F&Q TECH's Plastic Injection Molding Services

     In April 2025, Apple CEO Tim Cook said in an interview: "The core reason why Apple insists on manufacturing in China is not cheap labor, but China's irreplaceable 'skill density'." This view not only reveals the underlying logic of Apple's supply chain, but also reflects China's global competitiveness in the field of precision manufacturing. This article will deeply analyze how China has become the preferred partner for CNC processing and mold injection services for European and American companies by relying on its technical talent reserves, supply chain efficiency and innovation ecology.

 1.1 “Skill Density” in Cook’s Eyes

     Cook has repeatedly stressed that the core advantage of China's manufacturing industry lies in its large-scale and systematic talent pool. For example, the number of mold engineers in a certain province in China can "fill several football fields", while the United States "can't even gather enough engineers for a meeting." This gap stems from:

Education system support: China's vocational education system focuses on training technical workers, covering high-skilled fields such as CNC programming and mold design.

Industry chain collaboration: From raw materials (such as aluminum alloys and engineering plastics) to precision processing, China has formed a "one-hour industrial circle" to achieve rapid response and cost optimization.

 1.2 The “micrometer-level” threshold for precision manufacturing

     Apple products require mold precision up to micron level (such as the surface fit of iPhone shell), which relies on the following technological breakthroughs:

Popularization of 5-axis CNC machining: China's leading factories have widely used 5-axis linkage machine tools, which can process complex curved parts with an accuracy of ±0.01mm.

Injection molding process innovation: For example, the glass panel produced by Lens Technology for Apple Vision Pro uses high-precision hot bending technology, with a yield rate of over 99%.

Dimensions

Comprehensive cost

Delivery cycle

Technical adaptability

Chinese Manufacturers

Labor + equipment depreciation costs are 30%-50% lower

Average 2-4 weeks (relying on clustered supply chain)

Support flexible production from prototype to mass production

European and American local suppliers

High labor cost, suitable for small batch customization

Prefer standardized large-volume orders

Complex parts take 6-8 weeks

     In the development of plastic products, choosing between 3D printing and injection molding requires comprehensive consideration of factors such as cost, precision, batch size, and design complexity. The following is an analysis of the two processes from the two core dimensions of cost optimization and high-precision requirements, combined with the characteristics of the two processes, and provides a basis for decision-making.

 1) Production batches determine the core cost structure

3D printing: suitable for small batches (usually <1000 pieces) or single-piece production. It does not require mold costs, has low material loss (only the support structure may waste a small amount of material), and is flexible in iteration. For example, when using FDM technology to print a prototype, the cost per piece may be only 1/10 of that of injection molding.

Injection molding: more cost-effective in large-scale (>1000 pieces) production. Although the mold development cost is high (thousands to tens of thousands of yuan), the cost per piece decreases significantly as the batch increases. For example, in one case, the injection mold cost $10,000, but the cost per piece was only $0.1 when producing 100,000 pieces.

 2)Design and iteration cost comparison

3D printing: CAD models can be directly printed after modification, without additional costs, suitable for the prototype stage where the design is frequently adjusted. For example, a company shortened the R&D cycle from 4 weeks to 48 hours by using 3D printing molds.

Injection molding: Mold modification costs are high (especially metal molds), suitable for mass production after the design is finalized. If the mold structure needs to be adjusted, it may be necessary to re-open the mold, which will increase the cost by tens of thousands of yuan.

 3)Material And Post-Processing Costs

3D printing: limited material types (such as PLA, nylon, resin, etc.), some high-performance materials (such as PEEK) are expensive; post-processing usually only requires grinding or sandblasting.

Injection molding: wide selection of materials (such as ABS, PP, PC, etc.), lower prices; but post-processing such as mold polishing and electroplating may increase costs.

Decision suggestions:

Small batch/prototype: choose 3D printing (FDM, SLA or SLS);

Large batch/finalized product: choose injection molding.

 1) Process accuracy comparison

3D printing:

SLA/DLP: accuracy of ±0.01 mm, smooth surface, suitable for precision medical or electronic parts.

SLS/MJF: accuracy of ±0.1 mm, suitable for complex structures but slightly rough surface.

FDM: lower accuracy (±0.2 mm), obvious layer pattern, need post-processing.

Injection molding:

accuracy is usually ±0.05 mm, high surface finish (Ra 0.8~1.6 μm), no additional processing required.

 2)Material strength and stability

3D printing: weak interlayer bonding, which may affect mechanical properties; easy to deform at high temperatures (such as PLA softening point is 55°C).

Injection molding: The material is dense, high in strength and isotropic, and has better temperature resistance (such as ABS can withstand 80~100°C).

 3) Complex structure adaptability

3D printing: It can manufacture complex structures that are difficult to achieve with traditional processes, such as hollowing and conformal water channels. For example, the curved cooling channel in the mold can improve the injection efficiency.

Injection molding: Due to the mold demolding requirements, the design must avoid internal right angles or too deep cavities, otherwise it will increase the difficulty of processing.

Decision suggestions:

High precision + complex design: choose SLA or metal 3D printing (such as SLM), but you need to accept higher costs;

High precision + large batch: injection molding combined with CNC precision mold to ensure dimensional stability.

Clear requirements: batch, budget, design complexity, precision level, material performance.

Cost accounting: compare mold costs, single-piece material costs and post-processing costs.

Technology matching:

If fast iteration or small batches are required, 3D printing is preferred;

If high strength or surface finish is required, injection molding is preferred.

Hybrid solution: For example, use 3D printing to make prototypes or conformal water channel molds, and then mass produce them through injection molding.

1) Pepsi bottle mold: By combining 3D printed inserts with traditional metal molds, the cost is reduced by 96%, and the production cycle is shortened from 4 weeks to 48 hours.

2) Medical implants: Use SLA to print high-precision prototypes, and then switch to injection molding for mass production after verification.

3) Shoe mold manufacturing: 3D printing can achieve complex patterns, replacing traditional CNC, and increasing efficiency by 50%.

Between low cost and high precision, a balance needs to be made according to specific scenarios:

3D printing: the first choice for small batches, complex designs, and rapid iterations;

Injection molding: an economical solution for large batches, high precision, and high-strength scenarios.

In the future, hybrid manufacturing (such as 3D printing molds + injection molding mass production) may become the mainstream direction for balancing cost and performance.

     In the field of plastic injection molding, the "tonnage" of an injection molding machine directly determines its capacity limit. Tonnage does not refer to the weight of the entire machine, but the size of its clamping force, measured in tons (T). This parameter represents the maximum closing force that the clamping system of the injection molding machine can exert, which is used to resist the huge expansion pressure generated when the molten plastic is injected into the mold. If the clamping force is insufficient, the mold will be stretched open, resulting in flash burrs; and excessive tonnage will cause energy waste and equipment loss.

The calculation of clamping force follows the core formula:

Clamping force (T) = product projection area (cm²) × mold pressure (kg/cm²) × safety factor / 1000

The mold pressure depends on the material properties:

Ordinary plastics (such as PP, PE): 250-350 kg/cm²

Engineering plastics (such as PC, nylon): 350-500 kg/cm²

The safety factor is usually 1.1-1.2.

Injection molding machines can be divided into four categories according to tonnage, which have significant differences in mechanical structure, application scenarios and technical requirements:

（1）Small machine (30-100 tons)

Structural features: mostly vertical or angular design, mainly fully electric drive, small footprint

Injection volume: usually ≤200 grams (based on PE)

Typical applications:

Electronic connectors (USB interface, SIM card tray)

Precision gears (clocks, micro motor parts)

Medical equipment (syringe needles, test tubes)

Advantages: high precision (repeat error ±0.01mm), energy saving (60% less power than hydraulic presses), no oil pollution

（2）Medium-sized machine (150-500 tons)

Mainstream machine: hydraulic or hydraulic-electric hybrid drive, horizontal structure

Injection volume: 300-2000 grams

Application scenarios:

Household appliance housing (rice cooker, vacuum cleaner housing)

Daily necessities (washbasin, chair, toy)

Automotive interior parts (dashboard frame, door handle)

Technical highlights: Can be equipped with multi-color injection molding system (such as P-type/L-type double shot) to achieve dual-material composite molding

（3）Large machine (600-1000 tons)

Structural features: two-plate clamping mechanism, enhanced rigidity and mold opening space

Injection volume: 2500-5000 grams

Typical products:

Logistics pallet (1200×800mm standard size)

Automobile bumper

Large trash can

Challenge: Need to cooperate with mold temperature control system to prevent shrinkage of thick-walled parts

（4）Ultra-large machine (>1000 tons)

Representative models: Haitian 1600T, Fuqiangxin 1900T three-color machine

Capacity indicators: up to 4000 tons, injection volume exceeds 20kg

Application areas:

Automobile instrument panel (one-piece molding)

Yacht deck parts

Large turnover box (volume>1000L)

Innovative design: horizontal two-color machine (H type) with overlapping mold technology, production capacity increased by 70%

Table: Comparison of injection molding machine tonnage and key parameters