Injection Molding Process

April 22, 2018/0 Comments/in China mold company, china plastic injection molding, chinese mold, Custom Molds, injection mold, Injection Mold China, injection molding, injection mould china, injection moulding, molding plastic, mould making, plastic molds, plastic mould/by admin

Injection Molding Process

The thought of processing PEEK (polyetheretherketone) or other high-temp resins can send nervous tremors through many a molder’s body. I know, as a molder who learned the craft on a steady diet of PP and PE closures with their low melt temperatures and cold a plastic molds, my first PEEK experience made me edgy to say the least. But I’ve since come to realize that PEEK is just another thermoplastic resin and, like the others, can be molded safely and efficiently with just a few precautions.

PEEK is widely believed to be one of the highest performing thermoplastics on the market and its end properties more than justify any trials and tribulations you may encounter processing it. PEEK is a linear aromatic, semi-crystalline thermoplastic having excellent wear, chemical and hydrolysis resistance. It has very low flame/smoke toxicity and excellent electrical properties that preclude the need for additives in many cases.

PEEK processes at a high melt temperature nearing 720°F, and both the press barrel and controls must be capable of this. On many plastic molding machines the high heat software is an option and I recommend ceramic high-temp heat bands whenever possible. A special screw and barrel are generally not needed, but consider hard units if running filled PEEK resins. We typically use sliding ring non-return valves, GP or Eliminator™ tips and don’t recommend ball checks or shutoff nozzles.

A hot mold is the key to achieving crystallinity in PEEK parts. Purging PEEK allows you to see the color change from a translucent to a solid colored crystalline state. If the mold is too “cold” (i.e. not hot enough) the parts will have that discoloration or partial translucency, and the quality of the end product will be compromised. The mold, in most cases, must be between 350°F and 450°F. This is steel temperature and requires oil or cartridge heat to maintain this level. Complex parts may require better temperature control so oil would be the preferred option. We also recommend the use of thermocouples to verify and monitor the steel temperature.

These plastic molds must be specifically designed to run high-temp materials with draft, finish, undercuts and steel types all factored in from the beginning. Insulator plates between press platen and mold clamp plates are a must. The preferred steel type would depend on whether or not the resin uses any abrasive fillers but should have a minimum hardness of 52-54 Rc.

The resin also must be very dry to process well and achieve the desired end properties. This means that the resin must be at 0.02% moisture or below. We typically recommend drying the resin at 300°F for at least 3 hours. We also suggest the use of a moisture analyzer to assure dryness.

PEEK can be quite costly, but you should be able to use 30% dry first-pass regrind with unfilled PEEK and 10% with filled PEEK.

Safety should be a primary consideration when molding PEEK, both for purging and while working with the mold. Wear safety glasses and/or a face shield, Kevlar or Kevlar/stainless steel sleeves, and heavy cotton cloves when purging and reaching into the mold.

When preparing for your PEEK experience, research it well with your resin supplier. The above information is based on my experience, but it should used as a reference only. Also, make sure you don’t neglect recognized scientific principles when working with any thermoplastic material. With a bit of common molding sense, your PEEK experience can and should be a rewarding one. click here to get more detail about plastic molds and plastic molding technology.

Injection Molds

April 22, 2018/0 Comments/in China mold company, china plastic injection molding, chinese mold, Custom Molds, injection mold, molding plastic, mould making, plastic components, plastic injection molding, plastic mold, plastic molding/by admin

Injection Molds

The world has become very dependent upon plastic products. From household items to industry and aerospace, plastic in its many formulations has transformed modern manufacturing and created conveniences and economies unimagined in the early decades of the 20th century.

Injection Molds
The injection moulding industry took hold in 1946 when James Hendry built a screw injection molding machine. But, his technology was based on an earlier invention by John Wesley Hyatt who, in 1868 injected hot celluloid into a mold to make billiard balls. Hyatt’s method used a plunger to force the ma

Plastic molds

terial inside a mold. Hendry’s improvement was revolutionary because it eliminated the plunger and replaced it with an auger-type action that better distributed material and facilitated the use of plastic inside molds.

Today’s plastic molds use much the same process and produce a wide variety of products from car panels to outdoor furniture, small toys and tools. Injection molding is ubiquitous in manufacturing and uses many different materials from polymer plastics to aluminum, copper and other metals. The plastic bottles and kitchen implements people use in everyday life are products of the injection process.

Because the metal molds are generally expensive to produce, Plastic molding is most economically used when thousands of pieces are being manufactured. Molds are made of hardened steel or, more recently, aluminum which is less expensive.

The Injection Process
Described very simply, molten plastic is injected into the mold under high heat and pressure. The goal is to have the molten plastic material evenly flow to all parts of the mold, creating an exact, consistent, solid plastic replica of the mold cavity. After a brief cooling cycle, the mold or tooling mechanically ejects the plastic part which then moves on through the manufacturing process. In the injection molding industry, this is a completely automated process that’s very fast and extremely efficient.

Rotational Molding
Rotational molding is yet another method of producing multiple products, most often made with a variety of plastic powders. This process is usually used in making hollow products such as traffic cones, canoes, kayaks, bicycle helmets and giant tanks used for water or chemical storage.

Like Injection molding, rotational molding had its roots in the 1940s. But it was not until the technology was more sophisticated and new polymer and plastic formulations became available that the rotational process became a mainstream manufacturing method.

Rotational Process
The two processes are quite different. Let’s consider, for example, a 300 gallon water storage tank made of polyethylene. Picture a master mold made of aluminum or steel. The plastics manufacturer pours poly resin powder into the mold that is fitted inside an oven. Once sealed, the mold is mechanically turned on at least three axes, moving much like a gyroscope. At the same time, the oven is raised to an appropriate temperature and the polymer – or other material – tumbles inside and slowly coats the inner walls of the mold, melting as it rotates.

Plastic mold

Once the optimal temperature is reached, the mold is cooled. As the temperature of the mold itself falls, the product on the inside shrinks away from the inner walls and is easily removed. This is not always the case with injection molds that are often more difficult to successfully remove. The shrinking action of rotational molding is particularly desirable when the product is very large and awkward to handle.

Rotational molding is also more economical for some products because less material is used. In addition, the polymer that is left over from one mold can be used in another. The method itself is more streamlined than injection molding, which requires more interlocking parts.

Materials Improve and Expand
Most products made with the rotational molding method are from the polyethylene family. Other materials include nylons, polypropylene and PVC plastics. Some manufacturers have developed formulas that integrate the use of natural materials such as sand and chips of stone to make products.

Plastic and resin products are now an integral part of everyday life and supply us with items as tiny as paper clips and as big as storage tanks. As the industry developed, so too has environmental awareness about the safety and use of these petrochemical-based products. Today, materials can meet the specifications of FDA requirements, and other health and safety related regulations. Producers are also cooperating to create products that can be recycled.

Injection Molding Machines

April 22, 2018/0 Comments/in China mold company, china plastic injection molding, chinese mold, Custom Molds, injection mold, plastic components, plastic injection molding, plastic mold/by admin

Injection Molding Machines

The injection molding process was invented in 1872. Since then, the injection molding business and the plastic industry has ballooned into a multi billion dollar business venture. In fact, thirty two percent of plastics by weight are processed through injection molding. Injection molding has greatly helped in making the US economy boom because through it, cheap and durable consumer and industrial items essential to almost all industries is made possible.

Components of the injection molding machine

The injection molding machine converts granular or pelleted raw plastic into final molded parts through the use of a melt, inject, pack and cool cycle for thermoplastics.

A basic injection molding machine is typically composed of the following: injection system, hydraulic system, mold system, clamping system and control system. The clamping tonnage and shot size are both used in identifying the dimensions of the injection molding machine for thermoplastics, which is the main factor in the whole process. Other consideration include rate of injection, pressure, design of screw, thickness of the mold and distance between tie bars.

Functions of the machine

The injection molding machine can be classified into three categories, namely: general purpose machines, precision/tight-tolerance machines and high-speed thin-wall machines. All three types require auxiliary equipment to function. These support equipment includes dryers (resin), material handling equipment, granulators, mold temperature controllers and chillers, part-handling equipment and part-removal robots.

There are a lot of companies specializing in quality plastic molding, but they are not all the same. The best ones fast, flexible and customer driven both for large and small quantities. These companies usually have state-of-the-art facility with full scale thermoplastic and thermoset capabilities, computer-aided manufacturing, skilled machine operators and quality assurance team. Injection Molding provides detailed information on Injection Molding, Plastic Injection Molding, Injection Molding Machines, Custom Injection Molding and more.

Plastic Mold

April 22, 2018/4 Comments/in China mold company, china plastic injection molding, chinese mold, Custom Molds, injection mold, Injection Mold China, injection molding, injection mould china, injection moulding, molding plastic, mould making, plastic components, plastic injection molding, plastic mold, plastic molding, plastic molds, plastic mould, plastic parts, plastic products/by admin

Plastic Mold

Plastic has, quite literally, become the cornerstone of our society. We make so many things from plastic that it is hard to imagine what our lives would be like if it was never invented. With so many of our everyday products being made of plastic, it is easy to understand why plastic injection molding is such a huge industry.

Approximately 30% of all plastic products are produced using an injection molding process. Of this 30%, a large amount of these products are produced by using custom Plastic Mold technology & injection molding technology. Six steps are involved in the injection molding process, after the prototype has been made and approved.

The first step to the injection molding process is the clamping of the injection mould. This clamping unit is one of three standard parts of the injection machine. They are the mold, the clamping unit and the injection unit. The clamp is what actually holds the mold while the melted plastic is being injected, the mold is held under pressure while the injected plastic is cooling.

Next is the actual injection of the melted plastic. The plastic usually begins this process as pellets that are put into a large hopper. The pellets are then fed to a cylinder; here they are heated until they become molten plastic that is easily forced into the mold. The plastic stays in the plastic mold, where it is being clamped under pressure until it cools.

The next couple of steps consist of the dwelling phase, which is basically making sure that all of the cavities of the mold are filled with the melted plastic. After the dwelling phase, the cooling process begins and continues until the plastic becomes solid inside the form. Finally, the mold is opened and the newly formed plastic part is ejected from its mold. The part is cleaned of any extra plastic from the mold.

As with any process, there are advantages and disadvantages associated with plastic injection molding. The advantages outweigh the disadvantages for most companies; they include being able to keep up high levels of production, being able to replicate a high tolerance level in the products being produced, and lower costs for labor as the bulk of the work is done by machine. Plastic injection molding also has the added benefit of lower scrap costs because the mold is so precisely made.

However, the disadvantages can be a deal breaker for smaller companies that would like to utilize plastic injection molding as a way to produce parts. These disadvantages are, that they equipment needed is expensive, therefore, increasing operating costs.

Thankfully, for these smaller companies, there are businesses that specialize in custom plastic injection molding. They will make a mock up mold to the exact specifications, run it through the complete process and present the completed piece along with an estimate to complete the job to the customer.

Linda Moore writes on a variety of subjects including home ownership, travel, personal enrichment,

Injection Molding

April 22, 2018/1 Comment/in China mold company, china plastic injection molding, chinese mold, Custom Molds, injection mold, Injection Mold China, injection molding, injection molding parts, injection mould china, injection moulding, molding plastic, mould making, plastic components, plastic injection molding, plastic mold, plastic molding, plastic molds, plastic mould, plastic parts, plastic products/by admin

Non stick coatings for injection molding Parts?

Yes! Just recognize the difference between ‘lubrication’ and ‘release’ and you need never fail again.

Today, there are a number of hard coatings for you, the mold maker, to choose. Many are conformal in nature and replicate surface geometry and finish. Many, too, resist thermal oxidation and can wear well. But what about release? You know, actual non-stick properties, like an egg cooked in a fry pan?

The answer for injection molding is not lubrication. And here is why.

Lubrication is defined as a means to reduce friction or wear. That is true. But it is meant to be a substance between two bodies in relative motion, a load bearing interface between two solid, cohesive surfaces. And that is not what you find when you heat the mold surface above your material glass transition temperature (Tg). Which is why hard coatings designed exclusively for lubrication fail.

Injection molding

Depending on the compounds you are molding, ‘sticking’ failures can manifest in a number of ways: skinning, loss of polymer mobility, lower gloss and surface roughness. Hard coatings ‘with lubrication’ can negatively affect heating and cooling which, alone, can alter depth and visibility of weld lines.

On the other hand, hard coatings for non stick can make significant improvements to finish. Surface flaws can be eliminated. And that means no more painting. Structural imperfections, too, like molded in stresses, which lead to warping or distortion, can be a thing of the past.

Unfortunately, Plastic mold makers who have had negative coating experiences are reluctant to re-consider. No different than those currently experiencing satisfactory but marginal performance. Why change, they say. Especially when you believe you have tried or know about all the coatings available, today, like plating, Teflon or PTFE, PVD or PACVD.

So, where is your answer? Just ask around. You will not have to look far. The answer, you will discover, is with those who understand surface forces, the characterization of adhesion, non stick coatings for injection molding parts.

Want more information? Need help with your surface engineering?

William Gunnar, a degreed scientist, researcher, engineer, and friend, has helped thousands of ‘best of class’ product designers and equipment manufacturers — for nearly 20 years now — surface engineer with coatings for success.

His publication, brings wisdom, honesty, leading edge information, and no nonsense advice to thousands weekly. Put together by some of the world’s leading experts in coatings and manufacturing, his FREE newsletters are truly must-reads for those who want to be ‘in-the-know’.

Custom Injection Molding

If your business needs plastic molding products with specific types and dimensions, then you should turn to custom injection molding companies. These manufacturers have the ability to make plastic parts for specific applications – they can customize virtually all plastic components per your requirements. They can stamp your logo or messages, produce unique colors and designs and package them specifically based on what you want and need.

Choosing a custom injection molding company

Most of the custom injection molding companies can produce any plastic product you specify, but not all of them go the extra mile to take care of ‘finishing services’ such as decorating, assembly, labeling and packaging. Some even have a design group that can assist clients with plastic part and mold design. From rapid prototyping and tooling to injection molding, ultrasonic and plastic welding and stamping, these companies can assist you every step of the way. Go for manufacturers that offer these added perks – you will end up saving time, money and effort.

Custom Injection molding

Note that some custom injection molding companies do not do these extras in-house – they hire sub-assemblers and finishers, but are still able to produce products at par with your standards.

Also examine the manufacturing company’s logistics and scheduling system. They should be able to handle your delivery needs no matter how demanding they may be. You should also go for companies that implement strict controls to monitor the whole custom injection molding process. They should have the latest inspection equipment at hand to allow them to match the closest tolerance and thus provide quality consistently.

The custom injection molding company’s plant climate is also very important. They should have facilities that ensure mold cooling system control. You may contact any companies in the internet directory for your custom injection molding needs. injection Molding provides detailed information on Plastic Molds, Injection Molding, Plastic Injection Molding, Injection Molding Machines, Custom Injection Molding and more.

What Is Plastic Molding

April 22, 2018/2 Comments/in China mold company, china plastic injection molding, chinese mold, Custom Molds, injection mold, Injection Mold China, injection molding, injection mould china, injection moulding, molding plastic, mould making, plastic components, plastic injection molding, plastic mold, plastic molding, plastic molds, plastic mould, plastic parts, plastic products/by admin

What Is Plastic Molding

Plastics are synthetically produced non-metallic compounds. It can be molded into various forms and hardened for commercial use. Plastic molding products can be seen everywhere. Examples are jars, protective caps, plastic tubes, grips, toys, bottles, cases, accessories, kitchen utensils and a lot more.

Even the keyboard and the mouse that you use are made through plastic molding. Even the plastic parts of the chair that you are sitting on are created this way.

The basic idea in plastic molding is inserting molten liquid plastic into a ready shaped mold, for example the mold of a bottle. It will be then allowed to cool, then the mold will be removed to reveal the plastic bottle.

Plastic molding

Plastic moulding can also custom-mold a wide variety of plastic products including: garden pots, cabinets, office trays and boxes, barriers, barricades and traffic signage and displays for product and marketing promotions.

If you are planning to go into plastic molding business, you should first know the different processes. Choose from a plastic molding process that fits your budget, your expertise, and your resources. Here are basic definitions of various methods of plastic molding.

The Plastic Molding Processes:

1. Injection Molding

In Injection Molding, melted plastic is forced into a mold cavity. Once cooled, the mold can be removed. This plastic molding process is commonly used in mass-production or prototyping of a product. Injection molding machines were made in the 1930’s. These can be used to mass produce toys, kitchen utensils, bottle caps, and cell phone stands to name a few.

2. Blow Molding

Blow molding is like injection molding except that hot liquid plastic pours out of a barrel vertically in a molten tube. The mold closes on it and forces it outward to conform to the inside shape of the mold. When it is cooled, the hollow part is formed. Examples of blow molding products are bottles, tubes and containers.

Equipments needed in setting-up a blow molding business are relatively higher than injection molding.

3. Compression Molding

In this type of plastic molds, a slug of hard plastic is pressed between two heated mold halves. Compression molding usually uses vertical presses instead of the horizontal presses used for injection and blow molding. The parts formed are then air-cooled. Prices of equipment used for compression molding are moderate.

4. Film Insert Molding

This plastic molding technique imbeds an image beneath the surface of a molded part. A material like film or fabric is inserted into a mold. Plastic is then injected.

5. Gas Assist Molding

Also called gas injection molding is used to create plastic parts with hollow interiors. Partial shot of plastic is then followed by high-pressure gas to fill the mold cavity with plastic.

6. Rotational Molding

Hollow molds packed with powdered plastic are secured to pipe-like spokes that extend from a central hub. The molds rotate on separate axes at once. The hub swings the whole mold to a closed furnace room causing the powder to melt and stick to the insides of the tools. As the molds turn slowly, the tools move into a cooling room. Here, sprayed water causes the plastic to harden into a hollow part. In this type of plastic molds tooling costs are low and piece prices are high. Cycle time takes about 40-45 minutes.

7. Structural Foam Molding

Structural foam molding is a process of plastic molding usually used for parts that require thicker walls than standard injection molding. Inserting a small amount of nitrogen or chemical blow agent into the plastic material makes the walls thicker. Foaming happens as the melted plastic material enters the mold cavity. A thin plastic skin forms and solidifies in the mold wall. This type of plastic molding can be used with any thermoplastic that can be injection molded.

8. Thermoforming

In this plastic molding process, sheets of pre-extruded rigid plastics are horizontally heated and sucked down into hollow one-piece tools. When the hot plastic solidifies, its shape conforms to that of the mold.

Tooling costs are usually low and piece prices vary on the machinery.

Plastic molding is a very technical process. It needs experts in this type of manufacturing business for it to be competitive in the market. Therefore, a very scientific and systematic study should be first made before going into this endeavor, if you want to know more about us, please go to our mean website to know more.