New Plastic Molding in china

New Plastic Molding in China

Multi-cavity plastic molding in china  technology requirements are often higher than the single-cavity mold, out of each cavity is the same, this will need a very high machining accuracy, as for many years engaged in the professional factory of plastic molding in china, we know that how to make the highest quality multi-cavity plastic injection molding , and high precision plastic products

Mold making in China

Our experience in plastic molding engineering thermoplastics is well recognized. Choosing the right type of raw material  for the plastic molding job is often critical and we are confident of the quality of our advice, because it is based on knowledge we have gained through many years in the industry.

We moulded plastic parts and components for many well-known products in many sectors of the china plastic industry ,Electrical, Lighting, Swimming Pool, Water Filtration,Hospitality Medical, Furniture,  Electronic, Automotive,Housewares, Scientific, Closures, and consumable products are just some of the industries we supply.

Our machines range in size from 80 tonnes to 650 tonnes. We can mould items (see below) weighing over 5 kg (5000 grams).

mold makers and plastic molding in china

mold makers and plastic molding in china

visit more information ablout plastic mold ,plastic molding from our website please

China plastic injection molding machine back pressure knowledge

china plastic injection molding company machine chooice

China Plastic Injection Molding Machine back pressure

The back pressure is one of the important parameters, it is control melt quality and product quality in china plastic injection molding process, the right back pressure plays an important role for improving product quality.    First, the back pressure of the formation    Plastination process in the plastic melt, melt constantly move the barrel front end (measuring indoor), and more and more, and gradually form a pressure to push the screw to the back. In order to prevent screw back too fast, to ensure uniform melt and compacted to provide a pressure in the opposite direction, you need to screw the opposite direction to prevent screw back pressure known as the back pressure.   China plastic injection molding machine back pressure, also known as the plasticization pressure, its control by regulating the injection cylinder back to the oil throttle. The back of the injection cylinder pre-plasticizing screw injection molding machines are equipped with back pressure valve to adjust the injection cylinder when the back of the screw rotation speed of the drain, so that the fuel tank to maintain a certain pressure (shown below); traverse the whole motor screw ( resistance) is controlled by AC servo valve. Second, the appropriate adjustment to the back pressure benefits     1, can barrel melt compaction, increase density, improve the stability of the injection amount of the products weight and size.     2, the gas within the melt can be squeezed out, reduce product surface air spend, internal bubbles, improve gloss uniformity.     Slow down the screw astern speed, so that the melt inside the barrel fully plasticized by Toner, Color Masterbatch and melt mixed, to avoid products blending phenomenon.     Appropriate to enhance the back-pressure, can improve shrinkage and product around the product surface to go plastic.     China plastic injection molding machine can improve the melt temperature, melt plasticization to improve the quality and improve mobility in the melt filling the product surface cold glue pattern.

China Plastic injection molding parameter and pressure

Two, the back pressure is too low, prone to the following questions     A back pressure is too low, the screw back too fast, flowing into the barrel the front of the melt density (loose), the folder into the air.     Will lead to poor quality of plastics and injection volume instability, product weight, product size changes.     3, the product surface will appear to shrink, spent gas, cold feed grain, gloss unevenness and other undesirable phenomena.     4, the inside of the product is prone to bubbles, the product of peripheral and bone bit easy to walk, dissatisfied with glue.     Third, the high back pressure, prone to the following questions     A barrel the front of the melt pressure is too high, the high melt temperature, viscosity decreases, the melt in the screw slot counter current barrel and screw clearance leakage flow rate increases, will reduce the plasticizing efficiency (per unit time plasticizing The feeding amount).     Poor thermal stability of plastic (such as: PVC, POM, etc.) or coloring agents, due to increased melt temperature and heating time growth in the barrel caused by thermal decomposition, or the degree of increase of colorants color, the product surface color / gloss worse.     3, the back pressure is too high, slow screw back, pre-plastic material back for a long time, will increase the cycle time, resulting in decreased productivity.     4, high back pressure, high melt pressure injection nozzle prone to melt salivation phenomenon; next injection nozzle flow tract of cold material can clog the nozzle or products of cold material spot.     5, in the pre-plastic process, often due to back pressure is too large, nozzle leakage glue phenomenon, a waste of raw materials and lead to burn near the nozzle heaters.     6, pre-plastic bodies and mechanical wear of the screw tube increases.     Fourth, the back pressure tuning   China plastic injection moulding machine back pressure adjustment should be considered the performance of raw materials, dry conditions, product mix and quality status the, backpressure general adjustment in 3-15kg/cm3. When the product surface to spend a little gas, blending, shrink and product size, weight changes may be appropriate to increase the back pressure. Drooling, salivation, melt thermal decomposition of the product color and return the material is too slow when the nozzle may be considered appropriate to reduce the back pressure.

welcome discuss for injection molding technology, or visit more from our plastic injectin molding information and our china mold makers capacity

Plastic mold maintenance experience

Maintenance plastic mold in china

Usually, customer will store  plastic mold in our factory long time, how to protect it and keep it working is very important.plastic mold

In order to secure production of high-quality and size of qualified injection molding of plastic parts, injection mold processing and storage, as well as during production, particularly carefully. When the mold is closed to start the next cycle, stranded in the mold plastic parts will suffer wear and this damage could further jeopardize the use of molds. Therefore, usually take measures to ensure that the plastic mold parts release and plastic mold parts reset before allowing the mold closed, with the one used to detect the plastic injection moulding parts falling photo tube enough for single-cavity mold. For multi-cavity mold, you can not use this methodology. In this case, using the following methods:- Template to reset device- Multi-pulse Ejection Equipment (pulse ejector)- Mechanical and electrical mold protection device- Air discharge device- Top of the board reset safety device .   Most of the above measures related to machine attachment, because they do not affect mold design, so this will not be discussed. However, the top of the board reset safety device need to change the mold structure. These elements will be discussed below.

Some plastic mold case

Cases 1l

To push the board to reset the safety device , plastic molded parts located in the dynamic model of the core or the back of the slider, then push the board reset safety device is used to check mold release parts back to the initial position of the molding. If not, it will interrupt the molding cycle. This safety device need to set up a moving mold mounting plate with a switch located in the mold on a receiver, when the push plate to the initial position, the mold on the switch on the action. Only when molding template light reset device, namely in deed piece was the top, the clamping device is closed, the spring force push down board back to the molding position, the push plate reset safety device was therefore play a role. By that time, the control system before the issue of ‘closed mold’ command. When the molds require long stroke of the mold release, the push plate by the spring return is usually not very reliable. To this end, a plastic moulding reset mechanism to meet this function. In Figure 1.40 shows the attachment of the push plate to reset the safety device.    This single-cavity mold for the production of an elbow

1. Two long side of the core 2 intersected 90 · shorter side of the core is driven by the oblique guide column 3, driven face a longer side of the core by the guides. The difficulty is the sheet push rod 5 is located below the two side core. Plastic parts, mold release, when the mold is closed, before the two core reset sheet putter must return to the initial molding position, or Q8 damaged sheet putter. Otherwise, the possible consequences is not only a broken flake putter, and damage to the cavity. Any kind of damage will result in the production of long-term interruption. To this end, the putting on did not set a coil spring, it is to reset the device plays a template role. The coil spring to push the board reset. In order to ensure normal production, set up a micro switch, the driver switches the pin 10 is based on the push plate on the moving mold fixing plate 8. In the cable and the moving mold fixing plate micro switch shell connection, the top of the board reset the circuit of the safety device connected. More detail of our mould quality experience, you can visit to review.

General new plastic materials R & D and classification of traditional materials

General new plastic materials R & D

plastic material

University of Massachusetts Amherst Paul J. Dauenhauer led research team found that the new method, a production of biomass plastic, low-cost, most of the biomass as a raw material can be to 75% the yield of xylene (biomass plastic raw materials), the study results were published in the journal of the American Chemical Society (ACS), the “catalyst”. Xylene was used to produce PET (polyethylene terephthalate) plastic, the scope of uses including many products, such as carbonated beverage bottles, food packaging, synthetic clothing, and even auto parts. At present, the plastics industry is the oil as raw material to produce para-xylene; new method is a renewable way of biomass raw materials of the chemical, thereby producing marked with the triangular recycling logo “1 #” plastic products. This method uses molecular sieve catalyst, through the three-step reaction can be conversion of glucose to para-xylene in the high-temperature bioreactor. Nano-structure of the catalyst has a great effect on the biological response, the catalyst of this particular design is the key to success, it has been a series of optimization improvements, used to promote the reaction of p-xylene, and improve yield. This is a major breakthrough, because the other method for the production of renewable xylene, or expensive (eg fermentation), or low reaction efficiency, low production yield. In the future, the method can be further optimized to improve the yield of para-xylene and reduce costs. This finding is part of the innovative energy catalytic center (CCEI), a breakthrough research to the manufacture of biofuels and chemicals from lignocellulosic biomass program.

Traditional plastic materials classification

There are 2 kinds of classification methods, in accordance with the possibility of recycling is divided into: 1, thermoplastic plastic material. Means can once again recycled plastic. Such as ABS, PP, PE, PS,.2, thermosetting plastics. Meaning that it can recycle the heat after molding can not be recovered. Such as phenolic resin, urea resin. In accordance with the classification of use: 1, general plastic field: the use of general plastics in daily life. In recent years, pointing to the general plastic changes, generally refers to the pure resin, not through enhanced or modified plastics, such as ordinary ABS, PP, PE, PS, PC,.2, engineering plastic. Generally refers to the high performance plastics used in industry and other high-end applications. More recognized industry argument is, plus fiber, fireproof, high temperature resistance, chemical corrosion resistance, weather resistance and so on. For example, LCP, PPS, PEEK, PTFE and so on. That is, general plastic material such as ABS, PP, PE etc. such as Fruit through the modification, the formation of the ABS fiber, ABS fire, ABS heat resistance, we also called engineering plastic material. The same applies to the PP, PE, PS and other plastic material.

Injection mold company cost accounting


mold making in injection mold companyprecision injection mold company process

How plastic injection mold company cost accounting

An empirical calculation method Mold Price = material cost + design fees + fees and profit + VAT + test mold fee + packing and shipping fee. The ratio is usually as follows:

The injection mold company cost of materials: materials and standard parts accounted for 15% of the total cost,  30%;Processing fees and profits: 30% -50%;Design Fee: 10% of the total cost of the injection mold company to 15%;Tryout: large and medium-sized injection mold can be controlled within 3%, and small precision injection molds is controlled within 5%;Packaging and transportation costs: according to the actual calculation or of 3%;VAT: 17%

(2) the material coefficient method . The injection mold company material cost can be calculated according to the injection mold size and material prices. Injection mold company price = (6 ~ 10) * Material fee forging dies, plastic mold = 6 * The cost of materials Die-casting mold = 10 * materials fee Injection mold company quotation estimates . A first look at customer requirements, calling for a decision on the choice of materials and heat treatment.

2,  select the good material, and a rough injection mold program map, from which to calculate the weight of the injection mold (to calculate the price of the mold core material and the mold material) and heat treatment costs. (Rough weight)

3, the processing costs, according to the complexity of the mold core, general processing costs and the mold core material prices from 1.5 to 3:1, the processing cost of the mold is generally 1:1.

4, the risk premium is 10% of the total amount above.5, tax 6, the design fee is 10% of the total amount of the mold.Bidding strategies and settlement of the mold .The purchase and settlement of the mold is a continuation of the mold valuation results. From the valuation of the mold to mold the offer, only the first step, the ultimate goal of the mold through the mold manufacturing after the delivery of settlement, the formation of the final settlement price of the mold.

Injection mold company valuation the mold

In this process, people always want the valuation of mold = mold price = mold settlement price. In practice, the four price is not exactly equal, there may be fluctuations in error. This is to be discussed below. When the valuation of the mold, the need for proper handling, finishing into a mold quotation, signed mold contract basis. Through repeated negotiations to discuss the final form of the mold price, both sides recognized the signing of the contract. To officially start the processing of the mold.A mold valuation and offer quotations and molds price After the valuation of the mold, and can not immediately directly as a quotation. In general, we must conduct a comprehensive analysis based on market conditions, customer psychology, competitors, status and other factors, the collation of appropriate valuation, an increase of 10-30% the first offer on the basis of valuation. Bargaining, can be reduced according to the actual offer. However, when the injection mold company to discuss the offer of 10% below the valuation, the need to re-mold improve and refine the estimates, in Guaranteed favorable circumstances, the signing of the mold processing contract to finalize the mold price. Mold price has been accepted by both sides and signed the contract price. At this time, the formation of injection mold company price may be higher than the valuation or lower than the valuation. Mold price is lower than the discussions of mold in this price into the need to re-propose amendments to mold requirements, conditions, and programs to reduce some of the requirements may reduce the cost of the mold, signed mold-price contract, and then re-estimate the It should be noted that the mold belong to a higher technological content of the specific products should not be cheap, even at a loss to meet the customers. But should be good quality and inexpensive, to ensure mold quality, accuracy, life the first place, rather than the price of the injection mold company a little too seriously, they are liable to be misleading action. Pursuit of mold cheap, it is difficult to guarantee the quality, accuracy, life of the mold. Cheap is not generally die industry for. However, when the mold manufacturing and product development and production of the same accounting unit, or economic interest, in this case, the purchase of the mold should be its cost price as a quotation. The valuation of the mold only to estimate the basic cost of part of the mold, and other costs, profit not to consider, be the profit of the products produced after extraction of the added value of the mold fee as compensation. But at this time offer can not be used as the price of the mold, only as a mold pre-development costs. The future, once the products successfully developed to generate profits, you should extract the added value of the mold fee, returned to the mold manufacturing units, two together, to form the price of the mold. At this time the formation of mold price may be higher than the price of the first case, the mold, and even high rates of return, which is several times of the normal mold price, ranging from several hundred times. Of course, there are the possible rate of return equal to zero. Second, the regions of the injection molding price and time differential Here should also be noted that the valuation and price of the mold in various enterprises, various regional, national; at different times, different environment, its meaning is different, that is, there are regional differences and the time difference. Why would the price difference, this is because: the one hand, enterprises, regional, national  injection molds manufacturing conditions are not the same, equipment, technology, technology, personnel concepts, consumer standards in all aspects of the different, resulting in the cost of the mold, profit targets, estimates vary, resulting in a different mold price difference. Generally more developed areas, or high technology, and equipment into the more advanced, more standardized, large-scale mold enterprise, their goal is high quality and high prices, while in some areas with low level of consumption, or low-tech, equipment and less on small and medium-sized mold enterprise, the relative mold prices estimated to be lower. On the other hand, the mold price there is still time difference, namely, aging poor. Different times, resulting in a different mold price. This limitation difference has two aspects: First, a pair of injection molds have different prices at different times; two different mold manufacturing cycle, and its price is also different.