The Processible Plastic for Mold Making

1.       Introduction

The processible plastic — Hongke material is a fundamental casting material with high density, high precision and high stability and is suitable for cutting in high speed. It is widely used abroad in aviation, navigation stage properties, and electrical appliance where high quality mold and module are required.

Concurrently, only few countries in the world are able to produce this kind of processible plastic. With the development of high technology, the demand for high quality mold with a complicated curve shape, and difficult technique in manufacturing is increasing, As a result of their own limitation, the traditional casting material such as plaster, paraffin and wood etc, can not realize CNC numerical control rnanufactuimg and satisfy the need for development. Therefore the processible plastic replaces the primeval mold making material. Particularly in the 90's, with rhe spread of numerical control manufacturing technique, the phenomenon is even more outstanding. In early 80's, similar materials has been invented for smiuktmg cutting arid mold making on numerical control machine, but in our country this kmd of material relied totally on import until 1997. This fully demonstrated the importance of this kind of material for our mold making industry. For example mold making,casting mould,plastic injection mold etc.According to statistics, till April 1998, we have already 400 set of numerical control center (5 axises, 5 axises) of our mold making industry. It showed product simulating cutting requiring processible plastic. The demand is evident. As specified in 95 national plan, the annul output after 2000 of automobile will reach 2 million 7 hundred. Some 175 to 440 kinds of basic body type of automobile will leave for renovation and reform. The cycle for automobile type renewal is 6-10 years in our country. In the foreseen years the processible plastics will be used more extensively in life. Therefore the processible plastics - Hongke plastics is produced to meet the demand, its performance index has already reached the international standard for likewise products.

2.       Develop of the product

At the moment, only few countries are able to manufacture processible plastics worldwide. Before 97, china has spent over tens of millions US dollars on this material. To produce and nationalized the material and to cut the cost and replace the import products become urgency. It's a common knowledge that mold-making industry is the mother of modern industry. It is a significant symbol of industry development of the country. One cannot separate the development of mold material when talking about mold making. In the recent years, our mold making industry is transiting into modem industry development, CAD/CAM technique, numerical control manufacturing are widely used, consequently the requirement for the mold material is higher. Once a technician of a famous mold workshop discuss with us about producing a kind of basic casting material for high speed cutting on the numerical control machine, which should not be transfigured by the process,

of which the amount of abrasion of the knife should be low, and doesn't absorb moisture

and is antisepsis, with a sufficient degree of finish on the surface^ and be preservable over

long-term. The factory is allocated with CAD/CAM technique together with advanced

numerical control manufacturing center. But the so-called " processible material" has been

relied on import, which is expensive to buy and gives a long cycle for supplying. Hence we

made a survey over the mold making industry, and the result verified that the material has

a potential huge market. At that time, no such material was available nationwide, it is totally

relied on import. Therefore Honke material co. Ltd. began to engage itself on the research

and development of the material, during the formulation of the prescription, through

selecting various chemical structure of macromolecule to adjust, modify, and add ancillary

preparations and filling, can prepare double component mash like material and panel

material of different high and low density and performance index. When basal material is in

the basic system of macromolecule, add different modification monomer material of all

conditions, such as elasticizer, activator,  and filling etc can greatly improve the

technical performance of the processibel material. Below is a brief description at initial period of matching the material and reaction procedure.

Of which   Rl - diphenol  U- ammonia ester conjunction radical

R-       radical or hydrogen      - position of activity core

Hongke processible plastics has been identified as the provincial new product in 12, 1999, the serial number is Liao Jing ke jian zi No. 991072. The unified conclusion of Slie experts is Hongke processible plastic is the initiate of the country, which reaches the: International standard and can compete with the congener products abroad. Aftei Hcrgke processible material came into market, by 2-year trial making rind sdiing, it gained the praise of the industry and is able to replace the products of same category abroad. For example mold making,casting mould,plastic injection mold etc

3.pracal applicalions

As for automobile bumper, application of Hongke 970850 processible plastic, which has a unique rough integrated design, is the mold structure not available abroad, and it does not require bonding. From the product design we understand that mold material which have the following characteristics 1. Spare material 2. Save cost 3. Save the manufacturing time, are considered highly by the companies of the industry.

4.features and function

Hongke material is attaining credits from the industry for 3 great characteristics, which are

easy to manufacture, high stability and low cost. The   of the material, accommodates

the need for the development of the industry, shorten the mold making period, lower the cost and raise the precision. Copy the mold with the original, the material selected for copying the mold doesn't shrink, the stability of the dimension is sound, the adopted material has no ill effect on the original metal and non metal mold, easy for clean, has no limit on the dimension of the copied model, can adjust the time for mold making at will, Hong Ke Material guarantees the uniformed solidity of the copied mold, it is a beneficiary for the outside dimension of the whole mold, and raise greatly the quality of the mold product.

4.1     High precision, light weighted, applicable for all kinds mold design.

4.2     High precise processible plastics, easy to manufacture manually or by machine, high stability of the dimension.

4.3     Affirm CAD/CAM program, mold design, compound mold, and simulate structure mold.

4.4     Main mold fabricate, basal mold fabricate, copy mold, cast mold and clamp.

4.5     Use under the condition of rotate speed of 1 OOOrpm/min of the knife in milling

center, Hongke product is not disfigured or destroyed etc.

4.6     Appropriate rigidity, use 0.66mm milling cutting, with a depth of 10mm, chip removal is normal, long life of the knife.

4.7     After Hongke processible plastics is manufactured, the surface of the material has a high degree of finish, it is suitable for post orders techniques such as    and spray painting.

4.8     The measurement of the reproduced mold has a high stability, the made clamp performance has already reached the performance index of like products abroad.

Hongke Material        density 078g/ cm3

Qiba Material          density 0.77g/cm3

Thermal expansion

Name  Temperature  Relative elongation indicator      Average linear

expansion coefficient

°C    X L0 ~ *      X 10 ~ e/ °C

Qiba Material     20       0        0

Hongke Material 20 0        0

Qiba Material      50      1.643  41.1

Hongke Material 50 1. 682 51.1

Qiba Material     60       1.794  52.1

Hongke Material 60 2. 201 55. 9

Bend Resistant Strength obb (test condition span 30mr\, indenter diameter 20mm)

Name  Color of the Sample Sena resistant strength bbb(mpa)   Sample

measurement # 25

Hongke Materia!      white  32

Hong Kong Material          red     26

Pressure Resistant Strength

Name  Color of the sample  y

Hongke Material      white  pressure resistant strength is 26 tbb         -,

Hong Kong Material          red     when reach pressure resistant strength 25, Djrt?

bbb destabilized

The Above data is checked by Research Institute of Metal of China Science Institute. From the data, we can tell the China made Hongke processible plastics has a higher bend and pressure resistant strength than Hong Kong Qiba. Hence the made product     , hard and not easy to be damaged. The thermal expansion coefficient is little bit lower than Hong Kong Qiba material. This can be adjusted by changing the material recipe. For example mold making,casting mould,plastic injection mold etc