Are you still struggling with inconsistent PET preform quality or moulds that wear out prematurely? The choice of mould material might be the crux of the problem. The right selection ensures higher quality products and a longer, more efficient lifespan for your valuable tooling.

For PET preform moulds, the optimal material choice ultimately depends on your specific production needs, quality standards, and budget. Generally, high-quality hardened stainless steels (like S136) are favored for critical forming components due to their excellent durability, polishability, and corrosion resistance. However, a well-designed mould often combines various materials, such as using P20 or 4Cr13H for mould bases and H13 for hot runner manifolds, to achieve the best balance of performance and cost-effectiveness.

Choosing the right materials for your PET preform moulds, with so many steel grades and considerations, might seem like a daunting task at first. However, understanding how different materials affect the overall performance of the mould—from the quality of the preform to the lifespan of the tool itself—is absolutely critical. I remember when I first entered this industry, I tended to focus only on the core and cavity material. It took a few challenging projects for me to fully appreciate how every component's material selection plays a vital role in the grand scheme of achieving efficient, high-quality PET preform production. Next, let's delve into what constitutes a high-performance mould and why these material choices are so fundamental.

How do Cold Half materials impact PET preform mould performance?

Are you worried that the final shape, precise dimensions, or clarity of your PET preforms are not up to par? The materials used in the Cold Half of your mould are absolutely key. Making the right choices here is fundamental for achieving consistent, high-quality results day in and day out.

Cold Half materials, especially for the mould base and supporting plates, directly influence the mould's structural integrity and the alignment of forming components, which in turn affects preform dimensions and appearance. Steels like S136H offer excellent polishability and corrosion resistance for parts needing high surface quality, while 4Cr13H provides a good balance of hardness and cost. P20, being a more economical option, is often used for mould bases where an ultimate surface finish isn't the top priority.

The Cold Half of a PET preform mould is fundamentally where the preform takes its final external shape and achieves its precise dimensions. You can think of this section as the primary sculptor of your product. I recall a project early in my career where we were intensely focused on the core and cavity steel (which is, of course, vital) but didn't give enough consideration to the mould base material for the Cold Half. To save on initial costs, we opted for a very basic steel. But over time, we noticed issues with alignment and plate deflection under clamp tonnage, which subtly affected preform consistency. That was a valuable lesson: the entire Cold Half assembly matters.

Here's a comparison of commonly used materials for mould bases/plates in the Cold Half:

Feature	S136H (or other high-grade stainless)	4Cr13H (or similar pre-hardened 1.2316)	P20 (or similar 1.2311/1.2312)
Primary Use	High-demand mould bases, cavity plates	Medium-high demand bases, structural parts	Standard mould bases, support plates
Typical Hardness	~30-35 HRC (pre-hardened) or higher (can be heat-treated)	~30-35 HRC (pre-hardened)	~28-32 HRC (pre-hardened)
Corrosion Resistance	Excellent	Good	Fair (requires anti-rust measures)
Polishability	Good to Excellent	Fair to Good	Fair
Relative Cost	High	Medium	Low
Machinability	Fair	Good	Excellent
Application Scenario	Situations with high demands on mould life and surface	General applications balancing performance and cost	Standard applications focusing on cost-effectiveness

For instance, when you're considering mould plates that hold the cavities or provide backing support, if parts of these plates affect the preform's final quality, or if extreme longevity and corrosion resistance are paramount, then S136H stainless steel is a premium contender. Its polishability is good, but more importantly, its excellent corrosion resistance is a lifesaver, especially if your plant has high humidity or if you're processing materials that might release slightly corrosive gases. This prevents rust from forming on critical surfaces or in cooling channels—rust can be a nightmare to deal with.

Then there's 4Cr13H (or pre-hardened stainless steel like 1.2316). I often recommend this as a reliable mid-range option for mould bases or support plates. It can be heat-treated to a respectable hardness, giving it better wear resistance and compressive strength than ordinary carbon steels. Compared to P20, it also offers better corrosion resistance. For many medium to high-volume applications where you don't need an extreme polish but still require good durability, 4Cr13H provides an excellent balance of performance and cost. It's often used for mould bases supporting S136 cavities and is a robust choice.

And what about P20? This is a widely used pre-hardened tool steel, often chosen for mould bases due to its good machinability and cost-effectiveness. For structural parts of the Cold Half that don't directly contact the plastic and don't require an extreme surface finish, P20 is usually perfectly adequate. It provides the necessary strength to support the cores and cavities under clamping force. However, its polishability and corrosion resistance are not on the same level as S136. If P20 is used for cavities in high-volume preform production (especially transparent ones), it may lead to more frequent maintenance or a shorter overall mould life. We once tried to save costs by using P20 for a medium-volume project; while it worked initially, its surface finish degraded much faster than we anticipated.

Why is FS136 the top choice for core PET preform mould components?

Are your preforms showing scuffs, drag marks, or slight dimensional inconsistencies sooner than expected? The material choice for your mould core, cavity, and even the stretch rod is absolutely vital for long-term performance. For these critical parts, FS136 steel often emerges as the leading recommendation.

For the most critical forming components in the Cold Half—the mould core, cavity, and stretch rod—FS136 (a high-purity grade of S136 stainless steel) is highly recommended. Its exceptional hardness after heat treatment, capability to achieve a true mirror polish, and outstanding wear and corrosion resistance directly contribute to superior preform quality and significantly extended mould operational life.

When we drill down to the absolute heart of preform creation within the Cold Half—the mould core (which forms the inside of the preform), the cavity (forming the outside), and the stretch rod (critical for the preform's base and later blowing process)—the demands on the material escalate dramatically. These components are in direct, high-pressure contact with molten PET, cycle millions of times, and define the final product's quality. This is precisely why I, and many in the industry, strongly advocate for FS136 steel. FS136 is typically an Electro-Slag Remelted (ESR) or similarly high-purity grade of S136 stainless steel. This refining process helps to minimize non-metallic inclusions and impurities within the steel, which is the secret to its ability to achieve an incredibly smooth, defect-free mirror polish.

The mirror polish achievable with FS136 (often to A1 or SPI A-2 standards) isn't just for show. For PET preforms, especially those for clear bottles, it's essential for optical clarity. More practically, an ultra-smooth surface significantly reduces friction as the cooling preform ejects from the mould. This means less likelihood of scuffs, drag marks, or sticking preforms, which can lead to faster cycle times and reduced part damage. I worked on a high-cavitation mould project once where a switch from standard S136 to an ESR-grade FS136 for the cores and cavities noticeably improved part release and reduced minor surface imperfections that were causing rejects.

Beyond polishability, FS136 can be heat-treated to a high hardness (typically in the 48-52 HRC range). This high hardness provides exceptional wear resistance against the abrasion of PET resin, especially if it contains fillers like titanium dioxide (TiO2) or recycled PET (rPET), which can introduce more variability. In contrast, some less hard or less tough materials, like improperly treated common tool steels, would wear out much faster under the same conditions. The stretch rod tip, in particular, which forms the critical gate area and experiences significant wear, benefits immensely from this toughness. Furthermore, as a high-chromium stainless steel, FS136 offers excellent corrosion resistance, protecting the meticulously polished surfaces from attack by moisture, condensation, or any acidic byproducts that might arise from PET processing (especially at high temperatures). This ensures the mould retains its performance and preform quality over a very long production life, often running for many millions of cycles with proper care. Admittedly, the upfront cost is higher, but the reduced downtime, lower scrap rates, and consistent quality make it a very sound investment for serious preform production.

What role do Hot Half materials play in efficient PET preform production?

Are you experiencing frustrating issues with inconsistent PET melt flow, temperature variations, or premature wear in your hot runner system? The materials chosen for your Hot Half components are often the unsung heroes—or culprits—in efficient PET preform production.

The Hot Half, particularly the hot runner system, demands materials that can withstand continuous high temperatures and ensure smooth, controlled flow of molten PET. H13 tool steel is a common and robust choice for the manifold plate due to its high-temperature strength, while specialized components like valve pins or nozzle tips might use other exotic alloys. In some designs, graphite-infused copper alloy plates may also be used to enhance thermal conductivity and reduce friction in moving parts.

Let's pivot to the Hot Half of the PET preform mould. This section is all about managing the molten PET resin, keeping it at a precise and uniform temperature, and delivering it efficiently to each cavity via the hot runner system. If the Cold Half is the sculptor, the Hot Half is the sophisticated delivery network. The main structural component here is often the hot runner manifold plate, and for this critical component, H13 tool steel is a very widely adopted and reliable choice.

Why H13? This steel is a chromium-molybdenum-vanadium hot-work tool steel, and its properties make it exceptionally well-suited for this demanding application. It boasts excellent "red hardness," meaning it retains its strength and hardness at the high operating temperatures (typically 270-300°C for PET) inside a hot runner manifold. It also has good thermal fatigue resistance, allowing it to withstand the constant cycling between high operating temperatures and cooler shutdown periods without cracking. Its good toughness helps prevent catastrophic failures. I've seen H13 manifolds that have been in service for over a decade, consistently performing their job. The manifold houses heaters and melt channels, so its ability to maintain dimensional stability and resist warping under prolonged thermal stress is paramount for balanced flow to all cavities. Other steels might soften or deform at such sustained high temperatures, leading to uneven flow and product defects.

Beyond the manifold block itself, other materials come into play for optimal performance. For instance, nozzle tips and valve pins (in valve gate systems) are highly critical. These components directly contact the molten PET at the point of injection into the cavity. They need to be extremely wear-resistant (especially at the gate area) and often require excellent thermal conductivity for precise temperature control at the gate to prevent issues like stringing or cold slugs. Here’s a comparison of common materials for nozzle tips/valve pins:

• Advanced Tool Steels (e.g., High-Speed Steel, PM Steel):
  • Pros: High hardness, good wear resistance, relatively moderate cost.
  • Cons: Thermal conductivity not as good as copper alloys; lifespan may be limited under extreme wear.
• Beryllium Copper Alloys (BeCu):
  • Pros: Excellent thermal conductivity, aids in precise gate temperature control, reduces cold slugs.
  • Cons: Hardness and wear resistance not as good as tool steels; higher cost.
• Carbide Inserts:
  • Pros: Extremely high wear resistance, long life, especially suitable for abrasive materials like glass-filled PET.
  • Cons: High cost, lower toughness, difficult to machine.
• Surface Coatings (e.g., TiN, CrN): Can be applied to tool steel components to further enhance surface hardness, wear resistance, and reduce friction.

In some hot runner designs, particularly around moving components or sealing faces within the manifold system, you might also find graphite-infused high-strength brass plates or bushings. The brass offers very good thermal conductivity, helping to distribute heat evenly and quickly, while the graphite acts as a solid lubricant, reducing friction and wear between sliding steel surfaces at high temperatures. I remember troubleshooting an older hot runner system that lacked these features; issues like resin leakage and seized components were far more common than in modern systems that thoughtfully incorporate such clever material combinations.

How does choosing the right steel affect PET preform quality and mould longevity?

Are you constantly battling issues like surface imperfections on your preforms, or finding that your moulds require frequent, costly maintenance and don't last as long as you'd expect? The steel you select for your mould components directly and significantly impacts both the quality of your PET preforms and the overall operational lifespan of your mould.

The right steel selection directly translates to better PET preform quality by enabling superior surface finishes, maintaining tighter dimensional accuracy, and ensuring clarity. Higher quality steels, such as properly heat-treated S136 or FS136 for forming parts, also dramatically extend mould longevity due to their enhanced wear and corrosion resistance, ultimately leading to lower long-term production costs despite a potentially higher initial investment.

The link between the steel chosen for your PET preform mould and the two critical outcomes—preform quality and mould lifespan—is incredibly direct. I often explain to my clients that skimping on steel quality is almost always a false economy in the long run. Let's break down how this plays out.

Regarding preform quality, several aspects are influenced by the steel:

• Surface Finish & Clarity: For preforms, especially those for clear beverage bottles, a flawless, glass-like surface is essential. Steels like S136 or, even better, FS136 (an ESR grade) can be polished to an exceptionally high mirror finish (SPI A1 or A2). This ultra-smooth surface on the core and cavity is directly imparted to the PET preform, resulting in high clarity and a blemish-free appearance. In contrast, softer or less pure steels cannot achieve or maintain this level of polish, potentially leading to duller preforms or visible surface defects. For example, using P20 steel directly as cavity material for transparent preforms would quickly lead to a rougher surface due to wear, reducing preform transparency and even causing fine scratches.
• Dimensional Accuracy & Consistency: High-quality tool steels, when properly heat-treated, offer excellent dimensional stability. This means they resist deformation under the high injection pressures and clamping forces inherent in the moulding process. This stability ensures that critical dimensions of the preform—like wall thickness, neck finish details, and overall weight—are maintained consistently from shot to shot and over long production runs. This consistency is vital for efficient downstream blow moulding. I've seen moulds made with lesser steels develop issues with 'flash' or inconsistent weights much sooner due to wear or slight deformation of the forming surfaces.
• Gate Quality: The steel used for nozzle tips and gate inserts in the hot runner, and the core pin tip in the cold half, directly affects the gate vestige on the preform. Wear-resistant steels maintain a sharp, clean gate, minimizing issues like stringing or oversized vestiges that can cause problems in blowing or handling.

Now, let's consider mould longevity:

• Wear Resistance: PET resin, especially when containing additives like glass fibers (less common for standard preforms but possible) or even pigments like TiO2, can be abrasive. The constant flow of molten plastic and the opening/closing cycles cause wear on mould surfaces. Hardened, high-quality steels like S136 (typically 48-52 HRC) offer far superior wear resistance compared to softer steels like P20 (around 30-34 HRC). This means critical dimensions are maintained for millions more cycles. I once ran a comparison: two moulds for the same part, one with P20 cavities, one with S136. The P20 mould started showing wear and flashing after about 1.5 million cycles. The S136 mould? It was still running strong well past 5 million cycles with minimal maintenance.
• Corrosion Resistance: PET processing can involve moisture, and cooling channels are obviously water-fed. Condensation can also occur. Stainless steels like S136 are inherently resistant to rust and corrosion, which can quickly damage polished surfaces or clog cooling channels in non-stainless steels if not meticulously maintained. One client I worked with extended their maintenance intervals by over 50% just by switching from a non-stainless cavity steel to S136, simply due to reduced corrosion issues.
• Resistance to Indentation & Damage: Higher hardness also means better resistance to accidental damage or indentation from small contaminants or mishandling, preserving the mould's integrity.

Investing in premium steel for the forming components is truly an investment in consistent quality and prolonged, trouble-free production.

S136 steel vs. P20 steel: What are the key differences for preform molds?

Feeling uncertain about whether to specify S136 or P20 steel for your next PET preform mould project? Understanding the fundamental differences between these two common mould steels is crucial for making a decision that aligns with your quality requirements, production volume, and budget.

S136 is a chromium stainless martensitic tool steel known for its excellent polishability (to mirror finish), high corrosion resistance, and good wear resistance after heat treatment; it's ideal for high-quality, high-volume PET preforms, especially clear ones. P20 is a versatile, pre-hardened carbon tool steel that is more economical and easier to machine but offers lower wear resistance, corrosion resistance, and polishability compared to S136, making it suitable for mould bases, shorter runs, or less critical applications.

The choice between S136 and P20 steel for PET preform moulds comes up frequently, and it's a classic case of balancing performance against cost. They are quite different materials suited for different roles within a mould or for different types of applications. I always try to lay out a clear comparison for my clients.

Let's look at a detailed comparison table of their key characteristics:

Feature	S136 (e.g., ASSAB STAVAX ESR, FS136)	P20 (e.g., AISI P20, DIN 1.2311/1.2312)
Steel Type	Martensitic Stainless Tool Steel	Pre-hardened Carbon Tool Steel
Corrosion Resistance	Excellent	Fair (requires protective measures like plating or diligent maintenance)
Polishability	Excellent (to SPI A1 mirror finish)	Good (typically to SPI B1 or C1, difficult to achieve mirror)
Hardness (Supplied/Typical Working)	Supplied annealed, heat-treated to 48-52 HRC	Supplied pre-hardened, ~28-34 HRC
Wear Resistance	Very Good to Excellent	Moderate
Machinability	Fair in annealed state, difficult after heat treatment	Good (in pre-hardened state)
Heat Treatment	Required (hardening & tempering)	Generally used as-supplied, no extra heat treatment needed
Weldability (Repair)	Fair to Good (with professional procedures and pre-heating)	Good
Relative Cost	Significantly Higher	Lower
Primary Use in PET Preform Moulds	Cores, Cavities, Neck Rings (high-quality, high-volume, clear preforms)	Mould Bases, Support Plates, occasionally Cores/Cavities for low-volume/opaque preforms
Maintenance Needs	Low (due to good corrosion and wear resistance)	Higher (attention to rust prevention and re-polishing after wear)

Diving Deeper into S136:
S136 (and its higher purity ESR variants like FS136 or STAVAX ESR) is the premium choice for the "wetted" parts of the mould – those that come into direct contact with the PET. Its high chromium content (around 13%) gives it its stainless properties, making it highly resistant to attack from moisture, corrosive elements in some additives, or even PVC contamination if that's a risk in your facility. The ability to be hardened to over 50 HRC means it stands up exceptionally well to the abrasive wear of plastic flow over millions of cycles. The key benefit, especially for PET bottles, is its superb polishability. The cleaner the steel (fewer inclusions thanks to processes like ESR), the better the mirror finish, leading to crystal-clear preforms. I've seen S136 cores and cavities run for 5-10 million cycles with just routine maintenance when producing clear preforms. P20 simply cannot match this performance in terms of finish or longevity in such demanding applications.

Diving Deeper into P20:
P20 is a true workhorse in the mould-making industry, widely used for mould bases and structural components. It comes pre-hardened from the mill, which means no additional heat treatment is usually needed for these applications, saving time and cost. Its machinability is also generally better than S136 in its annealed state. While it can be polished, achieving a mirror finish like S136 is not feasible. Its wear resistance and corrosion resistance are also notably lower. If P20 is used for cavities (perhaps for prototyping or very low-volume, non-critical preforms), expect a much shorter lifespan and more frequent maintenance for polishing and rust prevention compared to S136. One common scenario I've encountered is using P20 for the main mould base, which is perfectly acceptable, while specifying S136 inserts for the actual core and cavity forming surfaces. This hybrid approach can offer a good cost-performance balance, leveraging the strengths of both materials.

The decision usually boils down to: if you need high volumes (millions of cycles), exceptional clarity, and minimal maintenance for your preforms, S136 for the forming parts is the way to go. If budgets are very tight, volumes are low, or clarity is not critical, P20 might be considered for cavities, but it's generally best suited for the mould's supporting structure.

Is hardened stainless steel always the best option for PET preform molds?

Hearing so much about the benefits of hardened stainless steel like S136 for PET preform molds, you might wonder if it's the universal "best" choice for every single part of the mold. While it's certainly ideal for critical forming components, a truly optimized and cost-effective mold often uses a strategic combination of materials.

Hardened stainless steel (e.g., S136/FS136) is generally the best option for PET preform mould cores, cavities, and neck rings due to its superior polishability, wear resistance, and corrosion resistance. However, for other components like mould bases (P20, 4Cr13H) or hot runner manifolds (H13), different steels often provide the necessary properties like structural strength, machinability for large parts, or high-temperature stability more cost-effectively.

While I'm a strong advocate for using top-quality hardened stainless steel, such as FS136 or equivalent ESR grades of S136, for the parts of a PET preform mould that actually shape the plastic (the cores, cavities, and neck rings/gate inserts), it's not necessarily the optimal or most economical choice for every single piece of steel in the entire mould assembly. A well-designed, high-performance PET preform mould is often a sophisticated assembly of different materials, each chosen to do its specific job best. I remember a client who initially requested an "all S136" mould thinking it would be the ultimate solution. While technically possible, the cost was astronomical, and for many parts of the mould, S136 would have been complete overkill, offering no tangible performance benefit over more suitable, less expensive materials.

Here's why a tailored approach is better:

• Cores, Cavities, and Neck Rings: For these parts, yes, hardened stainless steel (like S136, heat-treated to around 48-52 HRC) is king. The reasons are clear:

  • Surface Finish: Achieves mirror polish for preform clarity and easy ejection. No other type of steel can match this for PET applications.
  • Wear Resistance: Withstands abrasion from PET flow for millions of cycles. For instance, P20's wear resistance is significantly lower, leading to a much shorter life for these components.
  • Corrosion Resistance: Protects the polish from moisture, condensation, and PET off-gassing. Non-stainless materials would rust quickly, impacting product quality.
    These directly impact preform quality and mould life in the most critical areas.

• Mould Base / Shoe Plates: These are the large structural plates that hold the cores, cavities, leader pins, bushings, etc. They need to be strong, stable, and accurately machined, but they don't contact the plastic or require a mirror polish. Using S136 here would be excessively expensive and difficult to machine in such large sections. More appropriate and cost-effective choices include:

  • P20: A very common choice, pre-hardened, good machinability, and sufficient strength. Compared to S136, the cost is significantly lower, and machining efficiency is higher.
  • 4Cr13H (or similar pre-hardened stainless mould base steel like 1.2316): Offers better corrosion resistance than P20 if the environment is a concern, and can have slightly higher hardness. An upgrade from P20 but still far from S136's performance in forming surfaces.
  • Medium Carbon Steels (e.g., S50C, 1.1730 in DIN): For less demanding structural parts, these can be even more economical. However, their rigidity and stability might be less than P20 or 4Cr13H.

• Hot Runner Manifold Block: As discussed earlier, H13 tool steel is the standard here. It's not stainless, but its ability to retain strength and stability at sustained high temperatures (red hardness) is superior to what S136 offers for this specific application. S136 might become too soft or lose dimensional stability if used as a large manifold block operating constantly at ~280°C.

• Leader Pins, Bushings, Wear Plates: These guiding and wear components often use specialized steels chosen for their specific friction and wear characteristics when paired with each other, sometimes involving surface treatments or dissimilar materials to prevent galling. For example, carburized steel or nitrided steel might be used for high surface hardness and a wear-resistant core.

The goal of intelligent mould design is to use the premium, more expensive materials only where their specific properties provide a direct and necessary benefit. For the rest of the mould, more standard, cost-effective materials that meet the structural and operational requirements are perfectly suitable. This strategic selection ensures the mould performs exceptionally well, lasts a long time, and is built at a reasonable cost. It’s about fitness for purpose for each component.

Conclusion

Ultimately, selecting the best materials for your PET preform mould—from high-grade S136 for cores and cavities to robust H13 for hot runners—is a critical investment that directly influences preform quality, production efficiency, and the mould's overall lifespan, ensuring long-term value and success.

Frequently Asked Questions (FAQ)

Q1: How long do PET preform molds typically last?
A1: The lifespan of PET preform molds varies greatly depending on several factors:

• Mould Material: Cores and cavities made from high-quality steels like S136/FS136 will last much longer than those made from ordinary steels like P20.
• Production Volume: Producing a few million versus tens of millions of preforms annually impacts mould wear differently.
• Preform Design: Complex designs or thin-walled products can place higher demands on the mould.
• PET Resin Quality: Using recycled material with more impurities can accelerate mould wear.
• Operation & Maintenance: Correct operation, regular cleaning, lubrication, and professional maintenance can significantly extend mould life.
  Generally, a well-maintained mould with high-quality steel for its core/cavity parts might achieve 5 million to 15 million cycles or even more, while the mould base will last longer.

Q2: Is higher hardness always better for mold steel?
A2: Not necessarily. While high hardness usually means high wear resistance, excessively high hardness can sacrifice the steel's toughness, making it more prone to cracking or chipping, especially when subjected to impact or complex stresses. The ideal mould steel should strike a balance between hardness, toughness, corrosion resistance, polishability, machinability, etc. For example, cores and cavities require high hardness and high polishability, whereas mould bases prioritize strength and machining economy.

Q3: How can one judge the quality of mold steel?
A3: Judging mold steel quality typically requires comprehensive consideration:

• Steel Mill and Brand Reputation: Choosing products from renowned steel mills (e.g., ASSAB in Sweden, DEW in Germany, DAIDO in Japan) usually offers more assurance.
• Material Certification: Request a Mill Certificate from the supplier to confirm chemical composition and basic properties.
• Purity: For steels requiring high polish like S136, refining processes like ESR (Electro-Slag Remelting) provide higher purity and fewer inclusions, which is crucial for polishing.
• Heat Treatment Process: Even good steel can be ruined by improper heat treatment. Choosing an experienced heat treatment provider is equally important.
• Third-Party Testing: If necessary, third-party institutions can be commissioned for metallographic analysis, hardness testing, etc.

Q4: Besides steel, are other special materials used in PET preform molds?
A4: Yes, apart from various grades of tool steel, PET preform molds (especially hot runner systems) may also use:

• Beryllium Copper Alloys (BeCu): Due to their excellent thermal conductivity, often used for nozzle tips, cavity inserts, or areas requiring rapid heat dissipation to improve cooling efficiency and cycle times.
• Tungsten Carbide: Used for extremely wear-resistant parts like gate inserts or valve pin tips, especially when processing PET with abrasive fillers.
• High-Performance Engineering Plastics/Composites: May be used in small quantities for certain non-core components like thermal insulation or wear-resistant sliders.
• Various Surface Coatings: Such as TiN, CrN, DLC (PVD/CVD coatings), can be applied to steel components to increase surface hardness, wear resistance, self-lubrication, or anti-stick properties.

Q5: How important is daily mold maintenance for extending its life?
A5: Extremely important! Good daily maintenance is key to maximizing mould life and maintaining product quality:

• Regular Cleaning: Remove residues, grease, and moisture from mould surfaces to prevent corrosion and defects on products.
• Proper Lubrication: Regularly lubricate moving parts like guide pins, bushings, and sliders to reduce wear.
• Check Fasteners: Ensure all screws and locating pins are tightened.
• Cooling Channel Maintenance: Regularly inspect and clean cooling water passages to prevent scale and rust from affecting cooling efficiency.
• Correct Operation and Storage: Avoid rough handling; after production, clean, apply anti-rust agent, and store the mould properly.
  A single instance of negligent maintenance could lead to premature damage of a multi-thousand or even million-dollar mould. I always tell my team to treat molds like precision instruments.