) to eliminate internal stress and reduce deformation.

Quality Inspection:

Dimensional Inspection: Use large calipers or tape measures to inspect the barrel's mouth diameter, height, diagonal dimensions, and other dimensions to ensure deformation.

Appearance Inspection: Check for defects such as shrinkage, flash, burns, and missing material.

Functional Testing:

Drop Test: Fill the barrel with a certain weight of water and drop it from a specified height to test its impact resistance and ensure it cracks.

Sealing Test: For barrels requiring sealing, perform airtight or watertight testing.

Stacking Test: Test the stability and load-bearing capacity of stacked empty barrels.

Handle Strength Test: Test the secure connection between the handle and the barrel.

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