3D printing - Warping and its causes - Magigoo

21st August 2019

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Magigoo chemist Jean Paul Formosa, shares his insight and knowlege with regards to 3D print warping. Follow this 4 part blog series to learn how and why warping happens and how to best reduce it.

Introduction

In this 4 part series of blog posts we will be exploring:

  • Warping and its causes.

  • Factors that control the warp.

  • Effects of build plate temperature and how better settings result in less warping.

  • Improving the first layer adhesion further for perfect 3D prints


Thermoplastic materials of different material compositions achieve optimum adhesion with different adhesion products. PLA, ABS and PET-G adhere firmly to the Original Magigoo® adhesive when the build-plate is hot and are easy to remove once the build-plate cools down. In addition to the original Magigoo® adhesive which is suited for printing conventional FDM materials, the Magigoo® Pro range consists of four additional adhesives designed specifically for use with different engineering grade materials. The range includes Magigoo® PC for polycarbonate filaments, Magigoo® PA for Nylon and reinforced Nylon filaments, Magigoo® PP for polypropylene and other poly-olefinic materials and Magigoo® PPGF which is specifically tailored for glass fibre reinforced polypropylene filaments. Magigoo® products (seen in Figure 1) are designed and tested to be used on heated build-plates with glass surfaces, yet Magigoo products also work on other build surfaces such as aluminium, PEI and Kapton tape. 

Figure 1: The whole Magigoo first layer 3D printing adhesives offering for ABS, PETG, HIPS, Nylon, PC, PP, Glass and Carbon infused PP, PC and Nylon filaments and others.

At Magigoo our aim is to help make your bed adhesion issues a thing of the past by suggesting the optimal settings for reliable bed adhesion each time. Unfortunately every FDM printer and its environment is different so different materials will require different printer settings for optimal adhesion. 

Therefore, we have been testing many materials with different Magigoo® adhesives on the Ultimaker S5, so you don't have to. All the best settings will be shared as a downloadable file at the end of the series. Profiles for these tested materials can also be shared with those interested (kindly send an email to info@magigoo.com requesting these). Kindly scroll down to see this list.


What causes warping?

The FDM printing process requires that a polymer is molten and extruded onto a build-plate or a previous layer of extruded material, layer by layer. Each layer will thus be cooling at different rates leading to a temperature differential when the object is being printed. This manufacturing method will thus result in a part which is cooling non-uniformly, this leads to several issues including warping and print-failure due to insufficient adhesion.

Warping is when the print starts to lift up from the corners and deforming in a lateral direction (Figure 2). In extreme cases warping will cause the print to completely detach from the printer but even in mild cases it can be detrimental due to loss of dimensional accuracy which can lead to the part being unusable depending on the application. The severity of warp will depend on a number of factors with some materials being more prone to warp than others. It goes without saying that for a successful print this detrimental effect needs to be avoided as much as possible.


Nylon print warping due to insufficient bed adhesion on the left where regular glue stick was applied. Right side printed on Magigoo PA (Nylon) which shows no sign of warping.Figure 2: Nylon 3D print printed on Magigoo PA (Nylon) on the right shows no sign of warping. The left side printed on another adhesive shows warping due to insufficient bed adhesion.

The cause of warping can be attributed to the differential thermal contraction of each successive printed layer:

Figure 3: First Layer of a 3D print deposited on printing platformFigure 3: First Layer of 3D Print deposited on printing platform.

1. When the first layer is extruded onto the build-plate, it starts immediately cooling down to the build plate temperature, this will lead to the first layer to contract slightly (Figure 3).


Figure 4: Second layer of a 3d print deposited on the previous first layerFigure 4: Second layer of a 3d print deposited on the previous first layer.

2. The second layer will be deposited on the already contracted first layer while also cooling down, thus contracting on top of the first layer. Since the bottom layer is already slightly contracted when the upper layer is deposited, the upper layer will cause the layer below it to compress (Figure 4).

Figure 5: 3D Print warping due to thermal gradientFigure 5: 3D Print warping due to thermal gradient

3. This process will keep on repeating itself as new layers are added causing more lateral compression of the lower layers. This results in an overall sheer force between the printed layers which we can call warping stress. If the warping stress is larger than the stiffness of the part and the bed adhesion the bottom of the print will inevitably start pulling away from the build plate. (Figure 5).

The amount of warp depends on several factors including the material properties and the printing conditions which are not independent of each other. One of the most important material properties governing the amount of warp in a print is the CTE (coefficient of thermal expansion). The CTE describes the tendency of a material to change its shape, area and volume as the temperature changes. A material with a high numerical value for linear CTE exhibits large changes in length as a response to temperature change. As a result materials which have a high CTE are more prone to warping than materials which do not exhibit large changes in dimensions during the thermal changes present during FDM printing.

In addition to CTE, change in the crystallinity of the material during cooling need to be consider. Crystalline materials such as PP and PEEK will crystallise on cooling from the molten state. Crystallisation can lead to potentially higher shrinkage rates since crystalline structures tend to be more tightly packed. The crystallisation of a material depends on several factors and merits a discussion of its own, at this point it is sufficient to assume that crystalline materials such as PP, some nylons and PEEK tend to warp more than amorphous plastics.


In the next part of this series we will go into further details on how to prevent this warping effect. Make sure not to miss it. In the mean time:


Manufacturer

Material

Magigoo Type

1st layer build-plate temperature (°C)

Default Bed Temperature (°C)

Brim (mm)







BASF Innofil3D

Ultrafuse® PP GF30

PPGF

100

20

20

BASF Innofil3D

PP Natural

PP

80

70

20

BASF Innofil3D

ASA Natural

PC

110

110

No

BASF Innofil3D

PET CF

ABS

80

75

No

BASF Innofil3D

PAHT CF15

PA

80

75

No

Clariant

PA6/66 FR

PA

90

80

7

Clariant

PA6/66-GF20 FR

PA

80

80

No

Colorfabb

XT-Clear

ABS

75

75

No

DOW®

EVOLV3D™ OBC

PP

110

100

20

DSM

Arnitel® 2060 HT

Flex

90

80

20

DSM

Novamid® 1030CF

PA

70

65

No

DSM

Novamid® 1070

PA

95

85

20

DSM

Arnitel® 2045

Flex

80

70

20

DSM

Novamid® 1030

PA

80

80

7

DuPont™

Zytel® 3D1000FL

PA

100

90

20

DuPont™

Hytrel® 3D4100FL

PA

105

95

20

Fibreforce

Nylforce CF

PA

90

85

20

Fibreforce

Nylforce GF

PA

100

90

20

Filkemp

Nylon

PA

70

70

No

FormFutura®

Centaur PP

PP

80

70

20

IGUS®

I180

PC

110

110

20

Lehmann Voss

LUVOCOM® 3F PAHT CF 9742 BK

PA

105

100

No

Lehmann Voss

PAHT

PA

70

70

No

Lehmann Voss

LUVOCOM® 3F PAHT GK 9874 NT

PA

70

70

No

Matterhackers

Nylon X

PA

90

80

8

Matterhackers

Nylon Pro

PA

70

70

7

Matterhackers

Nylon G

PA

90

80

8

Owens Corning

X-Strand™ GF30-PP

PPGF

100

20

20

Owens Corning

X-Strand™ GF30-PA6

PA

75

70

No

Polymaker

PolyLite™ PC

PC

110

110

No

Polymaker

PolyMide™ PA6-GF

PA

75

75


Polymaker

PolyMax™ PC

PC

110

110

No

Polymaker

PolyMide™ PA6-CF

PA

75

70

No

Polymaker

PolyMide™ CoPA

PA

70

70

No

Taulman3D

Bridge

PA

70

60

20

Taulman3D

645

PA

70

60

20

Taulman3D

680

PA

70

60

No

Ultimaker

CPE

ABS

75

75

7

Ultimaker

TPU95A

ABS

0

0

8.75

Ultimaker

PC

PC

105

105

No

Ultimaker

Nylon

PA

90

80

No

Ultimaker

PP

PP

80

70

20

Ultimaker

ABS

ABS

85

85

7

Verbatim

PP

PPGF

80

70

20

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