Missler Software Customized to
Complement Mikron Machining Centers
High-speed processing requires perfect interaction of machining centers, CNC control units, and CAM software for quick and precise milling for precision metal part machining. This has been the primary motivation behind the cooperative efforts now underway between machine manufacturer Mikron and the French software company Missler.
In early October, Mikron introduced three new, ultra-high-speed machining centers and a continuous process chain for high-speed machining using various machines and 3D programming tools. The company also introduced the XSM 400 CNC control, equipped with the “Cyclone” expert system for ultra-high-speed processing, which was specially developed for Mikron and allows users to easily optimize all technical parameters for certain operations. Missler’s experts have customized the postprocessors of the TopCam CAM software to complement Mikron’s machines.
TopCam supports ultra-high-speed milling by letting a user select the functions needed for processing certain parts at a given time already at the programming level. The CAM system proposes a machining method that maintains the machining direction. In addition, the user is provided with tools with small cutting depths and large radial passes for high-speed milling.
Positive Outlook for Major
Italian Plastics Show Next May
The outlook for next spring’s PLAST Industry trade fair in Milan, Italy, is highly favorable, with the show management organization Enfiplast expecting a net exhibit space of 75,000 mm². PLAST Industry will run May 6–10 at the Fieramilano fairground. This triennial event is expected to be second only to the K Show in Düsseldorf. The previous PLAST show, in 2000, attracted 1,660 exhibitors, including 693 exhibitors from 47 countries.
As an international event, PLAST Industry is supported by Euromap (the European Committee of Machinery Manufacturers for the Plastics and Rubber Industries) as well as by Assocomaplast. Once again, there will be a comprehensive program of seminars.
The PLAST Industry wbite by https://plastic-industry.com/, they offer further details on the show, and exhibitors can use it to verify the allocation of all booths. For visitors, there is a preregistration option.
Many concerning the grownup men and ladies choose to possess the bar at home. But loads of space needs to acquire sacrificed for this. Once the home is relatively huge then it will not come going to be considered a problem. When each of the furnishings is made the decision then the turn arrives to the Bar Stool Moulds. Best suited after a stressful evening a relatively small cup of beer may nicely soothe. Some choose to stay in your own home to relieve the stress. So once the Bar Stool Moulds are selected they need to acquire careful. This small area concerning the bar can be to acquire decorated to game the surroundings. The lights, stools and relatively several other small factors need to acquire concentrated to game the option concerning the grownup men and ladies who will use it.
There are relatively several products present inside the Bar Stool Moulds. There is leather, metal and wooden also. The Bar Stool Moulds are comparatively of the bigger height. The products utilized should game using the decor inside the room. This could give a brilliant ambience as well as a visual element to the room. It is consistently preferred to take advantage of the stools which could tolerate the liquids. If some delicate substance is utilized then it is relatively challenging to clean up the mess if one thing spills out. The stools may nicely be relatively plain and backless. But some stools could have back again to help he individual getting sitting on it. The colors as well as the styles are relatively decent in these stools as they are able to be us only for decoration.
The are for the most part height adjustable type. The individual getting sitting on these stools may nicely be tall or short. To create the table reachable to the proper dimension these adjustments is relatively necessary. These Bar Stool Moulds will help the grownup men and ladies to sit within of just one corner to appreciate their beverages and snacks. The quantity of Bar Stool Moulds needed as well as the design and design is particular choice. Each and every individual getting has their individual option in designs. The dimension concerning the measurement concerning the stools is taken. This could help the individual getting to select what sort of stool and what measurement needs to acquire taken. Some bars may nicely be near to the swimming pool side. Then the products concerning the stool need to acquire decided.
IBM Confirms Intention to
Acquire EADS Matra Datavision
IBM has confirmed its intention to acquire EADS Matra Datavision, a major supplier of engineering applications and services that is a wholly owned subsidiary of the EADS Group. Once complete, the combination of IBM and EADS Matra Datavision will significantly enhance IBM’s product lifecycle management (PLM) offerings.
Product lifecycle management refers to solutions and methodologies that allow manufacturers to integrate product development processes and knowledge across an extended enterprise. PLM enables innovation, improved product development efficiencies, and e-collaboration by all contributors involved in a product rollout, including engineers, production teams, operations personnel, suppliers, and after-sales service specialists. The PLM services market is expected to grow from $1.9 billion in 2001 to $5.5 billion in 2006, for a combined annual growth rate of 23.4%.
EADS Matra Datavision has been IBM’s top producing PLM business partner since it entered an alliance with IBM in 1998. The transaction is expected to be completed by January 1, 2003, at which time EADS Matra Datavision will become part of IBM.
Trumpf Reports 2001-02 FY Results;
Laser, Medical Technologies Growing
The Trumpf Group reports that its 2001-02 fiscal year has ended with €1.17 billion ($1.04 billion) in consolidated sales, close to the the previous year’s level of €1.22 billion ($1.09 billion). Despite the recession that continued throughout the company’s entire fiscal year, group sales remained stable and total earnings high. Orders received totaled €1.14 billion ($1.02 billion), slightly less than sales.
While sales decreased in Europe and the United States, Trumpf grew in Asia. The overseas share of consolidated sales totaled 64%.
The company’s Laser Technology and Medical Technology divisions increased sales by 12% (to €319 million) and 27% (to €117 million), respectively. The Machine Tools division experienced a drop in sales of 9.2% (to €971 million), and sales were down by 8.3% in the Power Tools division (at €39 million).
Plastic Mold developing is getting a leap forward in conditions of efficiency and precision by method of the acceptance of 5 axis machining engineering which persists to be benefiting other sectors belonging using the production business for some time. 5 axis machining is one of the best process for plastic mold manufacturing.
Getting in a location to appliance all 5 sides of the element developing utilization of precisely the exact same set-up saves time and minimizes the chance of individual error. Getting in a location to exchange these benefits to Plastic Mold developing persists to be considered a boon for this part belonging using the production industry. Acquiring the right run product holding method is essential using the achievement belonging using the process, with best quality engineered options emerging to delivery efficiency gains and vastly reduce waste.
There is routinely a steep knowing curve with 5 axis machining for new operators, and between the spots in which a brand name new participant can have problems is in holding the run product to make certain that 5 sides belonging using the product could possibly be machined effectively. The subsequent particulars concerning the two most common methods may possibly be of support to new operators:
Mechanical Clamping Systems:
These are one of the most common systems, and resemble a vice but with additional clamping force. This method allows minimal interference using the slicing area and allows the subjected surfaces getting machined using an increased level of accuracy.
This clamping method can sustain tiny to method sized run pieces really easily, but for bigger pieces, a riser is recommended so that you simply can achieve the run piece. They are not common type clamps but extremely engineered pieces of offers which take advantage of force have been it is most needed. Additional protection is supplied in using pointed grippers inside the vice jaws.
A common method will be to fix the run product to some magnetic pedestal. On account of the reality the run product is then elevated, the 5 sides could possibly be machined in an extremely individual set-up, which also significantly minimizes the margin for error. The true machining processes don’t alter the magnetic pull. that is on account of the reality the 5 axis increased pace methods need a complete great offer increased spindle speed, much lighter chip loads and sooner feeds overall. These reduce torque and cutter pressure, so there is no danger belonging using the run product relocating although getting machined.
Another method could possibly be using magnetic pallets which allow the movement belonging using the run product from the individual appliance to another. This method needs cautious preparing and layout on the outset, but pays dividends inside the financial savings gained through the production process.
Business proprietors who purchase high-end 5 axis models after which skimp concerning the worth of run product holding techniques will not obtain the whole advantage belonging using the efficiency and efficiency gains accessible with this machining technology. Operators at CNC Townsville workshops are presently proving that these techniques are worth the investment.
Ever wondered how plastic mould in to the exceptionally very helpful factors that people utilize within our each day time life? Is it as easy as melting plastic and lathering the sides of the mould with it and cooling it, a great offer like chocolate? The answer, actually, is no. Plastic mould is frequently merely a tiny even more intricate than that. Plastic is developed producing utilization of the procedure often named plastic injection moulding.
What is this sort of moulding
Plastic injection mould could be the means of producing factors developed of thermoplastic and thermosetting plastic by melting and forcing into moulds in which they awesome to type the preferred object.
How does plastic injection moulding work?
The process of plastic injection moulding usually starts with a commercial customized or engineer who styles a product. This really is put into practice up in the run of the toolmaker or mould maker who helps make the mould to suit the design and design created. These moulds are metallic and usually developed producing utilization of possibly metal or aluminum.
Using machines, they are developed to acquire the exact type preferred in the design. The moment in time this really is done, the procedure of truly producing the plastic follows. This requires thermoplastic and thermosetting plastic getting fed in to a heated barrel and mixed. This melted substance is then forced in to the cavity of the mould and there it cools and hardens to type the preferred part.
Some features near to the process:
1. I utilizes melted and mixed thermo plastic mould or thermoses plastic since the base
2. It utilizes a plunger which functions like a screw or perhaps a ram to force the melted substance using the mould
3. It helps create a type that is open-ended and has used the type near to the cavity near to the mould
4. It exhibits a parting collection and gate represents near to the finished merchandise as well as the ejector pin represents may also usually be developed out
Please go to our home page to know more information about plastic mould and plastic injection molding
HYX MOLD. has announced the launch of a trade exposition and conference in Southern California next year for the tool & mold and related molding industries. The event, Plastic Tool & Mold Expo (TME), will be held at the Anaheim Convention Center in Anaheim, California, October 28-30, 2003.
Plastic Tool & Mold Expo (TME) will be a trade event designed as a networking platform for suppliers to tool & mold makers, buyers/operators of tools & molds, and tool & mold makers themselves. It will present new sourcing opportunities and help all areas of the tool & mold industry to find solutions for designing, manufacturing, buying and operating tools & molds.
The exhibitor base will include tool & mold makers, suppliers to the tool & mold industry, and suppliers to mold-related plastics processing companies. The attendee base will come from the key buying groups of the industry: molders, OEMs, tool & mold makers, tool & mold–related subcontractors, and service organizations.
For suppliers, TME will be an opportunity to present their products and services to the full spectrum of the tool & mold industry in the heart of the West Coast market, renowned for its concentration of medical, defense, electronics, aerospace and other high-technology industries. For tool & mold makers, TME will be a superb opportunity to promote their services and expertise and, as a result, sell more molds in one of the most attractive plastics processing markets in the world.
According to Clay Camburn, President of Access Communications, “Early response to the expo and conference has been very enthusiastic from all segments of the industry—mold makers, suppliers to tool & mold makers, and the buyers and operators of tools & molds. This event is needed and will be particularly important to the tool & mold industry at a time when global competition is becoming more aggressive, and as the US economy continues to recover.”
HYX MOLD. (ACI) is an international communications company specializing in trade publications, websites and events. ACI publishes North American Plastic Tool & Mold Making Product News (TMPN), European Tool & Mould Making (ETMM), EDM Europe (EDM-E) and a host of Internet communication vehicles. ACI has offices in the USA, Canada, Germany, and Hong Kong.
The answer is, of course, yes. Plastic Mold Maker can mold anything, right? More of the companies moving into MIM these days are moving in from plastics molding than from any other quarter. They’re following existing customers there, and finding new ones.
Many who have called MIM home for a while now-like Steve James, executive vp of MIM molder Injectamax Corp. (Escondido, CA)-welcome the additional business plastics molders are bringing into their changing neighborhood. But James and others like him are quick to write some words of warning on the welcome mat: “We hope that nobody enters in innocence and sours a market on the technology.”
Paul Hauck, director of design engineering, marketing, and sales for another MIM molder, Kinetics Inc. (Wilsonville, OR), explains that this innocence may stem from a basic misunderstanding of what’s involved.
“The common response to your question is probably ‘yes,'” he says. “Yes, but. It’s true the technology is very capital intensive. One very important piece that is missing from that, though, is that the technology is also very intelligence intensive.”
Hauck speaks for the majority of those already serving IMMC markets that we contacted for this special report. He stresses that success in MIM requires interdisciplinary technological expertise. MIM integrates a variety of separate-but-equal disciplines, including powder metallurgy, feedstock formulation, compounding, setter staging, debinding, and sintering. All this and more, and molding, too.
Everything has to work together seamlessly all the time to make consistently good parts. Sure, anyone can invest the capital. But as Dunstan H. Peiris of Singapore MIM molder Ceramet Technologies asks, “Does buying a lathe make you a machine shop?”
Hauck recommends that companies that are interested in MIM first determine whether they already have the talent in-house, or whether they can draw appropriate talent from elsewhere. This is the first thing they must do before deciding to make the move.
Others echo his advice. Neal C. Nordstrom, the director of MIM technology at Carpenter Parmatech (Petaluma, CA), explains some of the consequences:
“We have some very good competitors, but there are many of them out there who don’t know what they’re doing. MIM is a challenging technology that is more involved than custom plastics molding. It’s growing, but it’s far from mature. Some oversell what MIM can do. We have to go in and try to resell it. MIM has multiple enabling processes. You’ve got to be able to put it all together, or everyone suffers.”
Injectamax’s James agrees, concluding, “The worse thing that could happen now that things are at such a critical mass is for someone to land a big account, mess things up, and alienate an entire industry to the technology. The last thing that we need is for ‘MIM’ to become a dirty word.”
Today’s plastics are one of the most used materials on a volume basis in U.S. industrial and commercial life. Plastics are broadly integrated into today’s lifestyle and make a major, irreplaceable contribution to virtually all product areas. Although the plastics industry in the United States is now in its second century, the most important developments have occurred since 1910. However, the roots of these modern developments go back not only to the research of cellulose nitrate by John Wesley Hyatt in the 1860s, but also to the plastic-like compositions used by man through the centuries. to work or make parts by plastics, you need to have plastic mold and know things about plastic molding process
Origin of Plastics
One can go as far back as the Old Testament to find references about natural materials used as fillers, adhesives, coatings, and the like. These materials were the precursors of modern plastic materials. Historians continue to differ as to the exact year or decade that the plastics industry began because the definition of “plastic” is a matter of interpretation.
Certainly, the history of the rubber industry has a bearing on plastics. This is because ebonite, or hard rubber, discovered in 1851, was the first thermosetting material to be prepared and the first material that involved a distinct chemical modification of a natural material. But ebonite was not exploited commercially for some years after its discovery; for that reason, its historical importance has become somewhat blurred.
While the basic processes of rubber silicone molding technology were developing, other important discoveries were taking place in Europe. Following work by Pelouze, Schonbein established conditions of controlled nitration of cellulose. The product soon became of interest as an explosive and in the manufacture of collodion, a cellulose solution in an alcohol-ether mixture. In the 1850s, the English inventor Alexander Parkes observed that the solid residue left after the evaporation of the solvent of photographic collodion was a “hard, horny elastic and waterproof substance.” In 1856, he patented the process of waterproofing woven fabrics by the use of such materials.
In 1862, at the Great Exhibition in London, Parkes introduced a new material named for himself- Parkesine. Parkesine was obtained by dissolving cellulose nitrate in a minimum of solvent. The mixture was then put on a heated rolling machine from which some of the solvent was then removed. While still in the plastic state the material was then shaped by dies or pressure. In 1866, Parkes organized the Parkesine Company to manufacture products from his new material, but the company failed in 1868. This appears to be due, in part, to Parkes’ attempt to reduce production costs that resulted in the production of inferior items.
One year after the failure of the Parkesine Company-the molding company, an associate of Parkes, Daniel Spill, formed the Xylonite Company to manufacture products similar to Parkesine. Once again, economic failure resulted and Spill’s company went bankrupt in 1874. Undaunted, Spill moved to a new site, established the Daniel Spill Company, and continued production of his material, Xylonite.
First Plastics in the U.S.
In the United States during the 1860s, John Wesley Hyatt experimented with cellulose nitrate. In 1865, Hyatt became involved in devising a method for producing billiard balls from materials other than ivory. Originally using mixtures of cloth, ivory dust, and shellac, he patented in 1869 the use of collodion for coating billiard balls. The patent came one year after his collodion material was introduced commercially.
John W. Hyatt and his brother Isaiah took out U.S. Patent 105,338 in 1870 for a process of producing a horn-like material using cellulose nitrate and camphor. Although Parkes and Spill had mentioned camphor in their work, the Hyatt brothers recognized the value of camphor as a plasticizer for cellulose nitrate. In 1872, the term “celluloid” was coined by Isaiah Hyatt to describe the Hyatts’ commercially successful product.
The validity of Hyatts’ patents was challenged by Spill, and a number of court actions took place between 1877 and 1884. In the final action, it was found that Spill had no claim on the Hyatt brothers’ patents, the judge ruling that Parkes was the true inventor of the process because he had mentioned the use of camphor in his patents. Thus, there was no restriction on the use of these processes and any company, including the Hyatts’ Celluloid Manufacturing Company, was free to use them. After that decision, the Celluloid Manufacturing Company prospered( who make plastics, plastic parts and plastic molds, is plastic molding company as well, changed its name to the American Cellulose Chemical Corporation, and eventually was absorbed by the Celanese Corporation.
Next to cellulose nitrate, the most important material in the early history of plastics was formaldehyde. Around 1897 there was a demand in German schools for a white chalkboard. Efforts to obtain such a product resulted in the discovery of casein plastics, produced by reacting casein (milk protein) with formaldehyde. The material soon became established under the trade names of Galalith and Erinoid. Today, casein still is used by the button industry.
In 1899, Arthur Smith took out British Patent 16,275, the first dealing with phenol-formaldehyde resins for use as an ebonite substitute in electrical insulation. During the next decade, the phenol-formaldehyde reaction was investigated mainly for academic interest. In 1907, however, Leo Hendrik Baekeland discovered techniques to control and modify the reaction so that useful products could be made from it. Thus, phenolics were the first fully synthetic resins to become commercially successful.
Prompted by the success of phenolic moldings, research began on reacting other materials, such as urea and thiourea, with formaldehyde. These materials were used to manufacture molding powders. Unlike phenolics, they could be molded into light-colored articles and rapidly achieved commercial success. Today, these urea-based resins are used for molding powders, adhesives, and textile and paper finishing, while the related melamine-formaldehyde resins are used in decorative laminates.
Growth of Modern Plastics
Cellulose acetate, a thermoplastic, was developed about the same time as the urea-based resins. Similar in structure to cellulose nitrate, it was found to be safer to process and use. Cellulose acetate was introduced as a molding compound in 1927.
The period 1930-1940 saw the initial commercial development of today’s major thermoplastics: polyvinyl chloride, low density polyethylene, polystyrene, and polymethyl methacrylate. The advent of World War II in 1939 brought plastics into great demand, largely as substitutes for materials in short supply, such as natural rubber. In the United States, the crash program leading to large-scale production of synthetic rubbers resulted in extensive research into the chemistry of polymer formation and, eventually, to the development of more plastic materials for plastic molding company and plastics industry
The first decade after World War II saw the development of polypropylene and high density polyethylene and the growth of the new plastics in many applications. Linear low density polyethylene was introduced in 1978 and made it possible to produce polyethylenes with densities ranging from 0.90 to 0.96. Large-scale production of these materials reduced their cost dramatically. The new materials began to compete with the older plastics and even with the more traditional materials such as wood, paper, metal, glass, and leather. The introduction of alloys and blends of various polymers made it possible to tailor properties to fit certain performance requirements that a single resin could not provide. The demand for plastics has increased steadily; plastics are now accepted by designers and engineers as basic materials along with the more traditional materials. The automotive industry, for instance, relies on plastics to reduce weight and thus increase energy efficiency.
At plastic molding china company and our southern facility, Technology Molded Plastics, we specialize in tight tolerance custom injection molding, proudly serving the automotive, Lawn and Garden, recreational and other major industries
Austin Drinkall, son of the company’s founder William Drinkall, has run the company with a “customer first” philosophy. Our customer needs perfect quality, our customer needs technological support, and our customer needs great value. Internally, the only way to give our customers what they need is with outstanding teamwork, commitment, and a relentless drive for improvement.
Pursuit of this philosophy has lead to several quality milestones. Preferred vendor status with Chrysler in 1986, GM’s Spear 1 in 1987, GM’s Target for Excellence in 1990, Ford’s Q1 in 1991, Chrysler Pentastar Gold in 1995 and 1996. Our latest achievement was the third party certification of both plants to the rigorous QS 9000 standard (SBP in January 1997, TMP in July 1997).
Both manufacturing facilities are easily found. South Bend Plastics is just a few minutes south of the Indiana Toll Road in North Central Indiana. Technology Molded Plastics is just a few minutes off the U.S 65 in North Central Alabama. Both plants are within 25 minutes of full service airports if emergency transportation is required.
plastic molding china company is a privately held company, which has been devoted to quality and value for nearly 40 years
Our QA Department acts as auditors over the production process to make sure your blue print requirements are strictly followed.
QUALITY ASSURANCE EQUIPMENT
Programmable Coordinate Measuring Machines
Gear Lead and Involute Checking Instruments
T.I.R and Runout Checking Equipment
Hommel Gear Tester
Micrometers & Calipers
Tensile Strength Tester
plastic molding china company and subsidiary Technology Molded Plastics have successfully implemented a quality system in compliance with ISO 9002, and QS-9000 standards. This compliance underlines our absolute commitment to quality.Coordinate measuring machines speed the delivery time of vital layout information to engineering. Statistical controls attribute and hand checks at the press give immediate quality feedback to our production crew. All operators and inspectors who use quality checking equipment are certified to do so through annual training and verification programs.
Building successful partnerships require communication above all other aspects. Our customer service representatives interact with all other departments to provide timely and accurate information to our customers. Consider them your “One Stop Shop” for project information.
To reach our customers who are not local to South Bend Plastics and Technology Molded Plastics, we employ manufacturer’s reps. These individuals are close to your facility, familiar with our operations and can provide valuable feedback to inquiries.
Quick response to your needs is an absolute priority. Utilizing Electronic Data Interchange (EDI), Material Resource Planning (MRP) and Bar Coding, South Bend Plastics can process your order, immediately schedule the job, and make shipments your personnel can scan and send on their way. Manual releases are also accepted through fax or regular mail and upon our entering them, flow through the MRP system.
South Bend Plastics provides a complete engineering team to work with you from start to finish in the production of your design. Close attention is given to details to guarantee the outcome you expect . A project engineer is assigned to each program to ensure successful product launches.
Auto Cad, Version 14
Catia, Version 4.0
The above equipment and software provide our staff with the ability to service your prototype needs and advise you on potential conflicts in your part design. Working closely with tool sources, our engineers ensure the mold designs will provide consistent quality and durable performance for your production needs.plastic molding company
South Bend Plastics provides a complete plastic mold repair and maintenance facility. Included in our piece price is the regular repair and maintenance of your production mold. A staff that includes 5 full time mold makers can respond immediately to mold damage and return molds to production ready status in short periods of time. Our tool repair facility allows production to conistently meet their schedule demands.
FULL COMPLIMENT TOOLING EQUIPMENT
lathes, Milling and Grinding Equipment, EDM Machines, Engraving Capabilities, Maxi Blast Plastic media cleaner.
The demand of plastic based consumer products in increasing day by day. The cost of material as well as the manufacturing synthetic products is relatively low. Therefore the need of such type of products is on the rise today. Plastics are nonmetallic compounds. It can be molded into several forms. Besides it can be hardened for commercial use. The uses of molding products are common in our day to day life. We use jars. Toy, bottles, kitchen utensils. Accessories and a lot more. Even the mouse and keyboard we are suing are made through PVC molding.
Basically in plastic injection molding molten liquid is inserted into a ready shaped plastic mold. Then it will be allowed to cool. After then the mold will be removed. For example if it is a mold of the bottle then after cooling we get a bottle. Plastic mold for sale in China can also custom mold a variety of products. The products include office trays and boxes, traffic signage and displays for product and marketing promotions, barricades, barriers and cabinets etc.
If you are planning to move into plastic molding and plastic molds business, first you need to find a Chinese mold partner and you need to know the different processed. Go through the details of every process and collect as much information as you can. And finally choose a process that fits you budget and resources. Let’s get some information about various plastic molding methods.
Blow molding is a process that begins by the melting of the liquid plastic in the chamber of the machine. Then the liquefied plastic is sent to the desired shape. This type of process specializes in creating the hollow products that includes bottles, hoses, motorcycle fuel tanks and other hollow products. In this method the air poured in the mold. Then it will harden and thus it creates the desired shape. Then the mold is pulled out through a mold cavity.
Care and use of your plastic mould
Depending on the material your plastic mold is made out of, you will need some sort of lubricant to make it possible to remove your casting from the mold. Concrete will stick to some types of molds better than others. There are commercially produced mold released if you are inclined to use them. Personally in think there are a waste of money.
I have found that motor oil, Vaseline or petroleum jelly. Cooking spray on lubricants used in the automotive industry work well and are cheap. Surprisingly cooking spray does not working very well and in my opinion should not be on the list. I know why but I have never had a hell of a lot of luck with. Maybe it is because I bought the cheap stuff I do not know. Petroleum jelly is best used if you have wooden mold because it does not soak in like oil does. Be generous with it. Especially on new wood.
I am not going to mention cooking spray, because I never use it. But spray on oils is easy to use and work well on any metal or plastic mould, however I have to say that my favorite is 10 weight engine oil. It is around a dollar a quart, buy the cheapest stuff you can find. It is easy to use. Just pour some on a rag and rub it on your mold. The important thing is to make sure that you got whatever lube you are using into all the corners. And that is not puddle up anywhere.
Depending on the size of the casting, you may decide to put in some wire mesh for reinforcing. I do not usually bother if it is something I will be hanging however if you are casting steppingstones or something like that is a good idea to use some form of reinforcement. A general rule for me is anything over a foot square will have reinforcement. If you are making a hanging, be sure to have the hangar ready to insert. You do not wantto be looking for something to make out of in the middle of casting it.
Once you have used your plastic mold and removed your casting another very important thing is to clean you mold, immediately. Before you put it away. I have found the best thing to use is ordinary liquid dish soap. Like yoou use the sink, not the stull from the dish-washing machine. Be sure you do a good job and then hang up you mold out for the sun and it will server you for a long time.