Pilot injection molding machine type relief valve failure and troubleshooting

July 30th, 2010

With the injection molding machine hydraulic system moving in the direction of the development of high-pressure, pilot relief valve is widely used in injection molding machine control circuit in the hydraulic system.

In the use of practice in order to maximize its effectiveness, protection and control system, accurate, timely diagnose, Pai Chu Xing pilot relief valve of the failure is the key Huan.

Pilot-type relief valve failure, will result in injection molding machines can not move.

According to the phenomenon, analysis of reasons: the pilot valve spool spring break; damping hole plug; pilot valve port seals bad; the main spool stuck so.

Exclude the corresponding measures are: to replace or add in a broken office flat pad to emergency use; clean dredge; grinding or the oil circuit breaker to emergency use; grinding, cleaning.

 

Voltage instability limit:   limit pressure relief valve Pilot-type instability, manifested as low or high pressure hydraulic systems, hydraulic actuators action unable or tubing, pump, valve burst. 

 Reasons causing the failure:  improper pressure adjustment; pilot valve spool spring bend or soften; oil too dirty or poor oil flow. 

 Corresponding exclusion measures:  re-adjustment; correction, plus pad, or replaced; replacement, cleaning.

 Pilot-type pressure relief valve limits for the gradual onset unstable failure, pilot relief valve failure for the sudden failure of the exclusion of complete breakdown, should be limited to injection molding machine system pressure relief valve on the pilot-based control pressure to re-adjust.

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The Profile for stretch packaging technology

July 19th, 2010

Stretch packaging is introduced in the 20th century 70s, a new packaging technology, which is evolved by the shrink packaging. 

Stretch packaging is to rely on mechanical devices at room temperature, the elastic film are wrapped around the lap, Jin Guo, and the ends to seal a packaging. As the stretch wrap without heating, so the energy consumption of only shrink 1 / 20. 

 Stretch wrap packing individual items can also be used for tray packing like a collection of packages, instead of small containers. 

 It has granted Jiangdi cargo volume packaging costs 30 percent more than they have been Guangfan for metal, mineral, chemical, pharmaceutical,  machinery, etc.

The whole set Duozhong product packaging Shang; in warehouse storage areas, Guowai Yejiaoduodi Li Yong three-dimensional tensile stretch film pallet packaging storage and transportation, to save space and covers.

A stretch film

Stretch film (also known as stretch film) in the packaging process does not require shrinking treatment can not be applied to some of the heat of the product packaging will help save energy, easy container transport, and lower transportation costs.

1) Tensile performance packaging

For stretching the plastic film must have some self-adhesive, toughness, strain rate, retention, and Xu Yong tensile stress range and the optical properties and sealing capabilities.

① self-adhesive

Thin film adhesion between the contacts, in the stretch after the winding process and package, and will not allow packaging fastening loose.  Self-adhesive effect by outside factors.  Such as humidity, dust and pollutants. Be self-adhesive film There are two main ways.

The first process has a shiny smooth surface film; second is to use additives to increase adhesion of the filling to make films the effect of wet surface to enhance adhesion.

 ② toughness

Toughness is the resistance to expose the film and the integrated nature of the tear.  Ability refers only to tear film was laid bare by the post-tension level when the tear.  Tear value must take the risk level of the horizontal, ie perpendicular to the machine operation, because in this direction would tear loose packages, even if longitudinal tear occurs, packages remain strong.

③ Tension

Stretching is a film produced by the post-tension elastic elongation capability.  Vertical stretch, and finally make film thinning, shortening the width.

Although the vertical stretching is beneficial, but excessive stretching often is not desirable.  Because it would thin film, easy to tear, while increasing the tension imposed on the packages.

④ stress stranded

 Tensile stress retention is wrapped in the course, exerted on the film can maintain the level of tension.

⑤ allowable tensile

 Allowable tension is used in certain circumstances, can maintain all the necessary features can be imposed maximum tensile. 

 Allowable tensile change with the different uses. The greater the amount of stretch film allowable less the lower the packaging cost.

 In addition to these indicators, the optical properties and sealing properties, for some special packages is important.

Choose what kind of stretch film, stretch film with a thickness much according to the type of goods, shape to decide. 

 Commodities firm, high strength, heavy, should choose strength, especially tensile strength and tear strength of plastic film and thick films (such as 50μm thick) strain rate can also be larger, such as up to 150 % ~ 170%. 

 For the fragile goods, food, light weight, in contrast, the thickness should be used 15 ~ 30μm, the tensile rate of 130% of normal stretch film.2) the commonly used stretch film

Commonly used stretch film material with PVC (polyvinyl chloride), LDPE (low density polyethylene), EVA (ethylene – vinyl acetate copolymer) and LLDPE (linear low density polyethylene).

PVC film the lowest cost, using the first, better self-adhesive, tensile and toughness is good, but the stress of poor retention.

Low-density polyethylene stretch is low, less self-adhesive and anti-puncture strength. Ethylene – vinyl acetate copolymer thin film self-adhesive, tensile and toughness, stress retention of all good.  Characteristics of linear low density polyethylene film integrated the best.

3) stretch the form of packaging tray bodies

 Stretch film packaging all have to be stretched, tray packaging machinery, the tensile form of direct tension and pre-stretch (shown in Figure 1, graph (a) that direct tension, (b) said pre-tension) .

Direct tension is between the finished film in the tray and the stretch.

This method of stretching draw ratio is low (about 15% to 20%), if the draw ratio more than 55% to 60%, exceeding the yield point of the original film, film width is also reduced, puncture performance is also lost out, membrane is very easy to break.  And 60% stretch rate, tension is also great for light goods, is likely to palletized.

Pre-stretch is divided into two types, one is pre-stretch rollers, a tension is electric.

 Pre-stretch film by volume after the completion of two rollers. Pre-stretching of the two rollers roll is tied by the gear unit, draw ratio can vary according to gear ratio.  Tension generated by the turntable. 

 As the tension is generated within a short distance, the friction between the roller and the film are big, so wide Notations film, the film also maintains the original puncture performance down. 

 No stretching occurs when the actual winding, reducing the sharp edge or corner as result of fracture, this pre-stretch can stretch up to 110% magnification.

Power pre-stretch roller tensile pre-tension mechanism and the same, difference is power driven by the two rollers, stretching completely independent of the tray rotation.

So adaptable, light, heavy, no rules are applicable to the goods, due to packaging tension is low, so this method of pre-draw ratio up to 300% and greatly reduce material cost savings. Suitable thickness of 15μm ~ 24μm.

2, the main use of the form of stretch packaging

Sealed packaging:

This package similar to the shrink film packaging and film around the tray to tray up the whole package, and then two hot claws to seal up both ends of the film. This is the first use of stretch film form, and thus the development of more packaging.

Full width of packaging:

This film wide enough to cover packaging requirements tray, tray shape the rules, it has limitations to use for film thickness of 17μm ~ 35μm; 

 Manual packaging:

 This package is the easiest stretch film packaging a membrane mounted on a rack or by hand, by the film around the tray tray rotation or turn.Mainly used in the wrapped pallet re-packing after damage, and the common tray packaging. The packaging was very slow for the film thickness of 15μm ~ 20μm;

Pallet packaging machinery.  This is one of the most common form of the most extensive mechanical packing, tray rotation or film by the rotation around the tray, the film can be fixed in the bracket up and down. The packaging capacity of large, about 15 to 18 per hour. Suitable thickness of about 15μm ~ 25μm;

 Horizontal packaging machine:

Unlike other packaging materials from the membrane around the turn, for long goods packaging, such as carpet, tile, fiberboard, heterosexual material, etc.;

Paper tube packaging:

 This is the latest use of stretch film, than old-fashioned paper tube packaging, better use of stretch film packaging. Suitable thickness is 30μm ~ 120μm;

Small items of packaging:

This is the latest packaging stretch film, not only to reduce material consumption, but also can reduce the storage space of the tray, in a foreign country, this package was originally introduced in 1984, just one year, the market there were many such on the packaging, this packaging has great potential. Suitable thickness of 15 ~ 30μm; pipe and cable packaging. 

 This yes stretch film application in special fields an example of packaging equipment installed on the production line last, fully automatic stretch film 既 can replace the tape bound material, and Qi Bao Hu role. Applicable thickness of 15 ~ 30μm.

3 stretch packaging technology

Stretch packaging in accordance with its use can be divided into sales packaging and transport packaging types. Different types of products, packaging machinery used is different, so there are a variety of packaging.

1) The sales packaging purposes

Degree of automation can be divided according to different hand-stretch packaging, semi-automatic and fully automatic stretch wrap stretch packaging three ways.

 ① manual method

 Usually by hand will be packaged in a shallow dish, and especially crisp and soft packaging products, and more than scattered 产品, If not a shallow dish is easy to damage. However, some products (such as small tools, etc.) itself has a certain degree of rigidity and strong, can not have a shallow dish.

② semi-automatic operation

Part of the packaging process in the mechanized or automated, can save manpower and increase productivity. Packages of mainly shallow pan with the packaging.

 The important aspect of packaging paper bag and stretch, to make the process of mechanization, the machine must increase the complexity of construction, prices must also increase, while the generic has been weakened.  Although the savings part of the manpower, production has increased (productivity is generally 15 ~ 20 / min), but generally not cost-effective measure. 

If only the supply, output and heat sealing part of the automation, packaging, speed will not improve much.Therefore, the practical application of semi-automatic operation in the use of less.

③ Automatic operation

Although there are many advantages of manual operation, but the labor intensity and motion single and frequent, and low productivity, high cost. Therefore, the manual operation so as to promote the rapid development of fully automatic packaging.

At present, automatic stretch wrap machine packaging process used can be broadly classified into two types: Shang push Shi operation France, Zhu Yao Yongyuxiaoshou packaging; Lianxuzhixian operation method, because package sizes Jiaoda, Chanpinjiaogao not sufficiently stable when Therefore, subject to certain restrictions on use.

2) use of transport packaging

Stretch packaging for transport, than the traditional wooden boxes, corrugated boxes and other packaging, light weight, low cost, so widely used. This collection of packaging are used for tray packaging, sometimes for no tray packs.

According to different film format, stretch packaging technology in two ways:

① parcel of film packaging method

As for the height of the goods or the wider film packaging of some of the whole site.  This method is suitable for packing shape Founder of the goods, the advantage of efficient and economic.

For example, ships loaded with common packaging of export goods, goods, heavy and unstable, and the unit of time requirements and high efficiency packed occasion. Drawback is to use a variety of width of the film.

 ② narrow winding film packaging method

Film width is generally 50cm ~ 70cm, packaging film from top to bottom in order to winding spiral form of goods, until the completion of binding, about one-third overlap between the two laps. 

This method is suitable for packaging stacked high or highly inconsistent, and irregular or light cargo. For different sizes of products, only one specification, the tensile membrane can, thus cheaper.

According to different stretch packaging equipment, stretch packaging technology, there are two methods:

Rotary stretch packaging technology.

The goods on a rotating platform, the film ends glued to the goods, then rotating platform, rotating side to side winding stretch film wrapped, turn off film after a few weeks, will be glued to the end of the goods.  Equipment used in this way are semi-automatic, that at the beginning of glue film, cut off the end of film.

Mobile stretch packaging technology. 

The goods on the conveyor belt, roller, or by a feeding push forward position in the packaging there is a gantry-style shelves, the two film rolls upright on the conveyor belt on both sides, and stretching with the friction roller.

 Start packing, the first two volumes of film ends seal on the goods, when goods move forward, it will be wrapped in his last film, while film stretch, to reach a certain location, with a closure device to film Shoulong cut off and the back end of stick in the goods.

Rotary stretch packaging equipment and mobile has two types of automatic and semi-automatic.

Semi-automatic equipment, the beginning of Bond films, cut off the end of film, by the manual.

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Damage and computer-aided analysis tool system

July 9th, 2010

I.    Introduction

 Cutting is the most widely used in machining processing methods, now part of the final form is still cutting processing. Cutting tool in the process of wear and tear damage to a two ways.

Tool wear is due to the workpiece – tool – chip contact area, where a strong friction, resulting in tool surface (front, flank) of the material has been gradually chip away or workpiece, tool wear in the form of rake face wear (crater wear) , flank wear, border wear, tip wear.

 Tool breakage is due to tool design, manufacture and use of improper or tools (particularly some of brittle tool materials such as ceramic cutting tool) is damaged by the impact of cutting force, tool breakage points early and late damage, there is chipping, peeling, broken off and the form of crack.

Tool wear and damage will affect the machining accuracy and machined surface quality, but also cause serious chatter, damaged machine, tool and workpiece, cutting impact of efficiency, quality, increasing production costs.

Therefore, the tool analyzes the causes of damage and take corresponding measures to avoid excessive wear and damage the tool has important practical significance.

Tool wear and breakage in the cutting force and cutting temperature induced by mechanical friction, adhesion, chipping, crushing, and cause plastic deformation, its causes are complex, mechanical, heat, the combined result of chemical reactions. 

Tool damage to the diversity and complexity of reasons, making it difficult for tools to analyze the causes of different forms of damage and the corresponding solutions.  Computer and database technology, tool damage form for the establishment of computer-aided analysis system possible. 

Computer-aided analysis system damage form tool application of computer and database technology, a collection of general turning, thread turning, milling, drilling and other cutting tools in the process of damage and reasons, get the text, graphics, data, and may be increased , delete, modify other database operations; according to the form of tool damage can quickly cause damage to retrieve the tool, and recommend solutions or improvements.

II.    System Design

A.    Data Structure

Tool damage in the form of computer-aided analysis system, each data structure of the database include:

(ID)； * Tool damage form number (ID);
(type)； * Tool damage form type (type);
(result)； * Tool damage form the consequences of (result);

* Tool damage form because (reason);

 * Solutions (solution);

 * Damage to the form of image access tool path (directory).

B.    Database Design

 Database structure design is a database system can efficiently and correctly run the key. Database structure should be designed to avoid redundancy and inconsistency, and the design of the application with ease.

According to different processing methods, tool damage form the database system is currently designed and built the following four sub-libraries:

 * General turning tool damaged database; 
* Thread turning tool damaged database;
* Milling damaged database;
* Driller damaged library.

 You can also add other needed processing sub-library.

C.   Functional Design

As modular design minimizes the coupling between modules and enhanced software portability, scalability and maintainability, thus, damage to the form of database management system tool has four functional modules:

• Management and maintenance module;
* Data query module;
* Image processing module;
* Input module and output module.

The four blocks from the main control module for unified management.

1, database management and maintenance of functional modules

In order to continuously update and improve the system, system management and maintenance modules designed to allow increased data, data deletion, data modification and other operations.

2, data query module

The module is the tool damage form the core of computer-aided analysis system, its main function is to quickly and accurately check a corrupted form of tools and the countermeasures.  The module man-machine dialogue, guides users to choose correctly, to obtain a corresponding solution.  For the convenience of the user application, the module also set up help function. 

 Data query module operations such as query tools in the ordinary course of turning the “crater wear” problem, tab control in the processing mode selected general turning, and then, in the data window control, select “crater wear”,

then, on the right picture control will display the appropriate tool crater wear the image to verify the correctness of choice, also shows that the tool will create the consequences of crater wear and crater wear causes and specific solutions. Solutions, including reasonable choice tool material, cutting parameters, such as whether the proposed use of coolant.

3, image processing module

In order to provide users with more detailed information to guide the user to select the correct form of tool damage, the system provides users with tools of various forms of damage to the image.  In application development, stored in a database by calling the corresponding image path to display images.

4, output modul

 To facilitate the use of user data, the design of the output function module, you can print out according to user requirements.

 D.  Conclusion

The form of computer-aided analysis tool damage computer systems, database technology analysis tool can cause damage to propose improvements. The form of computer-aided analysis tool damage system is modular design, better maintainability and scalability; friendly interface, simple and intuitive query accurate, and practical.

The system is very useful tool damage control features for the selection of tool materials, cutting conditions, increase productivity, processing quality assurance is important.

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Vacuum Packaging Machinery China Development Trends

July 5th, 2010

Vacuum packaging is to protect products from environmental pollution and extend the shelf life of packaged food, etc., can enhance product value and quality.

Vacuum packaging technology originated in the 20th century, 40s. Since 1950, polyester, polyethylene plastic film packaging has been successfully used in vacuum packaging machine can be developed rapidly.

User complaints Yinlu unknown insects in peanut milk .

 People live and work in the field of vacuum packaging a wide variety of plastic everywhere.

 Light, sealing, preservation, corrosion, rust-proof plastic vacuum packaging over from food to pharmaceuticals, knitwear, from precision manufacturing to metal processing plants and laboratories and other areas. Plastic vacuum packaging has been used widely to promote the plastic vacuum packing machine development, but also a higher demand for its.

At present, the current world vacuum packaging technology trends in the following areas:

 High efficiency: High efficiency vacuum packaging machine production efficiency from the number of items per minute to the development of dozens of hot forming – filling – sealing machine for production of up to 500 pieces / min.

Automation: A Japanese company produced TYP-B series rotary vacuum chamber packaging machine has a very high degree of automation, multi-position. The machine has two filling and vacuum turntable, filling a six-station rotary table, complete for the bags, feeding, filling up the pre-sealed vacuum packages sent to the turntable.

Vacuum turntable has 12 stations, which is 12 vacuum chamber, vacuum and sealed until the completion of finished product output, production efficiency up to 40 bags / min, mainly used for packaging soft canned foods.

Single multi-functional: in a single machine can be easily extended to achieve multi-use area.

Function must be used to achieve stand-alone modular design, through functional modules are transformed and combined, as suitable for different packaging materials, packaging materials, packaging requirements of different types of vacuum packaging machine.

Representative products are Germany, the company owned HESSER BOSCH factory production of multi-site bag vacuum packaging machine, the bag, weighed, vacuum filling, sealing and other functions can be completed in a single machine.

Group with production line: the composition of the production line when needed functionality more and more a long time, all the features will focus on a single structure is very complex operation and maintenance is not easier.

Then the function can be different to match the efficiency of the successful combination of several machines can be more complete product line. Such as France CRACE-CRYOYA and ISTM company developed fish, vacuum packaging line and the Swedish tree Macro International Research Institute of the Swedish textile and textile vacuum packaging systems.

Adoption of new technology: the packaging, the extensive use of inflatable packaging can replace the packaging, the inflation Chengfen, packaging materials and inflatable packaging machine to the study up close  in control technology, computer technology and more to Ying Yong microelectronics;

 In sealed areas, application of heat pipe and the cold seal technology; of advanced devices installed directly on the vacuum packaging machine, such as mounted on a precision computer-controlled combination of coarse-grained material balance; in the rotation or vacuum packaging machine, the application of advanced high-speed The circular surface cam machinery.

All of these new technologies makes vacuum packaging machine is more efficient and intelligent.

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About five general-purpose engineering plastics

June 27th, 2010

Generally refers to engineering plastics can be used as structural material to withstand mechanical stress, can in a wide temperature range and a more harsh chemical and physical environment, plastic materials used. General engineering plastics and engineering plastics can be divided into two major categories of special engineering plastics.

General engineering plastics often refer to large-scale industrial production, wider application of 5 plastic, that is, polyamide (nylon, PA), polycarbonate (polycarbonate, PC), polyoxymethylene (POM), polyester ( mainly PBT) and polyphenylene oxide (PPO).

  The performance of special engineering plastics are even more outstanding is unique, but most of the outstanding production of large-scale or small-scale industrial production, uses a relatively narrow number of plastics such as polyphenylene sulfide (PPS), polyimide (PI ), polysulfone (PSF), polyether ketone (PEK), liquid crystal polymer (LCP) and so on.

 

Excellent performance engineering plastics can replace metals as structural materials, which are widely used in electrical and electronic, transportation, machinery and equipment and daily necessities and other fields in the national economy becomes more and more significant.

Development of domestic production 

The technical development of engineering plastics in China, nearly 40-year history, though already has a technical foundation, but in terms of technical level, production capacity and production in such areas as the gap with foreign countries has a great, individual species (such as PPO ) basically blank.

On the scale of operation, the engineering plastics business in China are mostly ton production facility or industrial test equipment, and foreign enterprises is the annual production capacity of more than tons. Scale and technological level of the huge differences in domestic engineering plastics makes it difficult to meet domestic market demand, product performance and price could not compete with imported products.

Properties and Uses

Polyamide (PA) due to its unique low-weight, high tensile strength, abrasion resistance, good self-lubrication, impact toughness excellent performance with both Rigid won attention, coupled with its easy processing, high efficiency, the proportion of Light (only metal 1 / 7), can be processed into a variety of products to replace the metal, widely used in automotive and transportation.

Typical products are pump impeller, fan blades, valve seats, bushings, bearings, all kinds of instrument panels, automotive electrical instruments, hot and cold air conditioning valves and other components, some nylon products consumption per vehicle up to 3.6 to 4 kg.  The proportion of polyamide in the automotive industry the biggest consumer, followed by electrical and electronic.

Polycarbonate (PC) while the thermoplastic resin, but its not only the strength of non-ferrous metals with similar, while both scalability and robustness, its high impact strength, can not be destroyed with a hammer, able to withstand TV machine screen explosion.

 Polycarbonate has an excellent transparency, and may impose any color.  Because of these high performance polycarbonate has been widely used in various safety lamp, lights, stadium, stadium of the transparent protective plate, lighting glass, glass high-rise buildings, car mirrors, windshield panels, glass cockpit aircraft, motor car driving helmet.

Largest market is the amount of computers, office equipment, automotive, glass and sheet replacement, CD and DVD discs is one of the most potential market.

Polyoxymethylene (POM) as the “super-steel”, which is because of its superior mechanical and chemical properties, so it can be used as many metal and nonmetal materials, the materials are not competent enough, mainly for a variety of precision high pitch gear, precision instruments complex geometric surface parts, water faucet and burst gas pipe valves. China’s use of POM for agricultural irrigation machinery, you can save a lot of copper.

Polyethylene terephthalate (PBT) is a thermoplastic polyester, non-enhanced PBT compared with other engineering thermoplastics, processing performance and good electrical properties.  PBT glass transition temperature is low, the mold temperature at 50 ℃, the crystallization can be quickly, processing period is short.

 Polyethylene terephthalate (PBT) is widely used in electronics, electrical and automobile industry. As the PBT insulation and high temperature resistance can be used as TV flyback transformers, auto Distributors and ignition coils, office equipment, shell and base, a variety of automotive exterior parts, air conditioners, fans, electric stove base, office Shell pieces of equipment. 

Polyphenylene oxide (PPO) resin has good mechanical properties, heat resistance and electrical insulation, and low moisture absorption, high strength, good dimensional stability, high temperature creep resistant thermoplastic engineering plastics of all the most excellent.

 Compressor cover can be applied to washing machines, vacuum cleaner housings, coffee equipment, hair styling devices, massage devices, microwave ovens and small appliances apparatus side containers.  Noryl is also used for TV parts, telex terminal equipment, connectors and so on. 

Status and Forecast Demand

 With the rapid development of China’s national economy, domestic demand for engineering plastics for different occupations has grown rapidly, particularly in emerging sectors and countries is the pillar industry and new growth sectors such as electronics, automotive, transportation, building materials, packaging, medical equipment and human organs and so needed a lot of excellent engineering plastics, engineering plastics demand in China to make rapid progress in recent years.

In recent years, the demand for engineering plastics in China has grown rapidly, the average annual growth rate of 25%, in particular, PBT, Nylon, PPO’s annual average growth rate of more than 25%. 

According to the history of several plastic changes of apparent demand, combined with the scale and the world consider the latest market trends, respectively, five general-purpose engineering plastics demand predicted.

 PBT resin due to the changing needs of the history of no good rules to follow, so in 1998, after correction of apparent demand, based on the assumption that the future needs of development and GDP growth pace predicted the table next few years View requirements.  2000 and 2005, China’s apparent consumption of general engineering plastics will reach 33.8 and 528 thousand tons. 1999 and 2005 the average annual growth rate of 9.8%. 

 2003 to 2004 after the apparent consumption of polycarbonate may be more than polyamide, and has become the largest consumption of general engineering plastics. 

 Expected that by 2005, demand for 179,000 tons of polyamide, polycarbonate is 205,000 tons, 126,000 tons for the POM, PBT, 1.19 million tons, 06,600 tons of modified polyphenylene ether.

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A brief introduction to mold heat treatment

June 22nd, 2010

Hardness requirements; plastic mold should be moderate hardness and good toughness, different types of mold require different hardness, as thermosetting plastic mold is heated in the long run, to work under pressure, which requires heat treatment after the collapse of sufficient anti-heap capacity.

Heat treatment points; die during heat treatment, special attention should be protected cavity surface to prevent surface oxidation, corrosion, decarburization or by carbon.  If the surface carbon content is too high, you will increase the residual austenite, it is difficult or impossible to polish.  Quenching should be used more moderate cooling medium, so as to avoid distortion and quench crack.

Delayed cooling can be used hot bath quenching or quenching or air cooling. 

 Pre-hardened steel with cutting, can avoid quenching and deformation; using maraging steel or high-quality low-alloy steel, aging can control the deformation rate within 0.05%; in between roughing and finishing, and in high-precision before processing to stress treatment, the removal of residual stress caused by deformation processing; using reasonable heat treatment, so that die steel was stable organization can avoid the distortion caused by tissue changes; using thermal expansion coefficient of steel, can be reduced small thermal expansion and contraction caused by the deformation.

Mould tempering should be fully, tempering temperature should be higher than the operating temperature, so as not to die at work, tempering changes continue to occur, and thus the surface in the cavity of stress.
Mold heat treatment including preparation treatment; main purpose is to mold the final heat treatment for tissue preparation. 

 The key is to heat the heating temperature selection (to ensure full bath solution carbide or full solid solution of alloying elements), cold or warm temperature, speed or other options (to ensure the uniform distribution of carbide precipitation, cutting access to the appropriate hardness), such as normalizing high-temperature tempering, annealing, quenching and tempering treatment. Also includes the final heat treatment, such as quenching, tempering, surface hardening treatment. 
Cr12MoV steel tape recorder Die movement, average life of conventional heat treatment Greek 100,000 times, using conditioning and vacuum heat treatment, so that tool life increased to 25 million. 

 Forging process on the impact of die life; current low level of standardization of our module, steel specifications and few users will need to change the purchased round rough forging mold into the required, therefore, the primary purpose of forging die steels to per billet size and specifications, prepare for the subsequent processing. The second change forging Die Steel aims to improve the organization and performance, such as making large carbide broken, obtain a homogeneous distribution; improve the mold metal fiber direction, so that a reasonable distribution of flow lines; to eliminate or reduce defects such as welding metallurgy Hop pores, increase the density of steel. 

 Purchased from the steel metallurgy plant first test of the unevenness of eutectic carbide, carbide of grade if more than 3, the mechanical properties of steel drop forging change if not fully, due to tissue inhomogeneity which causes tissue stress, heat treatment are susceptible to deformation and crack.  Therefore, this type of steel is best to take several upsetting call to try to crush the carbon and metal fibers to improve the forging direction. 

Carbon and alloy tool steel elements are high, poor thermal conductivity, especially in high-carbon high-alloy steel forging a narrow temperature range, such as highly improper operation of forging crack. Therefore, the die steel forging process must be rigorous and reasonable.  First, the heating rate can not be too fast, even heating to pay attention to steel materials in the furnace position to choose when, and sometimes have to turn heating bar to make it heat evenly.  Heating temperature is not too high, to prevent overheating and over-burning. 

 Forged weight control when appropriate, to combat excessive force, deformation is too big, easy to crack.  Stop the cooling rate after forging is also important, cooling too fast too easy to crack. Therefore, if the forging process is unreasonable, not only fail to improve the quality of tool steel and high performance to catch the purpose of forging defects and even cause deterioration in the quality of steel. 

 Die in a parts plant material as Cr12, blank size φ90mm, eutectic carbide is greater than 5, without a change forging, rolled directly from the turning, life is only a few pieces to several dozen up to 3000, are chipping, cracking or vertical fragmentation and failure; after the switch to φ60mm bar, made by upsetting, forging φ90mm, eutectic carbide is 3-4 level, distribution is more uniform, made of die, the life 8000 pieces.

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Injection molding machine machining Analysis and elimination of noise

June 4th, 2010

Noise and Vibration pump failure causes: 
1, pump motor installation misalignment. 
2 Couplings loose. 
3, internal oil pump failure.
4, the oil level is too low, oil filtering network or connections from the junction to the oil in the air inhaled. 
5, fixed axle from the motor to breathe air.
6, oil plug oil filtering network. 
7, inhaling the air return pipe or tubing loose surface in the oil, mixing in the air to the oil.
 Exclusion method: 
1, concentricity should be adjusted to less than 0.1MM.
2, the amendment Couplings. 
3, repair or replace pump. 
4, increase the amount of oil in the oil filtering outline and location of 400mm or more joints. 
5, replacement of shaft seals.
6, net cleaning filter oil, filter oil.
7, cleaning mesh filter oil, filter oil. 
8, locking return lines, will reach into the oil return pipe extending below the surface. 
 Electrical fault causes the noise:
1, motor bearing damage. 
2, the motor coil winding fault. 
3, motor wiring error, the system pressure rises, the noise increases. 
Remedy:
1, replace the link bearings.
2, replacement or repair motor. 
3, re-wiring diagram light wiring. 
 Noise total pressure valve (relief valve) 
1, before the relief valve of the pilot valve chamber to the existence of air. 

 2, the main relief valve heart valve orifice was blocked oil properties.

3, pilot valve and valve seat with the strain does not seal. 
4, spring deformation, or installed wrong. 
5, remote control excessive oil flow mouth. 
6, hydraulic oil viscosity is too low or too high.
7, with the loop component resonance. 
Remedy: 
1, to enhance sealing, repeated several times down the exhaust pressure debugging. 
2, cleaning valve, so that orifice smooth. 
3, repaired or replaced. 
4, repair and replacement of springs. 
5, remote control port to reduce stream management. 
6, replacement of oil.
7, other components can not be set pressure relief valve pressure setting is similar. 
Hydraulic noise (1) oil is mixed with air or hydraulic cylinder is not completely drained of air, under high pressure generated in the cavitation caused more noise.  At this point, to be drained of air time.
(2) cylinder head or piston rod seals tight bend in the course of the campaign will be noise generated by other strength. At this point, to be timely replacement of oil seal or the alignment rod.

5.  Pipe noise. 

 Noise is usually because the hydraulic pipe tube bending die too much or caused by the loosening of the fixed sleeve. 

 Therefore, the Department of hydraulic pipe line to try to avoid dead corner, timely check the elastic sleeve.

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PP requirements on injection molding machines and processing technology

May 31st, 2010

 Processing of plastic raw materials are mainly particles melt, flow, setting a finished product after cooling is cooling after a heating process, but also to the plastic from the particles of different shapes to change the process, the following will explain the different stages of processing perspective process.

1. Melting

Unit heater (Heater) for raw material particles are melted into a fluid-like flow, mainly raw materials for different temperature regulation, increased temperature will accelerate the trend to enable movement of raw materials, increase the efficiency but not necessarily guaranteed yield, must obtain the appropriate balance.  Another case of good results with the PP pyrolysis characteristics of high fever, are the best production allow the smooth flow of raw materials to die in order to avoid the charge of inadequate material, or return to the phenomenon of production, return on behalf of material flows faster than the output rate will eventually increased efficiency resulting in an average flow equal to MFR increased, the processing methods available, but also resulted in abnormal distribution of MFR may lead to greater stability, resulting in poor rates may increase. However, because the application of the relationship between the PP product size are not very high precision products, the impact is not great.

2. Screw 

PP screw machining most are driven by liquidity, so screw design affect very large aperture size on output, the compression ratio affect the pressure also affect the size of output and the finished result, which also includes more kinds of materials (masterbatch, additives and modifier) of the mixing effect.

Material flows mainly by warmer, but also have a friction material changes the friction heat to promote mobility speed, the screw compression ratio of small-driven flow of a small speed must increase the heat caused by friction will be larger than the screw compression ratio and more.  So often say that no master of plastic processing, try to understand who is the master machine performance.  Raw materials not only heater to heat it, you must stay with frictional heat and smothering time and count.  So this is the practical problems and experience will help solve the problem of production and efficiency. If you need mixing screw particularly effective, sometimes two-stage design with different biaxial screw or screw and is divided into sections in order to screw up all kinds of different forms of mixing effects.

3. Mold or die 

Plastic re-shaped mold or die depend on the head, finished a three-dimensional injection molding, mold is a complicated problem even more to consider shrinkage, other are all flat, strips, needle continuous product die, if the special shape of the classified as abnormal, need to pay attention to immediate cooling stereotypes.  Plastic design of the machine are like the majority of syringes and needles, screw-driven compression force will cause great pressure on exports in the small, increase production efficiency.  When the die is designed to print how to make raw material evenly distributed throughout the surface, coat hanger die design on the importance of attention to the opportunity to increase the pressure pump gill stability of raw materials supply. 

4. Cooling 

In addition to injection mold runner gate perfusion raw materials, but also to the cooling ingredients designed cooling channels. Pressure within the wheel by forming the cooling channels to achieve the cooling effect, except there are air knife, cool water poured directly on the bags in the wind and blowing so hollow cooling. 

5. Extension 

Extension will increase product re-processing effects, such as by front wheel drive package with a different rate that is causing unintended effects, finished with an extension of anti-tensile force to strengthen the easy tear, but very easy to tear horizontally.  Molecular weight distribution also affects the high-speed production of unintended effects, including all the pressure of the finished products ranging from fiber has an extension of space vacuum and pressure forming can be seen as another form of extension. 

6. Contraction 

Have any material shrinkage rates, shrinking from the thermal expansion and contraction causes the formation and crystallization of the stress caused arising. 

Generally easier to overcome the thermal expansion and contraction can be processed in the extend cooling time, you can continue to do a good job packing, crystallization of amorphous materials tend to have more than the contraction of different terms to about 1000 per PP 16, but ABS is only about four thousandths, very different to die on this part to overcome, or is often added to reduce shrinkage additives to overcome, often add pressure LDPE flat out to improve the necking problem.

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PTFE technology Plastic Products

May 28th, 2010

PTFE tubing
PTFE Spiral

PTFE Spiral shielded cables can be used as aircraft engines and protection of cables, from the impact of high oil. Also can be used to connect the lower mechanical strength of ceramic, graphite, glass pipe; used tank truck and storage tank to the feed and discharge tube; for the wrong pipe connection, it connected to the pipeline due to thermal expansion can be balanced shrink the size of changes caused; also be used as conductors for flexible casing.

Fluorine plastic heat shrinkable tube

Main features: with shrinking, to form the protective layer close to the characteristics.

Main use: widely used in electrical, mechanical, chemical, printing and other departments as a reliable insulation and anti-sticking material.

PTFE lined steel pipe

Features: PTFE lined steel pipe with excellent corrosion resistance and good rigidity, and ability shock, vibration and distortion, it has become more widely used in petroleum, chemical industry, transport corrosive liquids and gases.

PTFE sheet

Varieties: turning board, molded board (bridge dedicated slider).

Features: PTFE molded sheet metal forming by suspension PTFE resin with good corrosion resistance, aging resistance, low coefficient of friction, using a wide range.

Main purpose: Machinable production liner, seal, lining partitions, scraper, guide, and a variety of frequencies used in electrical insulation parts, bridge bearing slide.

PTFE Rod

The main products: all kinds of domestic produce generic bar (push rod, molded rod, etc.).

Features: Good corrosion resistance and dielectric properties, aging, long-term use in the 180 ~ 250 ℃ environment, low coefficient of frictions.

Main use: all kinds of frequency components used in electrical insulation which including a variety of corrosive media sealing gasket, anti-sticking and lubrication materials.

PTFE film

Varieties: turning film, directed film, semi-directed film, color half-oriented film, color film in red, yellow, green and other colors.

Features: PTFE film with high tensile strength, good insulation, not sticky and so very good.

Main purpose: the capacitor insulating material, special cable insulation, electrical instruments, insulation, non-stick tape, sealing tape, can also be used for motors, transformers insulation.

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Injection and suppression of the two processes outlined

May 20th, 2010

 Cap is often overlooked details of the consumer, but for manufacturers, this is a big problem. 

 Italy’s Mr. Li Keping Jiffy special bottle and cap mold on many years of research, “the production of plastic caps looks very simple, but, plastic bottle mold manufacturing bears a very high professional and technical. Jiffy special company to design and manufacture of multi-cavity-bit, high-precision, hot runner injection mold known.  Jiffy 2000, the company developed a special 64-cavity cap mold rapid prototyping and rapid injection molding machine in Nestal to achieve an opening and closing of 3s, creating a level cap of 64 cavity mold opening and closing cycles of the world record.

 ”Many plastic bottle manufacturers in Europe is seeking to ensure the cap in the case of physical function, minimize the cap weight, increase productivity, reduce costs in order to increase market share.” Jiffy special company to meet market demand, developed MIVA Series cap.  To MIWA L3P example, 28mm, only 1.5 ~ 1.6g, than the traditional PET plastic bottle cap light 1g, such a cap as long as the rotation 90 ° to open, open the torque is low, suitable for young and old. Currently, there are seven sets of Jiffy this special offer of 64 cavity cap mold used in the Wahaha Group.

Jiffy special company also invented the non-rotating double injection mold patented technology for the production with a one-time pad caps.  The invention saves a bottle with a pad on investment in production equipment.  With the traditional pad cap is a plastic bottle production equipment, injection molding or plastic drop liner equipment and assembly equipment to achieve, especially with Jiffy’s double injection mold, injection machine in the original by adding a plastic injection unit can be easily the realization of the production cap with pad. 

Sacmi SACMI suppression cap is another technique, it different from traditional injection molding cap, is the first compression molded cover the mechanical equipment manufacturer market. Sacmi rotary hydraulic mold making simplistic, so the investment required for compression molding cost far less than the cost of injection molding.  As Sacmi also completely designed and manufactured plastic cap mold, it has more overall advantages. 

 According to Sacmi introduction, this cap is ideal for suppressing the production of circular cap.  Sacmi exhibited in July ProPak 600 / min playing cover machine, but they are the fastest to reach the 1200 products / min, there are already 7 sets of the product sold.

Injection and the suppression of cap represent two different processes, the former can buy all kinds of mold, pattern design for flexible, can be designed to cover a relatively complex, but the tooling costs are relatively high; and suppression of cap is relatively low cost.

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