• Car headlights Car headlights

    With the development of national economy, automobile industry has become the pillar industry of the country. At present, the rapid development of automobile industry has put forward higher and higher requirements for automobile lighting. Car headlights use the most popular injection mould double injection mold.   The quality of the lighting of the automobile is very important to the safety of the driving, so the laws and regulations of all the countries in the world today have strict requirements for the lighting of the automobile. The design of the lamp not only meets the safety requirements of the regulations, but also meets the requirements of some other aspects, such as the shape of the whole automobile, is beautiful and practical, meets the requirements of the aerodynamics, and makes the driver and the passenger feel comfortable and convenient. Therefore, the design technology of the lamp is changing with the development of…

    plastic products October 31, 2019
  • Bottom of expansion tank

    This is the cover of plastic water tank for a branded automotive company. The material is PP. The part features with a long BOSS and round undercut of 1mm. The BOSS structured with a round pin on the cavity followed by forced demolding. In most shops, slides are usually used to form the feature but this is a waste of money considering the quantity of the products. So we use insert to make the BOSS. Since undercut is to assembly the water tube, we have to keep tight control on the undercut measurement. After forced demolding, the size of would become smaller. So we have to check the dimension of of undercut after trial and then use mirror EDM to machine until we get the right size. This process usually has to been repeated over 2-3 times. For the water tank, the key technology is the part must be flat…

    plastic products October 31, 2019
  • Plastic tank of automotive

    This plastic mold for the bottom of water tank is the most simple one among those hundreds of complicate tanks we have ever made. As the same with other water tank, the key technology is to control the part flatness without any deform and assembly holes must be aligned perfectly. If there is any warp, the two parts could not be vibrated-welding together and water leaks. In order to solve the issue, firstly we have to run mold flow to do a pre-warp analysis so that the warp degree could be calculated and gate position decided. Mold flow is only an assistant tool in theory. Sometimes, mold flow result differs greatly with actual result. According to our years of experience in making water tank injection molds, we know where to put the gate and what size to better control the even flow of the plastic based on the reading of…

    plastic products October 30, 2019
  • The cause of shrinkage of injection molded parts and how to solve them

    I believe that many mold manufacturers have encountered a plastic defect-shrinkage on injection molded parts. Few processors really know how to solve the shrinkage issue technically.In most case, mold makers just increase injection pressure,use longer injection time,or open larger injection gate, only annoyed to find that the issue is still there. Among the commonly used raw materials, the shrinkage problem of modified PC and PP are the most difficult to handle due to fast cooling rate. Through 20 years, we have made plenty of plastic components with different kinds of resins for our global customers and has mastered some unconventional molding techniques to improve the shrinkage problem on plastic molded parts with thick wall. Basically, the plastic shrinkage defect could be contributed to 3 aspects, molding machine, plastic mold, and plastic material. Injection molding machine Cause:1: The injection pressure in the cavity is too low.2: Insufficient plastic in the cavity.3:…

    Injection molding process October 28, 2019
  • Vacuum cleaner product

    The part is main body for vacuum cleaner and plastic material is PP. Usually wherever the part undercut between is 0.2-0.5mm and there is no room for either lifter or slides, we will adopt use demolding. However, this under cut is as big as 10mm, so we have to use lifter on cavity and tunnel slides on the core. For the big size hole on the middle, it is 100mm deep and cooling water could not get into the block. So we have to use mold max as replacement for the cooling. Another issue comes out, use mold max as inserts on cavity, the insert line is unavoidable on cosmetic area. On one hand, machining need o be precise as possible to minimize the gap, this could be done on our high speed CNC machine. On the other hand, we suggest client to texture the area to cover the insert line….

    plastic products October 26, 2019
  • How to fix injection molding defect: Brittleness

    Nowadays most of our daily products are made from plastic materials.However, many plastic product manufacturers encounter one injection molding defect that happens from time to time and that is part brittleness.  Brittleness appears when the part breaks or cracks upon ejection or after it is ejected during handling.  According to our years of experience,  we found that the the likely causes could be contributed to either Material, Mold, or Machine causes.   Injection molding Process  Cause: (a) the melt temperature is too low (b) The plastic degrades in the shot cylinder, causing cracking of the molecular structure of the plastic. (c)  Mold filling speed is too slow.   Remedy: (a) increase the mold temperature. Keep sufficient supplementary material on the barrel of                              injection molding machine. (b) Reduce the temperature of the shooting tank in all areas.Reduce back pressure.Use…

    Injection molding process October 24, 2019
  • How to fix flow mark on automotive Dashboard

    More and more  large size of  plastic injection molding parts are used in automotive industry. For consideration of cost, the application of spray free injection parts is more and more extensive. However, this also requires higher cosmetic quality of injection molding parts. On some large parts such as bumpers, dashboards, door panels and long interior plastic accessories, it is very common to see an appearance defect characterized by a streak or stripes perpendicular to the plastic flow direction, which looks like a pattern on the skin of a tiger. We call this “Tiger Flow Line”, for more information on the flow line, please                                                              Tiger flow line   Below is an example to demonstrate how HSMold solve this kind of issues. Product name Dashboard Material PP Color black Mold Tem….

    Injection molding process October 23, 2019
  • Plastic housing for driving system of automotive

    This is the plastic housing for driving system of automotive. It is usually made of aluminium, but automotive companies are now using plastic as replacement to save cost and energy. Material is Nylon+35%GF. The mechanism of the plastic injection tooling is quite complex with 11 lifters on cavity and 4 lifters on the core. Firstly, as know, the part bottom needs to be quite flat without any warp,otherwise the oil may leak. Secondly, there are 16 locating holes around the parts, and each of them contracts towards different direction irregularly and the position of the holes move during the molding process. In this case, we have to make all holes as inserts and note down the molding parameter. After trial, we measure the actual position and make new inserts. This process has to be repeated until the holes fit with the assembly metal parts. The big hole on the middle…

    plastic products October 21, 2019
  • How to fix Tiger flow line on the automotive plastic part

    The amount of plastic used in automobile has become an important symbol to measure the level of automobile design and manufacturing technology. At present, more than 10% of the domestic automotive parts are made from plastic including exterior trims such as bumper, skirts and fenders, and exterior trims such as instrument panels, panels and pillars, also engine peripheral parts such as GOP, covers and inlet manifolds. Most of the plastic automotive parts are injection molded because the process has unbeatable advantages such as short molding lead time, high production efficiency and low manufacturing cost is low. However, the coin always have two sides. There are also some plastic defects such as Tiger Line that we could not overlook What is Tiger Flow Line then? Tiger lines are streaks, or wave lines –  look like patterns on tiger skin, with stripes about perpendicular to the direction of melt flow,which is a kind of flow mark.  It usually shows up on automotive…

    Injection molding process October 19, 2019
  • How to fix Splay mark on PP plastic injection molded part

    Splay mark, is also called as Splash Mark or Silver Streak.It is a cosmetic defect that occurs in plastic injection molding process, when silver or white streaks appear on the surface of the molded part. Sometimes Splay can be quite difficult to determine, as the appearance is very similar to other injection molding defects, such as surface scratches, scuffs, flow lines, delamination from contamination, and flaking (also known as cold slugs).   Why there is Splay? There are many possible reasons for the appearance of splay mark, molding process, the mold itself, the machine, or the material.   Material The most common cause of splay is material moisture. It is easy to identify that.  The moisture splay does not occur in the same place every time, or in some cases the splay is all over the part. In this case, use dry material, review material drying process, review material storage for contamination issues Molding process  Too much heat can have an appearance similar to moisture splay. The…

    Injection molding process October 19, 2019