There is the matter of complexity as well as the cost of the part and injection mold, not just the mold. A flower pot usually doesn't require an automotive finish, nor does it require the use of material specific to the automotive part. A flower pot is typically a straight pull part, here as the automotive part has undercuts, multiple areas of complexity with ribs, bosses, etc. and requirements for strength, tolerances, and cosmetics that are far beyond what a flower pot has. In terms of the human capital required to run the injection molding machine, one has to look at volumes and whether automation is cost effective for the run versus mold changes, material changes, etc.
Car molds are using engineering grade plastics due to a need for structural strength and flower pot molds are probably using consumer grade plastics, constituting a higher order of processing complexities. Not to mention the complexity of shapes hence mold design and the need for tightly controlled tolerances in accordance with the assembly's tolerance stacking.
One of the questions for you would be, do you want to go with an all electric or with a hybrid? For sure you want electric controlled injection at least for the shot repeatability. There are a lot of good brand injection molding machines out there mechanically. I lean towards the machine being user friendly. It has to be well received by the floor not by the engineering staff. Of course it also matters what part of the world you are buying for as the service can be an issue in different areas.
I'm assuming your needs are for the USA. I prefer the all electric Roboshot, but would also recommend the Sumitomo and the Nissei. Probably in that order. I think you should get with your local reps and make short trips to see the injection molding machines running and take someone from maintenance and the floor with you. Most of these folks will also give you an injection molding machine to trial, so depending on the time you have that is also, a good way to go.
In the automotive industry the requirement of using recycled plastics material is encouraged by European directives. In fact, particularly in the polyolefin sector large amounts of regrind materials are being used. The scrap ratio depends a lot of the sourcing of the regrind. In most cases manufacturers that use off grade, regrind material will make sure its single source regrind supplier , which is in its turn a challenge as the volumes offered are not constant. Off grade or regrind is a byproduct and as such not an intentional product to be produced!
While in the polyolefines sector intrinsic property differences caused by regrind can be influenced more easily by appropriate selection of additives and/ or other resins, it becomes more trickier for the higher end polar thermoplastics like e.g PC/ABS.
In order to make a decision if a regrind / off grade material has a negative effect statistical analysis and multi variable regression helps a lot to determine which factor is really the cause of the problem. Too often different views, impressions, thoughts, all equally valid, are being raised as possibilities but it needs to be supported by statistically significant data.
Custom plastic housing parts refer to the main body or enclosure of a plastic product. Almost all the plastic products you find in the market have their special cases.
Custom plastic housing parts require an injection mold, a professional mold maker would design and make the mold base on the quantity demand, finish etc. Good quality and competitive price are all important considerable factors, a family mold might have higher productivity but the initial mold cost would be unbearable for a low volume injection molding project.
Many plastic toys are made through injection molding, toys made in plastic have advantages of good strength, light weight, colorful decoration, complex design are possible, economic. China is the biggest plastic toys market, as well as the biggest producer, Many world famous plastic toys producer established their research center and manufacturing facilities in China
, such as Hasbro, Lego, Mattel.
| Plastic toy transformer, produced by Hasbro |
| Plastic toy truck, produced by Lego |
These gears share a common trait with TIR lenses for LED- automotive headlamps, LED-Streetlamps etc- being ultra precision in molded part along with thick thin sections making it impossible. Even long cycle times will cause geometry variation and compensating profile is only way out, unless you do two shot molding- first shot does the bulk of molding with zoned cooling so part has uniform average temperature in thick and thin wall, overmold with a uniform layer in second shot and that can help improve geometry. Here you could add lubricity in top layer having core of tough material that may be cheaper.
Make a decision you take you are own time and think about what you want to simulate. All I will suggest it to wait for Moldflow 2014 because Moldflow is the first software but for last 2 years the development are coming but the need of Hot runner and Mold making ppl are not satisfied fully because of Autodesk and all the internal things going around.
So I will suggest you to wait for 2014 and improve you are basics and try to balance the injection molding process which I see mechanically is Clamp force against Injection pressure and Thermally heating against cooling.
I have been using various types of rubber and flexible vinyl floor mats in my cars for more than 20 years and presently have clear vinyl mats in one of my cars. Some dealers often supply cheap black rubber ones with new cars, but they smell too much and the smell persists for months. Paper or thin PE ones are sometimes used by service stations to avoid dirtying the customer’s mats during servicing. Assuming we are talking about regular mats to be bought by car owners, there are many choices available in shops stocking automotive accessories and most seem to be rubber or flexible vinyl, which may be clear or pigmented.
You might hear from someone that injection molds from China are bad quality, but still many companies are buying molds from China, some of them with bigger purchase volume even set their own mold sourcing office in China. I don't think these companies are all stupid, then why is that?
The answer is China mold manufacturers can produce quality mold as good as Europe, US companies at even lower price, this is why the mold makers
outside China lost their jobs to Chinese.
Injection molding start talking about pressurizing the mold, before filling the cavity, when they try to improve the quality of the surfaces of the pieces made in structural foam. By mean of foaming agents, add to the raw materials, you can get lighter pieces with some remarkable advantages and one big disadvantage: the poor quality of the surfaces.
You recognize at the pieces made in structural foams these advantages:
- Raw material saving: up to the 35%, in direct function of the wall thickness. That normally shouldn't be < 5 mm.
- Absence of internal frozen stress, hence pieces free of warpage or deformation of any kinds;
- Absence of sink mark of any kind, ribs and bosses, also the external sharp corners are tight as expected.
- By the pressure of the foaming agent, you push the material in the periphery, this increase the 'Inertial Module' of the molded object, this compensates for the weight reductions, and you get the same mechanical strength of the integer piece.
- Now the one big disadvantage: the poor quality of the surfaces, everywhere ruined by silver streaks.
Asiamold Exhibition has established its position as one of the world's most famous exhibition for mold manufacturing, processing, design and application development. As Asia's leading mold exhibition, 2014 Asiamold Exhibitors and the number of visitors increased significantly, reflecting the exhibition provides a great extent, from design to molding and an one-stop solution for volume production. 320 exhibitors from 14 countries and regions participated, 10% increasing compare with 2013, visitors were 15,262, 22% higher than last year, 13,424 were domestic visitors, from 45 countries and regions, 1,838 overseas visitors, from 45 countries and regions, attend the event.
There is a trend, European and UK moulding companies are moving to other destinations for mold sourcing and are also moving back to their base location.
For many years we've all fallen over ourselves to get the lowest mold price and not looked at the true cost of purchase. The Germans have never done this and surprisingly they have a thriving manufacturing base and an economy that is pretty envious in the current situation.