Questions and Answers on Mould Manufacturing Technology

There are many problems to be paid attention to in mould manufacturing. If you don’t know its process and key points, you should learn more about the following knowledge.

1) What is the most important and decisive factor in choosing die steel for mold manufacturing?

Forming method – can be selected from two basic material types.

1. A) Hot working tool steel, which can withstand relatively high temperatures during die casting, forging and extrusion.

1. B) Cold working tool steel, which is used for blanking and shearing, cold forming, cold extrusion, cold forging and powder pressurized forming.

Plastics – Some plastics produce corrosive by-products, such as PVC plastics. Condensation, corrosive gases, acids, cooling/heating, water or storage conditions caused by long shutdowns can also cause corrosion. In these cases, stainless steel die steel is recommended.

Mould Size – Pre-hardened steel is often used in large-size mould. Integral hardened steel is often used in small size mould.

Mould life – Long-term use (more than 1000000 times) should use high hardness steel, its hardness is 48-65 HRC. Pre-hardened steel should be used for moderately long-term (100,000 to 1,000,000 times) mould with a hardness of 30-45 HRC. Short-term use (surface roughness – Many plastic mould manufacturers are interested in good surface roughness. When sulfur is added to improve metal cutting performance, the surface quality will decrease. Steel with high sulphur content also becomes more brittle.

2) What are the primary factors affecting the machinability of materials?

The chemical composition of steel is very important. The higher the alloy composition of steel, the more difficult it is to process. As carbon content increases, metal cutting performance decreases. The structure of steel is also very important for metal cutting performance. Different structures include forged, cast, extruded, rolled and machined. Forgings and castings have very

difficult surfaces.

Hardness is an important factor affecting metal cutting performance. The general rule is that the harder the steel is, the more difficult it is to process. High-speed steel (HSS) can be used to process materials with hardness up to 330-400 HB; high-speed steel + TiN coating can process materials with hardness up to 45 HRC; and for materials with hardness 65-70 HRC, cemented carbide, ceramics, cermet and cubic boron nitride (CBN) must be used.

Non-metallic impurities generally have a negative impact on tool life. For example, Al2O3 (alumina), which is pure ceramics, has strong abrasion resistance.

The last one is residual stress, which can cause problems in metal cutting performance. It is often recommended that the stress release process be carried out after rough processing.

3) What parts does the production cost of mould manufacturing consist of?

Roughly speaking, the distribution of costs is as follows:

Cutting 65%

Workpiece material 20%

Heat treatment 5%

Assembly/apintejinustment 10%

It is also very clear that good metal cutting performance and excellent overall cutting solutions are important for the economic production of mould.

PTJMould Industrial Company Limited, established in 2010, is a leading China mold factory. PTJMould specializes in plastic mould production for household appliances, medical equipments, electronic equipments, safety equipments as well as monitoring system.

The company has over 15000 square metres factory. With plastic injection tooling divisions possessing different machinery and expertise, PTJMould offers tools from small and precise mobile phone parts to as big as automotive parts. Our tools are mainly exported to U.S.A., Europe, Japan and UK. PTJMould’s diversification strategy and full service has won compliment from customers all over the world.

Our mission is to provide our customers high quality moulding products and services. We aim to exceed our customers’ expectations of pricing, quality and on-time delivery. To achieve our mission, PTJMould:

• Commits to continually improve employee skills and efficiency,
• Provides our employees a clean and safe working environment,
• Upgrades machine technology and support equipment through a strict maintenance program, and
• Maintains customers’ tooling to its highest peak of performance

For more about China injection molding cost,please visit https://www.plastics-moulding.com/

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