Factors to consider when planning your custom plastic molding project

When planning a Projects involving custom plastic injection molding. You must be as specific as possible as you convey your project to the manufacturer in order to get an accurate quote and a reasonable timeline. It helps to have as much information upfront as possible. As you plan your plastic molding project, here are a few factors to consider and to discuss with your manufacturing team:

Cost Limitations

The cost of your project can vary depending on how much homework you’ve done, among other factors. Here are a few examples of cost considerations you should make well in advance:

• Design: Has your project already been designed? If so, have you already created a prototype? If no prototype, do you have your design in digital format or paper? The more production-ready you are when you approach the manufacturer, the more likely you are to have a lower cost.
• Material: Do you have a specific material in mind for your project? If you are trying to keep expenses as low as possible, let the manufacturer know that you are willing to use the lowest cost polymer capable of producing a quality product. More on that below.
• Color and texture: Both of these elements can influence cost. Color, for example, can get costly if you’re expecting a product with a glossy finish. The level of texture detail can also drive up prices, although you have multiple options to keep costs down.

What Material to Use

When determining the material to use, you have to consider both preference and necessity. You can’t always opt for the cheaper option because of the risk of damage either during production or after you’ve received the product. A product that cracks or must be recalled later on can cost your company a huge amount of money — especially when compared with the cost of using the higher quality material in the first place. Plus, don’t forget about your brand’s reputation.

Thorough testing for maximum service temperature, maximum stress and environmental effects ahead of time can help you avoid potentially costly errors. Your manufacturer can help you with each of these, so it’s important to give them that freedom rather than relying solely on datasheets.

Size of Production Run

Naturally, the larger the production run, the more you will pay for material costs. However, larger production runs can save you in the end, as the reduced cost to manufacture in bulk can negate the cost of materials. Speak with your manufacturer to determine when it makes sense to up the size of your production.

Production Speed

How quickly do you need your product? As with any manufacturing process, plastic molding has its time constraints based on the size of the production run, the level of detail and the quality of the end product.

Be upfront about your expectations, and let the manufacturer know how much wiggle room you have. Your manufacturer might be able to suggest a more efficient process or one that can significantly increase the quality.

Jingwei industry has served the injection molding industry for over 15 years and has a team dedicated to providing you with the most cost effective solutions for design and manufacturing custom injection mold.Please visit us at :jweimolding.com or contact us via info@jweimolding.com.

03/01/2017

The Importance of Thermoplastic Materials To Plastic Product Manufacturing

The Importance of Thermoplastics To Product Development & Material Efficiency：When it comes to plastic prototype development or plastic product manufacturing, it is useful to understand which material to use. Typically, there are two types of plastic materials: thermoplastic and thermosetting resin.

To make a long story short, thermoplastic materials can be melted, cured (cooled down such that they become solid), melted again, cured again, and so forth. There is a limit to the number of times this process can be repeated depending on the particulars of the given material but the point is that thermoplastic materials can be melted multiple times without significantly degrading the material.

Thermoset materials, by contrast can only be melted once. After a thermoset material cures, attempting to heat it again to its melting point would cause it to burn (rather than melt) the material. It is useful to think of a 2-part epoxy when trying to understand thermoset plastics. An epoxy, like a thermoset material, is liquid prior to setting. Once the resin dries, however, it is not possible to melt it again.

When it comes to plastic injection molding, it is easy to misjudge the importance of thermoplastic and thermosetting materials. By the way, both thermoplastic and thermosetting materials can be injection molded. The major difference, when using a thermoplastic or thermosetting material, applies after the injection molding cycle when the molded plastic solidifies. During the molding process, plastic is heated and injected into a metal mold. To get to the cavity of the metal mold, however, the molten plastic first needs to pass through an array of entry points and tunnels known as sprues, runners, and gates. The plastic cools within the mold cavity as well as inside the channels that lead to the mold cavity. The plastic that solidifies inside the channels is not the component or part of the final product. It is just a waste.

Now, what happens to the “waste” during plastic injection molding?

Thermoplastic Materials

If a thermoplastic material were used for injection molding, the waste could be recycled and used again. The solid plastic left within the sprues, runners and gates can be combined with the raw material that goes into the injection molding machine. The same thing can happen with the material from rejected plastic parts. All the waste plastic can be collected and recycled back to the onset of the process. This all sums up into higher efficiency, and eventually means, lower costs of the final product and better margin for the producer.

Thermosetting Materials

If a thermosetting material were used for injection molding, the solid plastic from the sprues, runners, and gates is simply a waste, which has no practical use whatsoever. This means that the cost of the final product will be more.

To conclude, thermoplastic materials offer some major benefits to plastic product manufacturers, consumers, and even the society，as such materials are recyclable that we are more responsibly stewarding our natural resources. Indeed, when it comes to plastic prototype development or plastic product manufacturing, the manufacturer should choose and use thermoplastic materials.

Jingwei industry has served the injection molding industry for over 15 years and has a team dedicated to providing you with the most cost effective solutions for design and manufacturing injection mold.Please visit us at :jweimolding.com or contact us via info@jweimolding.com.

Plastic injection molding company workshop China

The importance of injection mold maintenance

Mold maintenance, or tool maintenance, refers to the cleaning and repairs that are needed to keep an injection mold in the best working order. Maintenance is performed routinely over the life of the mold, and also when any problems arise.Mold maintenance is crucial because it affects the quality of the plastic component as well as a company’s bottom line.

The condition of the injection mold affects the quality of the plastic components produced. Your molds and tools are critical assets to your company, yet many buyers overlook mold maintenance when making sourcing decisions. In fact, how your supplier maintains your molds is a critical aspect of a successful long-term business relationship.

What problems does mold neglect cause?

Injection molds undergo a lot of stress in the course of carrying out the molding process. Depending on the design of your mold, factors like temperature fluctuations, opening and closing of the mold, ejector pin action, and other movements can all cause natural wear and tear on a mold. A good injection mold will be designed to handle this wear and tear, but unpredictable situations can still arise as a result of these numerous stresses and the nearly innumerable permutations in which they can interact.

Temperature fluctuations, for instance, can cause both internal and external stress on the mold. Especially if the mold is not designed in such a way as to allow for more uniform cooling, molds can expand and contract in response to heating and cooling, and can weaken from the stress — and potentially even crack.

The moving parts of the mold are susceptible to friction, rough points of contact, and mechanical breakdown. A mold that doesn’t open and close smoothly, for instance, may be subject to impact stress as the two halves meet each other. Ejector pins may not function properly after a certain number of molding cycles. What’s more, the friction of the moving parts, in addition to creating extra heat, may eventually wear away at critical parts of the mold, creating unintended cavity shapes or compromised contact points.

Aside from the aspects inherent to the mold itself, there are also maintenance issues related to the material injected into the mold. As the mold completes more and more cycles, minute amounts of material residue can begin to collect inside the mold cavities. Over time, these deposits can accumulate and affect the interior shape of the cavity — and thus, the shape of the finished part. Deposits in mold runners or the mold cavity can also affect cycle time and, left unchecked, can even begin to prevent the substrate from reaching areas of the mold.

If a mold is used with different materials, these deposits might also create unintended interactions, depending on the chemical makeup of those materials. This, in turn, can affect the structural integrity of the finished product.

What does injection mold maintenance involve? 

The most important part of mold maintenance is creating a maintenance schedule and sticking to it tightly. Molds must be maintained regularly if their lifespan is to be prolonged. Ideally, manufacturers should perform cleanings, inspections and maintenance on molds after they have undergone a set number of cycles. However,Setting the schedule can be tricky, because different molds age at different rates, conditions wearing them out differ from manufacturer to manufacturer.  

One way to begin figuring out how often a facility should perform maintenance on each type of mold is to keep a log of all mold maintenance and repairs that become necessary. Be sure to keep track of the data and information you collect in a centralized log for easy reference.Knowing how often a given type of mold will break down without maintenance can help factories determine how often it needs to be inspected. The manufacturers of the injection mold will also be able to provide information on how often the mold will likely need maintenance. Advice from manufacturers will of course be more helpful if they have adequate information about the environment in which the mold will be used.

Regular mold maintenance and cleaning can improve shot quality, as molds will be in a more uniform state of cleanliness and wear and thus produce more uniform results. The most important factor in making sure molds are always in good condition is the regularity of maintenance, it is also essential that the right kind of maintenance is performed. It is especially important to pay attention to hot runners and water lines, as they often cause mold performance problems. Mold maintenance should also of course include lubrication, cleaning and tightening of all parts. Finally, rust prevention sprays must be applied to a cool, dry mold if they are to work.

Working with a reliable injection mold supplier as a strategic partner can help reduce many of the risks and costs. Jingwei industry has served the injection molding industry for over 15 years and has a team dedicated to providing you with the most cost effective solutions for design and manufacturing injection mold.Please visit us at :jweimolding.com or contact us via info@jweimolding.com.

Choosing the Right Material for Injection Mold Tooling

With many different types of mold material options available(Hardened steel,Pre-hard Steel,Aluminum) ,all formulated to meet specific requirements, ensuring the material used to produce your injection mold has a positive impact on the success of your next project. Similar to plastic resins being formulated to meet performance criteria in various applications, steel is also alloyed to meet specific requirements.Choosing the proper material for your next plastic injection mold can often be as critical as choosing the right plastic resin for your part.

Circumstances that effect choosing the proper injection mold material include:

• ensuring parting line integrity;
• wear resistance because of mechanical fatigue;
• wear resistance because of abrasive or corrosive plastic resins;
• inclusion of thermal properties needed to successfully mold your plastic part.
  

The most common materials used to construct plastic injection molds are pre-hard steel, hardened steel, and aluminum. This 3-part series will explore each and answer the important questions you should consider before choosing your material:

1,How many parts are expected to be molded?

Pre-hard Steel: Typically found with a Rockwell rating of RC 30-42 (in its pre-hardened state), this material is quite tough, easy to machine and relatively inexpensive. 250,000-500,000 cycles can easily be achieved when molding unfilled materials, and 50,000-100,000 cycles can be obtained with filled materials. The range is dependent on the amount of filler present in the plastic material. When total expected volume is less than 250,000 cycle’s, pre-hard steel is the way to go.
Hardened steel:Typically found with a Rockwell rating of RC 46-62 , it can be a great material for creating core and cavity detail. With hardened steel molds, one can easily achieve 1,000,000 cycles for unfilled materials and 250,000-500,000 cycles with filled materials. Once again, this range is dependent on the amount of filler present in the plastic material.
Aluminum: Generally speaking, aluminum molds are used in lower volume productions, not exceeding a few thousand parts.

2,What surface finish requirements are expected of the molded part?

Pre-hard Steel: This may include light to aggressive textures, EDM finishes or polish. An A-1 or better polish can be achieved but this is grade specific.
Hardened steel:As long as your requirements do not exceed that of an A-3 requirement, pre-hard steel is a great choice.
Aluminum: Most grades of aluminum machine, finish and accept texture proficiently. Most high-end aluminums have the ability to accept a polished surface, often ranging between a B-1 and A-3 polish.

3,What steel conditions exist as a result of the part design and are they conducive of excess wear?

Hardened steel: With hardened steels you can decrease the amount of draft of wiping shut-offs to about 3 degrees.
Pre-hard Steel:pre-hard steel has fair compression strength. Because of this, pre-hard steel is a great candidate for lower volume production tooling, including insert molding and overmolding.
Aluminum:Aluminum has very poor compression strength. If you happen to close the mold on a single part or insert, the aluminum will “hob” and become damaged, requiring expensive repair. For these reasons, aluminum is not well suited for any type of insert or over molding.

4,What type of plastic resin will be used on the molded part?

Pre-hard Steel:If molding highly corrosive molded resins, like PVC, common metals can quickly corrode, so 420SS is highly recommended. There are many options that offer different levels of hardness, as well as corrosion resistance.
Hardened steel:High heat resins such as PEI, PPS, PPSU, PPA, and PEEK, as well as filled materials (long and short glass fiber, carbon, stainless steel, etc.), can often be tough on pre-hard steels from a wear perspective. While certain steps can be taken, like inserting the gate area for easy maintenance and replacement, it should be expected that the life of the mold will decrease in these circumstances. If you find that your project requires between 50,000-100,000 parts over the life of your program, pre-hard steel is certainly adequate.
Aluminum:Aluminum is very vulnerable to fast wear and fatigue when high heat or highly abrasive materials are being molded, and should not be considered for any type of production molding. However, it can still be a great choice for extreme low volume (truly prototype) and non-cosmetic parts, even when running such materials.

By considering these 4 basic questions, you can make a more educated choice as to what the correct material is for you. While choosing the best option for your mold is not complicated once you understand the pros and cons of each material, it is a critical part of the process that can affect the success of your project. Research done prior to mold construction, and more importantly vendor selection, can help ensure you receive the performance you expect from your next mold.Jingwei industry has served the injection molding industry for over 20 years and has a team dedicated to providing you with the most cost effective solutions for design and manufacturing injection mold.Please visit us at :jweimolding.com or contact us viainfo@jweimolding.com.

Basics of Plastic Injecion Molded Parts Production

Creating a plastic part using injection molds requires three important components:The mold;An injection molding machine;Raw plastic.Making a basic plastic part is relatively simple if you have the right tools. Knowing what is needed can help you understand how your requirements will be met, and you can more easily communicate your needs to a plastic injection mold manufacturer.
Consider the size of the final part when you determine which machine to use. The more complex your design, the more features you are likely to need to consider. This ensures that you are able to select the right raw material and machine to complete your injection molded parts.
The strength and durability of the final product depends on which raw material you select for your injection molds. Molds for plastics come in many different shapes and sizes, and the success of your final product starts with the raw material.
The plastic mold itself is typically something you will have to develop. Experts can help you interpret your needs and design the right type of plastic mold for each unique project.
Before launching your next plastic mold project, remember these simple steps. Although the manufacturing process is straightforward, you need the right expertise for a high quality, on-time, cost effective finished product.Jingwei industry has served the injection molding industry for over 20 years and has a team dedicated to providing you with the most cost effective solutions for design and manufacturing.Please visit us at :jweimolding.com or contact us via info@jweimolding.com.

How to Optimize Your Plastic Injection Mold Designs

Designing better parts initially will help ensure a smoother transition to production and faster delivery of your new products.A lot of time and attention goes into making a successful plastic injection mold design. If you don’t get the design right, nothing you do is going to compensate for that later. Here are a few simple guidelines to help you get the right design from the beginning:

• Size of the mold:The maximum part outline that can be molded is approximately 18.9 in. (480mm) by 29.6 in. (751mm) or roughly equivalent to 175 sq. in. (1,129 sq. cm.). A maximum part volume of approximately 59 cu. in. Depth up to 4 in. (101mm) from the parting line with 3 degrees of draft, or up to 8 in. (202mm) total if the parting line can pass through the middle of the part, inside and outside. Deeper parts are limited to a smaller outline
• Tolerances:Typically,Jingwei industry can maintain a machining tolerance of ±.003 in. (0.08mm) with an included resin tolerance that can be greater than but no less than ±.002 in./in. (0.002mm/mm).
• Wall Thickness :With injection-molded parts, observing proper wall thickness helps parts avoid potential issues such as sink marks and warpage.
• Drafts :Drafts  are actually vital to ensuring that you have taken all of the other aspects into account and have worked to improve the mold based on any new information. Drafts give you a way of seeing where you have been and what did not work before or highlight areas where you think previous design versions were better.

Every mold design needs to take above four primary factors into account before being made.Size,Tolerances,Wall thickness should be located on the specifications or requirements for the mold. If you do not have these, that should be the first step in the process because these three factors tend to be the reason that a mold either succeeds or fails.

• Surface finish:Surface finishes play a critical role in both functionality as well as the cosmetic look and feel. Parts that are hidden may not require a surface finish at all;
• Undercuts:An injection mold undercut is any indentation or protrusion that prohibits an ejection of a part from a one-piece mold.Reducing the number of undercuts often helps to reduce the initial cost of tooling.Undercuts are critical on things like bottle caps, but not all molds will require undercuts as part of the plastic injection mold design.

Jingwei industry has served the injection molding for over 15 years and has a team dedicated to providing you with the most cost effective solutions for design and manufacturing your new products.To know more,Please visit us at :jweimolding.com or via info@jweimolding.com.