Get Adobe Flash player
PLASTIKS on line. Home
Русская версия
magazine conference catalogue
#11 (33), 2005
#10 (32), 2005
#9 (31), 2005
#7-8 (29-30), 2005
#6 (28), 2005
#5 (27), 2005
#4 (26), 2005
#3 (25), 2005
#1-2 (23-24), 2005
Mobile version

Molds: tendencies  #3 (25), 2005

 Innokenty Patrikeev,
general director of SmirnovTekhnologii

Molds: tendencies World tendencies show that plastics consumption has exceeded all expectations in recent years, and that is why application of injection molds becomes more urgent for Russian economy as well. On the other hand, however, interest in manufacture of products by applying of molds results in that there are a lot of new companies appear in the market. They only begin to master plastics processing and are not always acquainted with peculiarities of such a specific product as a mold is.

As a rule, would-be customers of molds are representatives of small and medium-sized business that have just come into being and cannot afford themselves large capital investments. Such customers produce ready-made products and try to reduce expenses of preparation for production to the minimum. In this connection moldmakers have to face up to the task of surviving in conditions of acute competition: to cut down production costs, to reduce production time, to increase operating reliability of the products.
World practice proves that solution of these global tasks could be found in creation of well-developed infrastructure that would provide maintenance of moldmakers. Specialization is essential for achieving maximum efficiency of operation. And set of equipment necessary for effective solution of the whole variety of tasks arousing in the course of molds production is very large and expensive. Moreover, even if a producer purchases such modern equipment he is inevitably faces up to a problem of its loading, as Russian market is still not able to provide loading stability in molds production.
So what situation is like in the market? Customers want cheap and quickly manufactured molds, and producers receive an order and try to keep their balance on the edge of profitability of their production and have to solve their problems by half-primitive methods. It seems like a vicious circle, doesn"t it?
pic 1. Structure of preparation for an electronic device production Let us go back to the beginning of the article. New molds customers have to minimize expenses on preparation for production and have to entrust key stages of components production to some other company leaving for themselves assembly production of ready-made wares. Let us examine the structure of such production using an electronic device as an example (picture 1).
As a rule, customers strive to minimize expenses while switching over from one stage to another - that is why it is to their interest to entrust all the elaboration stages to one company. Those companies able to carry out the whole work on a high level - beginning from elaboration of a product"s design to production of equipment and spare parts - are really appreciated by customers. So far there are not many of such companies, especially the ones having large experience in it. But still they exist. For example, Nypro, AB Universal, group of companies SmirnovDizain and SmirnovTekhnologii. The latter offers its customers the whole complex of services: from drawing-up market strategy, working out a brand, style of the company, packaging and industrial design of a product to molds production and supply of lots of plastic parts (picture 2).
pic 2. Outline of a complex solution of customers So, complex approach to customer"s needs is the main part of making producer"s work more efficient.
As it was mentioned above, the world of moldmakers develops according to the law of specialization. Nowadays acknowledged leaders in development of molds production are countries of Southeast Asia. How the development is going on? Let us consider molds production in China in detail.
In mid 60-s last century Chinese industry which was oriented on centralized management and planned economy could not be compared with the Russian one. However, reforms started by Den Syaopin had beneficial effect on increase of investments to certain regions of the republic (free economic areas). Foreign small- and medium-sized companies that always quickly respond to low taxes began to appear there. As a result, nowadays there are over 3 thousand small- and large-scale moldmakers only in one region Donguan. On average every such company has 100 workers in its staff and produces about 50 molds a month. More than a half of the equipment is manufactured for export mainly to Japan and America. Russian companies as well entrust a lot of their orders to them. So, what are the peculiarities of work with an average Chinese company that produces molds?
As a rule work at a factory is carried out by two work-teams in two shifts. Production cycle is divided into the following parts (for molds of average complexity and sizes):

1) working out of design documents - 4-7 days;
2) making orders for mold blocks - 7-12 days;
3) simultaneously - making orders for steel on forming elements- 5-8 days;
4) production of forming elements - 7-10 days;
5) thermal treatment of forming elements in specialized organizations - 3-5 days;
6) mechanical treatment of standard blocks - 3-5 days;
7) assembling of molds - 2-3 days;
8) total before the first tests - 26-42 days.
According to the dates we see that for 4-7 days one person works out the whole design documents for molds (in Russia this period may come up to 1-2 months). For such a short period a designer is not able to analyze profoundly all the peculiarities and subtleties of a construction and to find an optimal decision for a certain customer. Planning is conducted on the basis of typical completing parts and constructive decisions. Moreover, extra durability is attached to a mold which results in increase of its sizes and weight. Production costs of the product, however, practically do not rise as the cost of blocks purchased increases only a little with insufficient extension of sizes.
We should mention as well that if a customer does not point out constructive peculiarities necessary for his production, then all the work is carried out by the principle of saving production costs and labor consumption.In this connection many Russian customers who have no distinct idea what a mold is meet some difficulties with its operation. They are inclined to feel firm lack of sympathy to Chinese producers. On the other hand, equipment is manufactured fast and without large expenses. That is why effective results in cooperation with Chinese producers may be achieved only when all the necessary requirements to the mold ordered are clearly defined.
For Russian producers it is important to understand that modern Russian economy has undergone irreversible changes towards dynamic filling of economic gaps. Whether would-be customers of molds will survive in the market depends to a great extent on how fast they will present their new products. They are ready to take risks and to order tooling in Southeast Asia, even if there is no guarantee on the producer"s art, for the sake of reduction of time for introducing their products in manufacture.So, the second condition of increase of producer"s work efficiency is to apply typical decisions combined with the balance between price and quality.
Operation of many molds is carried out on equipment and with the help of other companies to which customers lease this equipment. Life of molds operation depends on conditions of their exploitation. However, such approach to organization of a production cycle of wares manufacture causes problems with molds exploitation. Problems appeared may be various, but we would like to consider the most frequent of them:
pic 3. Sectional elevation of a mold in injection molding machine
1) score on movable parts of pushing system;
2) deformation of forming elements" parts in "double pressing" of casting in case of its jamming in a mold;
3) break of parts of material in mold cavities or places of material injection (tunnel pouring gates) and scratches on forming elements" parts caused by careless extracting.
In the first, the most wide-spread case consequences may be various: from necessity to replace pushers to necessity to replace forming elements" matrix. Score on rubbing surfaces may be caused by small elements that can appear on them, by warp of mold plates in operation. To avoid this it is necessary to observe the rules of molds storage and to keep up cleanness in molding section. The rate of molds deterioration depends on how much the injection molding machine is worn out. Let us consider constructive methods of diminishing the consequences of this situation.
pic 4. Section of a pusher Pusher plates 1 (picture 3) in molds operation are connected by a shank 2 with injection molding machine 3 and undergo uneven working load which leads to warp of the whole pushing system. This results in fast deterioration of pushers. To compensate for warp it is necessary to use the length of pushers themselves and to leave precision landing only at their end (picture 4: 1 - wrong, 2 - right).
An important condition, both in the first and in the second case, is hardness of the parts. The harder the surface is the more wear-resistant the place of parts conjugation is and the higher their durability with warping loads is. However, hardness of parts influences greatly labor-consumption and the cost of production. If series of products manufactured are not large, the right decision will be to increase capacity of equipment operation; to choose gentle operating conditions; to have an operator who will constantly monitor the molding process; to apply protective micro-switches that would fix reverse motion of pushing plates.
In the second case an effective protective measure could be spring-loading of the central pusher (picture 5).
pic 5. Section of spring-loading mechanism It makes it possible to achieve stability of casting extracting, practically without increase of molds costs.
In the third case we deal with output of defective parts. Losses depend on how soon this damage would be found out. To prevent such situation it is necessary for tooling design to choose proper gradient angles of vertical walls of forming elements" parts in accordance with the type of surface selected and to carry out polishing of tunnel parts of pouring gate. It is also of a great importance to choose right places for arrangement of pushers.
These are only some problems that appear more frequently. Their solution does not claim for large expenses on the part of moldmakers, however, it contributes to increase reliability of tooling in operation in most various conditions that may arouse when the customer leases this tooling to some other company.
So the third condition for increasing effectiveness of producers" operation is to apply constructive decisions that improve reliability of molds in their exploitation.
The three development trends described above enable to improve the quality of moldmakers" operation and to increase their competitiveness in dynamically developing Russian market.

Beginning of the article To order the translation Back to contents
Complete or partial copying of articles in Internet is permitted only with special reference to "PLASTIKS: plastics processing industry" magazine's site, in printed media - with written permission of the editors.
Weekly news alerts
Яндекс цитирования
"ПЛАСТИКС" стал мобильнее

Уважаемые посетители сайта "Пластикс"

С июня 2013 года для пользователей планшетных компьютеров на Android и iOS доступно мобильное приложение (инструкция здесь).

Вы можете бесплатно ознакомиться с одним из номеров журнала (№6, 2015) через мобильное приложение.