Injection Molding Gate Types（Updated）
Injection molding gate design Considerations: 1.A small opening between the runner and the mold cavity, of which the location, quantity, shape and size, etc. have a direct influence on product appearance, dimensional accuracy, physical characteristics and injection molding efficiency. 2.The size of an injection molding gate is dependent on product weight, material properties and gate shapes. The length, depth and width of a gate should be minimized on condition that product mechanical performance and molding efficiency can be guaranteed. 3.If the gate is too small, product defects like insufficient filling, shrinkage, sinking and weld lines will tend to occur, and molding shrinkage will increase. 4.If the gate is too big, excessive residual stress will be caused around the gate, leading … Read more
Hot runner systems types of plastic injection mold
How the Hot Runner Systems Works The cold runner of a plastic injection mold refers to the section between the mold inlet and the gate. The molten plastic maintains its fluidity inside the runner by virtue of the injection pressure and its own heat. However, as a part of the molding material, the runner is not a product. As a result, when designing a mold, we need to consider not only the filling effects, but also the material-saving effect produced by shortening or downsizing the runner; but in actuality, it is not easy for us to have the best of both worlds. Types & Application of Hot Runners When applying the hot runner technology, the proper selection of gate type … Read more
Injection Mold Cooling Systems
The Purpose of Injection Mold Cooling Systems The injection mold cooling system purpose is to ensure uniform cooling of the molded product and then eject the product out within a short period of time. The layout of the cooling channel plays an important role in the injection molding quality as well as the production cycle (cost) of a product. Influence on Quality: During the injection molding process, the cooling channel is used to control mold temperature, of which the fluctuation has a direct influence on product shrinkage, deformation, dimensional stability, mechanical strength, residue cracks and surface quality, etc. Mainly include: surface glossiness, residue stress, crystallinity and thermal flexure. Influence on Production Cycle: An injection molding cycle is mainly composed of the following … Read more
Injection Mold Venting Slot Design
During the plastic injection mold trial process, defects like short-filling, trapped air burns, high internal stress, flow marks and weld lines often occur. For those problems, the first solution would be adjustment of the plastic injection molding process, and another consideration would be the reasonable design of the mold gate. Once both of these problems are solved, the possible trouble could mainly lie in injection mold venting, to which the main solution would be the design of venting slots. The Function & Design of Injection molding Venting 1. The Functions of Injection Mold Venting A venting slot mainly serves 2 purposes, 1) Removing air from the mold cavity during the injection molding process; 2) removing the various gases produced during … Read more
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.