i know that The Excel CLEAN function removes all non-printable characters from a supplied text string.for instance let us consider following command in excel

```
=CHAR(127)& "10"

```

result is

[![enter image description here](https://i.stack.imgur.com/GRs9K.png)](https://i.stack.imgur.com/GRs9K.png)

it is located at cell at A1,but command

```
=CLEAN(A1)

```

will leave result same,so what is problem? why it does not work