Sipxmach Deep drawing Products
Deep drawing is one of the most widely used processes in sheet metal forming. Apart from its use in many other sectors, it is applied in the automotive, furniture, kitchen, Electric industries. Sipxmach is a professional manufacture for different kinds of deep drawn parts in China.
Deep drawing brief introduction with Youtube video:
The method of deep drawing starts with metal blanks. Single blanks are typically used to promote the development of deeper shaped components or products. These metal blanks are sometimes put on a reel so that the metal can shape effectively. The metal blank is formed by pressure applied by a metal die at each phase of the deep drawing method.
Deep drawing is one of the most common techniques of metal forming accessible to producers–it includes the use of metal dies to form blank sheets of metal in a required form. In particular, if the depth of the generated product is equal to or higher than its radius, then deep drawing can be called the process of metal forming.
Drawing Material includes:
stainless steel, low carbon steel, copper, brass, silver.
In one word, the metal material must have good elongation, because deep drawing along with the material flow, otherwise parts will be fractured during the drawing process.
Deep drawn components:
deep drawn metal boxes, enclosures, cans, Aluminum box and enclosures
Deep drawing process:
Deep drawing is put a metal sheet or stainless steel plate on the mold, through place force it will deform the sheet metal material homogeneous. Depth drawn is a metal forming technology. Most punching and blanking technology through drawn or press let the material deformation to get what we wanted dimensions.
- When the product formed is deeper than half its diameter during stamping, we called deep drawing.
- During the pull process of depth drawing, the same dimension of the part can’t get required depth through one time drawn, most times to achieve what we required dimensions, we should press a few times. During drawing, the material flow from top to bottom and change the thickness of the part.
- Deep drawing the cold metal or cold sheet metal we called deep drawn. if we heat the material to melting point then draw to requirement depth, it is another technology-metal forging. Some times in order to draw more smoothly, we heat the material below their melting point, but it do not affect their organization structure, it is another kind of deep drawing
- stainless steel drawing some times only one time can not meet as you required dimension. It should draw many times, each drawing the stainless steel drawing part will become more rigid, then you should anneal the stainless steel drawn material to your required hardness, and draw it again.
Content you should consider when design a deep drawing part:
- Basics of formability
- Materials: steel, aluminum and high-strength steel
– material properties
– theoretical principles
- Forming methods
– deep drawing
– hydromechanical deep drawing
Benefits of Deep drawing products
Deep drawing is particularly useful when generating large quantities, as unit cost reduces significantly as unit count rises: once the tooling and dies are produced, the method can proceed with very little downtime or maintenance. Compared to comparable manufacturing procedures, such as progressive die stamping, tool building expenses are lower even in smaller quantities; deep drawing can also demonstrate to be the most cost-effective manufacturing option in these circumstances.
Deep drawing presents even more benefits when considering the functionality of the end product. The method is particularly suitable for products requiring substantial strength and minimal weight. The process is also recommended for geometries of the product that can not be achieved by other manufacturing methods.
Deep drawing may be most helpful for producing cylindrical items: it is easy to draw a circular metal blank into a 3D circular object with a single drawing proportion, minimizing both manufacturing time and cost. Aluminum cans production is one instance of this method’s common use.
Squares, rectangles and more complicated geometries can generate slight problems, but through the deep drawing method they are still readily and effectively produced. Typically, the amount of draw ratios and manufacturing expenses will improve as the complexity of the geometry rises.
Deep drawing can be a feasible manufacturing option for any manufacturing method requiring one or more of the following:
- A. Seamless parts: profound drawn components are made from a single sheet of metal
- B. Rapid cycle times: big amounts of goods are readily produced by profound drawing
- C. Complex axis-symmetric geometries: profound drawing provides outstanding detail and accuracy
- D. Compare with steel spinning and welding parts, deep drawing process have more good production efficiency.
- E. A single piece of sheet metal or plate material easy to form an integral part.
- F. Rather uniform material thickness can be achieved in metal steel shapes.
- G. Symmetrical material thickness of sheet metal shapes.
- H. Get deep parts without welding and avoid dimension distortion.
Cost Saving Tips for Deep drawing stainless steel products
- The metal will become strain hardened, and the potential of fracture will become big during drawing, so minimal deformation is ideal.
- Diameter and depth ratio will affect the difficult of forming, the ratio number much big will more difficult to draw. Try to minimize the ratio is a good way to save money.
- Typically limit to 2 reductions before needing stress relieving, ratio of depth to diameter ratio in 304 or 316 to no more than 1:1 in thicker material.
- Through annealing to relieve stress of stainless steel, ration of depth to diameter for 304 or 316 is better no more than 1:1.
- The thickness of stainless steel material also will affect the draw ability.
Other Factors That Affect Cost-Effectiveness of Deep Drawing
The expenses of manufacturing are increasing, the subsequent attraction of deep drawing is decreasing. Obviously, more complicated products will boost the cost of maintenance, labor costs and expenses of manufacturing. The following variables are probable to boost the anticipated cost when considering the cost of profound drawing:
A. Number of part features D. Protruding part features
B. Location of part features E. Part size
C. Direction of part features F. Material thickness
Blank Optimization for Deep Drawing
In choosing the nature of the metal flow and forces, sheet metal blank material, thickness and shape are key aspects. The quality of the portion will be affected by all the variables engaged in a deep drawing process. The formability of sheet metal components can be evaluated. Blanks are often printed in each grid box using a square grid with circles. As the method takes place, the squares and circles distort with the sheet metal. After drawing, it is possible to study the blanks as a consequence of the deep drawing method to determine blank distortion, thinning and general direction of metal flow. An understanding of the conduct of the blank can be developed by examining distinct proportions of bi-axial strain and tearing regions. Forming limit diagrams are often designed to quantify these experiments ‘ outcomes.
One significant objective is to optimize sheet metal blank shape for a certain method of deep drawing. Excess material in the job may interfere with metal flow and, while drawing, boost forces acting within the blank. The flow of material during an operation must first be understood to optimize the sheet metal blank shape. A popular square box is a deep drawing. When drawing a square box from a square blank, it is evident that from all directions the metal does not flow uniformly into the die.
Metal flows from the sides of the blank more quickly and easily into the die cavity than from the corners. More complicated metal flow in the corners makes material motion more difficult. As a consequence, less metal is extracted from these segments. Material removal from regions like this will enhance metal flow and decrease strengths. For distinct components and contours, the ideal blank shape will differ. Due to the parameters, computer programs were created to predict such forms. It should be remembered, however, that real path and error testing is a crucial component of the design of the deep drawing process and sheet metal production.
Defects with Deep Drawing Manufacturing
Defects that occur during deep drawing of sheet metal can be controlled by careful regulation of process factors. Tearing is one of the most common defects. Excessive thinning in areas of the sheet metal is also an unwanted defect. Causes of these are mostly too high or improper force distribution and material considerations. Many time the reduction ratio needs to be evaluated. Ratios for initial reduction are usually 35% to 45%, but can be lower. Redraws are always less. Reduction ratios may need to be lower, or annealing of the metal may be necessary to allow for sufficient redrawing. Usually maximum thinning of the cup wall occurs near the base. For this reason, tearing of the sheet metal is most likely to occur in this region even if the stress is originating somewhere else.
Another reason for the tearing of the sheet metal may be excessive force caused by material impediments, due to an inefficient blank shape. When tearing occurs at the corners of the wall it may indicate a problem with the blank’s geometry. Surface of the blank is important also, gouges, scratches and pits can all cause propagation of cracks. Blank holder force must be sufficient. However, friction between blank holder, blank and die surfaces will act to resist the movement of the blank’s material into the die. Thus, excess friction will increase the force the punch exerts to draw the sheet metal. Higher punch forces usually cause a tear in the weakest spot, predominately in the cup wall near the base. For this reason, the blank holder force must not be too high.
Deep drawing sheet metal die and blank holder surfaces must be as smooth as possible, ground and lapped to mitigate friction. Any sort of friction will improve the force and therefore the material will be stressed. A cause of failure can be friction between the punch and job surfaces, as well as friction across edges.
Lubrication is essential for sheet metal profound drawing.
Due to reducing friction, lubrication will facilitate metal flow and more evenly distributed metal strains. Lubrication also enables decrease tooling and equipment wear. Lubricants are introduced to the sheet metal blank on both sides. Oil, soap, emulsions, wax and sometimes strong lubricants are common lubricants used in profound drawing.
Wrinkling is another prevalent flaw and has been discussed previously in detail. Wrinkling can often happen when the strength of the blank holder is too small. Therefor optimization of blank holder force is necessary, since too high a force will cause excess friction. The thickness of the sheet metal is an important parameter. As mentioned previously, it is not possible to prevent wrinkling with a thickness ratio of.5 percent or even under a blank holder. If corner radius is not elevated enough tearing may happen, but if the radius of the corner is excessive, it may also trigger wrinkling. Like retaining force, the corner radius must achieve an optimum value.
Earing is a feature of the issue of profound drawing. Earing is forming wavy corners at the drawn cup’s open end. Usually these are trimmed. A specific sheet metal blank’s anisotropy is the predominant earning cause.
On drawn parts surface scratches or irregularities may occur. Make sure the surfaces are smooth to punch and die. Other causes of surface scratching may be insufficient clearance or insufficient lubrication.
Draw beads used in deep drawing tooling
Draw beads are sometimes used in the production of deep drawing to assist control metal motion. Bend and unbend beads as it move into the die cavity, changing its flow. Drawing beads can decrease the required blank holder strength.
|Drawing Without A Blank holder Metal deep drawing can be done under certain circumstances. This simplifies the production method and lowers the price of tooling in areas where it can be implemented. The method needs high-thickness sheet metal to prevent wrinkling. For profound drawing, the thickness percentage of the blank holder should be at least 3%. A sheet metal blank, comparable to the conventional deep drawing method, is put on a die and driven through a punch. The die will have a unique curve when drawing without a blank holder to promote the part’s forming in this way.|
Irregular Deep Drawings Common deep drawing part geometries that are not standard include stepped, tapered and domed cups. You can create stepped components by partial redrawing. Domed cups are created with a type method of stretch forming. Tapered cups can be made by first making stepped cups, then forming the sides to make the tapered shape.
Embossing in deep drawing
Embossing is an operation linked to deep drawing sheet metal forming. Embossing is typically used with a model or writing to indent the metal. Compared to coining, this production method. Unlike coining, embossing utilizes matching male and female death, and both sides of the sheet metal will influence the feeling.
Designing a Deep Drawing Operation
Designing a method of deep drawing will involve planning, calculations and possibly some in house testing. Calculate the completed part’s surface area and enable a cutting allowance. Set the part surface area equal to the sheet metal surface blank, then solve for Db. It is possible to add extra material to the blank (i.e.+ 10 percent Db), which will produce a flange that can be cut off the latter. This can assist calculate the operation’s optimum normal blank shape.
Measure the percentage of density= t / Db X 100%. The thickness ratio should exceed 1% or wrinkling may be an issue. Calculate a decrease in percentage. R= (Db— Dp)/(Db) X 100%. If the percentage decrease for redrawing activities is more than 50 percent plan. Redrawing will involve intermediate shape design. Consider the decrease when developing intermediate forms, then set the surface area of the blank, intermediate and final drawing components to be equivalent.
Using blank shape, blank thickness, punch and die shape, punch and die corner radius, sheet metal material and friction, the required punch and blank holder force can be calculated. Deep drawing process iteration can optimize the production procedure over time through trial and error. Process variables such as decrease quantity, blank shape, corner radius, or blank holder force may need to be adjusted depending on past process outcomes.
Deep drawing products Gallery
Sipxmach is a deep draw metal stamping leading manufacturer for the aerospace, communications, industrial, lighting, medical, military, and furniture sectors. Our expert engineers prepare each metal punching blank in advance of the deep drawing process to ensure that the results are free from tears and other defects. With more than 10 years of experience, our deep drawing products not only service china customers, we are also exporting to Europe and American.
Sipxmach workers drawing a sheet metal blank around a punch as it’s pulled through a die and formed the parts required dimensions and shapes. To get the deep drawn products visual, we browse through the examples below. Some of these examples represent multiple draws to achieve deeper results. You’ll also see examples of our secondary operations, such as black zinc plating, anodizing, polishing, CNC machining, heat treating, piercing, blanking, forming, welding, laser cutting and son on.
Deep drawing stamping process
and application analysis of different materials!
Deep drawing stamping is a special stamping method. The principle is to apply external force to the sheet, strip, pipe and profile by press and die to make plastic deformation or separation, so as to obtain the workpiece of the desired shape and size (Stamping). However, deep drawing stamping is still quite different from common continuous stamping and single-action stamping.
The first is the mold. The mold consists of a punch and a die. One station has a pair of molds, generally up to 18 stations. When designing the mold, it is usually considered to use all the stations, which makes the molding of each step more stable. Out of the product is better
Followed by the strip, the deep drawing process without conveyor. The product is stored in the mold separately. It can be transferred between the stations by the built-in robot. It can be reversed arbitrarily, which allows us to form relatively complex shapes. Such as: thread, side holes, side grooves, reverse stretching of the end face, etc., can produce a variety of products.
Compared with machined parts, cast parts, molded parts and ordinary stamping metal parts, it has obvious advantages of saving material cost, reducing waste, reducing assembly cost and time, and improving the product’s external structure to meet requirements and retain its own strength. The use of raw materials minimizes scrap rates.
Analysis of deep drawing applications with different materials
1. Low carbon steel deep drawing stamping
A. Low carbon steel Deep drawing Material characteristics:
Excellent formability (depending on material grade), high strength, light weight, cost-effective than other stretch materials, stable dimensional stability, low corrosion resistance, and need for post-treatment protection such as electroplating. Commonly used in various parts of automotive manufacturing, especially high-strength structural parts.
B. Low carbon steel material Impact on the stretch stamping process:
Rich in material procurement resources
Low tonnage machines are available (depending on material grade)
Good dimensional stability after molding
Particularly suitable for welding
There are different coatings in the raw material category, which eliminates the need for subsequent surface treatments such as plating
The molded product has a certain shelf life, depending on its corrosion resistance.
C. Our commonly used low carbon steel materials in deep drawing process
1008 low carbon steel HSLA Grade 50 low carbon steel
1010 low carbon steel HSLA Grade 80 low carbon steel
DC03 / DC04 B340LA / B410LA
SPCC / SPCD / SPCE
2, Stainless steel deep stamping
A. Stainless steel Material deep drawing characteristics:
High strength, light weight, high corrosion resistance, suitable for heat treatment, good wear resistance and no need for plating protection.
Commonly used in fuel supply systems, brake systems, exhaust systems, oxygen sensors and decorative components in automotive manufacturing.
B. Stainless steel Impact on the Deep drawing stamping process:
Large tonnage machines are required compared to other materials
Larger wear on the mold during stretching
Material prices are more expensive
Good dimensional stability after molding (/-0.02mm)
Hardening and resilience of the material during stretching
It is difficult to form the material during stretching and it is difficult to control the wall thickness of the product. It requires an experienced molder.
C. Our commonly used stainless steel DEEP DRAWING materials:
304(L) stainless steel
305 stainless steel
310 stainless steel
316 stainless steel
410 stainless steel
430 stainless steel
More information about the stainless-steel stamping please check: https://sipxmach.com/stainless-steel-stamping/
3, Aluminum alloy DEEP DRAWING stamping
A. Aluminum Material characteristics with deep drawing
Light weight (about 1/3 of low carbon steel), high strength, non-magnetic, no rust, suitable for heat treatment, can be anodized to prevent corrosion.
It is commonly used in heat dissipation devices, energy storage devices (such as batteries), beverage containers and the pharmaceutical industry in automotive manufacturing and other industries.
B. Alu material Impact on the deep stamping process:
Compared with other materials, low-tonnage machines can
Larger wear on the mold during stretching
Good dimensional stability after molding (/-0.04mm)
Easy to form and low resilience
The material does not easily harden when stretched
Aluminum alloy deep drawing is achievable for forming inconsistent wall thicknesses
C. Our commonly used aluminum alloy materials for deep drawing
3003 aluminum alloy
5052 aluminum alloy
6061 aluminum alloy
More information about aluminum stamping please check: https://sipxmach.com/aluminum-stamping/
4. Copper alloy deep stamping
A. Copper Material characteristics for deep drawing:
Anti-corrosion, easy oxidation (surface discoloration and stain), expensive and unstable, easy to weld.
B. Copper material Impact in the deep stamping process:
Machine tonnage similar to mild steel
Material ductility is very good
Due to the high price, the utilization of materials and the recycling of waste are very important.
Good dimensional stability after molding (/-0.04mm)
For alloys with inconsistent wall thickness, copper alloy stretching is achievable
C. Our commonly used copper alloy materials for deep drawing
C22000 copper alloy
C26000 copper alloy
C28000 copper alloy
C52100 copper alloy
More information about copper stamping please check:
How to solve the wrinkling of deep drawing
2.1 Why is there a deep wrinkle?
(1) Influence of stretching depth
There is a direct relationship between the material flow resistance along the die orifice distribution at the depth of the stretch. In the position of the concave and convex curves, excessive stretching depth can cause uneven distribution of deformation resistance, and wrinkles should be avoided.
(2) Adjust the size of the blanking force
When the wrinkles are uniformly generated around the workpiece, it should be judged that the pressing force is insufficient, and the pressing force is gradually increased to eliminate the wrinkles. When the cone and hemispherical members are stretched, most of the material is in a suspended state at the beginning of the stretching. It is easy to produce sidewall wrinkles, so in addition to increasing the blanking force, it should also be used to increase the radial tensile stress in the panel to eliminate wrinkles.
(3) Radius influence of the radius of the die
The radius of the fillet of the die is too large, and the flow of the blank into the die through the die radius is the bending resistance that causes the bending deformation to be smaller. The smaller the bending resistance, the more likely it is to cause wrinkles. The greater the bending resistance of the concave die with small bending deformation, the less likely it is to wrinkle, but it is easy to cause cracking and pulling of the workpiece.
Through a large number of production practice and accumulation of experience, the main reason for the wrinkling of stamping parts is caused by the accumulation of materials during the stretching process and the excessive speed of local material movement. When formulating the actual solution, it should be considered from the above aspects to adjust the corresponding mechanism of the mold, which will achieve good results.
2.2 Careful analysis of the reasons
There are many reasons for the wrinkles of the tensile members during the stretching process. The main reasons are as follows:
- The drawing depth of the stamping part is too deep, which causes the sheet material to flow too fast during the feeding process to form wrinkles.
- The R angle of the die is too large during the drawing process, so that the punch cannot press the material during the stretching process, causing the sheet to flow too fast to form wrinkles.
- The pressing material of the stamping part is unreasonable, the pressing material rib is too small and the position is not correct, which can’t effectively prevent the sheet material from flowing too fast and forming wrinkles.
- The pressure of the ejector pin is too small, so that the stamping parts are not formed completely and wrinkles are formed.
- The mold positioning design is unreasonable, which leads to the inability to press the material during the drawing process of the stamping part or the side of the pressing material is too small, which makes it impossible to press the material during the stretching process and cause wrinkles.
- The excessive gap between the convex and concave molds makes it impossible to press the material during the stretching process, causing wrinkles.
2.3 Measures to prevent wrinkling of stamping parts
The method to prevent wrinkling is to ensure that the metal stamping parts can press the material during the stretching process to ensure a reasonable sheet flow speed. When the stamping part is stretched too fast, the sheet material may be wrinkled; on the other hand, if the sheet material flows too slowly, the stamping part may be cracked.
(1) Using a reasonable press device
When the pressing device is used, the pressing device presses the deformed portion of the blank tightly and acts on the pressing force to prevent the flange portion from arching and causing wrinkles. The amount of pressing force should be appropriate. The pressing device is divided into two types: elastic pressing material and rigid pressing material. The elastic device is suitable for shallow drawing and the rigid device is suitable for deep drawing.
(2) Reasonable use of drawbeads
The provision of the drawbead on the pressing surface is an effective and used method for adjusting the deformation resistance. The drawbead can adjust the flow of the material well, so that the material flow resistance of each part during the stretching process is uniform, and the amount of the material flowing into the cavity is suitable for the needs of the workpiece, preventing more wrinkles and less cracking. The phenomenon. For curved joints with complex shapes, especially those with smaller flanges, drawbeads should be provided to increase the tensile stress of the stretch to control wrinkling; the position of the drawbeads is radially pulled. On the part where the stress is small, that means, it’s where the sheet is easy to flow. For parts with small flanges, in order to set the drawbeads, some materials (process supplements) can be added as appropriate, and this part is removed when trimming. For drawn members with large differences in stretching depth, the drawbeads should be placed at a location where there is less feed, so that too much material can be organized in the cavity to prevent wrinkles.
The above is a common cause of wrinkling during the stretching process of metal stamping parts, and specific analysis is needed in specific problems. Find the specific reasons based on the specific conditions of the stamping and stamping machines.