What is an insert injection mold?
Metal or other material parts such as bolts, terminals (pieces) embedded in the molding process or pressed into the molding process of plastic mold products are collectively referred to as embedded parts in plastic mold products. Molding OF INSERTS COMPLICATES OPERATIONS, LENGTHENING CYCLES, AND REDUCING PRODUCTIVITY (MANIPULATOR WITH AUTOMATIC CLAMPING INSERTS OR AUTOMATIC LINES ARE not INCLUDED).
The manufacturing process of insert molding
Insert molding is the process of molding a thermoplastic material around a preformed assembly (insert) to create a part containing a variety of materials. Inserts are usually metal parts used to enhance the mechanical properties of plastic parts. The insert is placed into a plastic mold, and then thermoplastic is injected into the mold to form the part. The USE OF moulDED INSERTS REDUCES COSTS BY ELIMINATING the NEED FOR SECONDARY INSTALLATION OF INSERTS, AS compared TO INSTALLING INSERTS INTO PLASTIC PARTS DURING post-MOLDING.
What is the purpose of an injection mold for an insert?
1, save injection mold manufacturing materials
The injection mold is fixed by a regular block of steel in a fixed shape, either front or back. If one part is higher than the other, inserts can be made to reduce the height of the mold.
2, convenient mold change
Where the injection mold is often modified, it can be removed to make inserts, and only inserts should be changed when the mold is changed later, and even a few inserts can be replaced when the mold is opened, so that it is convenient to modify the mold.
3, conducive to injection mold exhaust
Injection molding die exhaust is very important. If the exhaust is not good, there will be trapped gas in the mold cavity, especially in the relatively deep bone position. Injection molding, the product is prone to bubble or shrinkage, lack of glue, white or black spots and other adverse phenomena. Thus, inserts can be added where the mold needs to be vented, and the fit gap of inserts can be used for venting.
4, convenient injection mold processing
There are some deep bone positions in the injection mold, which are difficult to be processed by the cutting tool. Although the EDM can be processed by electric spark, the EDM processing speed is slow and the processing efficiency is not high, so the insert is generally chosen to reduce the processing difficulty and facilitate the exhaust. The other is the deep bone type saving mold, because the mold must save the place saving mold is very inconvenient, but in these places to open the insert, open the province is much more convenient.
5, extend the service life of injection mold
Generally speaking, the injection mold needs to design inserts, often is the easily damaged part of the mold, once the insert damage can be replaced, so as to extend the service life of the injection mold.
The characteristics of injection mold for insert
1, the easy molding of resin, bending and metal rigidity, strength and heat resistance of the mutual combination of complementary can be made into complex and delicate metal plastic integration products.
2, especially using the combination of resin insulation and metal conductivity, made of molding products can meet the basic function of electrical products.
3. The pre-forming combination of multiple inserts makes the post-project of product unit combination more reasonable.
4. Inserts are not limited to metal, but also cloth, paper, wire, plastic, glass, wood, thread, electrical parts, etc.
5. For rigid and flexible forms on rubber sealing pads, the integrated product can be molded by injection molding on the substrate, eliminating the complicated process of arranging the ring of seals and making it easier to automate the assembly of the subsequent processes.
6, because it is fused material and metal insert joint, compared with the pressing molding method, metal insert gap can be designed more narrow, composite product molding reliability is higher.
7. Senior VARIATIONS OF RESIN, SUCH AS GLASS, COILS AND ELECTRICAL PARTS MAY BE SEALED AND SET WITH RESIN FOR APPROPRIATE SHAPING CONDITIONS.
8, choose the appropriate mold structure, the insert can also be completely sealed into the resin.
9. The combination of vertical injection molding machine and manipulator, the whole line device of insert products, etc., can achieve automatic production in most of the insert molding projects.
10. After molding, the insert can also be made into a product with a hollow groove after the core hole treatment.
Points for attention in the design of insert molding mold:
1, insert molding is easy to produce forming shrinkage rate is uneven, in advance should do important parts of the shape, size accuracy limit test.
2. The insert is easy to deform and shift during the injection process, so the mold composition and the design of the mold shape that can easily maintain the insert should be fully considered. For products where the shape of the insert cannot be changed, prior testing is essential.
3. The arrangement and separation of the insert and the use of conveyors, the contact between the insert and the insert and the vibrating ball will cause subtle damage to the surface of the insert, and affect the quality of the product. The allowable limit of quality should be confirmed in advance.
4, should be determined in advance because of the embedded stamping process caused by sawtooth, warp, material thickness, diameter difference, gold processing caused by thickness difference. On this basis, the selection design of the automation device and the design of the mold structure are carried out.
5, mold gate location, molding cycle and other constraints on the mold structure of predictable matters, as far as possible to solve in advance or have the corresponding improvement countermeasures.
6. It should be confirmed whether the insert needs to be preheated or dried. The purpose is to ensure the stability of product quality and molding.
7. Various detection devices set in the mold are used to ensure the stability of forming action under the influence of heat, force, vibration and other environmental conditions of the mold. Whether to use them should be confirmed.