Check now
If you need a plastic part molded with extreme precision&#;for example, to ensure there&#;s no air leak between two molded sections or to be certain there&#;s no visible seal gap line&#;you likely require precision molding. The difference between a typical injection molded part and a precision molded part is the tolerance, or acceptable range of variation in dimension: While the majority of injection molded parts have a tolerance of +/- .005&#;, precision molding holds tolerances between +/- .002&#; and +/- .001&#; (or less, in some cases).
Let&#;s say, for example, you&#;re planning to manufacture a military projectile. In order for the projectile to fit properly in the firearm, handle the acceleration when it&#;s launched, and explode on impact, it requires very high precision.
If your application requires precision molding, you can&#;t leave anything to chance&#;so you&#;ll want to ask yourself the following three questions before you begin the process:
1. Have you determined which areas of the mold require precision?
Because precision molding is more expensive than typical injection molding, be certain which aspects of your part require tight tolerances&#;and whether those tolerances can be achieved through injection molding&#;before moving forward. For example, a surgical handle may only require precision for the piece that will connect with a pin, not the entire handle. Identifying your precision requirements from the get-go ensures you&#;ll get what you need without wasting money. In the case of the surgical handle, your injection molding partner may advise you to add the tolerances you need through tooling after the injection molding process is complete.
2. Have you selected a plastic material with low shrinkage?
The plastic material you select for your part makes a big difference in whether you&#;ll be able to do precision molding. For example, polypropylene has a shrinkage range of +/- .014&#; to +/- .022&#;, with an average of +/- .018&#;. This is a wide range for shrinkage, which makes hitting a specific tolerance extremely difficult. If you&#;re molding a toothbrush (which commonly uses polypropylene), dealing with shrinkage isn&#;t a big concern, as the toothbrush will function appropriately regardless of whether it&#;s slightly bigger or smaller than its counterparts. Acrylonitrile butadiene styrene (ABS)&#;another common thermoplastic polymer&#;has a much narrower shrinkage average of +/- .006&#;. That gives you a much better chance of hitting a tighter tolerance, but it still won&#;t reach the +/- .001&#; or +/- .002&#; tolerance needed for a precision part.
One way to hit high tolerances with your plastic material is to add glass or another filler resin (like carbon fiber or mica) into the material. This can minimize shrinkage and warp by providing more structure in the material. For example, if you include long glass fibers in a polymer material, the part will shrink more perpendicular to those fibers.
3. Can the mold manufacturer you&#;ve selected tool with high precision?
The process of creating plastic parts with tight tolerances begins with a high-precision mold. If each plastic part you create is not identical, you won&#;t have a precise product&#;and a precise mold ensures there&#;s no variation for each part. Because of this, it&#;s extremely important to select a mold manufacturer who understands the slow, steady process of building a high-precision tool. Keep in mind that selecting a mold manufacturer that specializes in rapid tooling is likely not your best option, as the goal of rapid tooling is to finish the mold quickly&#;but not necessarily precisely.
Let&#;s get your precision molding project started.
We have years of experience in precision molding, and would love to answer any and all of your questions. You can either contact us with those questions, or, if you&#;re ready to get your project started now, simply request a free quote. Once you submit the short form, one of our representatives will be in touch with you shortly to get the ball rolling.
Precision molding is a production process that uses more precise techniques and processes to make molds and parts than typical injection molding. If you want to ensure there are no air leaks between two molded parts or there are no visible seal gap lines, you need precision molding.
Yihua Mould are exported all over the world and different industries with quality first. Our belief is to provide our customers with more and better high value-added products. Let's create a better future together.
The difference between a typical injection molded part and a precision molded part is the tolerance or range of acceptable dimensional variation: while most injection molded parts have tolerances of +/- .005", precision molded parts have tolerances of +/- .002" and +/- .001" (or less in some cases).
If your project requires high-precision parts that require precision molding, before you look for the proper manufacturer to produce them, precision molding supplier Shengqi tells you that the following 3 questions you need to figure out can save you a lot of time and money.
1. Are you sure which areas of the mold need precision?
Because precision molding is more expensive than typical injection molding, determine which areas of the part require tight tolerances and whether those tolerances can be achieved with injection molding before moving forward. For example, a surgical handle may only require precision for the part attached to the pin, not the entire handle.
Get a handle on your project needs first and identify the parts and components that require high precision, which will effectively ensure that you do not waste money where it is not necessary.
2. Have you chosen a plastic material with low shrinkage?
The plastic material you choose for your part can greatly impact whether you can perform precision molding. For example, polypropylene has a shrinkage range of +/- .014" to +/- .022", with an average of +/- .018". This is an extensive shrinkage range, making it difficult to achieve specific tolerances. If you are molding toothbrushes (usually polypropylene), dealing with shrinkage is not a big issue because it works fine whether the toothbrush is slightly larger or smaller than its counterpart. Acrylonitrile butadiene styrene (ABS) - another common thermoplastic polymer - has a much narrower average shrinkage of +/- 0.006. This gives you a better chance of achieving tighter tolerances. However, it won't achieve the +/- .001" or +/- .002" tolerances required for precision parts.
One way to achieve high tolerances with plastic materials is to add glass or other filler resins (such as carbon fiber or mica) to the material. This can minimize shrinkage and warpage by providing more structure to the material. For example, suppose you include long glass fibers in a polymer material. In that case, the part will shrink more perpendicular to those fibers.
3. Can the mold maker choose a high-precision mold?
To manufacture high-precision parts, you first need high-precision tooling. Accurate tooling ensures accuracy and consistency in each part. Therefore, if you are after high-precision of parts, choosing a mold maker who understands the slow and steady process of making high-precision tools is essential. Sometimes we may choose a mold maker that makes fast molds for the sake of being fast, but this may not be the best choice for you if you are looking for precision because the goal of fast molds is to complete the mold quickly but not necessarily accurately.
Shengqi is a professional mold and parts manufacturer with many years of experience in precision molding. We are happy to answer any questions you may have about precision molding. You can contact us regarding these questions, or if you have a project that requires precision molding services, feel free to contact us. We will be sure to provide you with satisfactory service.
If you want to learn more, please visit our website precision mold parts.