As known, the manufacturing of plastic injection mold determines the quality of plastic molded parts, production effieciency and cost of finished products.Mold trial is run to solve any problems with the design, resin, tooling,machine. Thus procedures of mold trial is very important for a injection molder. Be sure to follow this nine-step process to make sure you’ll be making good parts through a successful trial.   Firstly, Keep the  injection mold run on the press without any resin to verify the function of  the mold    A. Check mold opening and closing condition at low pressure:   Mold should beopened and closed by 3 times at fast, medium and slow speed. During the process, there should be no abnormal sound nor block phenomenon;   Mold opening and closingshould go smooth  without any interference.   B.Checkejection system of the injection mold (at low pressure)   1.Check the ejection action at  fast, medium and slow speed.   2.Check whether ejector pins  or sleeves on the…

What proper gate design is important? The gate serves as the entrance to the mould cavity and should be designed to permit the injection mold to fill easily. It is very important to follow below gate considerations while picking gate location at the early stage of plastic mould design. Gates should not be placed where part-bonding or impact will take place in use. The gate area will usually have higher residual stresses than the rest of the part due to the packing that takes place. Therefore, it will be weaker than the rest of the part. Position the gate to minimize trimming problems. Scissor-type gate cutters, kept sharp, will work smoothly and leave no “blemish” marks. If possible, gate into the thickest section to avoid incomplete fill or sink marks. This will also minimize flow marks and distortion associated with setting into a thick section from a thin one. Position the gate so that venting…

It is rare to see the structure of slide coming out of lifter in plastic injection molds. We are not experts, but we just design a typical mechanism that works quite well based on our experience.  Hope that it helps you. Mold Design Concept If we use common mold slide, the steel circled in red get stuck. And the undercut could not be released with this. How to design lifter head?   Green block is lifter with a prominent tail while the purple block is slide which is to release undercut and drive lifter to release undercut downwards. Further explanation on slide out of lifter in plastic injection mold Mold lifter needs a limit screw to limit the stroke of lifter travelling down while the spring is to prevent lifter from moving right with slide The science of structure of slide from lifter   Angel lifter drive slide to move right And…

This article talks about  some basic rules for runner design of plastic toolings, which, if you follow, will help you succeed with an injection mold design.  To provide part-to-part uniformity in a multicavity mold, the runner system should enable each cavity to fill at the same rate. Designing runners involves several compromises: The runner system should be compact to minimize the amount of rework. The runners must deliver melt that has retained maximum heat to completely pack out the cavity. At the same time, runners must cool quickly after delivering the melt to aid ejection. If the flow distances from the sprue to the various cavities are equal, the runner system is balanced. Since balanced runner systems contribute to melt uniformity among cavities, dimensional tolerances are easier to maintain. Unbalanced systems can cause cavity to cavity variations. (Figure 1) Figure 1 Occasionally, balancing the runner system and minimizing runner length conflict. In most cases it is better to accept the additional rework and use a more balanced system. Increased injection…

Prototyping is an important step in the process of New Product Development. Prototypes can be inexpensively prepared by CNC machining stock shapes, by thermo-forming them from sheet stock, or simple injection molding tools can be made from soft steel or aluminum. In addition to providing a three dimensional presentation of the design, a prototype allows: Subjecting the part to the chemical and mechanical environment it will endure in real life Accelerated testing for part life Checking compatibility with anticipated secondary assembly operations How to protoype? Prototype molds may be simple or complex, steel or aluminum. Injection molded prototypes from molds that have cooling channels can supply cycle time estimates and guidelines for commercial tooling. Determination of shrinkage factors, optimum gate sizes, vent locations and effect of mold temperature should also be established. Molded prototypes are preferred because flow orientation may influence performance. The latter is particularly important in glass-filled compositions.HS Mold excels in…

Cold slug well is a very imporant part of plastic mold design. It is  defined as the small nub of plastic that cools and solidifies inside the nozzle tip during the cooling cooling phase of the injection cycle. It is designed to store cold slug  caused intermittently by the nozzle due to heat loss and low temperature. Cold slugs could clog or slow down the material flow in runner and cavity and cause cold scars or cold marks on plastic part. The cold slug well is usually placed at the end of primary runner. When the branch runner is too long, cold slug well should be designed as well to store the front plastic cooled by mold. Cold slug well is a very imporant part of gate system and it should not be neglected at mold design.   For molded plastic part made from flame-retardant PC, the design of cold well determines the the quality of…

Product name Plastic blower fan for power driven machine Product Material Engineering PP Injection molding machine 300 T Process Injection molding Runner Cold Sprue Cavity 1X1 This is a cold sprue injection mold for power-driven machine and the material is engineering plastic PP which is high temperature resistant. It is a thick wall plastic injection molded part. Our factory is equipped with various size of injection machine ranging in tonnage from 55 tons to 610 tons and shot capacities ranging from 1.3 oz to 80 oz. We can meet any of your custom injection molding needs using different types of plastics including ABS, PC, PP, Nylong and so on. We produce custom injection molded finished products and parts for direct shipment to oversea end customers  We produce standard and custom plastic products for various industries including Automotive, House hold application, Medical and more.  HS MOLD is a manufacturer of thermoplastic injection molding services including new product development,…

Product name Injection Molding Plastic Parts Product Material PP+30%GF Injection molding machine 480T Process Injection molding Runner Hot sprue Cavity 1X1 This is a hot runner injection mold for  injection molding plastic parts and the material plastic is PP+30%GF. A1 polishing finish on the surface. Our factory is equipped with various size of injection machine ranging in tonnage from 55 tons to 610 tons and shot capacities ranging from 1.3 oz to 80 oz. We can meet any of your custom injection molding needs using different types of plastics including ABS, PC, PP, Nylong and so on. We produce custom injection molded finished products and parts for direct shipment to oversea end customers  We produce standard and custom plastic products for various industries including Automotive, House hold application, Medical and more.  HS MOLD is a manufacturer of thermoplastic injection molding services including plastics engineering and design, custom injection molding, final product assembly, mold making, and prototype development.

Silver streaks are a very common phenomenon appearing on the surface of plastic injection molded products. They are shining line shaped patterns usually caused by moisture, but can also be caused by high filling rates and poor vents which can cause entrapping of gas either from the environment, mold water leaks, etc. These can be considered external appearance quality defects in exterior parts of consumer electrical products, automobiles, motorcycles, etc. The most commonly seen streaks are shown as below. Moisture streaks/splay marks Burning streaks/silver streaks   Dark streaks Color streaks     The cause for the formation of streaks can be deter-mined in many defective injection products only after costly investigations,especially as the appearance of burning and moisture streaks is similar.Extensive knowledge of the plastic,the mold design and the plastic injection molding processing are indispensable for overcoming the problem.Before launching expen-sive and time-consuming investigations the following points should be checked in the sequence given and if…

Product name Plastic motorcycle accessories Product Material PC Injection molding machine 480T Process Injection molding Runner Cold sprue Cavity 1X1 This is a hot runner injection mold for auto parts and the material plastic is ABS+30%GF. AND No black spots on the surface and no blinster！ Our factory is equipped with various size of injection machine ranging in tonnage from 55 tons to 610 tons and shot capacities ranging from 1.3 oz to 80 oz. We can meet any of your custom injection molding needs using different types of plastics including ABS, PC, PP, Nylong and so on. We produce custom injection molded finished products and parts for direct shipment to oversea end customers  We produce standard and custom plastic products for various industries including Automotive, House hold application, Medical and more. Since 2005, HS Mold has specialized in custom, high-volume plastic injection molding. Our team are committed to the success of your project and works hard to meet or…