How to choose the injection mold-oriented parts?

Injection mold in the production process have to assemble and test machine when the transfer mode assurance that direction and position between the male and female mold, guide parts should withstand a certain lateral force, played a role in guiding and positioning. This time we will realize the importance oriented parts, injection molds guide body parts including guide pillars and covers. So we have to analyze the problem of how to choose the orientation of parts:

1.Oriented structure of the overall design

(1) The guide member should be reasonably uniformly distributed around or close to the edge portion of the mold, the center to edge of the mold should be a sufficient distance to ensure the strength of the mold, to prevent the deformation of the press-fit guide pin and the guide sleeve.

(2) The mold according to the shape and size of a die typically requires 2-4 pillar. If, when the die punch and the die mold with the orientation requirements, the two guide posts of different diameters, or two of the same diameter, but the column-shifted position.

(3) Since the plastic parts are usually left in the male mold, so that the guide post in order to facilitate releasing the mold is usually mounted on a mother.

(4) Should guide post and guide sleeve bearing at the parting plane of flutes

(5) The axis of guide pins and bushings and guide holes should ensure parallel

(6) When be the plastic mold, should ensure that the guide member First contact, avoid public mode first into the mold cavity, damaged molding parts.

2.Design guide post

(1) A single section and stepped points

(2) The length of the guide post must be higher than the male die end face 6-8mm

(3) Part guide column head should guide cone or spherical

(4) There are riveted and fixation screws

(5) The surface should be heat treated to ensure wear resistance.

3.Guide sleeve and the guide hole

(1) Pilot hole without guide bush, directly open the template, the template is thicker, the pilot hole must be made blind holes, increased sidewall vent

(2) Guide sleeve has a sleeve type `stepped` convex Desktop

(3) In order to successfully enter the guide sleeve guide post holes, pour in the guide sleeve should have a rounded front r.

Line marks on the injection mold products, how to repair?

In the injection mould products surface, if showing a line marks, we should judge it was gas welding marks or scars? Mainly due to gas mark is produced by injection mold exhaust caused by bad, relatively good workpiece surface, would appear to be more dark. mainly due to the weld line is generated by the intersection of the plastic in the mold cavity will produce the weld lines, weld lines are unavoidable, can be used to increase flow rate, temperature, pressure, and other methods of reducing the apparent surface of the weld line to meet the requirements needed.

Fix two marks on the injection mold products are as follows:

The place where there is gas mark do some inserts:

1 plus exhaust can vent inserts molded in inserts in public;

2 Improved plastic mouth, or mouth into the plastic to increase the flow channel dimensions increased stiffener

3 products plus glue, or bottom

4 using high-pressure low-speed injection

5 die temperature rises

Weld line is to follow up the plastic mouth piece in the monument opposite direction, by adjusting the position of the plastic injection mold product not played, the product was out of position tuned piece of gum rift rift point of view on both sides of the plastic mouth is not very smooth, if it is, then it is the welding marks. From the reasons for the formation of weld lines, in order to reduce the weld lines, it is necessary to reduce injection or extrusion process material "after shunt convergence" phenomenon possibilities. In order to reduce and eliminate this phenomenon, the following methods:

1 Increase the mold temperature

2 Adjusting the injection speed

3 Full Exhaust

4 Keep the mold surface clean

5 Adjust the injection pressure and fill plastic pressure

The Guide for applying for China National Standards of Mould Industry

National Standardization Management Committee issued “2014 National Standards Establishmen Guide” on April 2014, proposed the key support direction, major domain and related requirements of China National Standards projects.

Plastic mould is the basis of manufacturing industry and the high-end manufacturing technique equipment. The basic manufacturing method, basic components and parts, high performance of machinery equipment ,and eco-friendly manufacturing development standard is the critical area for 2014 national standard establishment. The relative companies can use this chance to submit their standard in mold industry. There are two periods for submitting: April 1st ~ May 15th; July 1st ~ August 15th , the standard committee will sincerely offer organization and services work for submitting standards and project implement.

China Metal Tooling Exports May Exceed Japan

A few days ago, a Japanese media claim that, in the past Japan mold industry takes the leadership of the world, but now China has become a mold exporting superpower, threating the position of Japan mold industry. The statistics shows that the mould export of China is approaching Japan’s. Although the “Pure export” --the quantity which export minus import, Japan is twice of China, but there is some opinion says that China become the largest injection mold maker exporting country is only a matter of time.

The secret of China approaching Japan so quickly is the different manufacturing method. China implement line production via huge-crowd strategy, to make the mass production possible for mold making. In big scale mold factories of China, mold building are distinguished into different processes: design, machining, assembly, trial, correction etc. Japan’s molds are majorly built by small or medium scale factories. Among 8000 Japan mold factories, the small and micro factories with less than 10 staff. For 70% more. Japanese all-round mold makers constantly sharpen their skills, making the mould one by one, the work needs to be done by 10 persons in China can be done by only one in Japan.

The advantage of huge-crowd strategy is the workers can start work in a short time, but it also has lots of disadvantage such as a high employee turnover rate. The comment from the mould industry for the mold built in China is “ The price is 70% of Japan, and the quality is only 70% of Japan”. But China have begun the changes, more and more china injection mold manufacturer come to realize the importance of skillful employee, and there will be more factories introduce Japan manufacturing methods in the future.

Injection mold which elements in the design of an important consideration?

Injection mold manufacturer design has the following five points precautions. Below we explain each: 

Cavity Surface roughness: 

Injection mold cavity surface roughness directly affect gloss products, injection molding mold highly polished surface will be bright surface products, Wu Guang injection mold is prepared dull products. Multi-cavity die too if the surface roughness, the surface of the plastic sheet adheres easily mold cavity, the surface roughness value should be less appropriate injection molds. 

Implied ratio: 

Depth to width ratio than the plastic parts called extension, extension ratio reflects the ease of molding plastic parts, extension ratio increases, forming harder. And extension than the plastic variety, molding methods. 

Injection mold fillet: 

To avoid stress concentration, improve the impact strength, injection mold cavity surface edges and corners should be adopted fillets, corner radii should be equal to or greater than the plate (sheet) material thickness, but not less than 1.5mm. 

Slope: 

To facilitate the release, the slope of the mold is generally 0.5 ° -3 °, while the punch is 2 ° -7 °. 

Suction hole design: 

The most common is through the evacuation orifice. Suction hole size, quantity to meet the needs of molded plastic parts, generally for good fluidity, thin, plastic molding temperature is low, pumping holes should be smaller; plates thicker, pumping holes can be larger. Vacuum holes shall be designed to meet in a very short time the air out of the injection mold cavity, the article surface without leaving any trace request.

Injection mold of 3D surface model is the technical difficulties

Type in the manufacture of injection molds, 3D surface processing has always been a key,is also a difficulty.As early as in the traditional processing, type 3D surface has been made a lot of training to achieve, so that it will be affect the quality of the mould and processing effect.If can type surface 3 d modeling and nc machining

technology, so that can improve the work efficiency and quality of mould.Injection mould type surface 3 d modelling and numerical control processing technology is an indispensable part of modern mold production, is also cad/CAM technology applied in the mold production.

For injection mould type surface modelling and nc machining technology, has important theoretical and realistic significance.Injection mould, such as: small speakers front panel convex-concave shape is complex, modelling is difficult, the traditional processing and even difficult to achieve, even if also can not guarantee the accuracy, can be implemented machining efficiency.

Why automobile plastic mold shrink , how to solve?

Plastic products shrink is an inherent characteristic of the plastic mold products, because of thermal expansion and contraction causes.

When the injection mold products, the temperature is high, When finish auto plastic molding mold, temperature is low, Volume will be reduced, as to reduce the number of plastic mold products mainly to see what material!

For example, ABS shrinkage is 1.005, if done forming the size of 1000 plastic mold, die size should be 1005, Auto Mould size reach 1005, so that the size of automobile parts mold injection molding products out before they can meet the requirements.