Posts

Plastic Molding Machines

Plastic Molding Machines

Over-mold plastic molding and double injection molding are two distinctly different molding methods even though both are used to combine multiple polymers into a single part. Because of this similarity, the two are often confused or misapplied by the design engineer. The more finite capabilities of these two molding methods differ as much as their required tooling, machines and often, the resulting part cost. Choosing the right method can be a critical factor usd in achieving targeted features, cost and time-to-market. Both methods can be used to create the soft-touch products popular in today’s marketplace. However, both methods can be applied to other applications where multiple polymers must be combined into a single part. Over-mold injection molding is used for parts that do not require fine detail and can absorb the higher cost of machine time and labor. 2-shot injection molding is reserved for parts requiring fine detail and low part cost.

The 2-shot injection moulding process creates the first plastic component, and the material molded round it, using a single mold and a 2-shot injection molding machine. 2-shot machines have two-barrels (one for each material) and they have the ability to rotate the mold. The machine injects the first shot material into cavities on one side of the mold, rotates the mold 180 degrees, and then injects the second shot material onto the first shot. The first and second shots occur at the same time. When the mold opens, it ejects the completed parts from the second shot cavities and it rotates the mold to position the first shot for the second shot. This is accomplished in a machine running in an automatic cycle. Because the 2-shot injection molding process is fast and highly repeatable, the shrinkage of the first shot is very consistent and two materials can be molded together with virtually no flash. 2-shot molding is the process of choice when molded-in graphics or other fine details are required. The elimination of the shrinkage variable allows 2-shot molding to produce details impossible to achieve with over-mold injection molding.

Double injection molding

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.

Thermoplastic injection molding is the most widely used of all plastic processing methods. The injection molding machine reduces pelletized raw material and colorants into a hot liquid. This “melt” is forced into a cooled mold under tremendous pressure. After the material solidifies, the mold is unclamped and a finished part is ejected. Injection molding offers the lowest piece prices available, but tooling prices are generally the highest. Thermoset injection molding is similar to thermoplastic  injection molding except that uncured thermoset resins are mixed, injected, and held in the mold until cured. As with thermoplastic molding, the price per piece can be low, but the tooling prices are generally very high.

Thermoplastic Plastic Moulding

Thermoplastic Plastic Moulding and Plastic Molding Company

Thermoplastic plastic moulding is the most common way to manufacture plastic parts. Thermoplastics are polymers that can be heated to soften or melt, and cooled to solidify as a physical change, rather than a chemical change that takes place during molding of thermoset materials.
In a plastic molding company,The thermoplastic injection molding process begins by adding pelletized material to a hopper. In most cases, the material must is dried prior to molding, and frequently requires the addition of a color concentrate before loading.

The material is gravity fed into a heated barrel and screw. Rotation of the screw results in shearing action on the raw pellets causing them to melt. The screw rotation also pushes the molten plastic forward in the barrel toward the mold. The material is then injected into the closed mold at high pressure through a runner system to fill all the cavities.

The plastic mold is clamped shut under enough force to keep the mold halves together while the molten plastic is flowing. On a cold runner system, the plastic in the runner solidifies and must be discarded or ground into pellets to be reused, which we refer to as “regrind.” If a hot runner system is used, the plastic in the runner stays molten, and no material is wasted. When the mold cavities are filled, the part cools until rigid enough to be ejected. Part cooling within the mold is accomplished through water lines cut into the mold. At the completion of the cooling cycle, the mold opens and the part(s) are ejected for part removal.

Process called “decoupling” can be used for thermoplastic injection molding. In this process, the cavities are filled to approximately 95 percent of their capacity using high injection pressures. At a specific programmed position of the injection screw, the pressure is reduced and the 5 percent remaining portion of the mold cavity is filled at a lower pressure. This process eliminates over packing of the molded part and the resulting high internal stresses caused by over packing.

Plastic Mold Company Management

Job Shop Management Software Can Really Help A Plastic Mold Company

Wouldn’t it be great if there was some kind of job shop management software that actually helped run your business? One that was designed for small to medium-sized companies in a real-world job shop environment?

Personally, I think plastic molding manufacturing and plastic injection molding must be two of the most difficult to mangage businesses anywhere. But, maybe other industries say the same thing!


You have deadlines, due dates to meet

There is so much to manage and so little time to manage it

  • Plastic Mold Company to keep track of: steel, graphite, copper, mold bases, components, special items, cutters, grinding wheels, WEDM wire, etc.
  • Quotes need to be made and tracked
  • Progress reports must be made
  • Design must be done and kept current
  • Labor costs need to be tracked
  • Labor divisions need to be analysed for future quoting
  • And on and on and on

No modern business can function very long without serious shop management. A quality job shop management software program could make life a lot easier, if it really worked as advertised. The days of “winging it” are long gone. You might get away with it here and there, but in today’s competetive environment, you need more precise control over your operation.

Looking for good plastic mold company then china plastic injection mold could be one of the most important information for your new products development,

What about JobBOSS software?

JobBOSS, from Exact Software, is a real world job shop management software maker that actually has a program made specifically for mold and tool-and-die builders. It isn’t everyday that anybody even knows about moldmakers! What sets them apart is their experience and fully integrated program.

  • Made for small to medium sized job shops whose orders are custom
  • Made for the real world where customers demands are high and always changing
  • Enables you to know the profitability of each and every job, even as it is constantly being updated
  • It is easy to use and requires no extensive set-up time. You can use it on your next job
  • Has integrated purchasing that is tied to the job

Life in a plastic injection mold making job shop, or even a captive shop, is feast or famine, and when it rains it pours! Once you get your operation set-up in this software, you can experience the relative security of knowing what is really going on. This can really help with the stress levels and shop atmosphere as well. I know, I have personally seen it in action and it really works.

You can find out more about JobBOSS here. Just fill out the form and check your email inbox for all the information you need!

EDM Tooling

Which EDM Tooling Sytem Is Best?

There are several very well designed and reliable EDM tooling and electrode managing systems on the market today. Each has it’s advantages over the other, but all are quite good. Time spent analyzing the various systems available is time well-spent. Your needs are unique, and you will be “married” to the one you choose for a long time.

There is no question at all regarding the benefits of using an EDM tooling system. Your quality will increase, your productivity will increase and your plastic injection mould makers will quickly see the benefits. The electrical discharge machining operators will also be very grateful that they no longer need to indicate and locate everything ‘to death’.

Time is money, and an EDM tooling system saves a lot of time.

You might need to change your shop culture


A common problem with implementing a new electrode holding system is the change in shop culture that is required. This was especially a problem in the past. One of the best ways to do this is to designate two moldmakers as the team to study and develop the idea. They will feel personally responsible and take ownership of the project, which will influence the rest of the shop.

You must make sure your moldmakers understand what you are doing and why. Change is always difficult and many moldmakers have been doing things a certain way for many years. They often see this new system as a waste of money and unnecessary.

Time spent discussing the change, and showing how and why things will improve will go a long way. Very soon, everyone will easily see the rationale behind the decision and be “on-board.” A demonstration of the repeatability is a great way to convince the skeptics.

Once your moldmakers can see the labor savings and ease of use, they will be enthusiastic. Very few people really like making electrodes the “old school” way. For one thing, it is very tedious and messy. read more about EDM tooling please go to our plastic mold manufacturing company.

Features to look for in EDM tooling



  • Repeatability. In real life can it repeat within the tolerances claimed by the manufacturer?
  • Ease of set up and use. Does it take a lot of time and labor to mount electrodes and set it up in the EDM and CNC machining center?
  • Is it cost effective? Take some time to analyze the cost savings as well as the “headache” savings. Any EDM tool holding system is expensive, but, over time, the savings can be dramatic.
  • Does the system have compatible fixtures for various sizes of electrodes? You should be able to use different size holders interchangeably.


    Not everyone uses EDM tooling!

    Sure, there will always be the odd time when you need to use a “stick” electrode, maybe even often on certain applications. But any serious mold making shop today is crazy to still be using angle blocks, vee-blocks and so on. It is so incredibly inefficient to make tedious set-ups by hand, over and over again.

    Yet, this is precisely the case in the newly emerging areas, such as China. It is quite common to get a box of stick electrodes with the plastic mold that they have just sent. They figure that their labor is so cheap that they can afford to operate this way.  Most likely, it is just a matter of time before they figure out that this is a foolish way to operate. It just makes sense to have an integrated system that is reliable and that eliminates the need to constantly be checking for alignment and location.

Injection Molding

Plastic molding factory and injection molding


The injection molding process affords many opportunities to enhance part functionality and reduce product cost.

The injection molding process affords many opportunities to enhance part functionality and reduce product cost. For example, the per-part mold costs associated with adding functional details to the part design are usually insignificant. Molds reproduce many features practically for free. Carefully review all aspects of your design with an eye toward optimization, including part and hardware consolidation, finishing considerations, and needed markings and logos, which are discussed in this section.

Consolidation

Within the constraints of good molding practice and plastic mold construction, look for opportunities to reduce the number of parts in an assembly through part consolidation. A single molded part can often c

Injection molding process

ombine the functionality of two or more parts. a good plastic molding parts come from a good Plastic molding factory

Hardware

Clever part design can often eliminate or reduce the need for hardware fasteners such as screws, nuts, washers, and spacers. Molded-in hinges can replace metal ones in many applications. Molded-in cable guides perform the same function as metal ones at virtually no added cost. Reducing hardware lessens material and assembly costs, and simplifies dismantling for recycling.

Finish

Consider specifying a molded-in color instead of paint. The cost savings could more than justify any increase in material cost for a colored material with the required exposure performance. If you must paint, select a plastic that paints easily, preferably one that does not require surface etching and/or primer.

Markings and Logos

Secondary methods of adding directions, markings, and logos — including labels, decals, printing, stamping, etc. — add cost and labor. Molded-in techniques, when applied properly, produce permanent lettering and designs at a very low cost. Mixtures of gloss and texture can increase contrast for improved visibility.

Miscellaneous

Look for opportunities to add easily-molded features to simplify assembly and enhance product function such as aligning posts, nesting ribs, finger grips, guides, stops, stand-offs, hooks, clips, and access holes.

Rapid Injection Molding

Rapid injection molding & Chinese injection molding

Rapid injection molding is exactly what the name implies, but multiplied by a factor of 10! It is hard to imagine that anyone could offer a service that can guarantee a fully functioning injection mold in a day or two, but that is actually the case.

This is precisely what rapid injection molding is all about. Rapid, as in very rapid! These molds are made of high grade aluminum and can produce anywhere from a few parts to thousands.

Personally, I have worked on many aluminum molds that produce high quality parts even after several hundreds of thousands of cycles. At first I was highly skeptical, but after several years of making injection molding prototypes, It became routine.

How does rapid injection molding work?

It works by automating as much as possible in the mold making procedure. By taking the customer’s 3-D model and automating the design and manufacture of the mold, the lead times are cut down to a fraction of the conventional process.

One of the central parts of the automation process lies in the design of the plastic part. By working with knowledgeable designers, many features, such as undercuts, can be minimized or eliminated.

Some of the features that must be considered are:Chinese injection molding

  • Part draft angles and radii
  • Ejection
  • Using straight pulls whenever possible
  • Simple approaches to side actions
  • The CNC milling process
  • Part size limits

Rapid injection molding PDF papers

You can find out everything you need by reading the PDF papers on rapid injection molding. They cover every aspect of the process and are very well made. Just click on the design volume you wish to read about.

What are the advantages of rapid injection molding?

  • A way to bridge the time gap between prototype and full production. If you need a working injection mold right now, this is the answer.
  • Short run production to get your product in the marketplace immediately.
  • Gives engineers a working model to approach a full-blown design for a production tool.

What are the disadvantages of rapid injection molding?

  • The aluminum molds are low production.
  • Works best for simpler parts with minimal side action and undercuts.
  • EDMmachining is eliminated, thus some detail may be sacrificed.
  • The entire core and cavity are high-speed CNC machined, often on 5-axis CNC machines, therefore the design has limitations.

Is rapid injection molding expensive?

Surprisingly, the cost is quite reasonable, though there is always a premium to pay for extremely quick turnaround. Typically though, the cost is much less than might be expected. This is due to the highly developed automation process of this type of mold making.

Conclusion

Rapid injection molding is a niche market segment of injection mold making. It serves a highly specialized marketplace, yet is very important withing the niche. The ability to get your injection molded plastic part to market in a matter of days is very valuable to the right company.

Aslo, the ability to bridge the gap between prototype and high production is a very useful tool for custom injection molders.

One of the leading companies in rapid injection molding is https://www.hao-mold.com/. They have just about everything you might need when it concerns rapid injection molding or plastic mold, injection molding.

https://www.plasticmold.net/ is an injection mold china company that offer plastic mold design, mold manufacturing, export mold, plastic molding manufacturing, all in one service to the world customers. go to their official website to know more.

Plastic Injection Mold

What Are The Best Plastic Injection Mold Components?

Plastic Injection mold components are a very important for Plastic mold manufacturers, but often overlooked part of the plastic injection mold making process. These would include things such as: ejector pins, core pins, leader pins, leader pin bushings, pillar supports, rest buttons, interlocks, and much, much more.

mold components

mold components
Why are high quality plastic injection mold components important?

Cost- it is nearly always cheaper to purchase a custom mold base and the accompanying components. Why waste your time on the “grunt” work, when the profits are in the mold making? Of course, there are certainly exceptions, but generally, it is more profitable to purchase a standard mold base and the related components.
Consistency- Since a good supplier will guarantee close tolerances, you can focus your attention on the cores and cavities, instead of more general machining. The profit is in the cores and cavities, so why spend time making something that can be purchased cheaper and made just as well, or perhaps better? Even if it costs a bit more, it still makes good business sense most of the time.
Delivery- a good supplier will deliver just what you want, on time. Plus, you don’t have to pay for the scrapped parts he made while filling your order. This is especially true if you need more than one or two pieces.
Flexibility and innovation- companies are constantly searching for new and better ways to make components and improve their applications. Think about lifters, for example: there are numerous clever ways of making lifters, each one better than the rest! Take advantage of this collective inventiveness instead of relying on what worked 20 years ago.
Good communication- using standardized plastic injection mold components is often a selling point. Some companies have “favorite” suppliers for their hot-runner system, for example. This also can make communication easier, since the features and sizes are catalogued and common.
There is very little reason anyone would make most of the injection mold components used in their plastic mold. There is simply no way that to justify making things such as ejector pins, mold base bushings and leader pins. However, there are always special cases where it is practical to custom manufacture components. Special ejector sleeves, custom core pins, custom lifters or unique slides would certainly fall under this category.

Even in special cases, it is often well worth checking to see if a custom manufacturer can quickly make your special component. This can free your skilled mold makers to focus on the core and cavity work.

It is fairly common to waste huge amounts of hours making a mold component that you later discover could be purchased from a reputable supplier. Sometimes the cost savings are quite substantial, get to know more information about plastic injection mold components please visit our company website to know more.