Posts

The History of Pastic Injection Moulding

The History of Pastic Injection Moulding

In 1868, Hyatt developed and improved a plastic material and makes it in the shape of an article.  Then in 1872, he and his brother Isaiah registered the first patent plunger-type injection molding machine. Basically it is running like a giant hypodermic needle. This huge needles inject plastics into the mold through a heated cylindrical.

In the 1940s, during the Second World War, ​ huge demand of cheap mass-produced for the product made it popular.

In 1946 American inventor James Watson Hendry build the first injection molding machine, which makes the injection more precisely controlling the speed and quality of an article. In 1951 the United States developed the first screw injection machine.Plastic injection molding

In the 1970s, Hendry then developed the first gas-assisted plastic injection moulding process and allows the production of complex, hollow products, of rapid cooling. This greatly increases the flexibility and strength of the design and the end parts manufactured while reducing production time, cost, weight and waste.

Raving Jackpot Party Slot Letter free Super Jackpot Slots money real game machine black widow book from Williams Real download slots on money ghost busters here at Casino Games On Net. On the Odds It’s all about the ‘World’ in Almost Doubling Only, so the movies feature no real.

Today lots of injection molding machine from China market to the world, and there are lots of China molding company that sell plastic molding parts to the world, fast the high quality. you can  go to https://www.plasticmold.net/ , this is one of the injection mold china companies, for your reference.

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.

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 Process

The injection molding process

In the injection molding process, thermoplastic resins are melted and the melt is forced (injected) into a mold.

     In the injection molding process, thermoplastic resins are melted and the melt is forced (injected) into a mold. After this melt cools until the polymer solidifies, the parts are removed (ejected) from the mold. Injection molding permits mass production net shape manufacturing of high precision, three-dimensional of plastic parts[1]. One of the most common plastics manufacturing processes, injection molding can produce parts weighing as little as fraction of a gram or as much as 150 kg[2]. The process currently consumes 30% of polymeric resins[3] of which 90% are thermoplastics (i.e., capable of being remelted)1. Major advantages include capabilities to produce parts with: 1) virtually unlimited complexity, 2) fine details and good surface appearance, 3) controlled wall thickness and excellent dimensional stability, and 4) requiring limited or no finishing.

The five important thing in the injection molding process are the

1. Injection molding machine

2. Mold

3. Material

4 Method

5. Man (i.e., operator).

While there are many variations of each M, this discussion is limited to single-stage reciprocating screw injection machines and the flow of thermoplastic polymer melts in two-plate cold runner molds.

1. Injection Molding Machines

As illustrated in Figure 1, injection molding machines have three major components: the 1) injection unit, 2) clamping unit, and 3) controls. The injection unit plasticates (melts) and injects the polymeric material into the mold. The clamping unit supports to the mold and provides the mechanisms for opening and closing of the mold and for ejection of molded parts.Injection Mold China

Figure 1. Injection molding machine

During a thermoplastic molding cycle, the clamp of the injection molding machine closes, thereby closing the mold. Molten plastic located between the nozzle and screw in the barrel of the injection unit is forced (by the screw) into the mold. The controlled volume of melt injected into the mold typically fills the cavities to about 95 to 98% of their total volume. After injection is completed, the screw is pressured for a given period of time. In this packing stage, more melt is forced into the mold to compensate for shrinkage of the melt as it cools. The packing stage is followed by a holding stage, in which a controlled pressure is exerted on the screw for a specific length of time. Holding pressure prevents the melt from flowing back into the runners. When the gate freezes (solidifies), melt can no longer exit the cavity and the holding stage ends. While the melt cools immediately upon entering the cavity, a ¡°formal¡± cooling stage follows the holding stage. During this period, the part cools until it is capable of withstanding ejection forces. The screw also rotates to melt more plastic and build up the molten plastic shot for the next molding cycle. At the end of the cooling stage, the mold is opened and the part is ejected.

Today lots of person or companies are looking for Injection Mold China partners for their plastic molding business, this is high speed to American and Europe

The times associated with a convention,

all molding cycle are shown in Figure 2. For 2 to 3-mm thick parts, filling occurs in less than 5 s, packing requires one-third of the fill time[5], the holding time depends on the gate size, and cooling is longest part of the cycle. Thin-walled parts (i.e., wall thickness is less than 1 mm), however, filling in less than 1 s, typically have no packing or holding stage, and cool rapidly. go to our plastic molding official website to get free quote for your plastic molding project.

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.

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.