Others

Understanding Modern Press Brakes

This overview provides a brief discussion of press drives, crowning systems, and tooling setup found on today’s press brakes.

 

Does this sound familiar? An operator is working with a mechanical press brake, which has a ram that has to complete its full cycle and a stroke cycle speed that can’t be adjusted, but before he can get started he has to figure out the appropriate bend allowance and k factor for the job.

 

If that sounds familiar, you have been around press brakes for quite a while, or you have a good knowledge of how bending used to occur in fabrication shops. You also probably know that bending is not done that way for the most part today.

 

Modern press brakes are much safer and don’t require as much manual intervention as their predecessors. They are sophisticated machines designed to keep pace with today’s rapid fabricating environment. Let’s take a look at the different elements that separate today’s modern equipment from yesterday’s older pieces of iron.

 

The Press Drive

Hydraulic press brakes are not necessarily new, and that explains why they perform most of the forming work in fab shops.

 

Their operation is very simple to understand. These presses operate synchronized hydraulic cylinders on the C-frames that move the ram. A flow control feeds oil into cylinders to move pistons, which control the movement of the ram. It’s an inexpensive way to generate a lot of force.

 

In the old days, a limit switch was used for controlling the brake. Now CNCs are used. Along with high-precision flow control valves, today’s hydraulic press brakes provide a great deal of control and power cost-effectively.

 

Most of these hydraulic valves are mounted directly on the hydraulic cylinders. A number of years ago, fabricators had to deal with pipes breaking and rams falling. The press brake manufacturers solved the problem by eliminating or minimizing the piping. Today’s hydraulic press brakes should not be confused with those from several years ago.

 

Hybrid brakes are now more widely available than ever before. With a hydraulic drive, when you turn the pump in one direction, you are pumping the ram down. When you turn the pump in the other direction, you are pumping the ram up. The hybrid concept kind of simulates a screw and a nut. It’s a bidirectional pump, and a servomotor controls the pump’s back and forth motion. You don’t have a three-phase AC motor droning all day long, pumping the ram occasionally. Now the motor is pumping the ramp only when the CNC calls for the force.

 

What are the advantages? You get fast response time, minimal piping, good speeds (2 to 500 inches per minute [IPM]), and high efficiency when it comes to performance. However, a hybrid brake is not an inexpensive system.

 

Electric press brakes have made a big splash in the market in recent years. Many fabricators associate “electric” with direct-drive press brakes. In these electric devices, a ball screw system, which relies on recirculating balls to alleviate friction instead of lubricants, drives the rams down.

 

Roller screw technology has emerged as a new technology that helps to increase the load capacity for these electric brakes. These screw types have multiple threaded helical rollers that are found around a threaded shaft. This setup converts a motor’s rotary motion into linear movement to move a press brake ram. These roller screws tend to add more load-bearing surface in the press drive.

 

What are some of the advantages? It’s not necessarily the speeds, but the acceleration factor. Typically press brakes can accelerate only at a certain rate. With an electric brake, you can take that acceleration factor much higher without drawing air bubbles into the oil and so forth.

 

Some manufacturers are using dual drives on the electric brake; one drive is for rapid approach and the other drive is for the bending. This allows you to tune your ball screws and roller screws for different applications.

 

It should be mentioned that there’s another way to convert a small force to a large force. Let’s call it the block-and-tackle drive. Brakes with belts are an example. It also can be called a single-acting electric drive.

 

With this type of drive, the ram moves in one direction, which has certain advantages. Because it is a single directional system, it might be less complicated and less expensive. And you minimize some shifting time at the bottom of the stroke because you just released the servomotors and the ram reverses.

 

A lot of these belt or block-and-tackle drives also distribute bending load across the entire ram. Every time a belt is fed over a pulley, it’s like a 10-time reduction in the gear ratio. This can create big performance advantages for electric brakes when compared to hydraulic brakes.

 

The sweet spot for these electric brakes is the lighter tonnages. If you look at the conventional machines on the market, you will see a segment of equipment in the 100-ton or less range; that’s good for the electric and hybrid type of presses. At 100 tons and higher, an electric press brake requires plenty of kilowatts to generate the force necessary to do the job. At that point, any energy savings that the electric press brake generated when compared to a hydraulic brake is negligible. Simply put, you can’t get energy for nothing.

 

So how do you transfer the force from the drive to the press brake? The three concepts are the central drive, the dual drive, and the distributed drive.

 

The central drive is more cost-effective. It’s simple. It’s limited to basically center or near-center bending. You don’t have offset capabilities with the center drive system.

 

The single drive system does provide some advantage with machine deflection. If the ram is pushing down at the center of the upper beam and the lower beam is supported on the side frames, you get a deflection pattern at the center of the bend.

 

For a dual-drive system, which is conventional technology in today’s metal fabricating world, when you start forcing the ram down, the deflection in the center of the machine has to be compensated for. Press brake manufacturers address this deflection in many ways that might be worthy of an article on its own.

 

The distributed drive is a hybrid between the center and the dual drive in which the drive cylinders are moved in just a little bit from the side of the machine. This creates parallel deflection compensation. You can compensate a little bit for the machine flex by where you put those drives.

 

With the distributed drive, the load is spread across the entire ram. Practically no deflection on the ram is the result.

 

Bed Crowning

Crowning is how a press brake compensates for machine deflection.

 

Most of the machines have some sort of mechanical deflection device on the machines. Wedges and hydraulic cylinders are used to compensate as the load increases.

 

In closed-loop systems, the center of the brake is actually under CNC as well.

 

Tool Setup

The setup time on most press brakes is equal to the tool change time. Working under the premise that a program is done offline or that a job is being rerun, a press brake should have downtime only when an operator is changing out tools for the next job.

 

The most cost-effective means to address quick tooling changeover is to use tooling designed to be placed in and removed from the ram easily. The most common types of tools that fit this description are push-button or click tooling.

 

A push-button in the front of the tooling keeps the tool from falling out of the ram. A hydraulic cylinder not only clamps the tool, but seats it; clamping and seating the tool are done simultaneously. A high-precision tool setup can be done very quickly.

 

There is a weight limit on that click. When a segment gets above 30 lbs., the tool needs to be end-loaded. Many fabricators purchase smaller segments of the tool to stay under the 30-lb. limit, so all of the tools can have the clicks.

 

Bending Speed

Bending speed is the hot-button topic today in fabricating circles. A typical press brake, maybe 5- to 10-year-old technology, can make around 600 bends per hour if it is running at top speeds. A high-dynamic press brake, such as an electric brake, can make up to 900 bends per hour. That’s a significant improvement.

 

It’s important to note that the machine is bending only a certain amount of time, however, say 20 percent of the time during a shift.

 

Using a batch size of 25 as an example, you are looking at five minutes for setup; five seconds to pick and place the part; five seconds to bend; five seconds to reposition; five seconds to bend, until the part is finally put in the stack. The total production time might be 20 minutes, but the bending time is only six minutes, which is right around 30 percent of total time.

 

So what is the advantage of the high speed? It’s with the small parts. If you have a standard machine and a high-speed machine working on small parts, the high speed really has a tremendous advantage.

 

But as parts get bigger, it could take several minutes to turn and bend them. A fab shop can have a machine that is infinitely fast, but the throughput is minimized because of the extra material handling time.

 

Stroke Optimization

Stroke optimization is the next important discussion point in bending technology. A press brake can go only so fast before it starts to lose accuracy and performance quality.

 

In some European countries, the press brake can’t go beyond a certain threshold for safety reasons. The solution is to live with a fixed speed and find ways to optimize that speed and improve the number of bends per hour.

 

With the focus on stroke optimization, you will be seeing press brakes capable of up to 1,000 bends per hour without increasing the machine speeds.

 

Part Design

CAD systems, such as SolidWorks® and Pro E®, give any person the ability to draw a hole anywhere on a part—even when they shouldn’t be placing the hole there. You can tell the part designer that a hole shouldn’t be so close to the bend line, but the designer thinks that if the CAD software allows it, then it should be possible.

 

Using this example of putting a hole too close to a bend line, you can try and resolve the potential blowout with a rotating V-die set. Rotating supports in the die allow the bending process to mimic a folding operation. The result is a clean bend because the sheet metal is supported throughout the bending process. These types of tools also greatly improve the accuracy because the part is not allowed to move in the die.

 

The other solution is to solve this problem with software. Software can identify where the blowouts are going to be, and hopefully the part designer can move the hole to avoid the blowout.

 

Of course, nothing trumps experience. If the part designer has bending experience, he knows that a relief cut can be introduced to the bend line. This slit eliminates the deformation before the part hits the shop floor.

 

Automatic Tool Changing

Automatic tool changing is being found on more press brakes today, and this technology is making the biggest impact on shop floor operations.

 

The advantage is that tool changing is happening while the operator is doing other tasks. Normally the operator has to get some blanks, log in and out of a job order, take care of paperwork, set up bins around the brake, and set up support arms. While the operator is doing that, the tool changes are being done for him.

 

The hardest thing about running a press brake is the setup. Once the machine is set up, anyone can run the machine. The new controllers show inexperienced operators how to handle the part. Some of the machines today even project a video image on the ram right in front of the operator’s face, so there is no need to look to the side monitor.

 

The press brakes that have the automatic tool changing option come with different magazine styles for the tool changer. Some are located in the rear behind the backgauge. Some are located to the side of the press brake. Some are located behind the bending window, but along the side of the frame. These arrangements create different-sized footprints for the machines.

 

Automatic Angle Correction

Automatic angle correction addresses springback that occurs in certain hard-to-bend material. The value of this type of system is that you don’t lose time trying to achieve the desired angle. There is no need for repeated cycles of bending and releasing while hunting for that angle.

 

In press brakes with this type of angle correction, the ram drives the sheet metal into the die to achieve the angle in the loaded position. Whether the punch is long or short, the V die is large or small, the material is thick or thin, the loaded angle is maintained. When the ram releases and retreats, the sheet metal reverts to a rested state, with springback likely affecting a change in angle from that achieved under load. Lasers or sensors measure the current angle, and the control software determines just what sort of restrike is needed to achieve the desired angle. Typically after the restrike, the part meets customer specifications.

 

Human-Machine Interface

Modern controls have made it possible for North American fabricators to compete with cheap labor in other countries. A fab shop doesn’t need a $50-per-hour press brake operator to produce complex parts, which is good because that fabricator can’t sell those parts for $20 any longer. Today those parts go for $2 apiece. Modern controls make it so an operator with limited experience can follow the bending sequence on the monitor and produce a part with several bends in a respectable amount of time.

 

These controls also make it simple to program a job. Even though it makes more sense to put these programs together offline, away from the machine, many shops still program at the press brake. So how simple is it? The operator plugs in the parameters of the job and then drags his finger across the screen to create a profile shape. The control software takes that profile shape and produces a bend sequence to create it. The only thing left to do is assign a part number to the job. No one is figuring bend speed, bend allowance, or the correct backgauge height. When the program is generated, the operator just follows the instructions.

 

There was a time when people were required to know much more about the bending process and metal properties if they wanted to be successful press brake operators. Now a lot of that knowledge is contained in the control software. Operators just need to be engaged in completing jobs in an efficient and timely manner. That approach gets parts to the customer by deadlines and results in positive customer relationships.

 

Modern press brakes have evolved to keep up with the need for quick turnaround of parts. They are creating competitive advantages for metal fabricators that older press brakes simply can’t match.

 

If you are interested in learning more information about hydraulic press brake, I recommend that you can visit the website of Yeh Chiun Industrial Co., Ltd... It’s a professional company of specializing in press brake series. Feel free to contact them for further details you need.

 

Article Source: http://www.thefabricator.com/article/bending/understanding-modern-press-brakes

Share

Comments Off on Understanding Modern Press Brakes

No Machines Are Called Shoe Manufacturing Machines?!

Someone will need to buy shoe-manufacturing machines to make sandals, heels, and boots. However, they don’t know what they are called because running a “shoe making machine” query on Google simply isn’t working. In this article, I will tell you something about “shoe manufacturing machines”.

 

First and Foremost, There is No “shoe Making Machine” As Such.

 

Shoes are made on several machines including gluers, injection molders, sole makers, toe binders, riveters, upper stretchers, lasts, heat curing ovens, sewing machines, and more. There’s no one machine where you dump in plastic pellets, a square of leather and a buckle and a perfectly finished sandal is spit out the other end. There are lots of steps-each step requires a different machine and there’s some hand work too. Rivets are set by a worker using a riveter. Uppers are sewn by a skilled operator on a special sewing machine designed for sewing uppers. Soles are glued down and cured in a heat treater. So the machines you see are used for making shoes -even if they aren’t called “shoe manufacturing machines

 

Integral Parts of The Process in Footwear Manufacturing

 

You might want to become a bit more familiar with the tools, words and terminology and machines used in making shoes. Several fashion colleges have programs for shoe and footwear design starting with design and moving into making shoes and manufacturing processes. You will learn the way they are made and the correct words for each step in manufacturing. Speaking of words -change your search terms: you will have better luck searching for footwear manufacturing equipment and supplies. Again you will find injection molders, sewing machines, heat treaters, cement lasters, leather cutters, skivers, lasting equipment, belt solers, sanders, and band saws, welt stitchers, and more. While none are called “shoe making machines” all are integral parts of the process in footwear manufacturing.

 

To start you might want to learn custom shoemaking – this is far more doable with less investment. You can start by getting a job in a shoe repair shop and learning the equipment, how it works, what tools are essential (lasts are the most important piece of equipment and/or tool used in making shoes) what goes into making high quality shoes, and how to make and repair shoes. Or look for a custom footwear maker/seller and work there. Learning from a master is a time honored method of learning a skill. When you know what you need from seeing what the master crafts-person uses you can find the specific machinery you need.

 

Find Out The Right and Suitable Shoe Making Equipment

 

There are courses in custom footwear and shoe-making -these will help you get a handle on the tools, machinery and the process used in making higher quality footwear. Custom shoe-making can be done in an artisan workshop setting: high fashion shoes and boots made mostly by hand in small quantities can be sold for higher prices and for high profits -and with time you can start to make a name for yourself the same way people like Ferragamo and Louboutin started. Again you won’t find anything labeled “shoes making machine” but you will find lasters, stitchers and more and you will know why these machines are what you are looking for.

 

MINZ Inc. divided shoe making equipment into three parts, one is shoes cutting machine including plane type cutting machine and traveling head type cutting machine, another is cutting machine energy saving system, and the other is automation development equipment. Their average energy saving is 70~90% comparing to traditional power system. When the machine is not cutting, it generates zero noise, and the temperature of hydraulic fluid and motor are reduced half.

 

If you are interested in learning further details about related shoe making equipment, please feel free to send inquiries or contact with MINZ.

 

Article Source: https://answers.yahoo.com/question/index?qid=20130512161017AAfnama

Share

Comments Off on No Machines Are Called Shoe Manufacturing Machines?!

Why Do You Need A Recycling Baler?

One of the most useful recycling equipment designed in the recent time – Recycling balers

 

As cardboard is extensively used for packaging, a large amount it comes as waste in landfills. Recycling balers help conserve the environment by crushing the cardboard and compacting large amounts into a single are Cardboard Balers which is easy to transport. Cardboard balers are basically equipment in which cardboard is fed. The press installed within the balers helps to compress the cardboard. The compressed bales are tied off before it is released. Two types of balers are largely used – horizontal cardboard baler and vertical cardboard baler.

 

Why Cardboard Balers are rising in popularity?

 

Cardboard balers are becoming hugely popular these days as it not only helps conserve environment but also help companies save a huge amount of money. Commercial establishments that are increasingly making use of recycling balers include retail outlets, restaurants, office, convenient stores, warehouses, and pharmacies. Discussed here are some of the major advantages of a cardboard baler.

 

  • Follow rules and avoid fines

    – To conserve the environment, in many countries Governments have set up rules and regulation for companies regarding waste disposal. It is suggested that the producers of cardboard’s should be responsible for the reprocessing and recycling of cardboards. A fine is imposed on companies who fail to follow such rules. In this regard, cardboard baler helps companies abide by the rules and avoid fines.

 

  • Help economize on waste disposal

    – Through the use of recycling balers, the recyclable material is compacted significantly. Companies thereby save on the cost of hauling the recyclables. Besides, if a company does not have a recycling facility of its own and decides to sell the recyclables to a recycler, it again stands to make money.

 

  • Help reduce storage needs

    – As the cardboard’s are compacted through the use of balers, they’ll occupy less space. This means companies would not need to allocate a large amount of space for keeping the baled material. This not only helps companies economize on space, which is a valuable resource but also help safeguard the life of workers through efficient material management.

 

  • Helps reduce guilt

    – Environment is everybody’s concern. Throwing a large amount of material produces guilt in the minds of sensitive human beings. However, by making use of recycling equipment such as cardboard balers, people experience a feel good factor as they get a feeling that they too are doing their small bit towards environment conservation.

 

Godswill is the professional manufacturer of recycling equipment. They can offer baling presses machine, cardboard balers, paper baler, recycling balers, and more recycling equipment with high quality and competitive price. If you need more information about recycling balers, welcome to visit their website and feel free to contact with Godswill.

 

Article Source: http://www.norcalcompactors.net/cardboard-baler-why-do-you-need-one/

Share

Comments Off on Why Do You Need A Recycling Baler?

Coming Soon! The Grand Opening of Asia Food Expo 2017

Asia Food Expo 2017 Is Opening Soon. KWT Is Also An Exhibitor in This Grand Event.

 

The Asia Food Expo now on its 26th year showcases the most comprehensive line of food machineries and equipment for the food and beverage industry; AFEX showcases the latest top of the line packaging & food processing technologies, food marking and labeling services, material handling equipment, food storage systems, baking accessories and equipment, food services supplies & equipment, coffee machineries, confectionary machineries, process control technology, quality control technologies and solutions among other. AFEX is held in conjunction with Bakery Asia and Food Service Asia.

 

Profile for Asia Food Expo exhibit includes Adhesive Systems, Bag making, Bakery materials, Beverage processing equipment, Bottling equipment, Canning machinery, Catering equipment, Cleaning machines, Confectionery products, Cooking equipment, Dairy products, Dispensing machines, Filtration & Separation equipment, Flavors & fragrances, Food packaging equipment, Hotel equipment, Kitchen equipment, Refrigeration equipment, Water treatment equipment, Weighing equipment.

– https://10times.com/asia-food-expo

 

By the way, Taiwan local company KWT Machine Systems Co., Ltd. is also going to take participates in AFEX 2017. The company is famous for its bottle unscrambler, capping machine, filling machine, labeling machine, and induction sealing machine etc.

 

KWT also can provide high quality rinsing machine. They provide water and air cleaning systems, those are used in food filling applications to ensure food safety. The bottle rinser can utilize compressed air, wash liquid to clean dust or sanitize your containers prior to filling.

 

Don’t miss 2017’s Biggest Food Trade Show. For more information about Asia Food Expo 2017, welcome to click here: http://www.afex.com.ph

 

Details about KWT, check out here: http://www.kwt-auto.com/

 

KWT Machine Systems Co., LTD.

Booth: 41-D

Tel: +886-4-22773390

Fax: +886-4-22773412

Email: sales@kwt.com.tw

 

Share

Comments Off on Coming Soon! The Grand Opening of Asia Food Expo 2017

Basics of Rotary Die-Cutting

In today’s label production, die cutting in most cases is performed in a rotary process. Compared to flat-bed cutting, rotary cutting needs less pre-tension. The material web can be processed continuously and at high speeds. Flexible dies which are put on magnetic cylinders have been established as a standard tool. However, many factors need to be considered to create flawless die-cutting results. This article explains important basics of rotary die-cutting, which can help to prevent cutting problems.

 

Die-Cutting As The Interaction of Three Components

Label printers and converters need to produce quickly and trouble-free, in order to fulfill their customers’ high demands. Along with the printing quality, the die-cutting result is crucial for success. Very demanding customer needs, continuous developments in the material sector and time constraints – all of these factors make die-cutting a real challenge.

 

A high-quality die-cutting result principally depends on three components which must be optimally coordinated. These components are the material to be cut, the cutting unit (in rotary cutting in particular the cylinder gap), and the cutting tool. The following notes will introduce all three components in greater detail and explain their importance in successful die-cutting.

 

Rotary Die-Cutting of Labels – Label Material

First, let us take a look at the material to be cut. An infinite variety of self-adhesive labels are used in all walks of life and workplaces: food & drink, home and personal care products, medicine, pharmaceuticals, retail, office materials, logistics, automotive industry and industrial chemicals – to name just a few. The great variety of applications is a result of the multi-layered structure of the materials.

 

In the die-cutting process the face material is compressed by the tool’s cutting edge until it bursts. The silicone layer and the backing material should remain undamaged. This kind of cutting is referred to as “kiss-cutting”, and is the main application for self-adhesive label stock. It is also possible to completely cut through the whole material including the liner, for example in the production of perforations (also called “metal-to-metal” cutting).

 

Material Influences on The Cutting Process

The properties of the material have a considerable influence on the optimum design of the cutting tool: In rotary cutting, the thickness and properties of the liner material along with the gap determine the height of the cutting lines. Sometimes multi-layered materials are also used which require various heights in one tool. The cutting edge geometry (cutting angle, bevel etc.) is adjusted depending on the hardness and compressibility of the material.

 

Some materials (e.g. thermal papers) are very abrasive and lead to rapid wear of the cutting tool, which in such cases should be provided with a special coating or are laser hardened.

 

Optimal Cutting Results with Regard to Labels

In the cutting process the question is not only to detach the face material cleanly; detaching the adhesive layer is equally important so as to achieve optimum matrix stripping. The silicone layer and the liner material must remain undamaged, however. Cutting into the liner is classed as quality defects which can lead to problems in further processing of the labels (e.g. in dispensing machines). Moreover, no adhesive should leak from the sides of the labels. If the layers in the label roll stick to each other, considerable malfunctions can arise in the dispensing of the labels.

 

Apart from visual checking for obvious defects with regard to the dimensions and quality of the outer contours, what is known as an “ink test” is often used in practice to discover any damage to the silicone layer and the liner material. After stripping the matrix and detaching the labels, ink is applied to the liner and evenly rubbed in with a cloth. If the cutting has gone too deep, clear outlines will now appear. The ink test is not suitable for filmic layers, as they are not able to absorb ink. For these materials (like PET), penetration may only be discovered by light reflections from the liner.

 

Die-Cutting Unit and Gap

In rotary cutting, the material to be cut is passed through the cutting tool and the anvil cylinder in the die-cutting unit. The cylinders and the material web run at the same speed. For a high-quality cutting result, components of the cutting unit must be in perfect condition. The gap is of particular importance in rotary label cutting. To adjust the height of a flexible die perfectly to the material to be cut, the gap must be stated exactly. In Europe a standard gap of 0.480 mm (480 μm) is usual, while in North America 483 μm is common. Wear on the bearer rings and changes in the cylinders can cause the gap to vary considerably in the course of time, so that a satisfactory cutting result may no longer be achievable.

 

Deviations of ± 2 μm from the standard normally have no negative effects on the cutting result. If the gap is considerably smaller, however, the insufficient distance between the cylinders causes over-heavy cutting. Causes may be worn bearer rings or a fatigued anvil cylinder. If the gap on the other hand is considerably greater than the standard, the gap between the cylinders becomes too great and the cutting result is therefore too light. To compensate for this, a very high cutting pressure must be set; however, this puts a strain on bearer rings and bearings. If the gap varies over the width of the cylinder, the cylinders may be running out of true. There are also often combinations such as an insufficient gap on the drive side at the same time as an excessive gap on the operating side.

 

The gap and all components of the cutting unit should be checked regularly and measured to guarantee trouble-free die-cutting. Some tool manufacturers offer free gap measurements and also provide professional equipment for this task.

 

Pretension and Cutting Pressure

Along with the cylinder gap, the amount of the initial pressure (“pretension” or “preload”) in the cutting machine is critical for successful and precise cutting. The pretension needs to be greater than the resulting resistance of the material, which is mainly caused by the transversal lines. Another important factor in the cutting process is heat generation. This is caused by friction between the magnetic cylinder and the anvil cylinder during machine operation. The pressure in the cutting machine increases continuously due to this heat generation. This can lead to the cutting edges penetrating too deeply into the material and damaging the liner and wear is increased on all components involved.

 

For efficient die-cut processing, the use of a pressure control system can be very helpful. Such systems facilitate the adjustment and control of the cutting pressure. The cutting pressure can be evenly adjusted on both sides of the cylinder by means of pressure cells. If the cylinder generates too much pressure due to thermal expansion, this can be read immediately on the cell’s display.

 

Magnetic and Anvil Cylinders

The cylinders in the cutting unit are the basis for perfect die-cutting results. Magnetic and anvil cylinders must be manufactured to the highest accuracy. The manufacturing tolerances and concentricity should be only a few microns, otherwise even the most precise flexible die will not function properly. In addition, a sufficient width-circumference-ratio of the cylinder needs to be observed.

 

If rotary cylinders are sized incorrectly, there is a danger of bending. This applies especially to systems with no bridge and non-supported anvil cylinders. Dynamic forces in the cutting of transversal lines can deform cylinders. As a consequence, the cutting in the middle of the web becomes too light. A rule of thumb for magnetic and anvil cylinders is: The circumference should be at least as great as the maximum working width of the cylinder.

 

However, the cylinders must not only be very accurate and stable, but should at all times be in a perfectly clean condition. When cleaning magnetic cylinders the use of the right cleaning materials should be strictly adhered to. Some chemicals can attack the adhesive of the magnets, so that the cylinder starts to “bleed”, i.e. adhesive is exuded from the magnets, thus having a negative influence on the cutting result. For the prevention of “bleeding”, one should only use a cleaner which is recommended by a manufacturer, and the cylinders should be oiled with corrosion protection products after use.

 

The Die-Cutting Tool

Various die-cutting tools are used depending on the application, material and machine type or cutting unit. In order for the tool to be perfectly adapted for the desired purpose, all relevant parameters must be provided with the order.

 

Thanks to their many advantages, flexible dies in combination with magnetic cylinders have been established as standard in the label business. Flexible dies are not only relatively cost effective, but also shorten the set-up time at job changes, are easily replaced and their storing saves space. In order to guarantee manufacturing tolerances of a few microns, state-of-the-art CNC technology is used. The tool manufacturers offer flexible dies in various qualities and finishing options that are recommended for various applications, depending on the provider.

 

Often laser hardening is applied, which gives the cutting tip a particular stability and is therefore predestined for cutting through filmic materials in long runs. Special coatings (e.g., with nickel or chromium) protect the cutting lines from wear from abrasive materials and allow long lifetimes. Various non-stick coatings can be used against ink and adhesives residue, so that residues on the cutting edge and die surface are minimized.

 

On the other hand, solid dies (cutting cylinders) are still the first choice for some applications, e.g. when particularly voluminous materials are processed or punched parts need to be extracted. As a variant of the cutting cylinder, sheeting and slitting cylinders are equipped with interchangeable knives, which are used for tear-off or folding perforations, and other applications.

 

In contrast to flexible dies, solid dies offer the advantage that they can be repeatedly reworked and resharpened. However, solid dies are considerably more time and cost intensive to manufacture than flexible dies. Moreover, unlike with flexible dies it is not possible to undertake subsequent corrections by turning, shifting or under laying the tool.

 

Solutions for Cutting Problem

When cutting problems occur, the cause can usually be ascribed to one of the following three components. Therefore, it always makes sense to check the following points first:

 

  • Which material has been cut?

(Type and composition of the material, thickness of the liner, desired application: kiss-cutting and/or cutting-through)

  • Are cutting unit and cylinders in a flawless condition?

(Contaminants, wear, stability pretension / cutting pressure, size of gap, sufficient width-circumference ratio)

  • Is the cutting tool okay?

(Contaminants, wear, production errors)

 

In this context, the operator should always recheck the order details. A flexible die can only be manufactured perfectly, if all relevant material and machine specifications are delivered exactly and completely, along with the measurements of the labels.

 

If you are looking for ideal die cut machine, please don’t miss the website of Smooth Machinery Co., Ltd.. They are the professional flat-bed printing machine and semi-rotary machine supplier in Taiwan. Welcome to check out their product pages to obtain further details about die cut machine series. Feel free to send inquiry or contact with Smooth Machinery.

 

Article Source: http://narrowwebtech.com/dossiers/basics-of-rotary-die-cutting/

Share

Comments Off on Basics of Rotary Die-Cutting

What Are The Disadvantages of Fabric Dyeing?

Do you know how the colored fabrics get the attractive colors and in different shades? Mostly, the coloration of the greige fabrics is done in the dyeing process. I have explained different types of fabric dyeing processes in a separate article. In this post, I will show you various disadvantages of the fabric dyeing.

 

Disadvantages of Fabric Dyeing

Among the many drawbacks of fabric dyeing, the following are important.

 

Variation of shade from beginning till the end along the running length of the fabrics, thus resulting in tailing. This creates a greater number of shade lots resulting in more of color groups among the garments.

 

Variation of shade from one selvedge to the other, resulting in increasing the consumption and wastage of fabrics per meter while conversion to garments.

 

Below satisfactory packaging efficiency, below 80% in most of the mills, due to the above problems, which are just two out of the innumerable ones generated in fabric dyeing.

 

Although the cost is apparently lower in fabric dyeing, the lower packing efficiency and the higher number of reprocessing practically shoots up the fabric cost. Also, reprocessing in most cases is based on trial and error without a surety of getting the desired results.

 

What replaced fabric dyeing?

 

To overcome the drawbacks of fabric dyeing as well as to add value to the fabrics, yarn dyeing was introduced as an alternative. The advantages of yarn dyeing are:

 

Checks and stripes could be made easily which was difficult earlier. They added to the varieties of fabrics that could be made.

 

Dyeing a yarn was easier with the machines involved smaller in size and volume.

 

Reprocessing was easier with predictable results.

 

Fabric defects generated due to yarn dyeing was lesser as compared to fabric dyeing.

 

Although process cost is higher in a case of yarn dyeing as compared to fabric dyeing, the lower reprocessing rate and lesser fabric defects generated keep the fabric cost in control with more of varieties.

 

Yarn dyeing is however not a new innovation altogether; it was in fact extensively used for the purposes of surface designs, embroidery, and handcrafted textiles. The bulk operation of the same gathered momentum after fabric dyeing could not be improved beyond a certain limit in terms of efficiency.

 

 

Article Source: http://www.onlineclothingstudy.com/2017/07/disadvantages-of-fabric-dyeing.html

Share

Comments Off on What Are The Disadvantages of Fabric Dyeing?

Guide On How To Buy A Laser Cutting Machine

A laser cutting machine is a machine that uses laser lights to cut through different materials such as metal, wood, textiles, acrylic among many others. When it comes to metal cutting, you can use it to cut different types of metals such as stainless steel, steel, and aluminum.

 

Laser cutting is preferred by many people as its accuracy, has a very small kerf width, yields excellent cut quality, and has a small heat effect zone.

 

For you to buy the right machine you need to consider a number of factors:

 

Function

 

How will you be using the machine? You can use the cutting machine for two main functions: cutting and engraving. As mentioned, you can use it on different materials. The materials have different specifications; therefore, before you head to the stores you should decide on how you will use your machine.

 

Bed size

 

The bed size of the machine determines the amount of work you can do. The bed size varies from A3 to A1 where the bigger the size, the more the work that your machine can handle. The bed size is a permanent feature; therefore, you can’t change it in the future.

 

The decision should be based on the amount of work that you are planning of handling. For example, if you are planning of handling large projects you should go for a machine with a large bed.

 

Optic quality

 

The quality of the optics is the one that determines how well the machine performs. Many unknowledgeable people think that the wattage is the one that determines how effective the machine works, but this isn’t true.

 

When making the purchase you shouldn’t bother with the amount of power that the machine consumes-you should concentrate on the quality of the optics.

 

To determine the quality of the optics you should ask the seller to demonstrate how the machine works on different materials and settings.

 

Ease of use

 

If you are a new buyer you most likely don’t know how to use the laser cutting machine. A good machine should come with an easy-to-follow manual. The manual should not only show you how to use the machine, but also how to undertake minor repairs.

 

Conclusion

 

These are tips on how to buy the right laser cutting machine. Although, the machine is designed to cut different materials, you should avoid cutting plastic with it as plastic tends to give off chlorine gas which is harmful when you breathe it.

 

As a reputable manufacturer with over 35 years of experience, Tailift offers to our clients a wide range of Laser Cutting Machines. Their Laser Cutters are designed for a wide range of metal working applications. Learn more information about laser cutting machines, welcome to contact with Tailift right away.

 

 

 

Article Source: http://EzineArticles.com/9274665

Share

Comments Off on Guide On How To Buy A Laser Cutting Machine

Overview and Applications of Swing Arm Cutting Machines

Swing Arm Cutting Machine

For a highly efficient production in all kind of industries: Swing Arm Cutting Machine for Automotive Suppliers and Swing Arm Cutting Machines for saddlery.

 

A swing arm cutting machine is a highly efficient machine for the cutting of small parts in small and mean lot sizes. Swing arm cutting machines are highly efficient in all sizes of production.

 

It applies in almost all application areas and you can find it in almost all industries from small saddlery up to great automotive suppliers.

 

This type is also used as a further machine for the working of residual materials and in the lab.

 

Hydraulic Swing Arm Cutting Machine

Different cutting methods e.g. Laser Cutting, Water Jet Cutting or Cutters with oscillating dies, our Swing Arm Cutting Machines requires a Cutting Die with complete contour of the cut part.

 

Advantages of this cutting method are the complete and repeat accuracy cutting of a part in a reproducible work step. This means, that the accuracy of the cut parts are defined by the cutting die and will not be influenced by external causes.

 

Especially in middle and higher production volumes, the costs incurred in a cutting machine by cutting tools and cutting plates are lower than comparable cutting technologies.

 

Swing arm cutting machine also can be found in MINZ Inc. However, this cutting machine in MINZ is used for another application – shoe cutting. MINZ divided shoe manufacturing machines into three parts, one is shoes cutting machine including plane type cutting machine, traveling head type cutting machine, and swing arm cutting machine, another is cutting machine energy saving system, and the other is automation development equipment. Their average energy saving is 70~90% comparing to traditional power system. When the machine is not cutting, it generates zero noise, and the temperature of hydraulic fluid and motor are reduced half.

 

If you are interested in learning more information about MINZ’s shoe cutting machines, welcome to visit their website and feel free to contact with MINZ Inc.

 

 

Article Source: https://www.techco.de/swing-arm-cutting-machines/

Share

Comments Off on Overview and Applications of Swing Arm Cutting Machines

Introduction about Types of Milling Machine

The usual classification according to the general design of the milling machines is as follows:

 

Column and Knee Type Milling Machine

For general workshop the most commonly used is the column and knee type. These machines have a single spindle only. They derive their name “Column and Knee” type from the fact that the work table is supported on a knee like casting which can slide in a vertical direction along a vertical column. The up and down movement of the table can accommodate work of various heights.

 

Plain Milling Machine

These machines are of the column and knee type and consist of a rigid frame or box structure. It consists of a table, a saddle and a knee. This gives three straight-line movements perpendicular to each other. The arbor is fixed in position, and the tool rotates while the work is fed past the cutter in a straight line. It is a useful machine for manufacturing operation involving simple, straight line cut.

 

Universal Milling Machine

A universal milling machine is so named because it may be adapted to a very wide range of milling operation. A universal milling machine can be distinguished from a plain milling machine that the table of a universal milling is mounted on a circular swiveling base which has degree graduations and the table can be swiveled to any angle up to 450 on either side of the normal position. This is advantageous when milling spirals. Thus in a universal milling machine in addition to three movement as incorporated in a plain milling machine, the table may have a fourth movement when it is fed at an angle to the milling cutter.

 

Omniversal Milling Machine

In this machine, the table having all the movements of a universal milling machine, and can be tilted in a vertical plane by providing a swing arrangement at the knee. The entire knee assembly is mounted in such a way that it may be fed in longitudinal direction horizontally. The additional swiveling arrangement of the table enables it to machine taper spiral grooved in reamers, bevel gears etc. it is essentially a tool room and experimental shop machine.

 

Vertical Milling Machine

There are two types of vertical spindle milling machines. Fixed Bed Type VS Column and Knee Type. A vertical milling machine can be distinguished from a horizontal milling machine by the position of its spindle, which is vertical or perpendicular to the work table. The machine may be a plain or universal type and has all the movements of the table for proper setting and feeding the work. The spindle head which is clamped to the vertical column may be swiveled at an angle, permitting the milling cutter mounted on the spindle to work on angular surfaces. In some machine the spindle can be adjusted up or down relative to the work.

 

Manufacturing or Bed Type Milling Machine

  • Horizontal Simplex Milling Machine:

These types of machines are production type machines and are of rigid structure which yields high production of interchangeable jobs. It has got one spindle head.

 

  • Horizontal Duplex Milling Machine:

Milling machines using the two spindles. For finishing two surfaces of casting at a time.

 

  • Triplex Milling Machine:

Milling machines using the three spindles, two horizontal and one vertical for finishing three surfaces of casting at a time.

 

Planner type Milling Machine

They are used for heavy work. Upto a maximum of four tool heads can be mounted over it, which can be adjusted vertically and traverse directions. It has a robust and constructions like a planer.

 

Special type Milling Machine

  • Continuous Feed Rotary Milling Machine:

The construction of the machine is a modification of a vertical milling machine and adapted for machining flat surfaces at production rate. The face milling cutters are mounted on two or more vertical spindles and a number of work pieces are clamped on the horizontal surface of a circular table which rotates about vertical axis. The cutters may be set at different heights relative to the work so that when one of the cutters is roughing the pieces the other is finishing them. Operator may carry out a continuous loading and unloading of the work pieces, while the milling is in progress.

 

  • Drum Type Milling Machine:

The drum type milling machine is similar to rotary table milling machine in that its work supporting table which is called a drum, rotates in a horizontal axis. The cutters are face mills and are usually roughing and finishing cutters similar to those of a rotary table miller. Fixture is mounted to the drum either on each face or on the periphery. When the work is mounted on the periphery, the operation is usually facing the two ends of the work piece to the precise length. The finished machined parts are removed after one complete turn of the drum and then new ones are mounted on it.

 

Top-One Machinery Co., Ltd. is a professional milling machine manufacturer in Taiwan. You can find out bed type milling machine, universal milling machine, vertical turret milling machine, and so on machinery on our website. If you want to obtain more information about Top-One’s milling machines, please don’t hesitate to contact with us!

 

http://www.qhunt.com/2015/10/types-of-milling-machine.html

Share

Comments Off on Introduction about Types of Milling Machine

The Basics of High Speed EDM Hole Drilling

This article discusses how EDM hold drilling – designed for fast, accurate small- and deep-hole drilling applications – has become a whole new method of manufacturing molds and parts.

 

High speed EDM hole drilling was designed especially for fast, accurate small- and deep-hole drilling applications. Small holes that were once almost impossible to drill by conventional machine tools are now being performed with ease. With the capability of drilling through virtually any conductive material, the use of this technology is continually expanding.

 

Initially shops were using this technology specifically for start holes in wire EDM jobs. Because of this technology, workpiece materials are being sent out for heat treating prior to drilling the start hole. This removed two problems: (1) having to program, locate and drill the start hole by conventional machine methods in the “soft” workpiece prior to heat treat and (2) by sending the workpiece for heat treat before drilling the start hole, all the stresses were being removed from the workpiece prior to the EDM process being applied. As this process became more widely known, test burns were being done in more than just hardened tool steel; tungsten carbide, aluminum, brass and inconel were being tested. High-speed EDM hole drilling applications began to expand to mold and part manufacturing-injection nozzles, oil drain holes, hydraulic cylinders and dowel pins, as well as turbine blades, ball bearings and safety wire holes in hex nuts, to name a few.

 

Basic Features of the EDM Hole Driller Machine

  • Stainless steel work table
  • Rotating spindle
  • Drill chuck or collet system for holding electrodes
  • Ceramic or diamond guides
  • Power supply with control panel
  • Capacitor box
  • Dielectric fluid pump

 

The EDM Drilling Process

The process consists of using a precision tubular electrode (generally brass or copper) mounted into the drill chuck located on the “Z” axis and held in location on top of the workpiece by the ceramic guide. The top of the workpiece is located and the drilling depth is set. The electrode rotation is turned on and the deionized water solution, which is pressurized between 50 and 100 kg/cm2, is sent through the tubular electrode as a flushing agent. The power supply parameters are set-which normally consist of on-time, off-time, peak current and amount of capacitance. At this point, the discharge is turned on to begin the drilling cycle. At the end of the drilling cycle, the discharge is turned off and the “Z” axis is retracted above the workpiece.

 

Drilling Times

Drilling times are based on the hole size and type of material. Chart I lists a few samples for reference.

 

Chart I

Material Electrode Dia. Drill Depth Machining Time
Alloy Tool Steel .020″ 0.50″ 25 to 35 seconds
1.00″ 50 to 60 seconds
.040″ 1.00″ 55 to 65 seconds
Tungsten Carbide .020″ 0.50″ 4 to 5 minutes
1.00″ 8 to 9 minutes
Aluminum .020″ 0.50″ 40 to 50 seconds
1.00″ 90 to 100 seconds
.040″ 2.75″ 3 minutes

 

Observing the aforementioned times explains why high-speed EDM hole drilling has become an alternate method to conventional machining in mold manufacturing. In addition, this method of drilling produces burr-free holes, which results in the elimination of secondary deburring processes. Larger power supplies and drill/collet chucks have expanded the diameter range of standard drilled hole sizes from .010″ to .118″ to .010″ to .236″. EDM hole drilling can now be done on a manual, ZNC or CNC machine.

 

Today, many of the machines use distilled water as the flushing agent, which opens up new application possibilities in the medical field. With continued improvement in this technology, more and more applications are being seen on the horizon – EDM hole drilling has become a whole new method of manufacturing molds and parts.

 

If you need more information about drilling machine manufacturers or hole drilling, try to visit the website of EXCETEK, you’ll find what you need.

 

Article Source: http://www.moldmakingtechnology.com/articles/the-basics-of-high-speed-edm-hole-drilling

Share

Comments Off on The Basics of High Speed EDM Hole Drilling