Today's KNOWLEDGE Share : Why Do Plastic Parts Look Fine in Mold Trials but Fail in Mass Production?

Today's KNOWLEDGE Share

⭐ Why Do Plastic Parts Look Fine in Mold Trials but Fail in Mass Production?

Many projects go through the same pattern:

during mold trials, parts look good, dimensions are within tolerance, and assembly runs smoothly.

But once mass production starts, problems begin to appear —

warpage, dimensional drift, assembly issues, or surface defects.

This doesn’t always mean the mold suddenly became “bad.”

In reality, mold trials and mass production operate under very different conditions.

Here are the most common — and often underestimated — reasons why issues show up later �

1️⃣ The Process Window Shrinks in Mass Production

During mold trials, engineers typically:

run slower cycle times

fine-tune parameters carefully

optimize for single-part quality

In mass production, the focus shifts to:

stable cycle time

output and efficiency

long-term repeatability

When injection speed, holding pressure, or cooling time are tightened,

designs that were “just acceptable” during trials quickly reveal their limits.

2️⃣ Cooling and Shrinkage Differences Become Amplified

In trials, mold temperature is stable and cycle times are longer,

giving parts more time to cool and release stress.

In mass production:

cooling time is reduced

mold temperature fluctuates more

thermal buildup increases, especially in multi-cavity molds

The result is:

uneven shrinkage

increased warpage

declining dimensional stability

3️⃣ Internal Stress Accumulates Over Time

Many plastic parts look fine at T1 or early production,

but develop issues after storage, assembly, or actual use.

Common contributors include:

non-uniform wall thickness

unbalanced cooling

excessive injection speed

These stresses may stay hidden during trials,

but accumulate and release gradually during mass production.

4️⃣ Limited Design Margin Gets Exposed

Passing a mold trial does not mean the design is robust.

In mass production:

marginal draft angles

sensitive parting-line placement

aggressive wall-thickness transitions

reduce process flexibility.

Eventually, quality can only be maintained by slowing the cycle or adding rework.

� Key Takeaway

Mold trials confirm whether a part can be made.

Mass production proves whether it can be made consistently.

Reliable plastic part design is not about perfect T1 samples —

it’s about long-term stability under real production conditions.

� Have you experienced projects where parts passed mold trials but struggled in mass production?

Was the root cause design, process, or cooling?

If you’re moving toward mass production and want early feedback, feel free to connect.

source :Coco Ho

#polymers #InjectionMolding #PlasticDesign #MoldDesign #MassProduction

SABIC further divests its European Petrochemical (EP) business and its Engineering Thermoplastics (ETP) business in the Americas and Europe

The Saudi Basic Industries Corporation (SABIC) today announced the signing of two strategic transactions to divest its European Petrochemicals (EP) business to AEQUITA and its Engineering Thermoplastics (ETP) business in the Americas and Europe to MUTARES, for a total combined enterprise value of $950 million.

These transactions represent significant steps in the advancement of SABIC’s strategy and constitute a core component of its broader portfolio optimization program. The divestments together establish a strong foundation for future profitable growth and reinforce the Company’s long-term strategic positioning for maximum value add.

These efforts are a continuation of SABIC’s plans to improve returns, focus on high margin markets and products where we have clear competitive advantage, recycle capital to higher-return opportunities and improve free cash flow, whilst continuing to serve its global customers and maximize shareholder value. Additionally, these transactions do not impact the technology and innovation focus and commitment that SABIC has for its customers.

Commenting on the transactions, Chairman of the Board of Directors of SABIC Khalid H. Al-Dabbagh, said: “The Board endeavored to achieve these transactions, which represent a significant milestone in the execution of our strategy to further optimize our portfolio and maximize shareholder value by enhancing the Company’s cash generation capacity and achieving the highest possible return on our global businesses.

Abdulrahman Al-Fageeh, Chief Executive Officer of SABIC, said: “These transactions represent a continuation of our Portfolio Optimization Program, which started in 2022 and included previous actions, such as the divestment of Functional Forms, Hadeed and Alba. This strategic approach allows us to actively reshape our portfolio and sharpen our focus on areas where SABIC has clear and sustainable competitive advantages in a rapidly changing landscape”.

“I am pleased that both AEQUITA and MUTARES will work with us in the future to ensure that we continue to serve our global customers in a seamless manner,” Al-Fageeh also stated.

Salah Al-Hareky, Chief Financial Officer of SABIC, said: “These transactions are a clear demonstration of our disciplined approach and decisive execution regarding capital allocation and active portfolio management. By unlocking value to fund higher-return opportunities, we are improving the quality and efficiency of our capital employed and enhancing the group’s ROCE over time. Together, these actions position SABIC to deliver sustainable returns and create value for our shareholders.

These transactions reposition SABIC for longer-term success by refocusing financial resources and management attention towards growth areas where the Company has clear competitive advantages.

source : Sabic

Today's KNOWLEDGE Share : Choosing an Extruder Isn’t About Size but It’s About Suitability

 Today's KNOWLEDGE Share

⚙️ Extrusion Series Part 1: Choosing an Extruder Isn’t About Size but It’s About Suitability

▪️ Bigger isn’t always better. Smaller isn’t always worse.

Think of an extruder screw like a car engine.

A massive V8 looks great on paper, but if you’re stuck in city traffic, all that power turns into heat, waste, and noise.

Same thing on a cable line: run thin insulation on a big screw, and the melt lingers too long in the barrel.

Residence time stretches, temperature control drifts, and you start cooking polymer instead of shaping it.

Flip it. A small screw is a 1.3-liter turbo which is fast, efficient, perfect for low-wall runs.

But overload it with thick walls or high throughput and it gasps; pressure spikes, melt swings, higher shear rate and mixing turns uneven.

▪️ What Actually Matters

1. Barrel diameter → defines throughput capacity.

2. L/D ratio → controls how completely the polymer melts and mixes.

3. Compression ratio → stabilizes melt pressure; critical for different materials (LSHF ≠ XLPE ≠ PVC).

4. Die & crosshead size → must match the incoming core OD to keep centering and pressure stable.

▪️ Rough Sizing Guide

45–70 mm extruders

→ Typically handle 20–110 kg/hr (≈0.3 – 1.8 kg/min).

→ Good for small conductors and thin-wall jobs where melt demand is low.

90–120 mm

→ Comfortable around 120–380 kg/hr (≈1.5 – 6.5 kg/min).

→ Covers most LV and MV single-core work because the kg/min requirement matches a wide range of incoming diameters.

150 mm and above

→ Push 400+ kg/hr (≈7 – 15+ kg/min).

→ For big cores, thick sheaths, or very high line speeds where melt demand skyrockets.

▪️ Residence Time - The Silent Killer

Run a small cable on oversized extruder and the material just sits there… slowing being pushed out.

Example: for a 95 mm² cable with 1.8 mm XLPE insulation, a 120 mm extruder gives roughly 6 minutes from hopper to die.

Use a 200 mm instead, and that same polymer can take 30 minutes to reach the die.

That extra resident time invites premature cross-linking and gel formation which effectively spoiling your insulation before it even sees the crosshead.

▪️ Bottom Line

It’s not a diameter contest.

A well-matched 70 – 90 mm extruder will outperform a bored 120 – 200 mm any day if polymer, temperature, screw design, and residence time are all balanced with the required material output.

So pick by job, not by ego.

A good extruder, like a good engine, doesn’t shout.

It hums with steady flow, clean pressure, and perfect control.

Should I go for the screw design, crosshead or material for extruders next?

source : Hazim Shafik

Toray Advanced Composites completes NCAMP Qualification for Cetex® High Performance Thermoplastic Composite Materials

Toray Advanced Composites a global leader in advanced composite materials, today announces its Toray Cetex® TC1225 low-melt PAEK has achieved further National Center for Advanced Materials Performance (NCAMP) qualifications.

Toray has successfully qualified its high-performance #TorayCetex® LMPAEK™ TC1225/T300 fabric-based #thermoplasticcomposite material, now available in the NCAMP database. The material is available in both semi-preg and large pre-consolidated reinforced thermoplastic composite laminate (RTL) formats, bringing versatility of design and processing options.

The fabric-based semi-preg offers customers design flexibility and expanded process window for manufacturing optimization, whilst the reinforced thermoplastic laminates can be supplied tailored to customer-specific thicknesses and orientation requirements.

With FAA-accepted, statistically validated material property data now publicly available, customers can leverage NCAMP material, process specification, and design allowables to accelerate aircraft structural design and certification - reducing the time, cost, and risk traditionally associated with aircraft structure qualification. This milestone underscores the consistency and performance of Toray Cetex® while enabling broader industry adoption and streamlined integration into certified aircraft structures.

“Adding our fabric-based Toray Cetex® TC1225 material to the NCAMP database reflects Toray’s ongoing commitment to advancing thermoplastic composites and adoption of these materials across the aerospace supply chain,” notes Scott Unger, CEO of Toray Advanced Composites. “This milestone will be further strengthened by NCAMP qualifications on additional Cetex product types, which are expected to be finalized in the near future.

Toray continues to expand its NCAMP-qualified portfolio, with resin-rich surface configurations of both TC1225/T700 and TC1225/T1100 unidirectional tapes material qualifications in process. These developments will deliver even greater processing flexibility for manufacturers to create structural components using a wide range of processing methods. Data for these two material types is expected to be available in the coming months.

Toray Cetex® TC1225 is a semi-crystalline low-melt PAEK resin system known for its excellent mechanical properties and proven success for primary to secondary structures within the aerospace industry. The distinctive value of Toray Cetex® TC1225 over other composites with a #PAEK family matrix is its superior processability, excellent VBO (#VacuumBagOnly) performance, and suitability for a wide range of thermoplastic production methods. It is also the first approved thermoplastic material qualified by NIAR NCAMP in 2020.

source : Toray

Extruded long-glass thermoplastic siding developed for building applications

These composites have a combination of desired thermal properties and performance characteristics that enable use in building & construction applications as well as other markets where these combined characteristics offer improved performance over traditional products and materials. The developed #thermoplasticcomposites offer exceptional thermal properties & impact-resistance for such applications as siding, railing, dark coloured fencing and window parts.

After starting to study the development of a new class of siding in 2023, #GaMra realised that this material would not only be suitable for siding, but could also be used in many other products. Thanks to its knowledge of the existing siding industry and its extensive experience in improving the properties of thermoplastics, the company was able to develop a thermoplastic-based siding that could compete with products such as fibre cement (James Hardie) and oriented strand board (LP SmartSide). To be truly competitive, GaMra decided to manufacture a product that could be ‘hard nailed’, available in 16-foot-long (488 cm) panels, lightweight with good impact properties, a Heat Deflection Temperature (HDT) above 200°F (93.3°C), good weather resistance, & ideally, the ability to be used in ground contact situations where existing materials cannot be used.

One of its most important attributes of GaMra’s siding is that it is capable of being fastened by ‘hard nailing’. “We used the ancient Euler equation for column buckling to guide us toward specific coefficient of thermal expansion (COTE) goals,” said Greg Mitsch.

GaMra started out with a small strip die to begin the screening process and looked at a variety of resins including PVC, Polystyrene, PP, PE, ABS, #Polycarbonate and researched various methods to reduce the COTE of these materials to the target value. The result of GaMra’s development efforts is a siding material that can be hard nailed like any wood siding, cement board or oriented strand board, is #lightweight and strong enough to be handled, in 16’ (488 cm) lengths, by one person, cuts and drills with standard wood-working tools, resists winds up to 170 mph (274 km/h), remains undeformed at temperatures up to 250°F (121°C), is undamaged by 2” (5 cm) hail stones, can be used in ground-contact applications and can be recycled.

The extruded siding product is composed of about 40 wt% long-glass fibre and 60 wt% polypropylene co-polymers. Its density has been reduced to about half that of an unmodified composite.

Performance testing and weatherability development

Siding products are co-extruded with a weatherable polyolefin compositions capping at a thickness of about .015” (0,04 cm). This coextruded capping material gives a superior finish that is weatherable and far superior to paint. 

source : GaMra/Jeccomposites