Advantages of Secondary Processing
- Improve product appearance quality
- Increase product life
- Increase product corrosion resistance
- Add product features
- Increase product added value
- Save time and cost for customers
Secondary Processing types
Silk printing is silk fabric synthetic, fiber fabric or metal mesh wireframe on the net frame using manual engraving plate-film or optical plate making method to produce a silk printing plate. Modern silk printing technology is using photosensitive materials to make silk printing plates by photographic plate (making silk printing screen holes instead of graphics parts screen holes blocked).
Printing through scraper extrusion makes ink transfer to the substrate through the mesh hole of the text section forming text similar to the original document. Silk printing equipment simple operation convenient printing plate easy to plate low-cost adaptability strong. Silk printing applications are widely used in printed materials: color oil paintings posters, business cards, binding covers, commodity labels, printing textiles, etc.
Screen printing is not restricted by substrate size and shape, and it can use in different shapes and concave surfaces. A soft and flexible layout is one of the lowest printing pressure printing. Screen printing mode ink thick and strong adhesion. Only ink and paint can be used through a mesh diameter of mesh. It can print monochrome, also can color printing, and add screen color printing. It has strong light resistance, convenient plate making, low price, flexible printing style, diversified technology easy to grasp.
Pad printing is an indirect printing technology, a unique printing method, suitable for decorative three-dimensional and small objects, and the printing pattern is very well.
Etching images on a plate normally called plates. Each printing cycle includes printing ink on a printing plate making ink filled with concave image areas.
A scraping knife scraping ink on the engraving plane leaves oil ink in the concave image area. Then press print head press to engrave text, ink transfer to silica gel shift head. The image silica gel is moved and pressed back to the decorative workpiece so that the workpiece can be printed and imaged. At least in pad printing, the largest user is special advertising, then the automotive industry.
There are many decorative applications in the automobile industry, such as speedometer instrument lever ball adjuster and radio panel.
Heat transfer printing is a type of technology of printing the pattern on the heat-resistant adhesive tape and printing the design to the finished material by heating and pressing. Heat transfer is divided into Heat transfer (suitable for a large number of printing methods) and digital heat transfer (appropriate for small quantities and making products with their own characteristics).
The principle of heat transfer printing is to print the pattern we need on the special transfer film with the particular ink through the printer. And after that, use the heat transfer machine to transfer the design to the working surface at an appropriate high temperature and pressure. Then complete the thermal transfer process.
It can be applied in leather, textile cloth, plexiglass, metal, plastic, crystal, wood products, copperplate paper, and other relative plane materials, one-time multi-color, any complex color, transition color printing digital printing machine. It does not need plate making, color matching, or complex board process, and will not cause damage to the material.
Heat transfer technology can also use a variety of different transfer materials to achieve distinct printing effects. And its most important types are film transfer and sublimation transfer.
Water transfer is a printing method, which uses water as a medium to transfer color patterns on a paper base or special PVA to the surface of the substrate, including water stickers and water coating. In the transfer printing, the polymer film carrying the grain (the main component is PVA) will gradually dissolve in water, and the color lines can be uniformly transferred to the product surface by the principle of water pressure.
The process of water transfer is as follows: Film printing “spray primer” film extension “activation” transfer printing “washing” drying “spray painting” drying.
In short, it is to use water to transfer the base paper to print all kinds of patterns and then print the cover oil to make flower paper. Soak the flower paper in clean water to separate the pattern from the base paper. Paste the design on the decorated item, scrape off the moisture, and dry. Take post-processing means to combine the design with the object.
Water transfer has no restrictions on the shape or material of the substrate, and water transfer is environmentally friendly and pollution-free. In the printing process, because the product surface does not need to contact the printing film, it also reduces the possibility of damaging the product surface.
Because water transfer printing avoids direct printing on parts, and instead prints on a special permanent transfer base paper. It overcomes many products, like ceramics, wood, iron, and steel, etc., due to shape or material reasons. Hence, it is difficult to print directly on it for decoration, or the printing effect is poor. Printing with special water transfer base paper not only reaches the product decoration but also a better result of direct printing.
Painting is a kind of surface coating processing of industrial products. Generally, Painting processing is mainly engaged in plastic Painting, silk printing, and pad printing processing. It needs to meet the quality requirements of high temperature, friction, UV, alcohol, gasoline, and other test products.
Painting can make the monotonous product look more beautiful after spraying various colors, at the same time, it can also extend the service life and service life of the product due to more protection. It can solve the problems that the spray injection molding process encountered, such as flow lines, welding lines, with spray rubber oil (touch paint) experience, with touch paint rework technology.
Electrostatic spraying of powder coating uses static electricity to adsorb the powder coating on the working surface. Besides, the powder is baked at high temperatures to form a solid coating on the working surface.
Electrostatic powder spraying firstly must have an electrostatic generator to produce DC high voltage, as well as a spray gun, a power supply system, and a powder recovery system to spray and atomize the powder. The sprayed workpiece should be grounded to a positive pole, while the negative high voltage generated in the discharge needle gun connected to the powder outlet of the spray gun will produce corona discharge through the discharge needle. At this time, the negatively charged powder particles arrive at the workpiece’s surface under the action of static electricity and compressed airflow.
Since the electrostatic force attraction, the powder is uniformly adsorbed on the workpiece surface for time without falling off, and the workpiece enters the curing furnace to flow flat and solidify, control the humidity or time, and finally form a tight, uniform, smooth and dense coating that binds firmly to the workpiece. Powder spraying makes the product surface smooth and has a coating with strong acid resistance, alkali resistance, crashworthiness, and wear resistance. And products can resist strong ultraviolet radiation and acid rain for a long time without coating pulverization, discoloration, shedding, and so on.
Ultrasonic welding is a solid-phase welding method, and the connection between workpieces is realized by the high-frequency elastic vibration of the sound system and the pressure between the workpieces.
Ultrasonic welding technology is to convert electric energy into kinetic energy of high-frequency vibration through the ultrasonic generator, and then send it to ultrasonic welding joint (or ultrasonic mold) through related equipment, and transfer the energy of high-frequency vibration to the plastic workpiece to be welded, and convert it into thermal energy to weld the workpiece by friction. This kind of processing technology has the characteristics of high efficiency and low cost, and many plastic parts in our daily life are welded with this technology.
The advantages of ultrasonic plastic welding: fast welding speed, high welding strength, and good sealing; replace the traditional welding/bonding process, low cost, clean, pollution-free and will not damage the workpiece; the welding process is stable, all welding parameters can be tracked and monitored through the software system, once the fault is found, it is easy to remove and maintain.
Laser Etching is a process that uses high-power, computer-controlled lasers to carve, mark or cut into products. Advanced laser equipment provides the advantages of non-contact, wear-resistant, permanent labels.
The high-speed system is used for the manufacture of various kinds of beads and the application of new products to carve any special image. Through your .pdf, .JPG, .DXF, or .dwg files, we will convert your design into a CAD/ CAM file and upload it to our laser cutting machine. This process eliminates the need for molds, models, or parts. According to the design, laser cutting, laser engraving, or the combination of the wearer may be the best choice.
Laser Etching and marking methods are cost-effective and flexible to “mark” your products. Through computer control, our carving process is accurate, convenient, and fast, and the finished product is clean and clean.
This new precision and control function enables us to achieve a meticulous carving effect, which is unmatched by traditional carving methods. Making use of the new advantages of laser, we can customize any surface carving to meet your precise specifications. With our superb efficiency, we can accept a large number of accessories demand.
Anodizing divides into common anodizing and hard anodizing.
Metal anodizing is the process of forming a conversion film with wear and corrosion resistance, as well as other functional or decorative properties on the metal surface by electrochemical treatment in an electrolytic way. And the treated parts are the positive pole, while the corrosion-resistant material is the negative pole.
The objects of anodizing treatment can be aluminum and aluminum alloy, magnesium alloy, titanium and titanium alloy, etc. The anodizing of aluminum and aluminum alloy is a widely used and fast development in the market.
The main function of anodizing is to improve the hardness, wear resistance, corrosion resistance, and surface coloring of the workpiece, which plays a role in protecting and beautifying the workpiece surface.
Electroplating is using galvanolysis to plating other types of metals on the workpieces. It attaches parts surface to the metal film by electrolysis, and prevents metal oxidation (corrosion), improves abrasion resistance, conductivity, reflective resistance, corrosion resistance (copper sulfate) and beauty, etc.
Electroplated metal or other insoluble materials reduces the negative electrode of the positive electrode for the electroplated metal cation to form a coating on the workpiece surface. To eliminate interference from other cations and guarantee the plating uniform and firm, an electroplating solution should be applied for containing plating metal cations and keeping the same concentration of metal cations. Making the coating surface of the product consist of only the required coating metal to ensure the part quality.
Product assembly is the process of assembling dispersed parts into a complete product by the manual or automatic fixture. The scattered products include plastic, rubber, hardware, electronics, and so on.
Now our company has two assembly lines, including totally nearly 50 employees working on the assembly lines and provides you with assembly services. At present, our company mainly offers assembly services for household appliances, medical care, auto parts, toys, machinery, and other product types.
- Silk printing 1
- Silk printing 2
- Pad printing 1
- Pad printing 2
- Pad printing 3
- Heat Transfer Printing 1
- Heat Transfer Printing 2
- Water transfer printing 1
- Water transfer printing 3
- Water transfer printing 4
- Ultrasonic welding
- Laser etching
- Electroplating 1
- Electroplating 2
- Assembly 1
- Assembly 2
Kemal - Your Secondary Processing Partner
In addition to our expertise in plastic injection molding, we also provide additional value-added services for your products, like design, assembly, packaging, and transportation. Kemal is proficient in many assembly techniques and processes.
With more than 25 years of plastic experience, expertise, and fast response service, Kemal can successfully meet your assembly challenges. Some of these services include Silk printing, Pad printing, Heat transfer printing, water transfer printing, Painting, Powder coating, Ultrasonic welding, Laser etching, Electroplating, Heat Staking, Post-Molding Machining, Packaging, Assembly, etc.
We are proud of our manufacturability design and offer the most appropriate method for customers’ vital assembly requirements.
SECONDARY PROCESSING: THE ULTIMATE FAQ GUIDE
The secondary process helps to improve the product surface quality. Kemal provides qualified and excellent products with perfect secondary processing. That is why we have prepared this guide for your reference. And we hope that you can find what you want to know about secondary processing from this guide. Should you have any questions, please do feel free to contact us.
- What is secondary processing?
- What are the types of secondary processing?
- What are the advantages of secondary processing?
- What are the common quality defects in plastic secondary processing?
- What is screen printing in secondary processing?
- What is pad printing in secondary processing?
- What are the advantages of screen printing in secondary processing?
- What are the disadvantages of screen printing in secondary processing?
- What are the differences between screen printing and pad printing in secondary processing?
- What is heat transfer printing in secondary processing?
- What is water transfer printing in secondary processing?
- What are the differences between heat transfer printing and water transfer printing of secondary processing?
- What is the process for water transfer printing of secondary processing?
- How many types of laser engraving machine for secondary processing?
- Which aspects affect the laser engraving of secondary processing?
- What is IML and IMD for secondary processing?
- What are the advantages of IMD for secondary processing?
- What is electroplating for secondary processing?
- Which material can be used for electroplating of secondary processing?
- What are the requirements for the electroplating of secondary processing?
Q1. What is secondary processing?
Generally, secondary processing is about the processing progress of plastic injection molding products. It means the process of doing a second process on the part surface after plastic injection molding so as to make its surface satisfy the customized needs, and both of its outside and inside surface are qualified to customer’s expected properties.
Q2. What are the types of secondary processing?
For secondary processing in the industry of plastic injection molding, there are various types, such as screen printing, pad printing, heat transfer printing, water transfer printing, painting, powder coating, ultrasonic welding, laser etching, anodizing, electroplating, IML / IMD, etc.
Q3. What are the advantages of secondary processing?
Here are some advantages of secondary processing.
1.It is helpful to improve the product surface quality.
2.It can increase product life.
3.It helps to improve product corrosion resistance.
4.It is beneficial for adding product features.
5.It also helps to increase product added value.
6.It saves time and cost for customers as well.
Q4. What are the common quality defects in plastic secondary processing?
In plastic secondary processing, there are several common quality defects.
1.Painting: thin oil, less oil, frying oil, oil accumulation, dust spots, wrinkling of orange peel, polished mark, color difference, oil residue, etc.
2.Hot stamping: dust spots, wrinkles, dents, burnt, peel-off, and so on.
3.Screen printing/pad printing: ghosting, blurred fonts, lines without smooth, different font formats, color difference, and so on.
4.Flying oil: means the paint adhesion appears on the non-painting area, which is usually for the reason that the painting fixture and the product are not consistent in size. Besides, inappropriate fixture design or loose fixture not assembled in place will also lead to flying oil issues.
5.Oil accumulation: This means the spray is so thick that caused excessive paint accumulation. And the reason for this issue is spraying too much on the part. At the same time, it leads to wrinkle or orange peel on the part surface.
6.Color difference: is the deviation among the painting color, the model, and the color palette, which is because of the poor paint quality, improper paint ratio, or irregular painting movement.
Q5. What is screen printing in secondary processing?
Screen printing means using silkscreen as a plate base, a screen printing plate with graphics and text is completed by the way of photosensitive plate making. Screen printing includes these five elements: screen printing plate, scraper, ink, printing table, and substrate. Screen printing is based on the principle that the mesh of the graphic part of the screen printing plate can penetrate the ink, while the mesh of the non-graphic part cannot penetrate the ink.
Q6. What is pad printing in secondary processing?
Pad printing is one of the special printing ways in secondary processing. Through this way, text, graphics as well as images can be printed on the surface of irregular and heterogeneous objects, and now it has become more and more important in our daily life. For example, surface text and patterns on mobile phones are printed in this way, and the external printing of many electronic parts such as computer keyboards, instruments, meters, etc. is all done by pad printing.
Q7. What are the advantages of screen printing in secondary processing?
There are several advantages of screen printing in secondary processing.
(1) It is not limited by the size and shape of the substrate.
Screen printing can not only print on a flat surface, but also print on molded objects with special shapes (such as spherically curved surfaces), and even shaped objects can be screen printed as well.
(2)The layout is soft and flexible.
(3)It has Strong ink coverage.
(4)The ink type is not restricted.
(5)The finished product is not affected by temperature or sunlight.
(6)It has flexible printing methods.
(7)It is convenient in plate making, low in price, and easy-to-master in technology.
(8)It has strong adhesion.
(9)It can be printed either by hand or by machine.
(10) It is suitable for long-term display, which makes outdoor advertisements more expressive.
Q8. What are the disadvantages of screen printing in secondary processing?
There are also some disadvantages of screen printing in secondary processing.
As we all know, silk screen printing can only print a single color at a time. As a result, it is very necessary to carry out complex and tedious chromatography for multi-color printing! Chromatography has such high technical requirements that there is relatively few technical personnel. If you need to print four or five colors at a time, it is inevitable that there will be inaccurate chromatography, which will accordingly increase the scrap rate of the product and the total cost as well.
2. Small batch
If silk screen printing needs to print patterns, this set of processes is required: plate making and film production. If the printing quantity is small, then the total costs will be quite high. That’s why most screen printing companies do not take small jobs.
3. Radian limit
Screen printing is only suitable for relatively flat products, but cannot work for three-dimensional products.
4. Uncontrollable ink volume
Some products (especially textile products) need to retain their original state while printing. After printing, many customers want to maintain the effect of textiles, however, screen printing cannot satisfy such requirements.
Q9. What are the differences between screen printing and pad printing in secondary processing?
In secondary processing, there are several differences between pad printing and screen printing.
For pad printing, the ink layer is thin, and it can be printed on any object except water and air, so it has highly good color expression and printing adaptability.
For screen printing, it can only be printed on regular or curved surfaces. The ink layer is thick, and the printed pattern has a strong 3-dimensional effect. It is ideal for surface printing of high-end products. It also has good color expression but has difficulty in multi-color overprint.
For pad printing, it is limited to the printing area.
For screen printing, the printing area is basically unlimited, and the cost of the screen is low and can be recycled.
For pad printing, it has no limitation on the part appearance.
For screen printing, it needs the part surface to be a flat, pure plane, or regularly curved.
The pad printing machine can do up to 12 color chromatography on one machine, and print the products at one time. More importantly, its cost is quite low.
The screen printing machine can also do multi-color overprinting, but the cost is very high. In addition, one-time multi-color overprinting equipment occupies a large area and requires more labor.
Q10. What is heat transfer printing in secondary processing?
Heat transfer printing is a new method of printing patterns on articles of various materials, especially suitable for producing a small number of OEM / ODM products, and printing patterns with full-color images or photos. Its principle is to print the digital pattern on a special transfer paper with a special transfer ink through a printer, and then use special equipment to accurately transfer the pattern to the product surface under the conditions of high temperature and high pressure to finish the secondary process.
Q11. What is water transfer printing in secondary processing?
Water transfer printing is the latest digital imaging technology. It is superior to any printing technology of secondary processing. It can print images on any solid media with special paper made of nano-materials and special environmentally friendly inks. Its biggest advantage is that it does not require any special equipment, neither medium restrictions nor special consumables nor high-temperature heating, as long as there are image input tools (such as scanners or digital cameras) and drawing tools (computers) , image output tool (inkjet printer), together with water transfer ink and paper, images can be printed on any solid objects and curved surfaces.
Q12. What are the differences between heat transfer printing and water transfer printing of secondary processing?
The differences between heat transfer printing and water transfer printing of secondary processing are listed below:
Heat transfer printing is achieved by thermal transfer by thermal sol or thermal transfer coating absorbing sublimation ink; while water transfer printing is using molecular diffusion to transfer patterns (transfer films) to objects.
Heat transfer printing is achieved by heating devices; while water transfer printing only by water.
For heat transfer printing, it needs to transfer a pattern which is a mirror image.
But for water transfer printing, just requires the front image.
Q13. What is the process for water transfer printing of secondary processing?
The process for water transfer printing of secondary processing can be divided into the following steps.
1)Make water transfer paper
2)Soak water transfer paper
3)Print the pattern on the water transfer paper
4)Dry the water transfer paper
5)Do the painting (UV / PU / soft-touch)
6)Check the finished printing effect
7)Assemble the finished product
Q14. How many types of laser engraving machine for secondary processing?
Laser engraving machine uses laser beams to make permanent marks (such as patterns and text) on the appearance of different kinds of materials. For laser engraving of secondary processing, we can use these machines types: carbon dioxide laser machine, scanning laser machine, yttrium aluminum garnet laser machine, shielded laser machine, high frequency yttrium aluminum garnet laser machine, as well as excimer laser machine.
Q15. Which aspects affect the laser engraving of secondary processing?
With the rapid development of optoelectronic technology, laser engraving technology has been more and more widely used nowadays, and the engraving accuracy requirements are getting higher and higher accordingly. The 4 most important factors that affect laser engraving are engraving speed, laser power, engraving accuracy, and materials types. To reach a specified engraving effect on a specific material, we need to use a laser with a certain energy. This energy should be considered as the laser energy absorbed by the material = laser power/engraving speed.
Q16. What is IML and IMD for secondary processing?
IML means In-Mold Label. Its remarkable feature is: the surface is a layer of hardened transparent film, while a printed pattern layer in the middle, and a plastic layer at the back. Since the ink is in the middle, so it can prevent the product surface from being scratched and resistant to friction and can keep the color vivid and not easy to fade.
IMD refers to In-Mold Decoration, which is a molding method that a film with a printed pattern is placed in a metal mold, and the forming material is injected into the metal mold to attach the film so that the printed film and the resin are integrated and cured into a finished product.
Q17. What are the advantages of IMD for secondary processing?
IMD has the advantages of surface corrosion resistance, wear resistance, non-shedding, bright colors, color patterns to be replaced at any time, and excellent surface decoration effects. It is widely used in the surface decoration of MP3, mobile phones, instruments, home appliances, and meters, etc.
Q18. What is electroplating for secondary processing?
The electroplating process coats a layer of metal on a conductor based on the principle of electrolysis. Electroplating means that in a salt solution containing pre-plated metal, a surface processing method uses the base metal to be plated as a cathode to deposit the cations of the pre-plated metal in the plating solution on the surface of the base metal through electrolysis to form a plating layer.
Q19. Which material can be used for electroplating of secondary processing?
1.Chromium is a silver-white metal with a slight sky blue color. The chromium layer has high hardness, good abrasion resistance, strong reflection ability, and good heat resistance.
2.The copper-plated layer is pink, soft, has excellent thermal conductivity, ductility, and electrical conductivity, and is easy to polish as well.
3.Cadmium is a silver-white, shiny soft metal. It has a higher hardness than tin and is softer than zinc. It has better plasticity and is easy to forge and roll.
4.Tin is silvery-white in color. Tin has the advantages of corrosion resistance, non-toxicity, easy iron welding, softness, and good ductility.
5.After passivating, the zinc coating is dyed or coated with a light protectant, so as to improve its protective and decorative properties.
Q20. What are the requirements for the electroplating of secondary processing?
1.There should be good bonding force between the plating layer and the base metal, between the plating layer and the plating layer;
2.The coating should be crystallized finely, smooth, and even in thickness;
3.The coating should have a specified thickness and the pores should be as few as possible;
4.The coating should have the specified indicators, such as hardness, brightness, conductivity, and so on.;
5.The plating time and the temperature of the plating process determine the thickness of the plating layer. The ambient temperature is -10℃～60℃;
6.The input voltage is 220V±22V or 380V±38V;
7.The maximum operating noise of water treatment equipment should be under 80dB(A);
8.The relative humidity (RH) should be less than 95%;
9. The COD content of raw water is 100mg/L～150000mg/L.