Plastic moulding is the plastic work through the Injection moulding machine, The melted plastic will automatically molten after erupting out in all of the plastic moulding methods, injection moulding has been the most widely used. The method comprises the following steps: getting the thermoplastic plastic or the thermosetting plastic imported into the heating cylinder of the injection moulding machine, and when it is completely melted, it will produce heat and frictional heat by the pressure of the plunger or the screw, and is injected into the mould cavity of the closed mould, after curing, and then open the mould and take out the finished product.
Plastic Moulding Knowledge Guidance
1 The basic knowledge of plastic molding.
1.1 The characteristics and composition of plastic injection moulding.
Plastic Injection moulding is to fill the molten moulding material in a closed mould with high pressure. The pressure that the plastic molding cavity needs to be subjected to about 400 KGF / CM2, approximately 400 atmospheres. With such a high pressure to make a product is its characteristic which is not the only an advantage but also disadvantages. In other words, the mold always has to be made stable, therefore its’ price is always high. So must be mass-produced in order to buckle with high-priced mould costs. For example, the production of each batch must be more than 10000PCS to be reasonable. In other words, plastic molding work surely has to be a mass-production.
A few steps of the plastic molding process :
Close the security and then start moulding
1.1.2 Clamping mold
Moving forward the moving board in order to get the mould closed. When the mould is closed which means is also locked.
1.1.3 Injecting (including holding press)
The screw is quickly pushing forward, injecting the molten formed plastic material into the mould cavity to full fill it. Keeping the press at the same time after full filling it, this action is particularly named “holding press.” The pressing that the mold has to bear when it just gets full filled, generally called ‘Injection Press’ or ‘one press’.
1.1.4 Cooling off (and the next step of the plasticization project)
The process of waiting for the material getting cool formed in the mould cavity is called “cooling off”, At this time the injection device is also ready for the next step, this process is called “plasticization process. The moulded material is placed in the hopper, inflow into the heated tube to heat, it is based on the rotation of the screw turning the raw material into the molten status.
1.1.5 Opening the mould
Move the moving board to the backward and the mould will be opened.
1.1.6 Opening the security door
Opening the security door, then the machine will be in the standby status.
1.1.7 Picking up
Taking out the product, checking carefully if there is anything left in the mould cavity, and this whole forming operation is called moulding cycle time. The finished product is shaped by the shape of the mould. The mold is composed of the left mould and the right mould, These two sides of moulds are left with voids, and the material would flow into the voids and get compressed to finish the product. There are three main lines of the path of the molding material before it flows into the left side and right side, sprue, runner, gate, and so on.
1.2 Injection molding machine
Injection moulding machine is distinguished from two large projects, they are divided into two, clamping device and injection device.
1.2.2 clamping device
Closing the mould, the molding material would be cooled off and solidified in the mould cavity. Opening the mould cavity and take out the finished product is the action of the clamping device
1.2.3 Injection Device
Injecting the plastic material into the mould cavity called ‘Injection device’
The following describes the ability of the injection moulding machine, there are three provisions to distinguish the ability of it.
A. Clamping force
When the injection is made, the mould won’t be opened by the maximum clamping force, expressed as the number of TON.
B. Injection volume
The weight of a shot is generally expressed in terms of grams.
C. Plasticizing capacity
A certain amount of time able to melt the amount of resin, this is generally expressed in terms of grams.
The most important part is the clamping force, the area of the moulded article is referring the mould perpendicular to the shadow of the opening and closing direction (basically the moud’s area). The average pressure within the mold added to the projection area is called the clamping force. If the mold “projection area × average pressure” is greater than the “clamping force” then the left and the right side moulds will be pushed out.
Clamping force = projection area × average pressure within the mold In general, the mold can withstand the pressure of 400KGF / Cm2, so base on this figure to calculate the clamping force, but the clamping force often based on the shape of forming materials and the shape of the product’s vary, the difference between the larger parameters such as PE, PP, PS, ABS materials, these raw materials are used to make the shallow box, the parameter is 300KGF / CM2, , if the depth of the box is deeper then the parameter is 400 KGF / CM2, If it is the small but high precision products. The projection area is about 10CM2 or less, its parameters are 600KGF / CM2. The smaller parameters such as PVC, PC, POM, AS materials, these materials are also used to make a shallow box, the parameters of 400KGF / CM2, if it is a deep box of its parameters is 500KGF / CM2, if it is a small and high precision products, projection area of about 10CM2 below, its parameter is 800KGF / CM2.
To working with Plastic Moulding is not easy, if you have a project that needs plastic molding service you need to find a professional plastic molding company to support you, to reduce your plastic mold and Injection moulding cost, find a Chinese molding company to support you will be one of the best options, plastic mould and moulding parts from China mold company has inexpensive price and short lead time, this is no reason that you do not choose your plastic molding supplier from China, on the world, over 80% or overseas companies that buy products from China, China is the biggest manufacturer country on the world, this is no doubt about this,
Sincere Tech is an injection mold company in China, offer injection mould, plastic moulding service to the world, 90% of our mold and parts are export to American, Europe, and the world, if you want to know more information about service, you are welcome to send us an email, if you need price for your project, please send us your requirement for quotation, we will offer you the best price and service. Hope to work together in the near future.