FAQ – Frequently Asked Questions

Is the “shrink” process reversible?2020-07-31T16:21:52+12:00

The simple answer is No. So be careful before you apply heat shrink tube on your objects.

What is your lead time?2020-07-31T16:20:21+12:00

For products in stock, we would ship the same day or the next day. For Value-added services (like cutting to a length, printing on heat shrink tubes), we typically ship within 48 – 72 hours during the working days. For the products not in stock,  it will be shipped from China, the order period is 2 months ahead. Usually, Dicore will prepare a stock of heat shrink tubing for our long-term customer.

Do you have a minimum order?2020-08-21T17:01:52+12:00

Dicore is a factory who produces heat shrink tubing in China, so we mainly supply our products to industrial companies or distributors. We are not actually in the retail business. Our minimum order is $100 for general items in Stock. But for customized order, the MOQ (minimum order quantity) will be discussed case by case.

Why is flame-retardant important to heat shrink tube2020-08-01T13:39:19+12:00

Using flame-retardant heat shrink tube means safety to you and your society. Our heat shrink tube will be self-extinguishing when exposed to an open flame, it will effectively prevent the spread of the flame.

Our tubes are all flame-retardant and are compliant to UL VW-1 standard, we take our safety in the first place.

PVC heat shrink tube was very popular in the market in the old times, because of its low cost. Dicore doesn’t sell this kind of product. But even now it is still selling in the market, please don’t use this PVC heat shrink tubing for the sake of safety.


How long will you get a reply from Dicore?2020-07-22T11:58:01+12:00

We promise to reply to any enquiries within 24 hours in working date, our professional staff will get back to you as soon as possible.

Do you supply free samples?2020-08-16T09:47:29+12:00

Generally speaking, we could supply free samples for our potential customers to test. But the freight will be paid by our potential customers, either by providing their courier account or paying freight to our account.

What are the common materials of heat shrink tubing?2020-07-31T15:32:52+12:00

The most popular material used for making heat shrinks is Polyolefin (PE), there are also other materials such as PTFE (Polytetrafluoroethylene), FEP (Fluorinated ethylene propylene), PVDF (polyvinylidene difluoride), Elastomers, Silicon rubber, Viton, and other special materials.

There are also Polyvinyl chloride (PVC) heat shrink tubing which is not so popular now because it is not flame-retardant, but you could still see in the market due to its low cost.

How to shrink the heat shrinkable tubing?2020-07-31T15:29:58+12:00

In most instances, heat shrink tubing is very easy to work with and simple to shrink.

Heat Gun is the most common tool used for shrinking the heat shrink tubing. Heat oven is also used in some factory to make the Installation of heat shrinkable tubing stable and fast.

For some heavy wall heat shrink tubing, a Gas Flamer will be a better choice because of its higher temperature.

What is the Flat Width?2020-07-31T15:30:05+12:00

Inside Diameter is the diameter of the tube when it is round shape.

Flat Width is the diameter of the tube when it is flat.

Flat Width = Inside Diameter * π / 2

How do you choose the length of shrink tube?2020-07-31T15:30:10+12:00

Please note shrink tubing does not only shrink in diameter, but also the length. It is called Longitudinal shrinking.  but it’s usually less than 10%, so you should choose a shrink tube that is a bit longer than you need.

Which are the key parameters for correct heat shrink tubing?2020-06-30T03:10:11+12:00

Wall thickness before shrinking: Wall thickness before you shrink the tube.

Wall thickness after full recovery: The max wall thickness, usually the real thickness is smaller because it’s not fully recovered.

Inner Diameter before shrinking: Inner diameter before you shrink the tube.

Inner Diameter after full recovery: The smallest diameter, usually the real diameter is bigger because it’s not fully recovered.

Shrink ratio: Usually it is 2:1, 3:1, 4:1 or even 6:1

With adhesive or Not: Also recognised as a single wall or dual wall. Without adhesive means not waterproof.

Minimum shrink temperature: The Minimum temperature to make the tube start shrinking.

Operating Temperature: The temperature range the tube could resist for a long time, like years.

How do you choose the right size?2020-06-30T03:12:59+12:00

Heat shrink tubing has different shrink ratios, like 2:1, 3:1, 4:1 and 6:1. These describe the maximum size change before and after the shrink process. For example, the size of the shrink tubing is reduced from 10mm to 5mm, if the shrink ratio is 2:1.

So firstly, you need to measure the diameter of the biggest part and the smallest part of your object to cover, for example, 11mm and 5mm, then you will choose a tube of 3:1 shrink ratio, 12.7mm size.