Post-processing technology of injection products

 

Post-processing technology of injection products

For printing on the surface of the plastic products, printing or when the pattern. there are several methods.

1, Stencil printing of this method is the most common and also the most one method; they are generally suitable for flat or curvature of the small print.

2, The principle of curved surface printing flexography printing ink is first placed within the text or logo engraved gravure, then copy the text or images onto a surface. The surface will re-use the text or pattern is transferred to the surface of the molded product. And finally through an ultraviolet light irradiation heat treatment or the like so that the ink is cured.

 

injection parts processing-Surface printing process:

Skim A. molded products

1. molded product surface treatment (when necessary)
2. Printing
3. curing inks
4. applying post-processing such as excessive (if necessary)

injection parts processing-Printing Process

1. Gravure ink into the.
2. Scrape off the excess ink.
3. Extruded surfaces are made of ink.
4. The surface of the ink transferred to the surface of the molded article.
5. Cleaning surfaces, layout (if necessary), and printing will start with version patterns or patterns printed on the plastic sheet or rubber roller. The rubber roller will no longer sheet or pattern or pattern onto the surface of the beer.

Pros: Several colors can be applied in a single operation.

Disadvantages: lower productivity and not getting opacity strong prints. How to choose a suitable plastic sheet or rubber roller and oil, and so on.

1， The use of hot stamping foil and the color pattern engraved or font of the hot mold. Under controlled temperature and pressure. The surface of the emboss pattern of manufacturing color package or method of beer font member. Which is mounted on the operation only by fixing the press hot mold foil color on regional products across the pressure needed to be applied.

2, The paint surface treatment of plastic products (color) of the most commonly used techniques,

Can be divided into:

A general coloring, that this spray paints mostly by hand, do not have strong abrasion, easy to paint chips.

B, PU grade varnish this method is finished after the spray drying primer, then spray on the surface layer of the PU varnish method to achieve abrasion and gloss. General home appliances or many everyday items are through PU surface treatment.

C, UV grade varnish finish this method after spray primer and then sprayed with a layer of surface UV varnish, gloss, feel, rubbing can achieve very good results. General phone mold products and communications products die with such an approach.

 The use of the electrolytic plating method is electroplating the metal or alloy deposited on the surface, to form a uniform, dense and good adhesion of metal layers, called plating. Simple to understand, the physical and chemical changes, or in combination.

Purposes: a. Corrosion b. Protective decorative c. Anti-wear d. Electrical properties: According to parts work requirements, providing conductive or insulating coating performance e. Process requirements

The surface of the article by electrolytic uniform, dense, with good metal or alloy deposited layer forming process. The process is a relatively complicated process, but it has many advantages. Such as many types of deposited metal can be obtained in various colors, with Compare similar process being relatively cheaper than in terms of prices.

What is Custom Plastic Injection Molding

 Most Chinese injection mold manufacturers complete international trade by providing customized services, but lack of real understanding of the real meaning of customers’ need for customized services, resulting in some mold manufacturers can not accurately complete the highly specialized manufacturing after signing contracts.

Just because a mold maker can facilitate the development of the original mold does not constitute real customer service (or ensure an ideal result). These mold manufacturers lack the ability to export complex injection molded parts for experienced reasons to complete with standardized specifications and tight tolerances.

How to evaluate injection molds consistent with your project needs is a critical criterion for project success. For example, components used in medical or aviation, automotive applications need to be truly sophisticated in design, engineering, and equipment use, compared to common civilian products.

Experience has the rich injection mold division’s concentration and the actual field ability. plastic molded parts used in such applications must comply with strict inspection specifications and compliance assembly instructions.

CNmoulding Industries specializes in plastic injection molding in China to produce a wide variety of products from high-tech parts with very tight tolerances to consumer products, lawns, and gardens as well as entrepreneur’s inventions. We provide custom plastic injection molding for customers worldwide, in a variety of industries. We are the low-cost leader for high-quality injection molded plastics with a fast turnaround. Some examples of these products are pictured on our web.

We manufacture large and small moldings. we can manufacture almost any plastic part for any of your needs.

High volume custom injection molding capabilities

 Precision tool makers in our Factory allow us to provide quick-turn service on medium to high volume orders, where we build dedicated long-run production molds. We specialize in high-volume custom plastic injection molding projects. High-end second-op machining is also available. Our plastic injection factories in China manufacture very high-quality products that are extremely cost-effective. Custom injection molding in China is especially effective when the plastics require secondary operations for completion. These secondary operations include anything from cleaning parts, overmolding, painting, drilling holes, pad printing, screen printing, or partial sub-assemblies.

Before releasing it, we will make a packing inspection to ensure all the components, accessories, and documents have been enclosed.

Documents enclosed:

• Inspection Check for Shipping
• material Certification if need
• Latest Injection Report
• Drawing for Components of Mould
• Final Mold Layout
• Share Components List
• Feedback Form of Mould Quality

Custom Injection Molding Actual Performance

Rapid Turnaround: We offer the most efficient, safe, and affordable transportation

the method, our special channel shipping price is cheaper than any customer’s own forwarder price to suit your time and budget requirement.

Online Quotation: We provide a standard quotation for custom injection molding 24 hours in time through EMAIL, WECHAT, WHATSAPP, and SKYPE interactive online quotation system, also including mold and rapid prototyping parts processing.

Low Cost:  20 years complete supply production chain layout, so that we really complete each link of high efficiency, fully reflect the offshore manufacturing industry with a lower cost structure of facilities, in order to provide prices below our pure domestic competitors.

High Quality:  We are ISO9001：2015 certified, use CMS digital system so that the full qualified rate of mass product manufacturing is possible. The whole process of digital management makes the traditional manual single-piece measurement method can not compete.

A real example of custom molding TESLA Motor parts

CNMOULDING customers come from a variety of world-renowned automotive industries, such as electric car industry leader Tesla Motors. Electric cars have a large number of electronic parts to replace traditional car hydraulic parts, plastic shells need to protect the subtle automotive electronics parts, safely consistent with the brand established by Tesla. this is a high order for an offshore Chinese supplier, but we consistently produce and deliver quality parts that meet the required specifications. The injection mold is perfect for an enviable position.

The customer takes the initiative to cooperate with us. because producing specialized, complex solutions is commonplace. These include all kinds of car buckle, protective cover, decorative panel. produce $3 million of molds and automotive products annually.

our technical department works closely with the engineers of the customer to optimize the component design to reduce the development cost, introduce Moldflow analysis, identify and correct the problems that will be in molding and materials in advance before production. Custom features also allow medium-term production adjustments, including components modifications after assembly. The result of custom injection molding is quite different from that of the traditional mould.

 

5 types of mold surface treatment

 

5 types of mold surface treatment

 

The application of surface treatment in the mold is the most effective way to provide mold quality and service life and reduce cost.

By adopting different surface treatment technologies, only the composition, organization, and performance of the surface layer of the mold can be changed. Thus greatly improving and improving the surface performance of the mold. Such as hardness, wear resistance, friction performance, stripping performance, heat insulation performance, corrosion resistance. And high-temperature oxidation performance. The special properties of the cavity surface, such as anti-scratch ability, release ability, anti - bite, etc. Several times, dozens of times to improve the service life of the mold.

It is of great significance to improve mold quality, reduce the production cost, improve production efficiency. And give full play to the potential of mold materials. What methods of injection mold parts surface treatment in China?

The effect of injection mold surface treatment

1，Plastic Mold Parts

In-mold processing, the surface treatment can make the parts for the following properties: Increasing surface hardness, increase the compressive strength, abrasion resistance, improve corrosion resistance, and improve sliding, etc.

2, Plastic Molding parts surface treatment methods.

3, The injection mold Surface treatment method is many in China. But for the injection molded parts, the main methods of surface treatment are the following.

 

1，Carburizing

Carburizing is to the steel surface infiltration carbon atoms. It is to put the parts into can release the active carbon atom medium, heat insulation, make activated carbon atoms permeability and the surface of the steel. Its purpose is to improve the surface of the carbon content, the subsequent heat treatment, the surface hardness increased, While the core remains resilient. Therefore, carburizing steel must be 0.15% ~ 0.25% (mass fraction), the carbon content of mild steel. Methods include solid carburizing, carburizing liquid carburizing. And gas carburizing, which is a widely used gas carburizing.

2，Nitriding (also called nitride)

Nitriding is to the steel surface infiltration nitrogen atoms. Its purpose is to improve the parts table surface hardness, wear resistance, corrosion resistance, and fatigue strength. At present, the most widely used method of nitriding is gas nitriding. It is to put the parts into the airtight furnace, the ventilation with NH3, heating to 500 ~ 600 ℃, the ammonia decomposition of reactive nitrogen atoms. The nitrogen atom is easy to be absorbed by the workpiece surface and spreading inside, forming a nitride layer. The nitriding layer is 0.1 ~ 0.6 mm. The nitriding layer has high hardness and excellent dimensional stability. And can noticeably improve wear resistance and fatigue strength, corrosion resistance has greatly improved. In the mold processing, almost all steel nitriding processing. But it's a longer production cycle, high cost.

3，Hard chromium plating

Hard chrome plating is will adopt the method of plating chromium plating on the surface of parts. Thereby gaining the surface of the hard and wear-resistant. It contains the abrasive plastic molding parts, the hard chromium plating layer is very effective. In addition, the hard chromium layer can not only reduce the wear and tear, and can significantly improve the corrosion resistance of parts. It can also be used when repairing the wear surface hard chromium plating method processing.

4，Hard nickel plating

Hard nickel plating is to use the chemical method will nickel the plating layer on the surface of parts. In the process, the deposition of the nickel layer does not use imposed by the electron flow. so you don't happen like electroplating on the edge, especially along the edge to form the different thickness of electroplating film formation (edge) of the phenomenon. This method of nickel plating in the hole, opening, and the place such as contour surface defects will not appear. The nickel plating layer often about 40 microns thick. It can form has good corrosion and wear resistance of the surface.

5，Coated hard layer

In order to make the part surface with high wear resistance and corrosion resistance. There is new technology is in the surface coated with titanium nitride and similar material for the grass-roots approach. It is easy to operate, and the effect is very good.

Do you have a project need to find china injection mold company today, contact us now

We can give you a good solution for your mold making.

How about plastic injection molding china

 Product Name: transparent products, clear parts,

Transparent plastic material: PC, ABS, SAN, ACRYLIC

Description of products: these are clear products for new medicine and machine, with transparent covers. And supporter, these clear parts are used in America, Europe, Canada, and Australia industrial.

We make the mold in our mold manufacturer factory and then test it in our china plastic injection molding factory.
Plastic Injection molding in China is considered one of the most common plastic part manufacturing
processes. It can be used for producing parts from both thermoplastic and thermoset polymers. The process usually begins with taking the polymers in the form of pellets. Or granules and heating them to the molten state.
The melt is then injected/forced into a chamber formed by a split-die mold. The melt remains in the mold and is either chilled down to solidify (thermoplastics) or heated up to cure (thermosets). The mold is then opened and the part is ejected.

A Typical Plastic Injection Molding Process.
In spite of the relatively expensive tooling cost. Injection molding remains the most popular manufacturing process for plastic materials in mass production. Thanks to its low operational cost, high throughput, and the flexibility to make parts with complex shapes.

Polymers commonly used for injection molding include

• Polystyrene (PS)
• Acrylonitrile Butadiene Styrene (ABS)
• Polyamide (PA)
• Polypropylene (PP)
• Polyethylene (PE)
• Polyvinylchloride (PVC)
• Other short fiber reinforced plastics

General injection molding china  plastics making process

Plastic Injection molding china is used to produce thin-walled plastic parts for a wide variety of applications.
One of the most common is plastic housing. The plastic housing is a thin-walled enclosure. Often requiring
many ribs and bosses on the interior. These housings are used in a variety of products including household
appliances, consumer electronics, and power tools. And automotive dashboards. Other common thin-walled
products include different types of open containers. Such as buckets. Plastic Injection molding china is
also used to produce several everyday items. Such as toothbrushes or small plastic toys. Many medical devices,
including valves and syringes. Are manufactured using plastic injection molding china as well.

The characteristics of precision injection molding

The characteristics of precision injection molding are the size of the injection molded parts with high precision and small tolerance. To achieve the requirements of precision injection conditions must be met:

(1) The mold material is better, rigid, and with cavity dimension precision. And template between positioning accuracy is higher, with lower surface roughness.

(2) To adopt a precision injection molding machine.

(3) To adopt the precision molding process.

(4) To choose suitable for the precision injection molding process of the material. Commonly used precision injection molding materials have several: POM, POM = CF (carbon fiber), PNM = GF (glass fiber), PA \ FRPA66 (enhanced PA), PC, etc.
 
The precision injection process can ensure the size of precision injection molding. Is an important way to control the shrinkage of injection molded parts. Including thermal contraction. Disguised contraction of molded parts, orientation. And compressed contraction and elastic recovery. 

Unlocking Infinite Possibilities for Product Innovation – Your Trusted Partner in Rotary Overmolding Solutions

In today’s competitive landscape, where product excellence is paramount, single-material designs are increasingly inadequate to meet stringent market demands for functionality, aesthetics, and tactile quality.

Are you facing efficiency bottlenecks and weak interfacial adhesion in secondary injection molding processes?

Concerned about inconsistent quality and environmental drawbacks associated with adhesive bonding?

Compromised by visible assembly gaps that detract from aesthetic appeal and long-term reliability?

The solution lies in advanced rotary overmolding technology. What you need is a specialized mold engineering partner with proven expertise.

Why choose rotary overmolding? Advancing Beyond Traditional Manufacturing

Rotary two-shot injection molding is more than a production technique—it represents the convergence of precision engineering and innovative design. By utilizing a fully integrated mold system equipped with a high-precision rotational mechanism, this process enables the seamless co-molding of two dissimilar materials (e.g., rigid and elastomeric polymers) into a single, unified component within one continuous cycle.

Key benefits delivered through this technology include:

Superior Product Performance: Through molecular-level material compatibility and mechanical interlocking structures, rotary overmolding ensures robust, durable bonding between soft and hard components, significantly enhancing structural integrity, longevity, and functional reliability.

Enhanced Production Efficiency: Consolidating two molding stages into a single automated operation reduces cycle time, minimizes labor input, lowers operational costs, and supports scalable, high-volume manufacturing—making it ideal for cost-effective mass production.

With decades of dedicated experience in rotary overmolding mold development, we are not merely mold fabricators—we are comprehensive solution providers spanning concept design, prototyping, tooling, and full-scale production support.

Our technologies have been successfully implemented across diverse industries, including:

Consumer Electronics: Premium smartphone cases, TWS earphone charging cases, controllers, and smart wearable device straps.

Automotive Components: High-comfort steering wheels, gear shift knobs, ergonomic control buttons, and sealing profiles.

Power Tools and Appliances: Ergonomically optimized handles for power tools and heat-resistant grips for kitchen appliances.

Medical Devices: Anti-slip hearing aid housings, patient-comfortable respiratory masks, and precision surgical instrument grips.

 

Overcoming Smart Bracelet Screw Corrosion: A Targeted Solution

 Recently, a smart bracelet designed and manufactured for an Italian client with stringent quality requirements underwent a critical reliability test—metal screws embedded within the plastic housing exhibited signs of corrosion during actual use. Although seemingly minor, this defect not only compromises the product’s aesthetic integrity but also raises concerns regarding its long-term durability and functional reliability.

Screw corrosion is not an isolated issue; it represents a common challenge in plastic-encapsulated electronic devices, particularly wearable consumer electronics exposed to complex environmental conditions. The root cause typically stems from the interplay of multiple factors:

First, as a wearable device in constant contact with human skin, smart bracelets are inevitably exposed to sweat. Sweat contains water, salts, and weakly acidic components that continuously attack the most vulnerable points of metallic fasteners.

Second, early design iterations often employed carbon steel screws with electro-galvanized coatings for protection. However, if the plating layer contains micro-pores, exhibits uneven thickness, or sustains minor damage during manufacturing or assembly, moisture and electrolytes can penetrate through these defects, initiating localized corrosion.

Third, during the insert molding process, molten plastic at high temperature encapsulates pre-placed metal screws. Due to the mismatch in thermal expansion coefficients between metal and polymer, residual internal stresses develop upon cooling. These stresses can degrade the inherent corrosion resistance of the metal components.

Our Solution

1. Mold Structure Optimization  

The mold design was refined by improving the positioning mechanism and encapsulation method of the inserts. This ensures more uniform and complete coverage of the screws by the surrounding plastic, thereby minimizing the surface area exposed to humid environments.

2. Material Upgrade to AISI 304 Stainless Steel  

Superior Screw Material: We replaced the carbon steel with AISI 304 stainless steel, which has a self-repairing protective oxide layer that resists sweat and corrosion.

3. Selection of Enhanced Engineering Plastics  

Concurrently, we evaluated and implemented engineering plastics with superior chemical stability, lower moisture absorption, and reduced tendency to decompose into corrosive byproducts. This mitigates one of the key environmental contributors to metal degradation.

We thank our client for their valuable feedback. This solution underscores our commitment to continuous improvement and delivering durable, high-quality products.