Design of Home appliance mold manufacturer

Home appliance mold is the main technological unit common for molded parts from thermoplastic polymers. It consists of a static half and a movable half, which inside contain a forming cavity that sets the desired shape for the product.

Plastic injection mold designs are either single-cavity or multi-cavity. Moreover, molds with single-cavity are common to produce one part in one cycle. Molds with multi-cavity are designed to create a series of parts in one cycle. The cavities of multi-cavity molds interconnect by one injection gate.

Making Process of Home appliance mold manufacturer in China

Molds are designed separately for each product according to the customer’s specifications, taking into account the requirements for quality and accuracy of parts.

Work order:

The preparatory stage includes:

1. Development of project documentation;
2. Creating sketches;
3. Designing a 3D model for the product.
4. A mold prototype creates, testing performance, and the result analyzes.
5. With a positive test result, then we can proceed to the manufacture of molds.
6. Workpieces process for home-appliance injection molds. Auxiliary elements: bushings, shanks, ejectors, and various rods machine on lathes.
7. Holes drilled for fasteners, guide columns, and bushings.
8. Finishing of forms, grinding and polishing of the planes of plates, and forming cavities carry out.
9. Steel parts are heat-treated to relieve the metal stress and prevent deformation.
10. After heat treatment, the shaping faces of the core and cavity are polished and chromium-plated to increase strength, hardness and wear resistance. Moreover, to prevent the material from sticking and create a smooth surface of the castings, after chrome plating, re-polishing was performed.

Molded parts of the molds are sent to the home appliance mold manufacturer in China, where they are assembled, and tested. However, to create molds, CNC boring, milling, grinding machines and manual work of qualified turners and locksmiths are common.

Types of home appliance molds

Moreover, molds for plastic injection are automatic and manual, removable and stationary.

According to the molding technology, they are divided into:
1. Direct pressing. The molten polymer is poured directly into the cavity mold, after which the core mold lowers, giving the part the necessary shape. However, this method is suitable for creating small batches of products.
2. Injection pressing. The molten raw material enters through special channels (sprues) into a closed mold. Moreover, this technology allows you to create parts of any shape and size. It is suitable for high-volume production.

Two-plate molds

Cold runner designs with a single plane of separation are the simplest and most common forms.
However, they consist of a fixed plate and a movable plate.

Three-plate molds

They consist of a fixed plate and two movable plates. The mold opens on two planes. Moreover, one plane is common to extract the finished part, the second is common to remove the sprue. In this case, the sprue can place anywhere in the product. However, it is important that the opening lines are on an invisible part of the part.

They are common to create objects of complex configurations.

Hot runner molds

They have gating systems equipped with heating elements. Moreover, they consist of a set of nozzles and distribution manifolds located in the array of the cavity mold. However, in hot runners, the polymer mass remains hot for a long time and cools slowly. This reduces the amount of waste.

Mold design for home appliance molds

Plastic injection molds consist of some steel plates on which there is a fixed plate and a movable plate normally. Moreover, inside the structure there is a shaping cavity, exactly repeating the geometric parameters of future parts. Molten polymers are injected into the cavity through special gating channels.

The molds are equipped with:

• Bushings and columns that provide centering of molds when closing;
• Ejector pins or pushers for removing finished parts from the device;
• Backing bars and plates, providing the required amount of stroke of the pushers;

Cold runner or hot runner systems

Moreover, the set of molds’ elements remains the same, regardless of the configuration of the final product. Cavities and cores must be of exact geometric dimensions with a clear joining of surfaces. However, ensuring the creation of high-quality parts, contribute to the economical use of raw materials.

Design and Manufacturing for Home appliance molds

The creation of molds for plastic injection is an important process that requires strict adherence to the technological stages of work. Moreover, the quality of future molded parts directly depends on the accuracy of the tooling.

Violation of technology of the molds can lead to heterogeneity of the structure, the formation of cavities, shells, and cracks, and violation of the geometric parameters of future molded parts.

The production of molds carries out in stages

First stage: a design for home appliance mold

The creation of molds begins with their design. A sketch should be prepared, and the working drawings should be developed. A three-dimensional model of the product should be sent to the production department using 3D computer modeling. Most importantly, the working draft should be agreed upon with the customer.

Second stage: detailed prototype

In the second stage, a detailed prototype of the desired design comes. With the technology developed, technological programs for automated home appliance molds should be written.

Third stage: build the molds

Forms are created on milling and electro erosive machines

Shaping cavities cut out of steel blanks. The metal removes in layers. However, between the stages of work, steel normalizes to relieve stress in the array, hardening performs to increase strength and prevent deformations.

Grinding and polishing of products carry out. Moreover, finished elements assemble into a single mold. To increase wear resistance and create perfectly smooth surfaces, chromium plating of shaping surfaces performs.

Cooling systems of home appliance molds

Cooling molded parts is an important process, which determines the speed of the production cycle. The cooling system consists of straight, annular, and spiral channels with cooling liquid inside the shaping elements.

Moreover, for cooling, cold water, glycol solution, or temperature-controlled oil is common. The liquid is fed to and removed from the mold through special hoses.

Completion of the production cycle

After completing all work on the creation of molds,  home-appliance mold manufacturers in China will test the molded parts in working mode. The test can carry out in the presence of the customer.

Home appliance mold manufacturers in China will give test results, mold trial reports, molding process cards, and molded products to the customers for approval. Moreover, after acceptance of the samples, the mold and the finished equipment related to the mold will be packed, preserved, and then sent to the client.

Making Plastic Injection Molds

The injection mold is used for the production of molding plastic products.  Standard molds consist of fixed half and movable half.

Features and steps of the injection molding process

Firstly, the process of molding plastic products is carried out in injection molding machines with CNC and includes the following steps:

1. Preparatory work:
2. Calculation of the proportions of the material;
3. Setting up equipment and molding programs;
4. Installation and fixing of molds;
5. Loading the raw material into the hopper.
6. Heating polymers to a molten state.
7. Moving the melt with a screw through the gating runners into the mold.
8. Cooling and extraction of finished parts.

Moreover, if necessary, mechanical refinement of products is carried out.

Injection mold manufacturer in China: where to start

Secondly, the development of a plastic business of injection mold should begin with the selection of a production facility and the selection of personnel.

Choosing the right location

Business premises are best rented. This contributes to the rapid start-up of the production line.
There are some requirements for premises for locating production of plastic injection:

• Remoteness from residential buildings;
• The presence of natural ventilation in the premises;
• Compliance with fire regulations;

Moreover, the minimum area of the production workshop is 50 square meters, and the warehouse space is 80 square meters.

We calculate the required area depending on the size and number of products produced and based on the business scale.

Recruitments

Thirdly, and most importantly, the success of the enterprise and the quality of products directly depend on the professional of the production manager or technologist who manages and monitors compliance with the molding technology.

The company must have the following staff:

• Designers;
• CNC machine operators;
• Mechanics for maintenance of mills and mechanisms;
• Product quality control specialists;
• Movers and laborers.

However, to service a small manufacturing enterprise, a staff of specialists and auxiliary workers in the amount of 6-8 people may be enough. In addition, you need to hire proven and reliable specialists with work experience and relevant qualifications.

Main types of raw materials for injection molding in China

The selection of polymer compositions for the manufacture of plastic parts is the most important stage in the preparation of production.

Moreover, thermoplastic and thermosetting polymers, foam plastics are suitable for production:

• Polystyrene;
• Polypropylene;
• Polyethylene terephthalate;
• Polyvinyl chloride;
• Polyethylene of high and low pressure, etc.

In addition, the materials have different structures, melting points, and plasticities. Moreover, when changing raw materials, the equipment reconfigures. Polymeric waste should be sorted and crushed, washed, and dried.

Basic molding technology methods

However, for molding plastics, the following methods are good:

1. Extrusion – performed by extrusion or extrusion through a shaping mold. Moreover, it is good at manufacturing hoses, cable products, and other molded products.
2. Injection, in which the molten polymer, under high pressure, is injected into the mold. In addition, it is good for the manufacture of thin-walled parts of complex configurations, plastic cases of power tools and equipment, children’s toys.
3. Blow – to create hollow products: plastic containers, bottles, cans, medicine containers, paints.
4. Thermoforming – plastic products come by pressing. Moreover, good for the manufacture of disposable tableware, containers, packaging.
5. The intrusion casting method is good for casting thick-walled parts. However, the raw material pumps by means of a rotating worm screw.

In addition, there are complex technologies for molding: co-injection, sandwich, casting into rotary or multi-component molds.

These methods are good to produce multi-layer, two-component, multi-colored parts, products with a clear distinction between colors or outer coatings.

Injection molding technologies: production of thin-walled products

In addition, injection molding technology allows the production of thin-walled products of various configurations with thermoplastic polymers.

Moreover, the process of creating plastic products in injection molding machines includes:

• Loading raw materials into the receiving hopper;
• Moving granules under their own weight into the screw zone;
• Moreover, melting polymers to a liquid state;
• Injection of the molten mass under pressure into the mold;
• Cooling of the product with a gradual decrease in pressure and removal from the mold cavity.

Similarly, the produced items could also be reinforced, hollow inside, and multi-colored.

Choosing the right injection molding machine in China

However, the choice of equipment depends on the type of goods being produced.

Injection molding machine: electric or hydromechanical drive

In addition, it is an injection molding machine with an electric or hydromechanical drive for the creation of plastic products under pressure.

Consists of the following structural units:

• Loading hopper;
• Blocks of plasticization and preparation of raw materials;
• Main body;
• Closure nodes;
• Control module.

The press mechanisms can be located horizontally, vertically, be angular with a horizontal or vertical press. For various products, individual parameters are set for injection volume, speed, melting temperature.

However, injection molding machines can be with separate or combined plasticization and have several closure nodes. There are one or two-worm, piston, and worm-piston.

Modules of a fixed half and movable half

Moreover, inside they have a cavity for the injection of molten polymers. It is designed to create serial parts.

Molds are manufactured according to the customer’s specifications. The molds exactly repeat the outlines of future molded parts. However, finished molds are attached to the clamping elements of injection molding machines, and the molten polymer is injected into the cavity.

Vacuum raw material loader

In addition, units for injection molding automatically supply polymer granules to injection molding machines or extruders. Moreover, they consist of receiving hoppers, vacuum pumps, automatic dosing modules, air cleaners leaving the unit. There is monoblock and separate.

However, the compact monobloc loaders are easy to be placed directly on the injection molding machine.

Powerful separate loaders can transport raw materials

Feeding of raw materials is carried out by the method of vacuum suction of the material into the receiving hopper, from where the air pumps out by a vacuum pump. Moreover, under the pressure of its own weight, it enters the loading module of an injection molded in China, an injection molding machine, or an extruder.

Refrigeration unit for finished products

Similarly, this is good for cooling finished products in multi-batch production in injection molding machines.

Moreover, it shortens the production cycle for the manufacture of plastic moldings from molten raw materials. In conclusion, the automatic control system provides exact temperature parameters.