The shrinkage should be distinguished according to the size of the product and the thickness of the glue position. Our general design will have a range. For large-scale molds, a set of molds of basically the same size must be tested with materials first, and the actual shrinkage rate must be set before the mold is opened. The shrinkage of small molds is not much different. There are also different types of materials, and shrinkage will be different, so you must consider before opening the mold.

 

I think that ABS, PC, ABS+PC, AS, which have a small shrinkage rate, do not matter, but new materials or recycled materials with large shrinkage rates such as PP, PA, and PVC are quite different.

 

PMMA (Acrylic): 5/1000

POM (Saigang): 20/1000

PS (hard plastic): 5/1000

 PP (100% plastic): 16/1000

PC (bulletproof glue): 5/1000

ABS (super non-breaking glue): 5/1000

HIPS (not broken glue): 5/1000

AS (transparent viscose glue): 5/1000

GPPS: 5/1000

PBT:15/1000

PA66 (nylon): 16/1000

PA6 (nylon): 9/1000

TPR (soft rubber): 18/1000

TPU (soft rubber) 18/1000

PE: (soft rubber) 20/1000

KVA (rubber rubber): 20/1000

GP (hard rubber): 5/1000

CA (acid glue): 5/1000

K Tang (KRATON): 20/1000

ACETAL(AC):20/1000

PU: 20/1000

PVC (soft): 20/1000

PC+ABS: 5/1000

BDS(K-RESIN0)/K material: 7/1000

PA66+50%GPT: 2/1000

PA66+30%GPT: 3/1000

PA66+15%GPT: 8/1000

PBT+30%GPT: 3/1000

PP+20%GPT: 5/1000

PP+30%GPT: 3/1000

 

The above shrinkage rate is obtained after several years of practice, and it is absolutely reliable when the product does not exceed 300mm and the average glue thickness does not exceed 3mm. If the product size exceeds 300mm, the subtotal is 0.0005. If the product length, width and height are too different, the X axis, Y axis, and Z axis should be calculated separately. When the average glue position of the product is too thick, too thin (below 0.5) and the product Pay special attention to the large size.

 

In addition, different products of the same kind of plastic have different shrinkage rates in actual mold opening! The following is a complete list of shrinkage rates summarized by a senior engineer based on years of practical experience. Let's take a closer look~

ABS (Acrylonitrile Butadiene Styrene)

 

Figure ABS application in automobiles

Plastic name: ABS

Actual mold opening shrinkage rate: 0.0045

Mold product type: printer case, car audio panel, Samsung remote control lower cover

 

Plastic name: ABS

Actual mold shrinkage rate: 0.0035

Mold product type: 500X35X30 DVD surface

 

Plastic name: ABS

Actual mold shrinkage rate: 0.005

Molding product types: mobile phone cases, mobile phone buttons, cases, medical equipment, Midea water dispensers, electrical boxes, kitchen supplies, Samsung remote control electric covers, auto parts, car audio, car MP3 shells, flashlight shells, Fengfan brackets ( DVD cover), PDA/GPS holder, accessories for measuring instruments

 

Plastic name: ABS

Actual mold shrinkage rate: 0.003

Mold product type: key cap

 

Plastic name: ABS

Actual mold shrinkage rate: 0.0025

Mold-opening product type: bracket for VTech's sub-machine

 

Plastic name: ABS

Actual mold shrinkage rate: 5/1000

Mold product type: electrical enclosure

 

Plastic name: ABS

Actual mold shrinkage rate: 0.6%

Mold product type: auto parts (for export)

 

Plastic name: ABS

Shrinkage rate of mold opening: 0.015

Mold product type: controller box

Plastic name: ABS

Actual mold shrinkage rate: 0.003

 

Mold product type: housing (IML process)

Plastic name: ABS

Actual mold shrinkage rate: 0.0035

Mold product type: LCD frame

 

PP (polypropylene)

Plastic name: PP

Actual mold shrinkage rate: 0.035

Mold product type: 8" casters

 

Plastic name: PP

Actual mold shrinkage rate: 0.015

Mold product type: Midea electric kettle

 

Plastic name: PP

Actual mold shrinkage rate: 0.016

Mold opening product type: auto parts (reflector), kitchen supplies

 

Plastic name: PP

Actual mold shrinkage rate: 0.0155

Mold product type: Honda car shell

 

Plastic name: pp

Actual mold shrinkage rate: 0.018

Molding product type: trays, basins for medical use

 

Figure PP medical products

Plastic name: PP

Actual mold shrinkage rate: 0.025

Mold opening product type: password box

 

Plastic name: PP

Actual mold shrinkage rate: 16/1000

Mold product type: tableware

 

Plastic name: PP

Actual mold shrinkage rate: 0.06

Mold opening product type: cosmetic bottle cap

 

Plastic name: PP

Actual mold shrinkage rate: 0.020

Mold product type: medical equipment

 

Plastic name: PP

Actual mold shrinkage rate: 0.015

Molding product type: Yunnan Baiyao cover

 

PP+TA (calcium carbonate) 30%----------1%

PP+GF30 ------------0.5%

 

Plastic name: PP+30%GF

Actual mold shrinkage rate: 0.01

Mold product type: exhaust grille

 

Plastic name: PP

Actual mold shrinkage rate: 0.02

Mold product type: washing machine box

 

Plastic name: PP

Actual mold shrinkage rate: 0.011

Mold product type: rice cooker central

 

Plastic name: PP-R 4.2 wall thickness

Actual mold shrinkage rate: 0.017

Mold product type: PPR water pipe

 

Plastic name: PP-R 10 wall thickness

Actual mold shrinkage rate: 0.025

Mold product type: PPR water pipe

 

Plastic name: PP+15%GF

Actual mold shrinkage rate: 0.015

Mold-opening product type: headrest inner panel / lumbar inner panel of office chair

 

PE (polyethylene)

Plastic name: H-PE

Actual mold shrinkage rate: 0.018

Mold product type: Midea electric kettle

 

Plastic name: PE

Actual mold shrinkage rate: 0.02

Mold product type: soft gear

 

Plastic name: HDPE

Actual mold shrinkage rate: 1.02

Mold product type: Export products

 

Plastic name: HDPE

Actual mold shrinkage rate: 0.018

Mold opening product type: strong threaded bottle cap

 

PA (nylon)

Plastic name: PA6T, PA9T

Actual mold shrinkage rate: 3～5/％0

Mold product type: connector

 

Plastic name: PA66

Actual mold shrinkage rate: 16‰

Mold product type: window lock

 

Plastic name: PA66

Actual mold shrinkage rate: 0.0079

Mold product type: PCB connector plastic parts

 

Plastic name: PA+30%GF

Actual mold shrinkage rate: 0.013

Mold product type: Zongshen motorcycle accessories

 

Plastic name: PA66+30%GF

Actual mold shrinkage rate: 0.005

Molding product type: chair leg of office chair

 

Plastic name: PA+30%GF

Actual mold shrinkage rate: 0.0035

Mold product type: auto parts (reflection mirror)

 

Plastic name: PA66

Actual mold shrinkage rate: 0.09

Mold product type: Fan COVER

 

PA+30%GF

Actual mold shrinkage rate: 0.007

Power plug inner frame

 

 

 

PBT+30%GF

Actual mold shrinkage rate: 0.005

Power plug inner frame

 

Plastic name: PA66

Actual mold shrinkage rate: 0.018

Mold product type: locks

 

Plastic name: PA6

Actual mold shrinkage rate: 0.020

Mold opening product type: Locking rocker arm

 

Plastic name: PA66+%15GF

Actual mold shrinkage rate: 1.009

Mold product type: car gear handle

 

Plastic name: PA66+%30GF

Actual mold shrinkage rate: 1.005

Mold product type: car gear housing

 

Plastic name: PA+30%GF

Actual mold shrinkage rate: 0.013

Mold product type: switch housing

 

PA6 (nylon): 9/1000?

Can't this?

Can the shrinkage be so small?

I remember that several wheels I made were 14/1000.

 

Plastic name: PA66

Actual mold opening shrinkage rate: 0.009

Mold product type: cable tie

 

Plastic name: PA+15%GF

Actual mold shrinkage rate: 0.01

Mold product type: light-blocking core

 

Plastic name: PA+30%GF

Actual mold shrinkage rate: 0.005

Mold product type: 168 wind wheel

 

Plastic name: PA6512

Actual mold shrinkage rate: 0.015

Product: Fixer base

 

Plastic Name: Rubber Plastic Nylon

Actual mold shrinkage rate: 0.01

Mold product type: handle

 

Plastic name: PA

Actual mold shrinkage rate: 0.015

Mold product type: drawstring 107

 

Plastic name: PA66

Actual mold shrinkage rate: 0.010

Mold product type: household switch socket bottom plate

 

Plastic name: PA66

Actual mold shrinkage rate: 0.006

Mold product type: socket protection door

 

Plastic name: PA66

Shrinkage rate of mold opening: 0.012

Mold product type: gadgets

 

Plastic name: PA6+30%GF

Mold product type: switch cover

Shrinkage rate of mold opening: 0.0035

 

Plastic name: PA66

Actual mold shrinkage rate: 1.0%

Mold product type: connector

 

Plastic name: PA66GF30%

Actual mold shrinkage rate: 0.005

Mold product type: high-speed fan

 

Plastic name: PA66+NPG25

Actual mold opening shrinkage rate: 0.0045

Molding product type: a Siemens accessory (square cover, many ribs on the inner surface)

 

Plastic name: PA6+35%GF

Actual mold shrinkage rate: 0.004

Mold product type: auto parts (internal function parts)

 

PC (polycarbonate)

Plastic name: PC

Actual mold shrinkage rate: 0.005

Molded product types: mobile phone decorations, car audio buttons, mobile phone protective shells, medical equipment

 

Plastic name: PC

Actual mold shrinkage rate: 0.0055

Mold product type: auto parts

 

Plastic name: PC

Actual mold shrinkage rate: 8/1000

Mold product type: mobile phone crystal case

 

Plastic name: pc

Actual mold shrinkage rate: 4/1000

Mold product type: laptop battery cover (average thickness 0.6

 

Plastic name: PC940

Actual mold opening shrinkage rate: 8%

Mold product type: all kinds of plug socket shells

 

Plastic name: PC+15%GF+2%SI

Actual mold shrinkage rate: 0.002

Mold product type: printer case

 

Plastic name: PC+15%GF+2%SI+10%PTFE

Actual mold shrinkage rate: 0.0025

Mold product type: printer case

 

Plastic name: PC

Actual mold shrinkage rate: 0.004

Mold product type: mobile phone case

 

Plastic name: PC

Actual mold opening shrinkage rate: 0.0045

Mold product type: car audio button

 

Plastic name: PC

Actual mold shrinkage rate: 0.0036

Mold product type: laptop battery case

 

Plastic name: PC

Actual mold shrinkage rate: 0.6%

Mold product type: socket

 

Plastic name: PC

Actual mold shrinkage rate: 0.005

Mold product type: CD button

 

Plastic name: PC

Actual mold shrinkage rate: 0.006

Mold product type: switch

 

PS (polystyrene)

Plastic name: PS

Actual mold shrinkage rate: 0.005

Mold product type: Toshiba, Hualing freezer drawers, toys

 

Plastic name: PS

Actual mold opening shrinkage rate: 0.0045

Mold product type: printer product

 

Plastic name: PS

Actual mold shrinkage rate: 0.005

Mold product type: accessories

Click on the picture to view "A Picture to Understand: Five Plastics of Polyplastics in Japan"

 

PVC

Plastic name: PVC

Actual mold shrinkage rate: 0.025

Mold product type: auto parts

 

Plastic name: PVC

Actual mold shrinkage rate: 0.03

Mold opening product type: lock box handle

 

Plastic name: PVC

Actual mold shrinkage rate: 0.02

Mold product type: medical equipment, waterproof ring

 

Plastic name: PVC

Actual mold shrinkage rate: 0.005

Molding product type: blow molded bottle

 

Plastic name: PC

Actual mold shrinkage rate: 1.015

Mold-opening product type: transparent cover for lamp holder

 

Plastic name: CPVC

Actual mold shrinkage rate: 0.015

Mold product type: water pipe joint

 

PMMA

Plastic name: PMMA

Actual mold opening shrinkage rate: 0.000~0.004

Mold product type: mobile phone lens

 

Plastic name: PMMA

Actual mold shrinkage rate: 0.002

Mold product type: lens

 

Plastic name: PMMA

Actual mold shrinkage rate: 0.005

Mold product type: lens

 

Plastic name: PMMA

Actual mold shrinkage rate: 0.03

Mold product type: mobile phone lens

 

POM (Polyoxymethylene)

Plastic name: P