Transparent(clear) Plastic Materials’ Characteristics & Injection Molding Process
By virtue of its enormous benefits, such as light weight, outstanding toughness, easy molding and low cost, plastic is gaining more and more popularity in modern industry and the production of daily necessities, because it is an ideal substitute for glass. Especially, in the fields of optical devices and the packaging industry, it has witnessed an exceptionally rapid development. However, due to the fact that such plastic materials are required to be extremely transparent(clear), with great abrasion resistant and impact resistant features, a great deal of effort is needed in the aspects of plastic ingredients, as well as the technology, equipment and molds throughout the entire plastic injection molding process, so as to make sure that these glass substitute materials … Read more
Injection Molding Defects’Causes & Countermeasures
The causes and countermeasures described below are aimed to solve the commonly seen injection molding defects that might occur in ordinary circumstances. The examples are just based on my own personal work experience, so if there is anything inappropriate, you are welcome to correct me! Short shots (incomplete filling) (1) Short shots (incomplete filling): The molten plastic fails to fill up each and every corner in the entire molding space (the cavity). (2) Causes and Countermeasures Flash (1) Flash: Extra plastic material in the shape of films or burrs, which appears on the parting surface, around the runner or in the insert crevice. (2) Causes & Countermeasures (See the table below) *Note: Flash also tends to occur when the injection … Read more
Multistage Injection Speed Control
The proportional injection speed control system is extensively adopted by injection machine manufacturers. In this article, we are going to explain the benefits of applying the multi-speed injection molding process, while offering an overview on the role it plays in eliminating product defects, such as short shot, entrapped air and sink marks, etc. By virtual of its close relation with product quality, plastic injection speed has become one of the key parameters of plastic injection molding. By defining the front, center, and rear of the feeding speed segmentation, and realize smooth transition from one set point to another, a steady molten plastic surface speed can be guaranteed to turn out the desired product. We suggest the following speed segmentation principles: … Read more
Injection molding temperature for common plastic materials
Injection molding temperature is very important for plastic injection molding,right injection molding temperature is a guarantee of product quality and production effciency.we will show what is the best injection process for different plastic material. Front:The suck-back section is located at the forefront of the barrel, where the nozzle is situated. The temperature here should be a little lower than that of the plasticization area. Its main purpose is to prevent the molten plastic from flowing back through the nozzle under internal pressure. However, the temperature cannot be too low, or additional plasticization pressure will be required. Center:The plasticization area is located in the middle of the barrel, where the temperature will gradually rise above the melting point. The purpose of … Read more
Why is Mold Temperature So Important for Plastic Injection Molding?
In the plastic injection molding industry, some newcomers often ask: why the final plastic parts have a higher gloss when the mold temperature is higher. Now in plain language, let’s explain this phenomenon, as well as how to appropriately select the right mold temperatures. 1,Influence on Product Appearance: First of all, a too low temperature will affect the fluidity of the molten plastic, leading to incomplete filling; mold temperature influences the crystallinity of plastic materials. For ABS materials, if the temperature is too low, the final product will have a lower gloss. Compared with the filler, plastic tends to move to the surface when put under the high temperature condition. Therefore, a higher temperature will allow the plastic to contact … Read more
Wear Plate-Slider Components of plastic injection mold
Wear Plates The purpose of wear plates is to reduce the friction caused by slider movement, ensure smooth slider movement and thus increase mold service life; There are 2 types of wear plate: ① bottom wear plate and ② back wear plate; 5mm higher than the mold plate, the bottom wear plate is fixed on the mold plate and has direct contact with the slider; 0.5mm higher than the slider, the back wear plate is fixed on the slider and has direct contact with the wedge; The wear plate usually measures 8mm – 10mm in height; The contact area between the wear plate and the slider / wedge needs to be larger than 80%; when the slider is too big, wear plate … Read more
Angle Guide Pin-Slider Components
How to design an angle guide pin? The length of the angle guide pin is dependent on slider travel distance, usually a rounded number (5 times); a pocket hole needs to be set up on the mold plate since it’s longer than the slider; The angle of an angle pin cannot be larger than 25°; The angle pin hole on the slider is referred to as the pocket hole, with a clearance of 0.5mm of both sides and rounded off with a fillet; A slider can only be equipped with 2 angle pins at the most, which need to be distributed evenly; Slider travel distance = the distance between ① fillet tangent at slider pocket hole and ② the arc … Read more
Common Plastics Material Character and Performance
Polystyrene (PS) 1. PS Performance: (Hard Plastic) PS is an amorphous polymer with a density of around 1.04g/cm3, AKA standard plastic. With favorable fluidity and a low water absorption rate (lower than 0.02%), it is a transparent plastic material that is easy to plastic injection molding process. PS product’s light transmissionrate are typically as high as 88 – 92%, with strong tinting strength and high hardness; It is also non-toxic and odorless. However, PS products are highly brittle, stress cracks tend to appear (may be checked by soaking or wiping with kerosene); poor thermal resistance (60～80℃). 2. PS Applications: Ornaments, illuminated signs, lampshades, stationery, transparent toys, daily necessities, kitchen supplies, cups, meal boxes, cassettes and mirrors, etc. 3. … Read more
Mold Inserts for Injection Molding Tool
Mold inserts are the terms relative to the integrated core – when the mold core is made of a single piece of steel, it is called an integrated core, while an insert is a part that’s inserted into the mold core made primarily of the steel material. As a matter of fact, the biggest weakness of an insert is that it weakens the rigidity of the mold as a whole. However, the application of different insert materials is able to independently enhance the rigidity of the weak parts. Now, let’s see what the circumstances for mold inserts applications are: Material Saving. The dimensioning of a mold core is defined by its highest point. If there is only one single … Read more
Special Mold Design for Complicate Structure
Eco molding is a very professional injection molding company since 1998, we have accumulated lots of experience in plastic injection mold design, Now we share some special mold design for the complicated product. 1) sliders in sliders 2) design for bend tube 3, the design of a circular cylinder 4, Tubes with logo 5, slider on Arc 6, slider run by gears 7, special design 8, two times direction change