What are great attention in copper pipe welding process for refrigeration system?

 copper pipe welding summary

The refrigeration system of refrigeration air conditioning, generally with copper aluminum and other non-ferrous metal materials, in the process of manufacturing, installation and maintenance, pipeline welding is a key link, it not only affects the appearance, more important is to affect the system can work normally light problem, must cause great attention.

copper pipe welding process Selection of solder 

The pipe fittings of refrigeration and air conditioning are mostly copper (purple) pipes. The commonly used solder types are copper phosphorus solder, silver copper solder, copper zinc solder and so on. In welding, according to the characteristics of pipeline materials, correct selection of solder and skilled operation, to ensure the quality of welding.

2.1 Welding of similar materials

2.1.1 Brazing copper to copper

Phosphor copper solder or phosphor copper solder with low silver content, such as 2% or 5% silver base solder can be used. This solder is relatively inexpensive, has a good solution, uses caulking and wetting processes, and does not require flux.

2.1.2 Welding of copper and steel

Brass bar solder with appropriate flux is optional. When welding. After HEATING THE SOLDER TO a certain temperature, insert it into the flux, so that the flux is melted and attached to the solder, but after welding, the residual flux near the weld must be cleaned with hot water or steam to prevent corrosion. In the use of flux with alcohol diluted into a paste, coated on the surface of the welding, welding alcohol evaporates quickly and form a smooth film is not easy to lose, but also to avoid the risk of water immersion refrigeration system.

2.2.2 Welding of copper and iron

Phosphorous copper solder or brass bar solder may be selected, but the appropriate flux, such as borax, boric acid, or a mixture of boric acid, should also be used.

The welding operation：copper pipe welding process

The welding of different materials, different pipe diameter when the size of the welding gun and flame temperature is different, welding flame size can be controlled by two needle valve adjustment, flame adjustment according to oxygen, acetylene gas volume ratio can be divided into carbonization flame, neutral flame and three kinds of oxide flame.

8 tips Advantages And Disadvantages Of Plastic Injection Molding Process

 8 tips Advantages And Disadvantages Of Plastic Injection Molding Process

The Advantages Of Plastic Injection Molding Process

（1） the use of injection mould for the parison wall thickness distribution for precise control, make the container wall thickness is relatively uniform, avoids the general blow molding products of the corner part thinned phenomenon, products can be controlled in a heavy + 0.1 g, the precision of the screw thread can be controlled within the scope of the soil is 100 microns, the mouth size precision, thin neck high precision molding, products;

（2） the products do not need to be processed E times, no seams, saving the finishing hours of products;

（3）The billet made by injection can all enter the blow molding mold, and there is no waste in the processing process, which reduces the waste of molding materials;

（4） can get smooth surface products, no scratch, surface text and design is clear;

（5） can be economically small batch production;

（6） wide range of application to plastic varieties;

（7） high degree of automation, can be multi-mode production, high production efficiency.

The Disadvantages Of Plastic Injection Molding Process

（1）The shrink

Shrinkage generally occurs in the bone position, screw column and other glue position after the comparison of the area.

1) Structural design: uneven design of the workpiece wall thickness or too thick of the workpiece

The glue thickness is as uniform as possible, the uneven position should be smooth transition, and pay attention to the glue.

2) Mold design: the runner is too thin or the mold temperature is too high;

3) Injection design: insufficient pressure holding time, injection pressure is too small;

（2）Insufficient mold filling

1) Mold temperature, material temperature or injection pressure and speed are too low

2) Uneven plasticizing of raw materials

3) Poor exhaust

4) Insufficient liquidity of raw materials

5) the piece is too thin or the gate size is too small

（3）Crisp

1) The drying conditions are not suitable, and too much recycled material is used

2) The injection molding temperature setting is unreasonable

3) The gate and runner system are not properly designed

4) Weld mark strength is insufficient

（4）Burned in 4.

1) The drying conditions are not suitable, and too much recycled material is used

2) High melt temperature leads to material degradation

3) The screw speed is too fast

4) Poor exhaust system

（5）Fly-edge or drape

Often occurs in parting surface, line clamp, inclined top or insert position.

1) Insufficient clamping force;

2) There is wear and tear of the mold, insufficient hardness of the mold, and poor matching of the parting surface;

3) Unreasonable forming conditions (temperature is too high, pressure)

4) Unreasonable exhaust system design;

5) the glue has doping, so that the fluidity of the glue increases or the viscosity decreases;

（6）Plastic deformation

Internal stress is generated by high pressure during injection molding, and bending or warping occurs after demoulding. The most prone to problems are tablet-style products.

1) Structure design: the product is too thin to cause insufficient strength or too flat;

In structural design, the bone position and glue thickness should be appropriately increased to avoid large area plate products;

2) Mold design: the water outlet setting is unreasonable; The ejection mechanism force is too large;

The deformation of rubber parts should be considered in the design of nozzle.

3) Injection design: long holding time; Large injection pressure;

（7）More or less glue

Glue position deviation, mainly occurs in the thimble position. Multiple glue to consider whether affect the appearance or assembly, there is no need to not change.

1) Mold design more or less;

2) insufficient thimble length;

~ (If the thimble is too long, the top white will occur, and the injection pressure is too large, the ejection speed or the injection speed is too fast.)

3) Insufficient injection pressure or poor exhaust in the mold cavity

（8）Strain

The product is caused by friction mold in the process of demoulding.

1) Structure design: the inclination of drawing die is insufficient;

2) Mold design: the surface accuracy is not enough, and the error is large;

3) Injection design: excessive use of release agent (coating for separating products and molds);

What are the characteristics and advantages of CNC machining

 Rapid Prototype wants to introduce the characteristics and advantages of CNC machining.

To sum up, CNC machining has the following four characteristics in rapid prototyping services:

(1) High degree of automation and high production efficiency. Except for manually clamping the blank, all the other processing processes can be automatically completed by the CNC machine tool. If automatic loading and unloading means are used, it is a basic component of the unmanned plant. NC machining reduces the labor intensity of the operator and improves the working conditions; The process of scribing, multiple clamping and positioning, detection and other auxiliary operations are omitted, and the production efficiency is effectively improved.

(2) Strong adaptability to machining objects. When changing the processing object, in addition to changing the tool and solving the blank clamping mode, it is only necessary to re program without making any other complex adjustments, thus shortening the production preparation cycle.

(3) High processing precision and stable quality. The machining dimension accuracy is 0.005 ～ 0.01 mm, which is not affected by the complexity of parts. Because most operations are automatically completed by the machine, human error is eliminated, and the consistency of the size of the batch parts is improved. At the same time, the position detection device is also used on the precision controlled machine tool, which further improves the precision of the NC processing.

(4) It is easy to establish communication with computers and realize group control. Because the machine tool is controlled by digital information, it is easy to connect with the computer aided design system to form a CAD/CAM integrated system, and it can establish the connection between various machine tools, which is easy to achieve group control.

China Prototype started from CNC processing and has accumulated rich experience in CNC prototype production. If you have CNC Machining Manufacturer needs, please contact our sales engineers.