Plastic molds
Longxiang Group
Exhibitions for Plastic Molds



Overmolding Part design, Mold Design and material selection are important when you are considering overmolding plastic parts.An overmolded plastic part can aid in wide range of functional and structural uses. Utilizing two separate injection molds, materials can be bonded together through the injection molding process to enhance the cosmetic looks and/or functionality of your finished plastic parts.A wide range of materials are capable of being overmolded, including both hard and soft plastic resins. When you choose to overmold your parts most often you can reduce your overall investment by reducing added assembly processes and reduce extra material needed to manufacture your custom parts.Often product developers find that harder plastics may require softer qualities. Handles, knobs and cases are often overmolded with soft, non-slip grips that make products more comfortable and easier to handle.Overmolded plastic parts have a very wide range of uses and applications in a variety of end consumer products.Careful consideration and planning must be conducted from the concept phase and well into prototyping ensuring the right materials for the overmolded parts are chosen.

Wall Thickness

Maintain a uniform wall thickness throughout your parts designThick wall design is prone to warp or other cosmetic issues10% Increase in thickness will provide 33% more stiffness with most materialsGood part design starts with optimized wall thicknesses. Wall thickness will often determine the mechanical performance, cosmetic appearance, moldability and cost-effectiveness of your plastic injection molded custom parts.To achieve optimal wall thickness it is a balance between strength and weight which represents both durability and overall cost.Having to add or remove material from your tooling not only adds delays to the manufacturing process but can add significant costs to your tooling.During your design phase give careful consideration to wall thickness in order to minimize an expensive tooling change down the road.A 10% increase in wall thickness provides approximately a 33% increase in stiffness with most materials.Thick wall areas can sink, warp or contain voids resulting in undesired cosmetic defects.Utilizing ribs, curves and corrugations can help you to reduce material costs and still provide rigid strength and durability in you plastic molded parts.When designing your parts try to reach a uniform wall thickness throughout the part.This will help you develop stronger better looking parts while also aiding in the overall look and feel by reducing blemishes that may occur from stresses during the injection molding process.

What is the draft angle

Draft Angle In general, 2 degrees of draft should be the standard in your part design to maintain uniform wall thickness.Plastic parts should be designed with draft to prevent sticking and ejector pin push marks on the show surface during the molding process.Also, an adequate amount of draft is needed for surfaces that will be textured.Plastic parts should be designed with draft to prevent sticking and ejector pin push marks on the show surface during the molding process.Don’t forget ribs should not exceed 60% of wallthickness.

Get a Quick Qutation

1. If you have a CAD file ready, we can provide you an interactive quote in 24 hours or less. STEP or IGES files are preferred.2. If you don't have the CAD files, pls send the details pictures of the parts, and tell us the sizes, the weight, and what material you want.3. You can directly send the samples to us, we can make as same as the samples, or we can impove the samples which you send us.

Cost of Molding

How much does plastic injection molding cost? The most common question we hear from designers and product engineers is, “How much will a plastic injection mold cost to make my product?”.It’s a fair question and we understand that perhaps a bottomless pocket may not be part of your current budget. The manufacturing of an injection mold could possibly be the greatest expense a new product faces in the development cycle.Many factors play roles and directly affect the cost incurred to create an injection mold for your custom parts. Prices can vary greatly between US injection mold manufacturers and off-shore injection molders. In any case, a reliable injection molder should be able to provide an accurate estimate quickly from either a 3D CAD file, sketch or the general dimensions of your product.We have been in business since 1998 and understand that all injection molders are NOT created equally. Many molds created off-shore are not built to meet the strict tolerances your parts require, so be sure to take the proper precautions when pre-screening a potential injection molding supplier.Here is what directly effects the cost of your injection mold tooling…The number of cavities – The number of cavities you incorporate into your mold will directly correlate in molding costs. Fewer cavities require far less tooling work, so limiting the number of cavities in-turn will result in lower initial manufacturing costs to build your injection mold.The complexity of your part – As the number of cavities play a vital role in molding costs, so does the complexity of your part design. Complexity can be incorporated into many factors such as surface finishing, tolerance requirements, fine detailing or the number of undercuts that may be incorporated.In general, the cost of manufacturing an injection mold can potentially be a great expense. However, with the experience of Longxiang Group and proper understanding of what makes good part design can help reduce the cost and avoid unnecessary expenses.

Injection Mold Part Design Guide

 Designing better parts initially will help ensure a smoother transition to production and faster delivery of your new products Draft Wall Thickness Overmolding Tooling Hinge & Snaps Gates & Runners Ribs & Bosses Insert Molding Undercuts Tolerance Text On Part Sink & Warp Shrink & Flash Surface Finishes Threading Knit Lines

Plastic Injection Terminology

You should use and must know the belowing terms if want to develop the new tools. Belowing terms are used in the injection molding process. Use these and our design guidelines to help produce a quality injection moldable design.Part  Refers to customer’s custom plastic part to be made.Tooling  Refers to the injection mold that is created to make plastic parts in the molding processShrink Rate  Refers to how much the plastic material will shrink after cooled. This percent of shrink is added to the part before the mold is designed. Every plastic material has its own shrinkrate ranging from .001 per inch to as much as .060 per inch. Although most fall in between .004 and .021. It is important when selecting a range of plastic materials that you may want to test before building the injection mold.For example if you wanted to use ABS which is .006 per inch and Nylon which is .015 per inch you may want to build the injection mold to .010 or leave critical dimensions stock safe until a final material is selected.Gate  Referring to where the plastic enters into the cavity of the mold. Types of gates include; sub, edge, fan, cashew and XME exclusive vestige free edge for perfectshearVestige  Material or witness of material protruding from gate area after gate runner has been removed from the injection molded part. This vestige is usually trimmed by themolding machine operator.Shear  referred to when plastic enters into the mold and the melt is maintained by friction produced by speed and pressure. Too much shear can cause the plastic material to burn, too little cancause the material to freeze off causing short shot.Runner  A channel cut into custom injection molds, in which plastic travels from the injection molding machine, through the sprue, through the runner and then through thegate ultimately filling the part.Short Shot  Is the result of a plastic part not filling completely, including some or all of the details.Sprue  Is perpendicular to the runner and is the channel that links the injection molding machine nozzle to the runner.Hand Pull  Portion of the custom injection mold that is used for creating undercuts in plastic parts.Slide  Portion of custom plastic injection molds that is used for creating undercuts. Required for automatic injection molds. Gibbs  Portion of the custom injection mold that holds the slide down so the cam can actuate it. CAM/HORN PIN  The cam commonly referred to as Horn pin is used to actuate the slide on an automatic injection mold.Ejector Pins  Ejector Pins are used to push the part off the core half of the injection molds.Undercuts  Referring to the portion of the designed component where a slide or hand pull is required to create holes, windows or clips that are not inthe line of draw.Core  Refers to side of the tool where the plastic part will stick to and is ejected from, also known as bottom half of the tool. Cavity  Refers to the upper half of the injection mold usually the show surface of the finished product but is mainly concave. There is not as much standing core outs on this side of the tool.Therefore the part will generally not stick to it when the injection molding machine opens the mold. Core Outs  Refers to the portion of a part that is gutted out in order to achieve uniform wall thickness. This portion of the part has no end use function other than lightening the part andreducing warp.Line of draw  Line of draw is the direction in which the two custom injection mold halves will separate from the plastic part allowing it to be ejected without any obstructions from metalcreating undercuts.Side Action  Is the term used for slides and/or hand pulls used in the injection mold build process. If your design requires side action it will require a slide or hand pull to make the plasticpart in order to run in the molding process. )Piece Price  Refers to the cost of each plastic part as produced in the injection molding process.SLA  Stereo Lithography Apparatus. Using 3D printing technologies such as laser sintering and electron beam melting, “rapid prototyping” evolved into “rapid molding,” in which short run prototypesof actual finished molding components are made.FDM  Fused Deposition Modeling. Using three dimensional printing technology where prototypes are made by fusing layers of actual ABS plastic together. Much like an inkjet printer except itlays Plastic instead of ink.Operator  A person used to run a plastic injection molding machine. Mold may be a manual tool or product may require stacking so they do notfall on each other when ejected from the injection molding machine.Wall Thickness  This refers to how thick the cross section of the plastic part is. See (Fig.9)Thin Wall Molding  Thin wall molding is the molding of plastic parts with wall thicknesses .005 to .060thick.Boss  This refers to round protrusions on plastic parts and molds. See (Fig.7)Ribs  Refers to thin bladed features on a part that are used for strengthening wall sections and bosses. Also, used to minimize warp. See Sink Marks  Refers to areas of the molded part where it seems to be sunk in, due to un-uniformed wall sections, thick wall sections and rib/boss to thickness ratios being off. Warp  Refers to area of a injection molded part that distorts during cooling or molding, causing undesired results in the finished product. Usually caused by un-uniform wall sections. Draft  Refers to portion of injection molding part that has some sort of taper to it. Generally all plastic components should be designed with draft where possible. See here for tips.Heel  Refers to the portion of an automatic custom injection mold that keeps the slide in the forward position when the molding machine is closed on the mold. See (Fig.2) for Visual.Stock Safe  Refers to the amount of metal left on the mold in order to tweak in a dimension. For example, if you have an inside diameter that is supposed to be .500 you may leave the moldat .505 in case you get excessive shrink. It is cheaper to remove metal than it is to add it.Bulk Pack  Refers to shipping plastic parts in a box without any form of stacking. At the injection molding machine Parts will be dumped in a box and shipped.Reverse Engineering  Refers to the process of taking an existing plastic part and creating a 3D solid model for duplicating in the injection molding process. 


We are a custom injection molding manufacturer. Our system is comprised of a highly skilled team, state of the art equipment and proprietary software that allows us to quickly convert your 3D part data into a high quality injection mold faster than anyone else.The cost is often less than most injection molding companies charge for a prototype mold without the life expectancy limitations. Also, our customers are saying that they often skip rapid prototyping because our process is so fast and affordable.We can reduce a typical mold build time of 6-12 weeks to just a few days. With this advancement our customers are able to get real injection molded parts to use either as production or prototype.Try us! Create a quote and see the difference. When Quality, Speed & Pricing is Critical.We are dedicated and focused on completing your projects on time and on budget, with most completing in as little as 1-15 days.


DFMEA Design Failure Mode & Effect Analysis  should be prepared before the 2D tooling design ,which should include P/L, Gate location, Ejector pins and the basic structure of tooling as well as the comments for any parts design defects.  This is a good way to save much time and cost for tooling design and fabrication.When you submit a quote for plastic injection molding we will provide you a detailed report that provides you important information about the design of your custom parts and highlights any potential problematic areas.Injection molded plastic parts just got a whole lot easier.1. Minimize Tooling Costs2. Reduce Design Changes3. Expedite the Manufacturing Process4. Ensure Better Part QualityOur DFMEA will show you the belowing things:  PL PL Lifter Give you good suggestions Slide Slide Gate Location Inserts Ejector System Shrink  Draft Anagle Thickness Analysis

What is Prototypes?

What's Prototypes? A prototype is an example that serves as a basis for future models. Prototyping gives designers an opportunity to research new alternatives and test the existing design to confirm a product’s functionality prior to production.A prototype has many benefits, such as the developer and the implementer getting valuable feedback from the user even before the actual project is started. The actual process of creating prototype involves the following steps:1. Identify Basic Requirements: Basic requirements are determined, including input and output data needed.2. Initial Prototype Creation: The initial prototype is created.3. Review: The clients and the end-users verify the prototype and provide valuable feedback on additions or deletions. Also necessary changes are made to the final product.4. Revise and Improve the Prototype: Using the feedback from the client and end user, both the specifications and the prototype can be changed accordingly and improved. If changes are incorporated, a repeat of steps #3 and #4 may be required.

Are there any plastic mold exhibitions in April, 2018

International Exhibition on Plastics & Rubber Industries is a 4 day event being held from 24th April to 27th April 2017 at the National Exhibition and Convention Center, Hongqiao, Shanghai, PR China. This event showcases product from Plastic & Plastic Products, Rubber & Rubber Products industries. The coming edition will be a tech heavy one - apart from being a wellmixture of Chinese and overseas suppliers and exhibits, it will shine the spotlight on “Intelligent Manufacturing, High-tech Materials and Green Solutions.

What facilities do you have?

What facilities do you have? We have over 100 Injection Molding Machines in our factory, Our tonnage ranges from 80-3000 tons. We can manufactureparts as small as .075 ounce up to enclosures as large as 517 pounds.   Equipment nameModelEquipment RangeprecisionBuy YearManufacturerQTY(SET) CNC Machining    CNCVMC11601100*600*6000.015MM/800MM2011Taiwan1 VMC966900*660*6000.01MM/600MM20121 VMC850800*500*5000.01MM/600MM2010Shenzhen1 Wire-cutting machining  DK7740500*400*3500.01MM/500MM2013Jiangsu1 DK7740500*400*3500.01MM/500MM2014Jiangsu1 DK77801200*800*10000.01MM/500MM2017Jiangsu1 DK7732400*320*3000.01MM/500MM2016Jiangsu1 DK7732400*320*3000.01MM/500MM2016Jiangsu1 DK7740500*400*3500.01MM/500MM2016Jiangsu1 DK7740500*400*3500.01MM/500MM2016Jiangsu1 DK7740500*400*3500.01MM/500MM2016Jiangsu1 DK7740500*400*3500.01MM/500MM2016Jiangsu1 DK7740500*400*3500.01MM/500MM2016Jiangsu1 DK7740500*400*3500.01MM/500MM2016Jiangsu1 DK7740500*400*3500.01MM/500MM2014Jiangsu1 DK7740500*400*3500.01MM/500MM2014Jiangsu1 DK7740500*400*3500.01MM/500MM2014Jiangsu1 DK7755550*430*4000.01MM/550MM2014Shanxi1 DK77631000*630*6000.01MM/550MM2015Shanxi1 DK77631000*630*6000.01MM/1000MM2014Jiangsu1 EDM Machining TOPMA ED-540600*500*4000.01MM/600MM2013Taiwan1 TOPMA ED-450500*400*3500.01MM/500MM20131 TOPMA ED-450500*400*3500.01MM/500MM20131 High speed CNC engraving and milling machine CNC650600*500*2500.01MM/600MM2013Shenzhen1 CNC550500*400*2010.01MM/400MM2015Shenzhen1 Grinding machine KGS-250AH500*250*2500.01MM/500MM2011Taiwan1 DX614400*140*1500.005MM/400MM20111 HF-614400*140*1500.005MM/400MM20121 SH-618400*180*2000.005MM/400MM20121 4080AHR800*400*4000.005MM/600MM2012Shenzhen1 Milling machine Jinfeng-B4-3800*400*3500.03MM/600MM2013Taiwan1 Drilling machine ZQ3040800*400*3500.1MM/300MM2012Tengzhou1 Lathe  CA6140Ø400*6000.02MM/600MM2011GuangZhou1 Injection machine  Haitian-80T360*3602011Ningbo1 Haitian-80T360*3602011Shenzhen1 LiJing-150T460*4602014HongKong1 Haitian-160T460*4602012Ningbo1 HC-420-420T455*4552016Taiwan1 Haitian--450T660*6602013Ningbo1 HC-1000-1000T1150*23502016Taiwan1 HC-1680 --1680T1530*15302016Taiwan1 CMM  serein-Tango500*500*40020141

What is a plastic mold?

What is a plastic mold?  Injection molding basics is all about manufacturing products made of glass, metal, and elastomers but the most popular one is plastic. Raw materials are melted and injected into plastic mould or metal ones and the raw materials will then take the shape of the mold by the time it hardens. It is then ejected from the machine to be delivered and sold locally or abroad.A lot of useful products can be made through the application of injection moulding process. Toys, car parts, musical instruments, kitchen utensils, appliances, gadgets, strap buckles, military equipment, fashion accessories, and dog collar buckles are just some of the few products made through it.