Large-scale Complex Mould Manufacturing|Tool Building

or mould manufacturing, the larger dimensions, the higher surface quality requirements. With production  size increase, their corresponding mold design will also be increasing the difficulty.  Its difficulty is how to design gating system to balance of the whole products liquidity, low injection pressure and clamping force as far as possible, and how to prevent the shrink mark the local wall thickness is uneven and through effective to adjust the mold temperature control shrinkage. Moreover, large mould internal structure corresponding to the injection on to bring a certain degree of difficulty. So, mould design elements and analysis is very important before mould manufacturing, and we should take every step as per requirements, and deal with every detail very carefully.

Mould Orders & Requirements

Information from customers: parts drawing, CAD data model, injection machine to be used for mould, cavity, material type. Before mould design, potential elements analysis is need to discuss by production analysis meeting, that can ensure produce the mould more smoothly and success. Including:

Production Structure Analysis and Mould 3D Design

Good mould design is precondition of making good mould. Our experienced skill worker will do all-wave analysis for production and mould structure and make DFM, including following:
1） If parting line location, process precision is meet requirement, if will cause overflow plastic or not, if parts will stay at core after open mould
2） If draft way is correct or not; if ejector type, size, location, quantity are suitable, if eject bar will lock by core and damage to parts or not.
3） Temperature adjusting of mould. Such as heater power, quantity; cooling system gating location, size, quantity.
4） Ejection system, check if slide and ejector location is correct or not, will they be mutual interference
5） Feeding system, venting location & size.

Foe feeding system, the design challenge is how to design gating system, so that the whole product flow balance, injection pressure and clamping force as low as possible, and how to prevent shrink mark the local wall thickness is uneven, and products to avoid secondary processing spray processing.
Mold using a hot runner system, using open among big gate, plastic parts molding can be directly after the processing flow. Which can reduce some process and save material and cost. What’s more, the production are made with high quality.

Plastic Material Features and Mould Steel

Plastic usually use for household appliance are: HIPS, ABS, PC, POM, NYLON, etc.
* HIPS:   hard and rigid, thermal stability, mainly use for TV cover shell, printer, fax machine, stationery set ect.
*ABS: strong, hard, rigid, thermal stability, mainly use for TV cover shell, juice extractor, instrument panel of automobile,
* PC:   intensity of tension, flexural strength, high elasticity, shock-resistance, and all these features are similar with metals. And even under 140 centidegree, it also can keep these character, it is suitable for making helmet, machine elements, electrical insulators, strength and thermal stability of electromechanical devices parts.
* POM:   thermal stability, hard and rigid material, suitable for making auto parts, gears, etc.

*Mould steel: 45#、40Cr、P20、2738、2316、718、 718H、NAK80、S136,etc. Normally, household appliance can choose P20、718、S136、NAK8 etc. Customer can choose material by themselves according to their requirements.

Mould 2D Combined Diagram, Parts Drawing, 3D Assembly Drawing Check and Manufacturing

DELL Computer Display Shell Mould and Injection Parts Solutions

Before manufacturing, all Mould 2D combined diagram, parts drawing, 3D assembly drawing must be rigid check.
Mould is consist by cavity and core, core is fix onto injection removable panel and cavity is onto injection immovable panel; when injection, cavity and core close to form cavity and feed system. When mould move apart, plastic parts are stay at the core side, and they will eject by ejection system.
Mould manufacturing need many process, including: CNC precision cutting, EDM, wire-cut, milling, parts measurement, polish, texture, fitting, assembly and so on.

* CNC: used for cutting basic shape. The highest precision is 5μm, highest speed is 24,000 rpm, and biggest cutting knife is dia
* EDM: EDM is needed for those more complicated shapes which are unable to be cut by CNC. First, we have to cut copper (called Electrode) into the mirror shape of the steel component (namely shape of product), then load the electrode on EDM, and the electrode will cut the steel by constantly contacting discharging.
* Wire cut: Similar processing technique with EDM machine. Difference of wire cut is discharging is made by molybdenum wire instead of copper.
Wire cut machine includes 3 types: high speed, medium speed, and low speed. Lower speed is, higher precision is. Among the machining facilities, in general, low speed wire cut has the highest precision, before EDM, while CNC is the last one.
* Measuring: Measuring is frequently used during tool making. Besides, plastic part also needs measuring. A good measuring instrument is a must for all these requirement. Our lab is equipped with complete and advanced measuring instruments, like 3D CMM, projector, hardness detector, etc.. All these instruments must be regularly maintained.
* Fitting: Fitting is a very important process. Very rich experienced is needed for technician for he has to assemble many steel components together. Otherwise, the assembled tool will easily have problem in moulding.

Mould Test

When mould assembly finish, then proceed with inspection to check if the mould is meet requirements completely.
The inspection including 6 sections, feed system, slide system, ejector system, cooling system, location system and others. Every section needs double check and inspect.
Hereafter, soft reminder that every designer and skill worker may make mistake sometimes, so when testing mould, if we don’t pay attention to every detail, it might cause damage to the mould due to small mistake. Second, purpose of testing mould is to ensure the mould manufacturing can smooth, but if we don’t make it as per reasonable process and make suitable records that will not be sure to make mould successfully.
To keep all the test mould records safely, including cycle pressure, melt the plastic and mould temperature, feeding system temperature, injection time, and so on. In short, we should keep all the data for similar injection project of the future and get high quality products.

Mould Maintain & Maintenance

Mould maintenance is important than maintain, because the more maintain, the shorter of mould life. And if we keep mould in good condition, mould life can be longer.
-1. Daily maintenance: every movable parts such as ejector pin, slide block, guide pillar, guide bush should be lubrication, mould surface and cooling system should be clean.
-2. Periodical maintenance: including venting; damage, wear and tear parts should be modify.
-3. Appearance: mould base should smear rust-preventative oil; keeping the mould close to avoid dust when not use.

We can offer you service from product design, mold design & tooling to custom injection molding, as well as printing and assembly.

In mold area, HOLDSUN can offer you:
1) Quotation within 24hours upon receipt of RFQ
2) Mold layout within 1-2 days
3) Supply of prototype with 2-3 days if necessary.
4) Ensuring the tolerance +/-0.002mm
5) Weekly report of all project tracking
6) Urgent project mold can be finished in 25-30days offer correct samples.

Pls feel free to send ud inquiry, if you have any plastic parts need mold making.