Plastic injection mold steel materials selection principle
Plastic Injection Mold Steel Selection for Molding Components Molding components refer to the mold parts or components which have a direct contact with the plastic materials to form a product, such as mold cavities, mold cores, sliders, inserts and lifters, etc. The steel quality of the molding components has a direct influence on mold quality and service life, and determines the appearance and quality of a plastic injection molded product, so plastic injection mold making factory must make careful selection. Generally speaking, materials have to be selected based on contract stipulations, client requests, as well as product / mold requirements and characteristics. Principle for steel selection of molding components: different types of steels need to be selected based on types … Read more
How To Design Parting Line for Injection Molding?
Type of Injection mold parting line 1.Horizontal parting line 2.Oblique parting line 3.Curve parting line 4.Injection mold parting line on shut off holes 5.Injection mold parting line on side holes General Principles for Selection of Main Parting line Protect the Inserts Usually, product disassembly needs to be considered before selecting the main parting surface, i.e. identify the secondary parting surfaces, and find out the lowest surface of the cavity insert which will serve as the main parting surface. Try not to let the cavity core enter plate B from plate A, so as to prevent the insert from being damaged during mold disassembly. Simplify mold structure, increase mold plate strength Identify the main parting surface based on the special structure … Read more
The spring for plastic injection mold
As an elastic component, the spring plays a very important role in a plastic injection mold, because a properly located spring is able to provide the necessary driving force that the mold needs. For example, when the ejection mechanism completes the ejection action of a plastic part, a spring can be applied to force the ejection mechanism back to its original position, so as to ensure the work process goes smoothly, i.e. the so-called return spring. To meet this purpose, different spring designs are required for different structural locations. Usually, rectangular springs are used in plastic injection molds. When mounted in the same space, the loading capacity of a rectangular spring is about 45% higher than that of a cylindrical spring, … Read more
The runner design
The Runner Design Concept The runner refers to the melt flow passageway between the end of the main runner and the gate, which is used to change melt flow direction and allocate it to each cavity in a stable and balanced way. The basic design principle of the branch runner is little pressure/heat loss, with the minimum quantity of plastic retained in the runner. Sectional Shapes of the Branch Runner: –Circular, with the minimum specific surface area (runner surface area/runner volume), but during production, both sides of the mold plate need to be aligned. –The commonly applied forms, trapezoid and U-shape are easy to process. –Semicircle. –Rectangle, larger specific surface area and high resistance to flow, thus seldom applied. The … Read more
Injection mold sprue bush (Main Runner) design
Mold sprue bush,AKA.The main runner refers to the melt flow passageway from the joint between the injection molding machine nozzle and the mold sprue bushing to the starting point of the branch runner. –The design has to minimize melt temperature drop/pressure loss. –Adopt the cone shape design, to facilitate removal of the condensed material Forms of The Mold Sprue Bush Fixing Methods of the Mold Sprue Bushing The main runner is usually located along the center line of the plastic injection mold, overlapping with the axle of the injection molding machine nozzle. In horizontal and vertical injection molding machines, the runner axle should be perpendicular to the parting surface. To facilitate removal of condensed materials from the main runner, the main … Read more
O-ring
What is the O-ring used for? In a mold structure, the cooling channel tends to leak at the joints between mold plates as well as those between the mold plate and the core insert due to the existence of joint gaps. To prevent this from happening, O-rings are often applied to seal the joints. Mold structure design should take the following principle into consideration in case O-rings are applied: Ensure sufficient positive pressure between the mold plate and the core/Cav insert. Please click below for O-ring detail HASCO O-Ring size and spec.
Injection mold sliders designing
1. When designing the injection mold sliders, the biggest clearance between the slider and the product should be at least 2 – 3mm. The inclination of sliders should be kept between 15 and 25 degrees, and the inclination of the guide pin should be 2 degrees smaller that of the wedge. The available diameters of the guide pin are 6mm, 8mm, 10mm and 12mm, with the min and max values being 6mm and 12mm respectively. If a slider width is larger than 60 mm, deployment of 2 angle pins needs to be considered; if the width exceeds 80mm, a guide bar needs to be placed under the slider in middle. If the injection mold sliders is too high, the starting … Read more
Guide Pins of plastic injection mold
There are many types of guide pin structures in plastic injection mold application, among which the standard structural design is shown in the figure below. A guide pin has to serve as the cylindrical surface of concentric circles of different diameters. Based on structural dimensions and material requirements, a round steel bar with an appropriate size can be directly selected as the material. In addition, the technical requirements of guide pins need to be satisfied during the machining process. Fig. 8-2 Structural Shape of a Guide Pin Technical Requirements of Guide Pins (1) At the joint between the guide pin and the fixed mold plate, the diameter concentricity tolerance should not exceed 1/2 of the diameter tolerance in the working … Read more
Mold texture
Mod texture Definition Texturing refers to the process that produces various patterns on the surface of a metal product through chemiosmosis, such as stripes, images, wood grain, leather pattern and stain, etc., while also including sandblasting, which means spraying glass sands directly onto the surface of a metal product. The Purpose of Mold Texture Improve product appearance. The texturing process is able to camouflage part of the shrinkage, welding line, parting line and steps of slider, etc. Product surface strength can be improved via texturing and sandblasting. Varieties of Mold Texture Sand Pattern Characteristics: Fast process, low cost and able to produce fine and 2D patterns. Satin Pattern Characteristics: Fast process and able to be applied to a plane surface. … Read more
A Brief Introduction to Ejector Pins Design
The Purpose of Ejector pins: Eject the molded part from the injection mold. Considerations for the ejection system: 1. Ejector pin holes should be at least 3/32” away from other holes; 2. At least a clearance of 1/32” for pin holes on the ejector plate; 3. At least a clearance of 1/64” for pin holes on the mold plate; 4. All ejector pins should adopt the standard dimensions; the ejector base cannot be ground lower; 5. During the injection molding process of nylon, LDPE or PP, the diamter of each ejector pin must be measured, because flash might occur when the clearanc between the pin and the hole is greater than 0.02mm 6. All ejector pin holes must be vertical … Read more