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TTH sponsors hospitals and schools

As part of The Tool Hub Corporate Social Responsibility Policy a part of the profits are used to sponsor charities.

One of those is Tuki Nepal where The Tool Hub helps support the construction of a Hospital, a school, and 88 houses in  Jyamrung Nepal following the 2015 earthquake.

34 of the 88 of the houses are now finished and the hospital is fully operational. The school is under construction and is planned to be finished during 2018

One of the cornerstones in the project is to support the local community with technology and better building processes to prevent future catastrophes with collapsing houses.
Should you or your organisation wish to be a part of this project please let us know and we will put you in contact with Tuki Nepal
https://www.tukinepal.org/

Below is an example where a simple method for constructing bricks is used.

PUR-Foaming

There are basically 3 methods for PUR foaming.

RIM-process (reaction injection moulding) polyurethane is foamed to PU-compact and PU-integral skin foam. Application examples are: housing parts, dashboards, armrests.
SRIM-process (structural moulding reaction injection moulding) a glass-fibre mat is placed in the mould and is foamed around with a polyurethane hard foam. This technique is mostly used for interior linings or dashboards of coaches.
RRIM-process short glass fibres are blended with polyurethane constituents and injected in to the mould. Application examples are:for resistant bumpers.

The most common of the 3 is the RIM-process.
The plastics used are thermosets, like polyurethanes or foamed polyurethanes.
With the low viscosity and low injection pressures, large, complex parts can be produced more economically in low quantities.
Considerable design freedom is possible, including thick and thin wall sections that are not good for injection molding, due to the uniform shrink characteristics. Foamed polyurethanes are natural thermal and acoustic insulators.
Reaction injection molding is used in many industries for many types of parts. While bumpers for vehicles are produced in this process, most applications are for large, complex parts produced in quantities less than 10,000 units. Examples include panels, enclosures, and housings.

In some occasions as much as 70% savings can be achieved on tool cost when choosing a PUR process over a standard injection molding process.

PUR Advantages

  • Thick, light weight structural parts can be molded without sink
  • Walls can be thick and thin on same part
  • Tolerances approximate to Injection Molding
  • Can mold over metal, glass, wood, wiring, circuit boards, hardware, etc
  • Much better economies for lower volume parts

Injection Molding Advantages

  • Part cost lower in high volume
  • Plastic part can be colored; no need for paint
  • Finer part detail can be achieved
  • Greater range of material choices

Good luck and remember that there are often more than one way to get the result you are looking for.
Contact us at The Tool Hub and we will gladly help you with your project.

Turbulent Cooling

Injection moulding process is cyclic in characteristic. Cooling time is about 50 to 75% of the total cycle time. Therefore, optimising cooling time for best performance is very important from quality and productivity point of view.

cycletimechart

The real objective here is to control the cooling rate and temperature of the parts so they can be ejected at the earliest possible time, while maintaining the desired properties and dimensions.

Cooling channel design – location and size and type – should ensure that melt freezes uniformly inside the mould. Cooling channel design must be analyzed with the help of a Mold flow report.

Understanding Heat Exchange in the mould

During every injection moulding cycle following heat transfers take place:

  1. from the hot melt to mould steel (heat input to the mould) and
  2. from mould steel to coolant flowing through cooling channel of the mould. (heat removal from the mould)

If heat input is more than heat removal, then the mould temperature would keep on increasing from cycle to cycle. Therefore moulding quality would not be constant from cycle to cycle. The moulding quality would be erratic- i.e. varying from cycle to cycle. Therefore, there is a need to balance between the heat input and heat removal in the mould after the desired mould surface temperature is reached. In other words, removal of heat by circulating coolant through the mould cooling channel would arrest the rise of mould temperature above the desired value. In practice, it may not be possible maintain constant mould temperature with respect to time. However, the mould temperature would fluctuate between two values around the desired value.

Quick design tips

Cooling channel diameter should be more for thicker wall thickness:
For wall thickness up to 2 mm, channel diameter should be 8 – 10 mm.,
For wall thickness up to 4 mm, channel diameter should be 10 – 12 mm.,
For wall thickness up to 6 mm, channel diameter should be 10 – 16 mm.

The difference between the inlet and outlet water temperature should be less than 2 to 5 degrees C. However, for precision moulding, it should be 1 degree C or even 0.5 degree C.

It is often difficult to accommodate cooling channels in the smaller cores or cores with difficult geometry. In such case the core should be made of Beryllium copper or Ampco which has high thermal conductivity. These core inserts should be connected to a cooling channel to best dissipate the heat.

It is often a good idea to add thermocouples at one or two places in core as well as cavity to monitor the temperature of mould.

Turbulent Flow

Achieving a turbulent flow is a good way to increase the heat transfer without having to alter anything in an existing tool.

Studies have shown that for the same net flow through a cooling channel a turbulent flow can transfer as much as 150-500% more heat from the tool steel.

Turbulent flow begins when the velocity of fluid in a channel increases to a critical level. Above this critical velocity, vigorous internal mixing of the fluid occurs as it flows. This improves heat transfer by mixing warmer fluid near the wall of the cooling passage with the relatively cooler interior fluid. The precise velocity for turbulent flow depends on several variables, including the cooling passage geometry, fluid viscosity, and roughness of the pipe walls. The formula for a ratio known as Reynold’s number includes these variables. A Reynold’s number greater than 4000 denotes turbulent flow.

Boundary Layer

The boundary layer is defined as the area of the flow that has shear stress forces induced by the solid wall of the water block. What this basically means is that the boundary layer is the part of the moving water that is feeling the friction of the wall. The molecules of water that are closest to and touching the water block wall are not moving at all, but are stationary. As the distance from the wall increases, the molecules pick up speed until they are far enough away that the flow feels no effects from the wall.

The problem with having a boundary layer for heat transfer in a water block is that it is actually insulating the inner most layers of flow from being able to pick up the heat from the tool steel. This is especially true of laminar flow because the boundary layer is very thick. However, in turbulent flow the random action of the water molecules breaks up the boundary layer and disperses the majority of it, thus increasing the ability of all the water molecules to pick up heat from the water block wall.

Flow rate needed to achieve turbulent flow:

Pipe Size
ID of drilled passage (mm)
Min. flow rate for turbulent flow (L/min)
1/16 NPT
6.5
1.25
1/8 NPT
9
1.66
1/4 NPT
11
2.08
3/8 NPT
15
2.80
1/2 NPT
18
3.4

The best cooling system in the world won’t take away heat any faster than the molded part will give it up. Most unfilled resins transfer heat at a rate 1/10 to 1/25 that of steel. The outer walls of a thick part insulate the mold from the heat trapped in the center of the part. The message here is that for very thick part, the cooling system will have relatively little effect on cycle time.

Optimal flow economy

An increase high above the threshold for turbulent flow is not very beneficial. For optimal cooling economy we recommend to stay in the green zone.

Steel grades

A more detailed look at some of our steel grades and their characteristics.

Steel
Grade
Comparable Standard
AISI / JIS
Hardening Delivery Hardness
HRC
Characteristics Applications
ASSAB Steel
IMPAX
718S
P20 Modified Prehardened 31-36 Pre-hardened type, high purity with isotropic microstructure
contains 1.0% Ni
High quality mold inserts, best suitable for plastic molding of
PA,POM, PS, PE, PP, ABS.
IMPAX
718H
Prehardened 36-42
EM38 Prehardened 38-44 Good polishability, texturing, EDMing and machinability.
Homogenous hardness
Suitable for plastics injection mold, extrusion die and rubber
mold
STAVAX S136 420, ESR Through hardened 50-52 High purity, high polishability to mirror finish, with good
corrosion resistance and low distortion after heat treatment.
High quality mold inserts with mirror surface finish and good
corrosion resistance, anti-corrosive cooling channel, best suitable for
plastic molding of PVC, PP, EP,PC, PMMA, machine parts for food processing machinery.
STAVAX S136H Prehardened 31-36
STAVAX S136 SUP 420, ESR Through Hardened 50-52 Corrosion resistance and toughness are better than S136 Suitable for big plastic mold with high precision requirement
STAVAX S136H SUP Prehardened 31-36 Corrosion resistance and toughness are better than S136H
POLMAX 420 (ESR+VAR), Optical Grade Through hardened 50-52 Ultra-high purity and extremely low segregation by double
remelting process (ESR+VAR). Excellent polishability to attain optical requirement. Good corrosion resistance and low distortion after heat treatment
High quality molds for Lens, Optical Products, compact discs
and medical applications
CORRAX S336 Special Precipitation Hardening Stainless Steel Age Hardening 32 Excellent corrosion resistance, extremely good dimensional
stability during ageing, good weldability
Injection molds for corrosive plastics, rubber, medical and
food industry and plastic parts with complicated design.
ELMAX Special Powder Metal Through Hardened 50-52 High wear resistance. High corrosion resistance. High
compressive strength. Less distortion after heat treatment.
Suitable for plastic molds with the requirement of both high
corrosion resistance and wear resistance. Suitable for plastic molds for engineer plastics with additives such as glass fibers and/or fire retardent. molds for electronic encapsulation. Componen
168 (Ramax S/Ramax 2) 420+S Prehardened 36-41 High machinability. High corrosion resistance mold base with the requirement of high strength and corrosion
resistance. Plastic molds with corrosion resistance but do not require high surface finish requirement. Suitable for fixtures in electronic industries.
ORVAR 8407 H13, MICRODIZED + ESR Through Hardened 50-52 Hot work tool steel with high toughness and good high
temperature strength
Die casting, extrusion, cold hobbing, mold for PA, POM,PS, PE,
EP plastics
CALMAX 635 High wear resistance multi-functional tool steel Through Hardened 50-52 Extremely high toughness and high wear resistance, good
hardenability and weldability, good flame and induction hardenability to HRC56-60, with harden layer up to 5mm thickness.
High strength plastic mold and compacting die, suitableable for molding of fibre-reinforce plactics.
VANADIS 10 High performance powder
metallurgical cold work tool steel
Through Hardened 50-52 Extremely high wear resistance, sufficient toughness with very
high compressive strength and high dimensional stability during heat treatment.
High speed stamping of E.I. core and lead frame.
SSAB Steel
Toolox 33 Prehardened 30-36 Suitable for
tools and engineering components. It possesses good dimensional stability
after machining
High quality mold inserts, best suitable for plastic molding of
PA,POM, PS, PE, PP, ABS.
Toolox 44 Prehardened 44-50 Suitable for
tools and engineering components. It possesses good dimensional stability
after machining
The high steel cleanliness gives Toolox 44 very good polishing, A2 gloss, and texturing capabilities.
DAIDO  Steel
PX88 P20 Modified Prehardened 31-36 Good weldability, special alloying composition to reduce
sensitivity due to weld crack.
Medium production run plastic mold with good surface finishing.
PX5 P20 Modified Prehardened 31-36 Good weldability, special alloying composition to reduce
sensitivity due to weld crack, good machinability
Medium production run plastic mold
NAK55 P21+S Mod., ESR Prehardened 40-43 Pre-hardened type with high hardness, good machinability and
weldability
High precision plastic molds and rubber molds.
NAK80 P21 Mod., ESR Prehardened 40-43 Pre-hardened type with high hardness, good
polishability,excellent photo-etchingability, good EDM machining and
weldability
molds require high wear resistance and excellent surface
finishing.
S-Star SUS 420 J2 Mod., ESR Prehardened 31-36 High mirror surface polishability with corrosion resistance. High precision plastic molds with high mirror surface
finishing.
S-Star (A) SUS 420 J2 Mod., ESR Through Hardened 50-52 High mirror surface polishability with corrosion resistance.
Hardness can be obtained up to 50 – 52 HRC with proper heat treatment in order to obtain better polishability, wear resistance and/or corrosion resistance
High precision plastic molds with high mirror surface
finishing.
DH31-S SKD61  Modified Through Hardened 50-52 Good through-hardening properties especially for large molds, excellent resistance to thermal shock and to thermal fatigue, good resistance to heat erosion. AL, Mg  Die casting molds, Parts for die casting molds, AL die extrusion molds, Hard plastics molds.
DHA1 SKD61 Through Hardened 50-52 Good through-hardening properties, good resistance to thermal shock and thermal fatigue, good resistance to heat erosion. Zn, small size AL die casting molds,  Parts for die casting molds, AL die extrusion molds, Hard plastics molds.
GOA SKS3 Modified Through Hardened 50-52 High hardenability and wear resistance cold work tool steel Punches for cold forming and blanking, shearing blades for
metal sheet.
DC11 SKD11 Through Hardened 50-52 Excellent wear resistance with high chromium cold work tool
steel
Suitable for cold extrusion, cold drawn dies, punching and
blanking dies for stainless steel or metal sheets with high hardness.
DC53 SKD11 Modified Through Hardened 50-52 High toughness chromium cold work tool steel, high temperature
tempering after the heat treatment can reach the high hardness of 62 HRC,
especial good for much EDM wire cut works to reduce the breakage.
Suitable for stamping die, cold forming, deep drawing, thread
rolling, punches for high speed blanking, stainless steels materials.
Finkl
P20 HH P20 Modified Prehardened 36-42 With special chemical composition adjustment and good forging process/forging ratio, mechanical properties are better than normal AISI P20 tool steels. High quality mold inserts, best suitable for plastic molding of
PA,POM, PS, PE, PP, ABS.
P20 LQ P20 Mod. (Optical Quality) Prehardened 36-42 High purity and less segregation are obtained by double vacuum
melting processes (VAD + VAR) in order to obtain good polishability
Suitable for plastic mold with optical requirement without
requiring to handle corrosive plastics
Lung Kee Special Steel
LKM 638 P20 Prehardened 29-32 High machinability High quality mold base or large core parts.
LKM 2311  P20 Prehardened 29-35 Pre-hardened type tool steel for plastic mold. mold for high quality plastic with long run production.
LKM 2312 P20 + S Prehardened 29-35 Excellent machinability, most suitableable for high speed
volume machining.
Plastic mold for general use and core parts
LKM 738 P20 + Ni Prehardened 29-35 High quality pre-hardened type tool steel, uniform in hardness
and high machinability
Mold with high toughness and good finishing.
LKM 738H Prehardened 36-42
LKM838H P20 Mod. Prehardened 36-42 With special adjustment to the chemical composition, LKM838H’s
thermal conductitvity,machinability, polishability and weldability are better
than normal AISI P20 tool steels.
Suitable for plastic molding of PA,POM, PS, PE, PP, ABS with
the requirement of high hardness, polishability and wear resistance.
LKM818H P20 Modified Prehardened 36-42 Pre-hardened type, high purity with isotropic microstructure
contains 1
High quality mold inserts, suitable for plastic molding of
PA,POM, PS, PE, PP, ABS.
LKM 2711 P20, Premium Prehardened 36-43 High hardness and high toughness Suitable for medium plastic molds requiring high hardness with good toughness
LKM420 420 Through Hardened 50-52 Good anti-rusting property. Hardness can be increased up to HRC 50 – 52 for plastic mold application Plastic mold with requirement of anti-rusting
LKM420H 420 Prehardened 29-35 Good anti-rusting property. Plastic mold with requirement of anti-rusting and mouldbase
with corrosion resistance requirement
LKM 2083 420 Through Hardened 50-52 Hardness can be obtained up to 50 – 52 HRC with proper heat
treatment in order to obtain better polishability, wear resistance and/or corrosion resistance
Corrosion resistance plastic molds.
LKM 2083H Prehardened 29-35 Pre-hardened type, corrosion resistance, high polishabity
LKM 2316A SUS 420 J2 Through Hardened 50-52 Hardness can be obtained up to 47 HRC with proper heat
treatment in order to obtain the better wear resistance and corrosion resistance than pre-hardened condition
High corrosion resistance plastic molds.
LKM 2316 Prehardened 29-35 Pre-hardened type, high corrosion resistance
LKM 2316ESR SUS 420 J2, ESR Prehardened 29-35 High cleanliness, high corrosion resistance High corrosion resistance molds with good polishability.
LKM H13 H13 Through Hardened 50-52 Good toughness Suitable for hard plastic molds, sliders, zinc die casting
dies.
LKM 2343 H11 Through Hardened 50-52 Good high temperature strength and high toughness, good
resistance to heat checking
Suitable for die casting
for aluminium and zinc alloys, hard plastics molds.
LKM 2343 ESR H11 ESR Through Hardened 50-52 Homogenous structure and good isotropic property. Good plastic
mold with high polishing requirement
Suitable for die casting for magnesium, aluminium and zinc
alloys. Good for plastics molds with high polishing requirement.
LKM 2344 H13 Through Hardened 50-52 Good high temperature strength, suitable for die casting mold Suitable for die casting for aluminium and zinc alloys, hard plastics molds.
LKM 2344 ESR H13, ESR Through Hardened 50-52 Homogenous structure and good isotropic property. Good plastic
mold with high polishing requirement
LKM 2344-SUPER H13, MICRODIZED + ESR Through Hardened 50-52 High toughness and good high temperature strength, with high
impact strength exceeding 300J
LKM 2510 O1 Through Hardened 50-52 High hardenability and wear resistance cold work tool steel Shearing blades, cold forming, blanking and punching dies.
LKM 2379 D2 Through Hardened 50-52 High chromium cold work tool steel with good toughness. Suitable for cold extrusion and forming, cold drawn, punching
and blanking of high hardness metal sheet and stainless sheet.
LKM 2767 6F7 (High toughness multi-purpose tool steel) Through Hardened 50-52 High strength and toughness, can be hardened to HRC 50~54. Suitable for shearing and blanking of sheet metal with 10mm
thick or above
Sinto
PORCERAX II
PM – 35
Sintering power metallurgical porous material Prehardened 38-43 High quality pre-hardened type permeable porous material with
high corrosion resistance, high machinability and EDM machinability (Supplied
with 7 and 20 µm pore sizes)
molds for high quality plastic or die-casting parts with thin
wall or intricated structure. Remedy for quality and productivity problems
due to gas trapping during injection molding.
USA Brush Wellman Beryllium Copper  Alloy
MOLDMAX 40 Age Hardening 36-42 High strength beryllium copper alloy, very high thermal
conductivity, shorten molding cycle effectively.
Best suitable for mold core and insert which require rapid
cooling.
EDM Copper
C1100P JIS H3100 Extremely high purity, good electrical conductivity, high
machinability, low thermal deformation
EDM copper electrode.
USA ALCOA Aluminium Alloy
6061-T6/T651/T6511 Age Hardening Aluminium alloy with good corrosion resistance,  excellent joining characteristics and
anodizing
Thermoforming, blow molding, ultrasonic welding and machine parts.
SWISS ALCAN high hardness Aluminium Alloy
CERTAL 7022-T651/T652 AlZnMgCu0.5 Age Hardening 7 High Strength, high hardness, good machinability Plastic injection molding, blow molding, ultrasonic welding and machine parts
China high quality plastic mold steel
WY718 P20+Ni Prehardened 29-35 Prehardened plastic mold steel mold Base and core part of plastic mold
WY2311 P20 ` 29-35 Prehardened plastic mold steel mold Base and core part of plastic mold
High quality plain carbon steel
S50C – S55C 1050 – 1055 7-20. High machinability Suitable for plastic mold base and machinery parts

Rail transport from China

At The Tool Hub we can now offer 3 modes of transportation Air, Rail and Sea for tools and plastic parts.

Our newest route is the rail line passing through Chongqing.

Rail-Vs-Sea

Cost example

An example of transport costs by Rail from Shenzhen to Hamburg LCL below:

1 Revenue Ton = (1 cubic meter or 700 Kg)
Tool weight 4 Ton = 6 Revenue Ton

Pickup: USD 700 (shenzhen area)
Special handling fee for large forklift: USD 175
Railway rate: USD 220 x 6 Revenue Ton = USD 1320
Destination charges: USD 100 x 6 Revenue Ton = USD 600
Bill of Landing USD 190
Special handling fee: USD 100

Totally USD 3085 from Shenzhen to Hamburg.

Good luck with your transports and please contact us at The Tool Hub if you need any support

Calculating Air Freight

Air freight is a common mode of transport for plastic products. It’s fast, simple and safe – but not always the most cost efficient option compared to Sea freight.

The biggest benefit of air freight is the short time a delivery takes from pick up to delivery.

At The Tool Hub we can often get down to 2 days for plastic parts and 1 week for a tool if things are planned well.

Air freight Cost

The cost of air freight is constantly varying depending on factors such as demand and fuel cost.
Therefore we suggest that you request prices as close to shipping day as possible to avoid the need for safety mark up, and to get the lowest possible price.
Prices normally vary from 3-5 USD per Kg.

Air-freight

Actual weight Vs Volumetric weight

Air freight is calculated in two different ways, either by the kilogram or based on the volumetric weight (also called DMI weight, Dimensional weight). The volumetric weight is based on the volume of the cargo, if the volumetric weight is larger than the actual weight of the cargo – the volumetric weight is applied. The volumetric weight is calculated by multiplying the volume in cubic meters with a volumetric factor between 150 and 200.

Case studies

A (Actual weight)

  • Dimensions: 1 x 1 x 0.65 m (Equals: 0.65 cbm)
  • Weight 171 kg
  • Volumetric factor: 200
  • Volumetric weight: 0.65 cbm x 200 = 130 kg
  • Rate: 5 USD / kg

Result: The actual cargo weight is higher than the volumetric weight and thus the actual weight is applied.

Total price: 5 USD x 171 kg = 855 USD

B (Volumetric weight)

  • Dimensions: 1 x 1 x 0.65 m (Equals: 0.65 cbm)
  • Weight 91 kg
  • Volumetric factor: 200
  • Volumetric weight: 0.65 cbm x 200 = 130 kg
  • Rate: 5 USD / kg

Result: The actual cargo weight (91 kgs) is lower than the volumetric weight (130 kg) and thus the volumetric weight is applied

Total price: 5 USD x 130 = 650 USD

Conclusion

You can always find out if you should pay based on actual weight or by volumetric weight if you use a multiplication of 200 on your volume in cubic meters.

If the value you get is lower than your actual weight you should pay based on your actual weight.

Good luck with your transport, and please let us know if you have any questions.

The Tool Hub

Marking plastic products

The marking of components manufactured from plastics, rubbers and thermoplastic elastomers is one aspect of the Design for Environment (DfE) process, which aims to minimize the environmental impact.

In order to maximize the intrinsic value of these materials, they must be easily identified and then separated at end-of-life according to their material type and chemical structure. Attempting to recycle poorly separated polymer or rubber materials at end-of-life will result in a poor quality material, which has low or zero monetary worth and properties that make it suitable for only the most undemanding of applications.

Through ensuring that materials are properly separated prior to recycling, the mechanical and aesthetic properties of the resulting recycled material can be maximized, thus dramatically increasing the value and suitability of the recycled material for future applications. This is best achieved through providing a clear marking on the surface of the plastic or rubber component in line with ISO 11469 and associated standards. To identify all of the various plastics, rubbers and thermoplastic elastomers without the aid of markings would be prohibitively cost intensive and therefore must be avoided.

The marking for a polymer that contains fillers, plasticizers and flame retardants will look something like the following:

ISO 1043 example

 

 

 

In all instances, the letters and numbers representing the plastics, rubbers and thermoplastic elastomers are to be placed in-between “>” and “<” as indicated above.

For any questions regarding how to mark your plastic items please do not hesitate to contact us at TTH

Feedback
Please contact us and tell us how we can support.

Email: info@thetoolhub.com
Phone UK: +44 1865 922 550
Phone SE: +46 31 30 88 200

We are always happy to hear from you!