Mold Trial Review Skills

After the mold making process is finished, it’s time to have a mold test, normally we call it mold trial. (t0), as mold trial will produce some sample for us to review the mold. So we should have some basic skills on how to review a mold trial sample, here below is our experience how we do it.


Check all features of part are correctly made

When you take a molded parts, you should check the parts with your original drawing(2D and 3D), and see if all features are correctly made without any missing features. Since sometimes there is a possibility to miss some features from the parts. So you should open your drawing, and check all features on by one. If anything incorrect, you should make a record so as to modify it later.


Check if dimensions are accurately achieved

If all features are made properly, you should always check out dimensions by appropriate measurement tools, like CMM, projector, caliper, pin gauge, etc, and especially for those critical dimensions that noted with tolerance. Just check 5~10 piece of those molded samples. It’s easy to find out any imperfection or mistakes that existing on your parts.



Check the appearance

Appearance check is also an important rule to review your mold trial parts. Normally there might be flash, shrinkage, deformation, flow marks, welding line, burns, etc. however most of those defects can be avoided during the mold design and manufacturing. So our mold design should consider those elements in advance. Otherwise it will be problem for troubleshooting after mold is made.


Check the assembly and fitting


The last step is to try to assemble those relative parts together, and check out if any structural faults that might happen during the mold making process. It’s also a direct way to evaluate if your parts will function properly. So as to ensure our final products will work fine. If anything incorrect, we can arrange a mold modification immediately.

Engineering Verification Before Injection Mold Making

Image result for design verificationIt’s easy to find a mold manufacturer to get your plastic mold made, however few people realized the importance of engineering verification before you kick off an injection mold making. Because the engineering validation might reduce or avoid your mold change and mould modification after the mold is made. It will greatly save your timing and cost, as well making your project risk free. Therefore we would like to share some useful tips on how you should verify your product design before mold making.


3D drawing checking out

When you finish your 3D model design, you should always check out your design structure for individual parts and whole components. Normally you have to check out the thickness of wall, stiffness, fitting, surface treatment. Normally a product designer should consider and optimize the part structure on how to make the mold, how the mold structure will be easier and in which way the mold cost will be lower. And making these design as good enough to avoid shrinkage, break, and improper match with other components. If you don’t follow these rules, it’s most likely that you have make some mold modification or adjustment in future.


2D drawing checking

A 2D drawing is used to define the manufacturing process and some important specification, it’s a written communication document to involve anyone who might work with the products that you design for. Most of time, a product designer should specify and define some critical features with dimension and proper tolerance. In theory, we should always allow some manufacturing deviation to happen for most of dimension when plastic injection mold process, and put reasonable tolerance to control the critical dimensions. It will benefit for both products owner and mold manufacturers. If we don’t define our parts with 2D drawing. It’s very hard to control it and might need mold modification later again.


Prototype Verification

Everybody knows the prototype is a very common engineering work to verify a product design or an idea, which help people to check product design models and feasibility of a concept. So does for mold making. When you finalize a design, you should always make some prototype to check out the detail structure. It’s a very useful way to avoid mold modification, and get your project risk under lower.


Prototype Mold Verification

Sometimes when people would like to make some expensive mold and they are not sure if their mold design will be workable for their products, they will consider a prototype mold. Because the prototype mold is normally made with low cost of aluminum or other cheap material. For example, prototype mold of automotive mould is very common, for formal automotive mold might cost few thousand to million dollars. But you can make prototype mold to check out mold design and part design.


All in one word, if you are about to kick off your plastic injection molding project, please do systematic engineering validation for it. You will definitely save lots of time and money and avoid unnecessary engineering changes.

How to Budget Your Injection Mold Cost

budget for injection moldWhen we development a new project, injection mold is a essential cost. To budget a reasonable cost becomes very important. Since your budget would affect the timeline, quality, and cost of your project directly or indirectly.


You might be curious of how the budget of injection mold cost is so important. Yes, many people don’t realize it. Here below I would talk about how it’s so, as well share some tips how you should do with it.


Everybody knows that efficiency, quality, cost are the core points for manufacturing industry. So does to injection mold manufacturing. If you want to achieve high quality plastic injection molded products, you must prepare a good quality plastic mold. Otherwise it’s impossible to product quality plastic parts with consistent result. However the high quality injection mold tool always requires good mold steel, precision manufacturing process, and experienced mold makers. So it’s not realistic to source a high quality mold with low cost.


Let’s come to our topic that how you should budget your injection mold cost. From our experience, you should evaluate the total volume of your injection molding parts before you make a budget. For example, if you develop a products with goods sales and need more than 1 million injection molded parts, you should budget your mold cost with 2 times higher than normal mold tools. With this high mold cost, you can prepare a higher quality mold tooling for your future production; if you only need medium volume plastic injection parts, you just need to budget your mold cost at a middle level. And just find a medium or small size plastic injection mold die manufacturer. At opposite, if you are not sure how many your project might develop and don’t need high volume of production, we suggest you budget your mold cost at a relative lower level, then you can make cheap mold tool or trial mold. When your production goes higher, you can then make a high quality mold later, in this way, you can save lots of money for your project.


Finally there is a fixed way to budget your injection mold cost, sometimes many things will change. If you can’t make sure how you should prepare your plastic injection molding cost, you can ask Inno molding team for a help.

5 Important Factors of Plastic Injection Molding Contracts

image of injection molding contractManufacturing contract is a basic written agreement to limit a particular product to be manufactured between contract manufacturer and product owner. So does for plastic injection molding project, if you are going to launch your molding project in China, you should always have a comprehensive contract with your molding suppliers. Here below are some typical elements that should be included in your manufacturing contract.


Hit an agreed Lead-time of your project

After discussed with your molding manufacturers, you should finalize a lead-time of your project, which is achievable and measureable. Because the lead-time of your project is very important to your market launch, you should make every effort to hit your lead-time as earlier as possible. Most of time, people would set up a project schedule or plan to make the overall lead-time reality, follow-up and monitor each time zone to move forward.

Make clear cost list on the manufacturing contract

While making a manufacturing contract, you should make a clear cost list on the contract(or you can mark the quotation number in the previous quotation from your supplier), so as to avoid any hided cost that might raise up in future. If you disregard this step, it’s hard to debate any potential price raise up.


In China, there are many different level of manufacturing companies, some of them might be honest to clients whatever you have a clear contract or not, however some of them might not be. Therefore you should make the cost as clear as possible on the manufacturing contract.


List out your critical quality standard and requirement

Since plastic injection molding project is a serous engineering work, we should always define our quality standard and requirement. Some common quality issue of injection molding are as below:

  1. No obvious flash
  2. No deformation exists on the part
  3. No flowing marks on the surface of parts.
  4. All critical dimensions should be on spec
  5. No sink mark on outside surface
  6. Part fitting should be good while assembly test


Put a safe payment terms


The payment terms depends on your project and agreement of your molding supplier, since there are few different payment terms for plastic mold making and injection molding manufacturing. Normally we do 50%+50% for mold making, (some of mold companies do 40%+30%+30%), and 40%+60% for injection molding production. However this terms could be adjustable while the complexity of your project.  If a small project with less amount of money, you can do it more, if your project is big, you just need to make just 30% of total amount to kick off the production, and make the rest when the goods is ready to deliver.


Make a outstanding punishment terms if the contract is broken by any of sides


It’s important to write out the punishment terms if the contract is not followed or broken by any of sides. From our experience, you can make a 5%~10% of total amount for punishment if the lead-time is delayed for 10 days above. Meanwhile, you can also make a 5%~30% of money punishment if the product quality is not hit. With these punishment terms, your molding supplier will be more serous towards your project.


Mold Factory Closed for CNY Holiday

factory closed for holidayUp to now, it’s very close to Chinese New Year Holiday, many mold factories will be closed for this special holiday. It’s just like Christmas in the Western countries. It lasts for nearly two weeks( 90% of companies will close from 10th Feb~25th Feb). It’s good holiday for those mold makers, however it’s a not convenient for many companies who need goods from China during the period. Especially when you have a good sales season. If so, you must prepare your order 2 months ago and order your shipping companies 15 days in advance. Otherwise you will have problem with your Chinese molding sourcing.


If you are a new to Chinese sourcing, you must have this common knowledge for this holiday. And plan your schedule with your supplier very earlier. Perhaps you might sent RFQ to them and get slow response or no reply, but it’s a normal. Since all of Chinese workers are off during the holiday. In case you have any urgent request, you should urge them to reply you before they leave for holiday.


If you are experienced person, you should also kindly make a new year schedule and send to your Chinese mold factory before holiday. So they can prepare next early year’s production. Because even the mold makers back to their work after the holiday, they might not be good attitude towards their work, and still emerge in the holiday status.


All in one words. Just note this special holiday and avoid urgent order or request during the time. And have a good plan with your Chinese mold manufacturer in next year. Hope this information will be helpful for you. Once you still have question, you can feel free to contact Inno Molding company for help.