Plastic processing, also known as plastic molding, is the process of processing plastics or synthetic resins into plastic products. It can be said to be one of the largest production sectors in the plastics production industry. Plastic processing is developed because of the development of synthetic resins. With the continuous improvement of science and technology, plastics
The processing technology has also been greatly improved. At present, it is mainly composed of the steps of batching, molding, cnc plastic machining, joining, modification, and assembly. Let's take a closer look at its technological process.

Plastic Processing Process

1. Ingredients

This is the first step in the plastic processing technology. In addition to the polymer, it requires the addition of some plastic additives such as stabilizers, plasticizers, colorants, etc., so that the performance of the processed plastic products will be greatly improved. improve, and also reduce production costs. The polymer and additives are mixed together and dispersed as a dry mix. It can also be processed into pellets.

2. Forming

This is the most critical step in the plastic processing process. We need to make various forms of plastic into the desired shape. There are many ways to form this, and the choice is mainly based on the type of plastic, the initial shape, and the size and shape of the product. If it is a thermoplastic, extrusion, injection molding, calendering, blow molding and thermoforming are generally used; if it is a thermosetting plastic, molding, transfer molding, or injection molding can be used. In addition, there are castings using liquid monomers or polymers as raw materials.

3.CNC Plastic Machining

This step can be seen as an auxiliary process of forming. It can borrow the cnc plastic machining methods of metal or wood to manufacture some plastic products with precise dimensions or small quantities. However, the performance of plastic is completely different from that of metal and wood. The tools and cutting speed used in machining must conform to the characteristics of plastic.

4. Joining

This step is to join the plastic parts together. There are two main methods: welding and bonding. The welding methods are mainly hot air welding, hot melt welding, high frequency welding, friction welding, ultrasonic welding, etc. The bonding method is done using adhesives such as flux, resin solution and hot melt adhesive bonding.

5. Modification

The purpose of this step is to beautify the surface of plastic products, generally through mechanical modification, that is, grinding, filing, polishing, etc.; and then finishing, such as coating the surface of the product with paint, covering the surface of the product with a patterned film, etc. ; There are also coloring, such as painting, printing, etc.; there are also metal plating, including vacuum coating, electroplating, and chemical silver plating.

6. Assembly

This is the last step in plastic processing, which is to combine the individual plastic parts processed into a complete plastic product.

Several of the most common plastic processing processes

• Extrusion: Extrusion is also called extrusion in plastic machining and extrusion（Different from aluminum extrusion） in rubber processing. It refers to a processing method in which the material passes through the action between the extruder barrel and the screw, is heated and plasticized, and is pushed forward by the screw, and continuously passes through the head to make various cross-sectional products or semi-products. Extruded products are continuous profiles, such as tubes, rods, wires, plates, films, wire and cable coatings, etc. The extruded products produced by Baoyi use a variety of unused raw materials, among which the most commonly used are cnc machining peek,PC, ABS, PVC, PS, PE, PP, TPE, TPE, TPU, etc. After the processing is completed, there are many plastic products such as LED lampshades, drain pipes, supermarket price tags, etc. that appear in our lives. The processing technology is extrusion.
• Injection Molding: Thermoplastic injection molding, a method in which the plastic material is melted and then injected into the film cavity. Once the molten plastic enters the mold, it is cooled and shaped into a cavity-like shape. Injection-molded products are also very common in our lives. Our most common products are: computer case shells, connectors, mobile phone shells, keyboards, mice, stereos, etc.
• Blow molding: also known as hollow blow molding, a rapidly developing plastic processing method. The tubular plastic parison obtained by extrusion or injection molding of thermoplastic resin is placed in a split mold while it is hot (or heated to a softened state), and compressed air is introduced into the parison immediately after closing the mold to blow the plastic parison. It expands and sticks closely to the inner wall of the mold, and after cooling and demoulding, various hollow products are obtained. The plastic processing technology for bottles, barrels, cans, boxes and all containers for packaging food, beverages, cosmetics, medicines and daily necessities that are common in our lives is blow molding.

The above is the technological process of plastic processing. The most important ones are the first two steps. The latter four processes are carried out after the plastic has been formed into a finished product or semi-finished product, which is regarded as the secondary processing of plastic. In the process of plastic processing, it is inevitable to encounter various problems, among which the plastic processing shrinkage problem is the most common and the most difficult one. Only by minimizing this problem can a higher quality of the product be guaranteed. However, with the continuous improvement of plastic processing technology, it is believed that this problem will be solved in the future.

The Judgment Of God Is Real

In the 1950s a young songwriter wrote these lyrics, “What a day that will be when my Jesus I shall see.” For some people it won’t be a day to rejoice. Why? Because the judgment of God is real. Click on the link below to read this very evangelistic post. This is a post you will want to share. #2Thessalonians #BibleStudy #Devotions #eternity

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What Is The Will Of God For Me

Are you looking for God’s direction for your life? Are ready to GO but the Lord is saying NO! At least, not yet. We must make sure we know the fundamentals of Christianity. Check out today's post by clicking on the link below, you'll be glad you did. #1Thessalonians #BibleStudy #Devotions #GodsPurpose

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What is investment casting？Use a mold to shoot wax to make a wax pattern in the shape of a spare part; then apply it with a refractory material, then heat to remove the wax in the middle; then use it as a mold shell and inject molten metal iron. Wax casting (also called investment casting, lost wax casting). This casting method is extremely cost-effective when used to manufacture products such as complex and three-dimensional shapes.

1) Drawing
First of all, it is necessary to fully discuss various conditions such as the concept, purpose, and size of the product. In order to produce a product that pays attention to product economy and operability, it is necessary to conduct thorough communication and negotiation in all aspects such as shape and material.

2) Mold making
Secondly, the mold making of the forming wax mold is based on the pre-agreed design drawings, and the mold design of the neutron is carried out to improve the efficiency and reduce the cost.

3) Wax mold making
Wax is injected into the mold to make a wax pattern. The shape of this wax mold solidifies into the shape of the casting.

4) Group tree
The wax module of the product is welded to the casting rod and assembled like a branch, this state is called a group tree. Multiple castings can be produced at one time.

5) Shell making
The assembled wax mold is dipped into the slurry (binder), and the surface is coated with refractory material and allowed to dry. This operation is then repeated until it finally reaches a suitable thickness.

6) Dewaxing
The shell is heated with high temperature and high pressure steam, and the wax in the prototype of the product is dissolved and flowed out. The melted part becomes the cavity, which becomes the base of the shell.

7) Roasting
The firing of the shell is to improve the strength of the shell. In addition, it also has the effect of removing impurities in the shell by heat.

8) Casting
Dissolved metal steel water is injected into the fired mold.

9) Vibration shell cleaning
After casting, the outer shell is removed by sand cleaning of the vibrating shell, and the casting containing the casting rod product is taken out.

10) Cutting
The casting of the product is removed by laser cutting from the casting rod, and a prototype of the casting is completed at this stage.

11) Heat treatment
After heat treatment, the mechanical properties of the casting products are adjusted to achieve suitable properties.

12) Check
Inspection of appearance, shape, size, and inspection of casting defects are carried out. In addition, depending on the product, mechanical
Workmanship, surface treatment and other requirements.

13) Packing for delivery

God Gives Grace To The Humble

Both Peter and James included the following statement in their epistles. "God opposes the proud, but He gives grace to the humble." The Lord does something special for us when we are humble before Him. Click on the link below to read about it. #1Peter #BibleStudy #Devotions #Grace

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How Much Does God Love Me?

God’s love is immeasurable because the scripture tells us that God is love. With that in mind, how does His love relate to us? How much does God love you and me? Check out today's post by clicking on the link below. #1John #BibleStudy #Devotions #Evangelism #Love

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That Your Joy May Be Full In The Lord

How can you be sure that your joy may be full? The Apostle John answered that question in the first epistle he wrote. Jesus also gave us insight into having complete joy as well. Click on the link below to read today's post. #1John #BibleStudy #Devotions #joy

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How To Be Free In Life

Happy 4th of July, Independence Day. We celebrate it with picnics and fireworks and other summer activities. But today, as well as with everyday, we can also celebrate our dependence as we lean on our Lord Jesus. Click on the link below to read today's post on how to be free in life. #BibleStudy #Devotions #Romans #sin

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When You Make A Vow To God

God chose a man called Jephthah as one of the judges of Israel. This man earned his notoriety when he decided to make a vow to God. We can certainly glean some wisdom from Jephthah's story. Click on the link below to read all about it. #BibleStudy #commitment #Devotions #Judges

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Living Under The Shadow Of His Wings

If your answer is “no,” then, why not? Psalm 91 contains some of the great promises for those who answered “yes.” Maybe you’re not sure what it means to live under the shadow of His wings. Click on the link below because you will certainly benefit. #BibleStudy #Devotions #Evangelism #Psalms

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2205 duplex stainless steel (UNS S32305/S31803) is a duplex stainless steel composed of 22% chromium, 3% molybdenum and 5-6% nickel-nitrogen alloy. It has high strength, good impact toughness and good overall and local strong corrosion resistance.

Compared with 316L and 317L austenitic stainless steel, 2205 duplex stainless steel has superior performance in pitting corrosion and crevice corrosion, it has high corrosion resistance, and compared with austenitic, it has a lower coefficient of thermal expansion , the thermal conductivity is higher.

Compared to austenitic stainless steels, it has twice the compressive strength, and designers can save weight and cost less than 316L and 317L.

2205 (UNS S32205/S31803) 22% chrome, 3% molybdenum stainless steel

General Properties Application Areas Standard Corrosion Resistance Chemical Composition Mechanical Properties Structural CNC Machining And Welding

General properties 2205 duplex stainless steel is a duplex stainless steel machining composed of 22% chromium, 3% molybdenum and 5-6% nickel nitrogen. It has high strength, good impact toughness and good overall and local stress corrosion resistance. Compared with 316L and 317L austenitic stainless steel, 2205 duplex stainless steel has superior performance in pitting corrosion and crevice corrosion. It has high corrosion resistance and has a lower coefficient of thermal expansion than austenite. , higher thermal conductivity. The yield strength of 2205 is twice that of austenitic stainless steels, a feature that allows designers to reduce weight when designing products, making this alloy more affordable than 316, 317L. This alloy is particularly suitable for use in the -50°F/+600°F temperature range. For applications outside this temperature range, this alloy can also be considered, but there are some limitations, especially when applied to welded structures.

Application Field Of 2205 Duplex Stainless Steel

• oPressure vessels, high pressure storage tanks, high pressure pipes, heat exchangers (chemical machining industry).
• oOil and gas pipelines, heat exchanger cnc turning stainless steel fittings.
• o Sewage treatment system.
• o Pulp and paper industry classifiers, bleaching plants, storage and handling systems.
• o Rotary shafts, press rolls, blades, impellers, etc. in high-strength and corrosion-resistant environments.
• o Cargo boxes for ships or trucks
• o Food processing equipment

ASTM/ASME………..A240 UNS S32205/ S31803 EURONORM……..1.4462 X2CrNiMoN 22.5.3 AFNOR………… …….Z3 CrNi 22.05 AZ DIN ………………………W. Nr 1.4462

Corrosion Resistance Uniform Corrosion Due to the chromium content ( 22%), molybdenum (3%) and nitrogen content (0.18%), the corrosion resistance of 2205 is better than 316L and 317L in most environments.

Local corrosion resistance The content of chromium, molybdenum and nitrogen in 2205 makes it highly resistant to pitting and crevice corrosion in oxidizing and acidic solutions.

Corrosion curve 4 mpy (0.1 mm/yr) in sulfuric acid with 2000 ppm chloride

The dual-phase microstructure of stress-corrosion-resistant stainless steels contributes to improved resistance to stress-corrosion cracking of stainless steel parts. In the presence of certain temperature, stress, oxygen and chloride , austenitic stainless steel will undergo chloride stress corrosion. Since these conditions are not easily controlled, the use of 304L, 316L and 317L is limited in this regard.

Corrosion fatigue resistance The high strength and corrosion resistance of 2205 duplex stainless steel make it have a high corrosion fatigue resistance. CNC Machine is susceptible to corrosive environments and loading cycles, and the properties of 2205 are ideal for such applications.

Uniform Corrosion in Wet Machined Phosphoric Acid

Stress Corrosion Cracking

Average chemical composition (weight %)

Mechanical properties Mechanical properties at room temperature

Tensile properties at high temperature

Physical Properties

physical properties

The chemical composition of structure 2205 is 1900°/1922°F (1040°/1080°C) solution annealed to obtain the ideal microstructure of 50 α / 50 γ . Heat treatment at temperatures above 2000°F may result in an increase in ferrite content. Like other duplex stainless steels , 2205 duplex stainless steel is susceptible to intermetallic precipitation. The intermetallic phase precipitates between 1300°F and 1800°F , with the fastest precipitation at 1600°F. Therefore, we need to test 2205 to ensure that there is no intermetallic phase, and the test refers to ASTM A 923.

Processing Hot Forming We recommend forming at temperatures below 600°F as much as possible. During the hot forming process, the entire workpiece should be heated as a whole and should be done in the temperature range of 1750°F to 2250°F, where 2205 duplex stainless steel is very soft. If the temperature is too high, 2205 duplex stainless steel is prone to hot tearing. Below this temperature, austenite will fracture. Below 1700°F, intermetallic phases form rapidly due to the effects of temperature and deformation. Immediately after hot forming, they should be solution annealed at a minimum temperature of 1900°F and quenched to restore phase balance, toughness and corrosion resistance. We do not recommend stress relief, but if necessary, the material should be solution annealed at a minimum temperature of 1900°F, then rapidly cooled and water quenched.

Cold-formed 2205 duplex stainless steel can be cut and cold-formed. However, due to the high strength and hardness of 2205 duplex stainless steel, it needs to be cold formed more than austenitic steel, and because of its high strength, the springback factor should be fully considered.

Heat treated 2205 duplex stainless steel should be annealed at a minimum temperature of 1900°F, then rapidly cooled and water quenched. This treatment is used for solution annealing and stress relief. Stress-relief treatments performed at temperatures below 1900°F tend to result in the precipitation of detrimental metallic or non-metallic phases.

Machinability On high-speed machines , the feed rates and cutting speeds of 2205 duplex stainless steel are the same as those of 316L. With carbonized knives, the cutting speed is reduced by approximately 20% compared to the 316L, where the performance of the machine and its components plays a key role.

The weldability of welding 2205 duplex stainless steel is very good. The performance to be achieved by 2205 duplex stainless steel is that the weld metal and thermally modified parts still maintain the same corrosion resistance, strength and toughness as the base metal. The welding of 2205 is not difficult, but its welding procedure needs to be designed so that after welding, a good phase balance can be maintained and the precipitation of harmful metal phases or non-metal phases can be avoided. The 2205 can be welded in the following equipment: GTAW (TIG); GMAW (MIG); SMAW (“stick” electrode); SAW; FCW; and PAW.

Usually, alloy steel with a mass fraction of chromium greater than 12% (mass fraction) or a mass fraction of nickel greater than 8% is called stainless steel. Stainless steels are classified according to their metallographic structures, including martensitic stainless steel, ferritic stainless steel, austenitic stainless steel, austenitic + ferritic stainless steel and precipitation hardening stainless steel.

After the stainless steel is cut, the cutting surface and the machined surface are severely hardened, which can reach 1.4 to 2.2 times the hardness of the substrate, and the depth of the hardened layer is 0.1 mm, which brings difficulties to subsequent cutting; due to the high plasticity, toughness and tensile strength of stainless steel , the unit cutting force is 1.25 times that of cutting 45 steel; the thermal conductivity of stainless steel is 1/4~1/2 of that of 45 steel [50.2W/(m K)], so under the same cutting conditions, The cutting temperature is about 200 °C higher than that of cutting 45 steel; due to the plasticity, toughness, high cutting temperature and affinity of stainless steel with other metal elements, the tool-chip bonding and diffusion occur, and the tool is bonded and diffused. wear.

Also due to the serious hardening phenomenon when cnc machining stainless steel, it will increase the wear of the tool.

1. The tool material for turning stainless steel is required to have high heat resistance and wear resistance according to the above-mentioned cutting characteristics of stainless steel, and has a small affinity with stainless steel.
2. High speed steel. Ordinary high-speed steel (W18Cr4V) tools have low durability. W6Mo5Cr4V2Al and W12Cr4V4Mo high-performance high-speed steel should be used, which can double the durability of the tool.
3. Carbide. YG-type TaC or NbC fine-grained or ultra-fine-grained cemented carbides should be used, such as YG6X, YW4, YS2, YS8, YD15, 813, etc. If a coated blade is used, it is best to use TiAlSi coating, which can prevent adhesion and wear during the cutting process, and at the same time increase the surface hardness of the blade to 3600~4200HV.
4. Tool geometry parameters The rake angle of the stainless steel machining tool is γo=20°~30°, the clearance angle αo=8°~10°, the main declination angle κr=45°~75°, the secondary declination angle κr=8°~15 °, the edge inclination angle λS=-3°~0°, the radius of the tool nose arc rε=0.5~1mm. The form of broken (rolled) chip groove is full circular arc or straight circular arc, with groove width Bn=3~5mm, groove depth h=0.5~1.3mm, and broken (rolled) chip groove radius Rn=2~8mm.
5. Cutting amount Due to the cutting characteristics of stainless steel, the cutting speed is 40%~60% of that of cutting 45 steel, and the cutting depth ap and feed f should be greater than 0.1mm.
6. When the cutting fluid is rough turning, use emulsion or extreme pressure emulsion; when fine turning, use vulcanized oil (that is, mineral oil containing 2% sulfur).
7. Attention should be paid to turning stainless steel, especially austenitic stainless steel, should use a lower cutting speed (high-speed steel tool vc=18~20m/min; cemented carbide vc=40~60m/min) and a higher cutting speed than the hardened layer The depth of ap and f; when drilling with high-speed steel drills, the cutting edge of the drill should not stay on the cutting surface, so as not to aggravate the hardening of the cutting surface and bring difficulties to the next feeding; when reaming stainless steel holes, vulcanized oil should be used. Isobaric cutting fluid.