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

Plastic body components for electric scooters—such as the main housing, deck cover, front and rear fenders, battery compartment casing, handlebar display housing, and side deck trim—are large, integrated structural parts. These components must meet demanding requirements for large-surface-area thin-wall aesthetics, load-bearing structural strength, and outdoor weather resistance; consequently, the molding process is far more complex than that for small plastic fasteners. The complete molding workflow comprises five core stages: raw material pretreatment, mold setup and tuning, the injection molding cycle, post-molding shaping, and comprehensive quality control. Standardized controls are applied throughout to ensure the absence of weld lines, minimize warpage, guarantee aging resistance, and maintain dimensional stability.

I. Raw Material Warehousing and Pretreatment

As scooter bodies are exposed to prolonged outdoor sun and rain, three main types of materials are used: weather-resistant ASA, ABS+PC alloy, and modified PP. Ensuring material eco-friendliness, proper drying, and accurate mixing ratios is the critical first step in the molding process.

Upon arrival, materials must undergo verification of material specifications, UV aging resistance test results, and RoHS environmental compliance certificates. Only virgin material is permitted for visible body housings; regrind (reprocessed scrap/runners) may be used sparingly—limited to under 10%—whereas the inclusion of recycled material is strictly prohibited for structural battery compartment parts to prevent a reduction in impact strength. For coloring, high-gloss weather-resistant masterbatch is used in conjunction with UV-resistant masterbatch and a low-migration, eco-friendly mold release agent. These are blended in a vertical mixer at low speed for 8 to 12 minutes; low-speed mixing prevents frictional heat buildup that could cause pellet agglomeration or uneven pigment dispersion.

The drying and dehumidification stage directly determines the aesthetic quality of the bodywork. ASA and ABS+PC housings are dried in a hot-air dryer at a constant 85°C for 4 hours (extended to 6 hours for PC alloy parts) to keep moisture content below 0.04%. Insufficient drying results in surface defects such as "silver streaks" and bubbles across the large body panels, which can lead to paint failure (popping) during subsequent coating. Modified PP has extremely low water absorption; drying at 60°C for just one hour—specifically in rainy or humid conditions—is sufficient to remove surface moisture. Mass-production lines are equipped with a central material feeding and dehumidification system; once dried, raw materials are conveyed through sealed pipelines to the injection molding machine's hopper, preventing moisture re-absorption from the air.

II. Assembly and Pre-heating/Commissioning of Large Bodywork Molds

Given the large projected area of the bodywork parts, single-cavity large molds are typically employed, with targeted reinforcements applied to the mold steel, cooling, venting, and ejection systems. S136 mirror-finish steel is selected for the aesthetic cavity surfaces; polishing achieves a mirror-like finish, ensuring a high-gloss texture for the housing. For the battery compartment mold—which processes glass-fiber modified material over long production runs—cavities undergo nitriding treatment to resist erosion and wear from the melt flow. Conformal cooling channels are designed around areas with uneven wall thickness, while spiral cooling cores are installed inside thick-walled ribs to balance cooling rates, thereby resolving issues such as localized sink marks and overall warpage of the body shell.

Continuous, fine venting channels (0.015 mm deep) are machined around the perimeter of the parting line to rapidly evacuate trapped air during large-area filling, preventing scorching or blackening at the housing edges. For elongated components like fenders and long shrouds, multiple sets of ejector pins and balanced ejector blocks are added to prevent shell bending caused by uneven ejection forces.

The mold is hoisted onto a large-tonnage (800T–1300T) injection molding machine; clamping plates are secured to ensure uniform force distribution across the mold platens. Cooling water and mold temperature control lines are connected and leak-tested; once confirmed leak-free, the temperature control unit is activated to pre-heat the mold for 30 minutes. Mold temperatures are stabilized at 50–60°C for ASA aesthetic parts and raised to 80°C for PC alloy parts. Low-pressure mold-clamping protection parameters are calibrated so that the mold automatically opens if residual material (such as sprue remnants) is detected, preventing damage to the expensive large mold.

III. Complete Molding Cycle Process on the Injection Machine

The molding cycle for a body shell comprises six major steps: mold clamping, injection filling, multi-stage holding pressure, constant-temperature cooling, mold opening and ejection, and robotic part removal. The process centers on low-speed, low-shear, and uniform filling. The mold-clamping phase consists of four stages: slow closing, rapid advance, low-pressure protection, and high-pressure locking. Housings with large projected areas require high-pressure clamping to counteract the mold-opening force generated during injection, thereby preventing extensive flash at the parting line.

Barrel temperatures are controlled in zones: 170–200°C for ASA body components and 190–260°C for ABS+PC blends. Strict temperature limits are enforced, as excessive heat causes material decomposition, yellowing, and reduced toughness. Injection filling utilizes multi-stage speed control: medium-to-high speeds are used for thin-walled areas to ensure rapid filling and prevent premature melt cooling (short shots), while low speeds are used for ribs and thick-walled base sections to minimize internal stress caused by molecular shear, thereby reducing the risk of cracking during subsequent painting. Injection pressure is set between 90 and 120 bar; excessive pressure leads to severe flash and a sharp rise in internal stress, while insufficient pressure results in weld lines and incomplete filling.

Once the cavity is filled, a two-stage holding pressure process compensates for cooling shrinkage. Holding times are 15–22 seconds for the thick-walled battery compartment and 6–10 seconds for the thin-walled decorative housing to eliminate surface sink marks. During the holding phase, the screw simultaneously prepares material for the next cycle, thereby shortening the overall molding cycle time.

Cooling accounts for over 60% of the total cycle time, adhering to a standard of 3–5 seconds of cooling per millimeter of wall thickness; the standard 2mm-thick body housing requires approximately 10 seconds of cooling. Uniform circulating cooling water removes heat, ensuring stable mold temperatures and preventing warping or distortion caused by uneven cooling on one side of the housing.

After cooling, a three-stage slow mold-opening process is executed. The ejection mechanism gently releases the part, while a servo-driven robotic arm automatically grips the housing and simultaneously shears off the gate and runner waste. Finished parts are transferred to the assembly line, while sprue/runner scrap is collected, crushed, and stored in sealed containers. Manual contact with visible surfaces is strictly prohibited throughout the process to prevent fingerprints or oil residues from affecting the subsequent painting stage.

IV. Post-molding processing, stress relief, and shaping

Freshly demolded body housings often exhibit gate marks and fine parting lines, while some slender fender sections may show slight warping; therefore, standardized post-processing is required. Gate and Burr Trimming: For hot-runner molds, slight gate protrusions are removed via meticulous manual grinding; for cold-runner molds with large gates, hydraulic cutters ensure a smooth, clean cut. Fine flash along the parting line is lightly buffed using fine-grit sandpaper or a pneumatic grinding pen, followed by dust removal to ensure a smooth housing surface free of sharp edges.

Annealing for Stress Relief: Exterior body components undergo annealing prior to painting; ASA and ABS housings are baked in a 60°C hot-air oven for 2 hours, while PC/ABS alloy parts are baked at 70°C for 3 hours. Slow, natural cooling significantly eliminates internal molding stresses, preventing cracking during the painting/curing process or due to outdoor temperature fluctuations.

Thermal Shaping and Correction: Slightly warped fenders or side guards are secured in metal shaping jigs that match the product profile for low-temperature setting. They are released after cooling to correct warpage, ensuring uniform assembly gaps across the vehicle.

Surface Pre-treatment: Housings requiring painting or UV coating undergo electrostatic dust removal and degreasing steps to eliminate mold release agents and dust, thereby enhancing coating adhesion; matte housings that do not require painting proceed directly to quality inspection after burr removal.

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

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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.